x509.h

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECDH support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

#ifndef OPENSSL_HEADER_X509_H
#define OPENSSL_HEADER_X509_H

#include <openssl/base.h>

#include <time.h>

#include <openssl/asn1.h>
#include <openssl/bio.h>
#include <openssl/cipher.h>
#include <openssl/conf.h>
#include <openssl/dh.h>
#include <openssl/dsa.h>
#include <openssl/ec.h>
#include <openssl/ecdh.h>
#include <openssl/ecdsa.h>
#include <openssl/evp.h>
#include <openssl/lhash.h>
#include <openssl/obj.h>
#include <openssl/pkcs7.h>
#include <openssl/pool.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
#include <openssl/stack.h>
#include <openssl/thread.h>
#include <openssl/x509v3_errors.h>  // IWYU pragma: export

#if defined(__cplusplus)
extern "C" {
#endif


// Legacy X.509 library.
//
// This header is part of OpenSSL's X.509 implementation. It is retained for
// compatibility but should not be used by new code. The functions are difficult
// to use correctly, and have buggy or non-standard behaviors. They are thus
// particularly prone to behavior changes and API removals, as BoringSSL
// iterates on these issues.
//
// In the future, a replacement library will be available. Meanwhile, minimize
// dependencies on this header where possible.
//
// TODO(https://crbug.com/boringssl/426): Documentation for this library is
// still in progress. Some functions have not yet been documented, and some
// functions have not yet been grouped into sections.


// Certificates.
//
// An |X509| object represents an X.509 certificate, defined in RFC 5280.
//
// Although an |X509| is a mutable object, mutating an |X509| can give incorrect
// results. Callers typically obtain |X509|s by parsing some input with
// |d2i_X509|, etc. Such objects carry information such as the serialized
// TBSCertificate and decoded extensions, which will become inconsistent when
// mutated.
//
// Instead, mutation functions should only be used when issuing new
// certificates, as described in a later section.

DEFINE_STACK_OF(X509)

// X509 is an |ASN1_ITEM| whose ASN.1 type is X.509 Certificate (RFC 5280) and C
// type is |X509*|.
DECLARE_ASN1_ITEM(X509)

// X509_up_ref adds one to the reference count of |x509| and returns one.
OPENSSL_EXPORT int X509_up_ref(X509 *x509);

// X509_chain_up_ref returns a newly-allocated |STACK_OF(X509)| containing a
// shallow copy of |chain|, or NULL on error. That is, the return value has the
// same contents as |chain|, and each |X509|'s reference count is incremented by
// one.
OPENSSL_EXPORT STACK_OF(X509) *X509_chain_up_ref(STACK_OF(X509) *chain);

// X509_dup returns a newly-allocated copy of |x509|, or NULL on error. This
// function works by serializing the structure, so auxiliary properties (see
// |i2d_X509_AUX|) are not preserved. Additionally, if |x509| is incomplete,
// this function may fail.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |crl| was
// mutated.
OPENSSL_EXPORT X509 *X509_dup(X509 *x509);

// X509_free decrements |x509|'s reference count and, if zero, releases memory
// associated with |x509|.
OPENSSL_EXPORT void X509_free(X509 *x509);

// d2i_X509 parses up to |len| bytes from |*inp| as a DER-encoded X.509
// Certificate (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509 *d2i_X509(X509 **out, const uint8_t **inp, long len);

// X509_parse_from_buffer parses an X.509 structure from |buf| and returns a
// fresh X509 or NULL on error. There must not be any trailing data in |buf|.
// The returned structure (if any) holds a reference to |buf| rather than
// copying parts of it as a normal |d2i_X509| call would do.
OPENSSL_EXPORT X509 *X509_parse_from_buffer(CRYPTO_BUFFER *buf);

// i2d_X509 marshals |x509| as a DER-encoded X.509 Certificate (RFC 5280), as
// described in |i2d_SAMPLE|.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |x509| was
// mutated.
OPENSSL_EXPORT int i2d_X509(X509 *x509, uint8_t **outp);

// X509_VERSION_* are X.509 version numbers. Note the numerical values of all
// defined X.509 versions are one less than the named version.
#define X509_VERSION_1 0
#define X509_VERSION_2 1
#define X509_VERSION_3 2

// X509_get_version returns the numerical value of |x509|'s version, which will
// be one of the |X509_VERSION_*| constants.
OPENSSL_EXPORT long X509_get_version(const X509 *x509);

// X509_get0_serialNumber returns |x509|'s serial number.
OPENSSL_EXPORT const ASN1_INTEGER *X509_get0_serialNumber(const X509 *x509);

// X509_get0_notBefore returns |x509|'s notBefore time.
OPENSSL_EXPORT const ASN1_TIME *X509_get0_notBefore(const X509 *x509);

// X509_get0_notAfter returns |x509|'s notAfter time.
OPENSSL_EXPORT const ASN1_TIME *X509_get0_notAfter(const X509 *x509);

// X509_get_issuer_name returns |x509|'s issuer.
OPENSSL_EXPORT X509_NAME *X509_get_issuer_name(const X509 *x509);

// X509_get_subject_name returns |x509|'s subject.
OPENSSL_EXPORT X509_NAME *X509_get_subject_name(const X509 *x509);

// X509_get_X509_PUBKEY returns the public key of |x509|. Note this function is
// not const-correct for legacy reasons. Callers should not modify the returned
// object.
OPENSSL_EXPORT X509_PUBKEY *X509_get_X509_PUBKEY(const X509 *x509);

// X509_get0_pubkey returns |x509|'s public key as an |EVP_PKEY|, or NULL if the
// public key was unsupported or could not be decoded. It is similar to
// |X509_get_pubkey|, but it does not increment the reference count of the
// returned |EVP_PKEY|. This means that the caller must not free the result
// after use.
OPENSSL_EXPORT EVP_PKEY *X509_get0_pubkey(const X509 *x);

// X509_get_pubkey returns |x509|'s public key as an |EVP_PKEY|, or NULL if the
// public key was unsupported or could not be decoded. This function returns a
// reference to the |EVP_PKEY|. The caller must release the result with
// |EVP_PKEY_free| when done.
OPENSSL_EXPORT EVP_PKEY *X509_get_pubkey(X509 *x509);

// X509_get0_pubkey_bitstr returns the BIT STRING portion of |x509|'s public
// key. Note this does not contain the AlgorithmIdentifier portion.
//
// WARNING: This function returns a non-const pointer for OpenSSL compatibility,
// but the caller must not modify the resulting object. Doing so will break
// internal invariants in |x509|.
OPENSSL_EXPORT ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x509);

// X509_check_private_key returns one if |x509|'s public key matches |pkey| and
// zero otherwise.
OPENSSL_EXPORT int X509_check_private_key(X509 *x509, const EVP_PKEY *pkey);

// X509_get0_uids sets |*out_issuer_uid| to a non-owning pointer to the
// issuerUID field of |x509|, or NULL if |x509| has no issuerUID. It similarly
// outputs |x509|'s subjectUID field to |*out_subject_uid|.
//
// Callers may pass NULL to either |out_issuer_uid| or |out_subject_uid| to
// ignore the corresponding field.
OPENSSL_EXPORT void X509_get0_uids(const X509 *x509,
                                   const ASN1_BIT_STRING **out_issuer_uid,
                                   const ASN1_BIT_STRING **out_subject_uid);

// X509_get_pathlen returns path length constraint from the basic constraints
// extension in |x509|. (See RFC 5280, section 4.2.1.9.) It returns -1 if the
// constraint is not present, or if some extension in |x509| was invalid.
//
// TODO(crbug.com/boringssl/381): Decoding an |X509| object will not check for
// invalid extensions. To detect the error case, call
// |X509_get_extensions_flags| and check the |EXFLAG_INVALID| bit.
OPENSSL_EXPORT long X509_get_pathlen(X509 *x509);

// X509_get0_extensions returns |x509|'s extension list, or NULL if |x509| omits
// it.
OPENSSL_EXPORT const STACK_OF(X509_EXTENSION) *X509_get0_extensions(
    const X509 *x509);

// X509_get_ext_count returns the number of extensions in |x|.
OPENSSL_EXPORT int X509_get_ext_count(const X509 *x);

// X509_get_ext_by_NID behaves like |X509v3_get_ext_by_NID| but searches for
// extensions in |x|.
OPENSSL_EXPORT int X509_get_ext_by_NID(const X509 *x, int nid, int lastpos);

// X509_get_ext_by_OBJ behaves like |X509v3_get_ext_by_OBJ| but searches for
// extensions in |x|.
OPENSSL_EXPORT int X509_get_ext_by_OBJ(const X509 *x, const ASN1_OBJECT *obj,
                                       int lastpos);

// X509_get_ext_by_critical behaves like |X509v3_get_ext_by_critical| but
// searches for extensions in |x|.
OPENSSL_EXPORT int X509_get_ext_by_critical(const X509 *x, int crit,
                                            int lastpos);

// X509_get_ext returns the extension in |x| at index |loc|, or NULL if |loc| is
// out of bounds. This function returns a non-const pointer for OpenSSL
// compatibility, but callers should not mutate the result.
OPENSSL_EXPORT X509_EXTENSION *X509_get_ext(const X509 *x, int loc);

// X509_get_ext_d2i behaves like |X509V3_get_d2i| but looks for the extension in
// |x509|'s extension list.
//
// WARNING: This function is difficult to use correctly. See the documentation
// for |X509V3_get_d2i| for details.
OPENSSL_EXPORT void *X509_get_ext_d2i(const X509 *x509, int nid,
                                      int *out_critical, int *out_idx);

// X509_get0_tbs_sigalg returns the signature algorithm in |x509|'s
// TBSCertificate. For the outer signature algorithm, see |X509_get0_signature|.
//
// Certificates with mismatched signature algorithms will successfully parse,
// but they will be rejected when verifying.
OPENSSL_EXPORT const X509_ALGOR *X509_get0_tbs_sigalg(const X509 *x509);

// X509_SIG_INFO_* are flags for |X509_get_signature_info|.
// X509_SIG_INFO_VALID means that the signature info is valid.
#define X509_SIG_INFO_VALID 0x1
// X509_SIG_INFO_TLS means that the signature is suitable for TLS use.
#define X509_SIG_INFO_TLS 0x2

// X509_get_signature_info retrieves information about the signature of |x509|.
// The NID of the signing digest is written to |digest_nid|, the public key
// algorithm to |pubkey_nid|, the effective security bits to |sec_bits|, and
// flag details to |flags|. Parameters other than |x509| can be set to NULL if
// the information is not required. It is an error to pass a null pointer to
// |x509|.
OPENSSL_EXPORT int X509_get_signature_info(X509 *x509, int *digest_nid,
                                           int *pubkey_nid, int *sec_bits,
                                           uint32_t *flags);

// X509_get0_signature sets |*out_sig| and |*out_alg| to the signature and
// signature algorithm of |x509|, respectively. Either output pointer may be
// NULL to ignore the value.
//
// This function outputs the outer signature algorithm. For the one in the
// TBSCertificate, see |X509_get0_tbs_sigalg|. Certificates with mismatched
// signature algorithms will successfully parse, but they will be rejected when
// verifying.
OPENSSL_EXPORT void X509_get0_signature(const ASN1_BIT_STRING **out_sig,
                                        const X509_ALGOR **out_alg,
                                        const X509 *x509);

// X509_get_signature_nid returns the NID corresponding to |x509|'s signature
// algorithm, or |NID_undef| if the signature algorithm does not correspond to
// a known NID.
OPENSSL_EXPORT int X509_get_signature_nid(const X509 *x509);

// i2d_X509_tbs serializes the TBSCertificate portion of |x509|, as described in
// |i2d_SAMPLE|.
//
// This function preserves the original encoding of the TBSCertificate and may
// not reflect modifications made to |x509|. It may be used to manually verify
// the signature of an existing certificate. To generate certificates, use
// |i2d_re_X509_tbs| instead.
OPENSSL_EXPORT int i2d_X509_tbs(X509 *x509, unsigned char **outp);

// X509_verify checks that |x509| has a valid signature by |pkey|. It returns
// one if the signature is valid and zero otherwise. Note this function only
// checks the signature itself and does not perform a full certificate
// validation.
OPENSSL_EXPORT int X509_verify(X509 *x509, EVP_PKEY *pkey);


// Issuing certificates.
//
// An |X509| object may also represent an incomplete certificate. Callers may
// construct empty |X509| objects, fill in fields individually, and finally sign
// the result. The following functions may be used for this purpose.

// X509_new returns a newly-allocated, empty |X509| object, or NULL on error.
// This produces an incomplete certificate which may be filled in to issue a new
// certificate.
OPENSSL_EXPORT X509 *X509_new(void);

// X509_set_version sets |x509|'s version to |version|, which should be one of
// the |X509V_VERSION_*| constants. It returns one on success and zero on error.
//
// If unsure, use |X509_VERSION_3|.
OPENSSL_EXPORT int X509_set_version(X509 *x509, long version);

// X509_set_serialNumber sets |x509|'s serial number to |serial|. It returns one
// on success and zero on error.
OPENSSL_EXPORT int X509_set_serialNumber(X509 *x509,
                                         const ASN1_INTEGER *serial);

// X509_set1_notBefore sets |x509|'s notBefore time to |tm|. It returns one on
// success and zero on error.
OPENSSL_EXPORT int X509_set1_notBefore(X509 *x509, const ASN1_TIME *tm);

// X509_set1_notAfter sets |x509|'s notAfter time to |tm|. it returns one on
// success and zero on error.
OPENSSL_EXPORT int X509_set1_notAfter(X509 *x509, const ASN1_TIME *tm);

// X509_getm_notBefore returns a mutable pointer to |x509|'s notBefore time.
OPENSSL_EXPORT ASN1_TIME *X509_getm_notBefore(X509 *x509);

// X509_getm_notAfter returns a mutable pointer to |x509|'s notAfter time.
OPENSSL_EXPORT ASN1_TIME *X509_getm_notAfter(X509 *x);

// X509_set_issuer_name sets |x509|'s issuer to a copy of |name|. It returns one
// on success and zero on error.
OPENSSL_EXPORT int X509_set_issuer_name(X509 *x509, X509_NAME *name);

// X509_set_subject_name sets |x509|'s subject to a copy of |name|. It returns
// one on success and zero on error.
OPENSSL_EXPORT int X509_set_subject_name(X509 *x509, X509_NAME *name);

// X509_set_pubkey sets |x509|'s public key to |pkey|. It returns one on success
// and zero on error. This function does not take ownership of |pkey| and
// internally copies and updates reference counts as needed.
OPENSSL_EXPORT int X509_set_pubkey(X509 *x509, EVP_PKEY *pkey);

// X509_delete_ext removes the extension in |x| at index |loc| and returns the
// removed extension, or NULL if |loc| was out of bounds. If non-NULL, the
// caller must release the result with |X509_EXTENSION_free|.
OPENSSL_EXPORT X509_EXTENSION *X509_delete_ext(X509 *x, int loc);

// X509_add_ext adds a copy of |ex| to |x|. It returns one on success and zero
// on failure. The caller retains ownership of |ex| and can release it
// independently of |x|.
//
// The new extension is inserted at index |loc|, shifting extensions to the
// right. If |loc| is -1 or out of bounds, the new extension is appended to the
// list.
OPENSSL_EXPORT int X509_add_ext(X509 *x, const X509_EXTENSION *ex, int loc);

// X509_add1_ext_i2d behaves like |X509V3_add1_i2d| but adds the extension to
// |x|'s extension list.
//
// WARNING: This function may return zero or -1 on error. The caller must also
// ensure |value|'s type matches |nid|. See the documentation for
// |X509V3_add1_i2d| for details.
OPENSSL_EXPORT int X509_add1_ext_i2d(X509 *x, int nid, void *value, int crit,
                                     unsigned long flags);

// X509_sign signs |x509| with |pkey| and replaces the signature algorithm and
// signature fields. It returns the length of the signature on success and zero
// on error. This function uses digest algorithm |md|, or |pkey|'s default if
// NULL. Other signing parameters use |pkey|'s defaults. To customize them, use
// |X509_sign_ctx|.
OPENSSL_EXPORT int X509_sign(X509 *x509, EVP_PKEY *pkey, const EVP_MD *md);

// X509_sign_ctx signs |x509| with |ctx| and replaces the signature algorithm
// and signature fields. It returns the length of the signature on success and
// zero on error. The signature algorithm and parameters come from |ctx|, which
// must have been initialized with |EVP_DigestSignInit|. The caller should
// configure the corresponding |EVP_PKEY_CTX| before calling this function.
//
// On success or failure, this function mutates |ctx| and resets it to the empty
// state. Caller should not rely on its contents after the function returns.
OPENSSL_EXPORT int X509_sign_ctx(X509 *x509, EVP_MD_CTX *ctx);

// i2d_re_X509_tbs serializes the TBSCertificate portion of |x509|, as described
// in |i2d_SAMPLE|.
//
// This function re-encodes the TBSCertificate and may not reflect |x509|'s
// original encoding. It may be used to manually generate a signature for a new
// certificate. To verify certificates, use |i2d_X509_tbs| instead.
OPENSSL_EXPORT int i2d_re_X509_tbs(X509 *x509, unsigned char **outp);

// X509_set1_signature_algo sets |x509|'s signature algorithm to |algo| and
// returns one on success or zero on error. It updates both the signature field
// of the TBSCertificate structure, and the signatureAlgorithm field of the
// Certificate.
OPENSSL_EXPORT int X509_set1_signature_algo(X509 *x509, const X509_ALGOR *algo);

// X509_set1_signature_value sets |x509|'s signature to a copy of the |sig_len|
// bytes pointed by |sig|. It returns one on success and zero on error.
//
// Due to a specification error, X.509 certificates store signatures in ASN.1
// BIT STRINGs, but signature algorithms return byte strings rather than bit
// strings. This function creates a BIT STRING containing a whole number of
// bytes, with the bit order matching the DER encoding. This matches the
// encoding used by all X.509 signature algorithms.
OPENSSL_EXPORT int X509_set1_signature_value(X509 *x509, const uint8_t *sig,
                                             size_t sig_len);


// Auxiliary certificate properties.
//
// |X509| objects optionally maintain auxiliary properties. These are not part
// of the certificates themselves, and thus are not covered by signatures or
// preserved by the standard serialization. They are used as inputs or outputs
// to other functions in this library.

// i2d_X509_AUX marshals |x509| as a DER-encoded X.509 Certificate (RFC 5280),
// followed optionally by a separate, OpenSSL-specific structure with auxiliary
// properties. It behaves as described in |i2d_SAMPLE|.
//
// Unlike similarly-named functions, this function does not output a single
// ASN.1 element. Directly embedding the output in a larger ASN.1 structure will
// not behave correctly.
OPENSSL_EXPORT int i2d_X509_AUX(X509 *x509, unsigned char **outp);

// d2i_X509_AUX parses up to |length| bytes from |*inp| as a DER-encoded X.509
// Certificate (RFC 5280), followed optionally by a separate, OpenSSL-specific
// structure with auxiliary properties. It behaves as described in
// |d2i_SAMPLE_with_reuse|.
//
// Some auxiliary properties affect trust decisions, so this function should not
// be used with untrusted input.
//
// Unlike similarly-named functions, this function does not parse a single
// ASN.1 element. Trying to parse data directly embedded in a larger ASN.1
// structure will not behave correctly.
OPENSSL_EXPORT X509 *d2i_X509_AUX(X509 **x509, const unsigned char **inp,
                                  long length);

// X509_alias_set1 sets |x509|'s alias to |len| bytes from |name|. If |name| is
// NULL, the alias is cleared instead. Aliases are not part of the certificate
// itself and will not be serialized by |i2d_X509|.
OPENSSL_EXPORT int X509_alias_set1(X509 *x509, const unsigned char *name,
                                   ossl_ssize_t len);

// X509_keyid_set1 sets |x509|'s key ID to |len| bytes from |id|. If |id| is
// NULL, the key ID is cleared instead. Key IDs are not part of the certificate
// itself and will not be serialized by |i2d_X509|.
OPENSSL_EXPORT int X509_keyid_set1(X509 *x509, const unsigned char *id,
                                   ossl_ssize_t len);

// X509_alias_get0 looks up |x509|'s alias. If found, it sets |*out_len| to the
// alias's length and returns a pointer to a buffer containing the contents. If
// not found, it outputs the empty string by returning NULL and setting
// |*out_len| to zero.
//
// If |x509| was parsed from a PKCS#12 structure (see
// |PKCS12_get_key_and_certs|), the alias will reflect the friendlyName
// attribute (RFC 2985).
//
// WARNING: In OpenSSL, this function did not set |*out_len| when the alias was
// missing. Callers that target both OpenSSL and BoringSSL should set the value
// to zero before calling this function.
OPENSSL_EXPORT unsigned char *X509_alias_get0(X509 *x509, int *out_len);

// X509_keyid_get0 looks up |x509|'s key ID. If found, it sets |*out_len| to the
// key ID's length and returns a pointer to a buffer containing the contents. If
// not found, it outputs the empty string by returning NULL and setting
// |*out_len| to zero.
//
// WARNING: In OpenSSL, this function did not set |*out_len| when the alias was
// missing. Callers that target both OpenSSL and BoringSSL should set the value
// to zero before calling this function.
OPENSSL_EXPORT unsigned char *X509_keyid_get0(X509 *x509, int *out_len);

// X509_add1_trust_object configures |x509| as a valid trust anchor for |obj|.
// It returns one on success and zero on error. |obj| should be a certificate
// usage OID associated with an |X509_TRUST| object.
OPENSSL_EXPORT int X509_add1_trust_object(X509 *x509, const ASN1_OBJECT *obj);

// X509_add1_reject_object configures |x509| as distrusted for |obj|. It returns
// one on success and zero on error. |obj| should be a certificate usage OID
// associated with an |X509_TRUST| object.
OPENSSL_EXPORT int X509_add1_reject_object(X509 *x509, const ASN1_OBJECT *obj);

// X509_trust_clear clears the list of OIDs for which |x509| is trusted. See
// also |X509_add1_trust_object|.
OPENSSL_EXPORT void X509_trust_clear(X509 *x509);

// X509_reject_clear clears the list of OIDs for which |x509| is distrusted. See
// also |X509_add1_reject_object|.
OPENSSL_EXPORT void X509_reject_clear(X509 *x509);


// Certificate revocation lists.
//
// An |X509_CRL| object represents an X.509 certificate revocation list (CRL),
// defined in RFC 5280. A CRL is a signed list of certificates, the
// revokedCertificates field, which are no longer considered valid. Each entry
// of this list is represented with an |X509_REVOKED| object, documented in the
// "CRL entries" section below.
//
// Although an |X509_CRL| is a mutable object, mutating an |X509_CRL| or its
// |X509_REVOKED|s can give incorrect results. Callers typically obtain
// |X509_CRL|s by parsing some input with |d2i_X509_CRL|, etc. Such objects
// carry information such as the serialized TBSCertList and decoded extensions,
// which will become inconsistent when mutated.
//
// Instead, mutation functions should only be used when issuing new CRLs, as
// described in a later section.

DEFINE_STACK_OF(X509_CRL)
DEFINE_STACK_OF(X509_REVOKED)

// X509_CRL is an |ASN1_ITEM| whose ASN.1 type is X.509 CertificateList (RFC
// 5280) and C type is |X509_CRL*|.
DECLARE_ASN1_ITEM(X509_CRL)

// X509_CRL_up_ref adds one to the reference count of |crl| and returns one.
OPENSSL_EXPORT int X509_CRL_up_ref(X509_CRL *crl);

// X509_CRL_dup returns a newly-allocated copy of |crl|, or NULL on error. This
// function works by serializing the structure, so if |crl| is incomplete, it
// may fail.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |crl| was
// mutated.
OPENSSL_EXPORT X509_CRL *X509_CRL_dup(X509_CRL *crl);

// X509_CRL_free decrements |crl|'s reference count and, if zero, releases
// memory associated with |crl|.
OPENSSL_EXPORT void X509_CRL_free(X509_CRL *crl);

// d2i_X509_CRL parses up to |len| bytes from |*inp| as a DER-encoded X.509
// CertificateList (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_CRL *d2i_X509_CRL(X509_CRL **out, const uint8_t **inp,
                                      long len);

// i2d_X509_CRL marshals |crl| as a X.509 CertificateList (RFC 5280), as
// described in |i2d_SAMPLE|.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |crl| was
// mutated.
OPENSSL_EXPORT int i2d_X509_CRL(X509_CRL *crl, uint8_t **outp);

#define X509_CRL_VERSION_1 0
#define X509_CRL_VERSION_2 1

// X509_CRL_get_version returns the numerical value of |crl|'s version, which
// will be one of the |X509_CRL_VERSION_*| constants.
OPENSSL_EXPORT long X509_CRL_get_version(const X509_CRL *crl);

// X509_CRL_get0_lastUpdate returns |crl|'s thisUpdate time. The OpenSSL API
// refers to this field as lastUpdate.
OPENSSL_EXPORT const ASN1_TIME *X509_CRL_get0_lastUpdate(const X509_CRL *crl);

// X509_CRL_get0_nextUpdate returns |crl|'s nextUpdate time, or NULL if |crl|
// has none.
OPENSSL_EXPORT const ASN1_TIME *X509_CRL_get0_nextUpdate(const X509_CRL *crl);

// X509_CRL_get_issuer returns |crl|'s issuer name. Note this function is not
// const-correct for legacy reasons.
OPENSSL_EXPORT X509_NAME *X509_CRL_get_issuer(const X509_CRL *crl);

// X509_CRL_get0_by_serial finds the entry in |crl| whose serial number is
// |serial|. If found, it sets |*out| to the entry and returns one. If not
// found, it returns zero.
//
// On success, |*out| continues to be owned by |crl|. It is an error to free or
// otherwise modify |*out|.
//
// TODO(crbug.com/boringssl/600): Ideally |crl| would be const. It is broadly
// thread-safe, but changes the order of entries in |crl|. It cannot be called
// concurrently with |i2d_X509_CRL|.
OPENSSL_EXPORT int X509_CRL_get0_by_serial(X509_CRL *crl, X509_REVOKED **out,
                                           const ASN1_INTEGER *serial);

// X509_CRL_get0_by_cert behaves like |X509_CRL_get0_by_serial|, except it looks
// for the entry that matches |x509|.
OPENSSL_EXPORT int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **out,
                                         X509 *x509);

// X509_CRL_get_REVOKED returns the list of revoked certificates in |crl|, or
// NULL if |crl| omits it.
//
// TOOD(davidben): This function was originally a macro, without clear const
// semantics. It should take a const input and give const output, but the latter
// would break existing callers. For now, we match upstream.
OPENSSL_EXPORT STACK_OF(X509_REVOKED) *X509_CRL_get_REVOKED(X509_CRL *crl);

// X509_CRL_get0_extensions returns |crl|'s extension list, or NULL if |crl|
// omits it. A CRL can have extensions on individual entries, which is
// |X509_REVOKED_get0_extensions|, or on the overall CRL, which is this
// function.
OPENSSL_EXPORT const STACK_OF(X509_EXTENSION) *X509_CRL_get0_extensions(
    const X509_CRL *crl);

// X509_CRL_get_ext_count returns the number of extensions in |x|.
OPENSSL_EXPORT int X509_CRL_get_ext_count(const X509_CRL *x);

// X509_CRL_get_ext_by_NID behaves like |X509v3_get_ext_by_NID| but searches for
// extensions in |x|.
OPENSSL_EXPORT int X509_CRL_get_ext_by_NID(const X509_CRL *x, int nid,
                                           int lastpos);

// X509_CRL_get_ext_by_OBJ behaves like |X509v3_get_ext_by_OBJ| but searches for
// extensions in |x|.
OPENSSL_EXPORT int X509_CRL_get_ext_by_OBJ(const X509_CRL *x,
                                           const ASN1_OBJECT *obj, int lastpos);

// X509_CRL_get_ext_by_critical behaves like |X509v3_get_ext_by_critical| but
// searches for extensions in |x|.
OPENSSL_EXPORT int X509_CRL_get_ext_by_critical(const X509_CRL *x, int crit,
                                                int lastpos);

// X509_CRL_get_ext returns the extension in |x| at index |loc|, or NULL if
// |loc| is out of bounds. This function returns a non-const pointer for OpenSSL
// compatibility, but callers should not mutate the result.
OPENSSL_EXPORT X509_EXTENSION *X509_CRL_get_ext(const X509_CRL *x, int loc);

// X509_CRL_get_ext_d2i behaves like |X509V3_get_d2i| but looks for the
// extension in |crl|'s extension list.
//
// WARNING: This function is difficult to use correctly. See the documentation
// for |X509V3_get_d2i| for details.
OPENSSL_EXPORT void *X509_CRL_get_ext_d2i(const X509_CRL *crl, int nid,
                                          int *out_critical, int *out_idx);

// X509_CRL_get0_signature sets |*out_sig| and |*out_alg| to the signature and
// signature algorithm of |crl|, respectively. Either output pointer may be NULL
// to ignore the value.
//
// This function outputs the outer signature algorithm, not the one in the
// TBSCertList. CRLs with mismatched signature algorithms will successfully
// parse, but they will be rejected when verifying.
OPENSSL_EXPORT void X509_CRL_get0_signature(const X509_CRL *crl,
                                            const ASN1_BIT_STRING **out_sig,
                                            const X509_ALGOR **out_alg);

// X509_CRL_get_signature_nid returns the NID corresponding to |crl|'s signature
// algorithm, or |NID_undef| if the signature algorithm does not correspond to
// a known NID.
OPENSSL_EXPORT int X509_CRL_get_signature_nid(const X509_CRL *crl);

// i2d_X509_CRL_tbs serializes the TBSCertList portion of |crl|, as described in
// |i2d_SAMPLE|.
//
// This function preserves the original encoding of the TBSCertList and may not
// reflect modifications made to |crl|. It may be used to manually verify the
// signature of an existing CRL. To generate CRLs, use |i2d_re_X509_CRL_tbs|
// instead.
OPENSSL_EXPORT int i2d_X509_CRL_tbs(X509_CRL *crl, unsigned char **outp);

// X509_CRL_verify checks that |crl| has a valid signature by |pkey|. It returns
// one if the signature is valid and zero otherwise.
OPENSSL_EXPORT int X509_CRL_verify(X509_CRL *crl, EVP_PKEY *pkey);


// Issuing certificate revocation lists.
//
// An |X509_CRL| object may also represent an incomplete CRL. Callers may
// construct empty |X509_CRL| objects, fill in fields individually, and finally
// sign the result. The following functions may be used for this purpose.

// X509_CRL_new returns a newly-allocated, empty |X509_CRL| object, or NULL on
// error. This object may be filled in and then signed to construct a CRL.
OPENSSL_EXPORT X509_CRL *X509_CRL_new(void);

// X509_CRL_set_version sets |crl|'s version to |version|, which should be one
// of the |X509_CRL_VERSION_*| constants. It returns one on success and zero on
// error.
//
// If unsure, use |X509_CRL_VERSION_2|. Note that, unlike certificates, CRL
// versions are only defined up to v2. Callers should not use |X509_VERSION_3|.
OPENSSL_EXPORT int X509_CRL_set_version(X509_CRL *crl, long version);

// X509_CRL_set_issuer_name sets |crl|'s issuer to a copy of |name|. It returns
// one on success and zero on error.
OPENSSL_EXPORT int X509_CRL_set_issuer_name(X509_CRL *crl, X509_NAME *name);

// X509_CRL_set1_lastUpdate sets |crl|'s thisUpdate time to |tm|. It returns one
// on success and zero on error. The OpenSSL API refers to this field as
// lastUpdate.
OPENSSL_EXPORT int X509_CRL_set1_lastUpdate(X509_CRL *crl, const ASN1_TIME *tm);

// X509_CRL_set1_nextUpdate sets |crl|'s nextUpdate time to |tm|. It returns one
// on success and zero on error.
OPENSSL_EXPORT int X509_CRL_set1_nextUpdate(X509_CRL *crl, const ASN1_TIME *tm);

// X509_CRL_add0_revoked adds |rev| to |crl|. On success, it takes ownership of
// |rev| and returns one. On error, it returns zero. If this function fails, the
// caller retains ownership of |rev| and must release it when done.
OPENSSL_EXPORT int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev);

// X509_CRL_sort sorts the entries in |crl| by serial number. It returns one on
// success and zero on error.
OPENSSL_EXPORT int X509_CRL_sort(X509_CRL *crl);

// X509_CRL_delete_ext removes the extension in |x| at index |loc| and returns
// the removed extension, or NULL if |loc| was out of bounds. If non-NULL, the
// caller must release the result with |X509_EXTENSION_free|.
OPENSSL_EXPORT X509_EXTENSION *X509_CRL_delete_ext(X509_CRL *x, int loc);

// X509_CRL_add_ext adds a copy of |ex| to |x|. It returns one on success and
// zero on failure. The caller retains ownership of |ex| and can release it
// independently of |x|.
//
// The new extension is inserted at index |loc|, shifting extensions to the
// right. If |loc| is -1 or out of bounds, the new extension is appended to the
// list.
OPENSSL_EXPORT int X509_CRL_add_ext(X509_CRL *x, const X509_EXTENSION *ex,
                                    int loc);

// X509_CRL_add1_ext_i2d behaves like |X509V3_add1_i2d| but adds the extension
// to |x|'s extension list.
//
// WARNING: This function may return zero or -1 on error. The caller must also
// ensure |value|'s type matches |nid|. See the documentation for
// |X509V3_add1_i2d| for details.
OPENSSL_EXPORT int X509_CRL_add1_ext_i2d(X509_CRL *x, int nid, void *value,
                                         int crit, unsigned long flags);

// X509_CRL_sign signs |crl| with |pkey| and replaces the signature algorithm
// and signature fields. It returns the length of the signature on success and
// zero on error. This function uses digest algorithm |md|, or |pkey|'s default
// if NULL. Other signing parameters use |pkey|'s defaults. To customize them,
// use |X509_CRL_sign_ctx|.
OPENSSL_EXPORT int X509_CRL_sign(X509_CRL *crl, EVP_PKEY *pkey,
                                 const EVP_MD *md);

// X509_CRL_sign_ctx signs |crl| with |ctx| and replaces the signature algorithm
// and signature fields. It returns the length of the signature on success and
// zero on error. The signature algorithm and parameters come from |ctx|, which
// must have been initialized with |EVP_DigestSignInit|. The caller should
// configure the corresponding |EVP_PKEY_CTX| before calling this function.
//
// On success or failure, this function mutates |ctx| and resets it to the empty
// state. Caller should not rely on its contents after the function returns.
OPENSSL_EXPORT int X509_CRL_sign_ctx(X509_CRL *crl, EVP_MD_CTX *ctx);

// i2d_re_X509_CRL_tbs serializes the TBSCertList portion of |crl|, as described
// in |i2d_SAMPLE|.
//
// This function re-encodes the TBSCertList and may not reflect |crl|'s original
// encoding. It may be used to manually generate a signature for a new CRL. To
// verify CRLs, use |i2d_X509_CRL_tbs| instead.
OPENSSL_EXPORT int i2d_re_X509_CRL_tbs(X509_CRL *crl, unsigned char **outp);

// X509_CRL_set1_signature_algo sets |crl|'s signature algorithm to |algo| and
// returns one on success or zero on error. It updates both the signature field
// of the TBSCertList structure, and the signatureAlgorithm field of the CRL.
OPENSSL_EXPORT int X509_CRL_set1_signature_algo(X509_CRL *crl,
                                                const X509_ALGOR *algo);

// X509_CRL_set1_signature_value sets |crl|'s signature to a copy of the
// |sig_len| bytes pointed by |sig|. It returns one on success and zero on
// error.
//
// Due to a specification error, X.509 CRLs store signatures in ASN.1 BIT
// STRINGs, but signature algorithms return byte strings rather than bit
// strings. This function creates a BIT STRING containing a whole number of
// bytes, with the bit order matching the DER encoding. This matches the
// encoding used by all X.509 signature algorithms.
OPENSSL_EXPORT int X509_CRL_set1_signature_value(X509_CRL *crl,
                                                 const uint8_t *sig,
                                                 size_t sig_len);


// CRL entries.
//
// Each entry of a CRL is represented as an |X509_REVOKED| object, which
// describes a revoked certificate by serial number.
//
// When an |X509_REVOKED| is obtained from an |X509_CRL| object, it is an error
// to mutate the object. Doing so may break |X509_CRL|'s and cause the library
// to behave incorrectly.

// X509_REVOKED is an |ASN1_ITEM| whose ASN.1 type is an element of the
// revokedCertificates field of TBSCertList (RFC 5280) and C type is
// |X509_REVOKED*|.
DECLARE_ASN1_ITEM(X509_REVOKED)

// X509_REVOKED_new returns a newly-allocated, empty |X509_REVOKED| object, or
// NULL on allocation error.
OPENSSL_EXPORT X509_REVOKED *X509_REVOKED_new(void);

// X509_REVOKED_free releases memory associated with |rev|.
OPENSSL_EXPORT void X509_REVOKED_free(X509_REVOKED *rev);

// d2i_X509_REVOKED parses up to |len| bytes from |*inp| as a DER-encoded X.509
// CRL entry, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT X509_REVOKED *d2i_X509_REVOKED(X509_REVOKED **out,
                                              const uint8_t **inp, long len);

// i2d_X509_REVOKED marshals |alg| as a DER-encoded X.509 CRL entry, as
// described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_REVOKED(const X509_REVOKED *alg, uint8_t **outp);

// X509_REVOKED_dup returns a newly-allocated copy of |rev|, or NULL on error.
// This function works by serializing the structure, so if |rev| is incomplete,
// it may fail.
OPENSSL_EXPORT X509_REVOKED *X509_REVOKED_dup(const X509_REVOKED *rev);

// X509_REVOKED_get0_serialNumber returns the serial number of the certificate
// revoked by |revoked|.
OPENSSL_EXPORT const ASN1_INTEGER *X509_REVOKED_get0_serialNumber(
    const X509_REVOKED *revoked);

// X509_REVOKED_set_serialNumber sets |revoked|'s serial number to |serial|. It
// returns one on success or zero on error.
OPENSSL_EXPORT int X509_REVOKED_set_serialNumber(X509_REVOKED *revoked,
                                                 const ASN1_INTEGER *serial);

// X509_REVOKED_get0_revocationDate returns the revocation time of the
// certificate revoked by |revoked|.
OPENSSL_EXPORT const ASN1_TIME *X509_REVOKED_get0_revocationDate(
    const X509_REVOKED *revoked);

// X509_REVOKED_set_revocationDate sets |revoked|'s revocation time to |tm|. It
// returns one on success or zero on error.
OPENSSL_EXPORT int X509_REVOKED_set_revocationDate(X509_REVOKED *revoked,
                                                   const ASN1_TIME *tm);

// X509_REVOKED_get0_extensions returns |r|'s extensions list, or NULL if |r|
// omits it. A CRL can have extensions on individual entries, which is this
// function, or on the overall CRL, which is |X509_CRL_get0_extensions|.
OPENSSL_EXPORT const STACK_OF(X509_EXTENSION) *X509_REVOKED_get0_extensions(
    const X509_REVOKED *r);

    // X509_REVOKED_get_ext_count returns the number of extensions in |x|.
OPENSSL_EXPORT int X509_REVOKED_get_ext_count(const X509_REVOKED *x);

// X509_REVOKED_get_ext_by_NID behaves like |X509v3_get_ext_by_NID| but searches
// for extensions in |x|.
OPENSSL_EXPORT int X509_REVOKED_get_ext_by_NID(const X509_REVOKED *x, int nid,
                                               int lastpos);

// X509_REVOKED_get_ext_by_OBJ behaves like |X509v3_get_ext_by_OBJ| but searches
// for extensions in |x|.
OPENSSL_EXPORT int X509_REVOKED_get_ext_by_OBJ(const X509_REVOKED *x,
                                               const ASN1_OBJECT *obj,
                                               int lastpos);

// X509_REVOKED_get_ext_by_critical behaves like |X509v3_get_ext_by_critical|
// but searches for extensions in |x|.
OPENSSL_EXPORT int X509_REVOKED_get_ext_by_critical(const X509_REVOKED *x,
                                                    int crit, int lastpos);

// X509_REVOKED_get_ext returns the extension in |x| at index |loc|, or NULL if
// |loc| is out of bounds. This function returns a non-const pointer for OpenSSL
// compatibility, but callers should not mutate the result.
OPENSSL_EXPORT X509_EXTENSION *X509_REVOKED_get_ext(const X509_REVOKED *x,
                                                    int loc);

// X509_REVOKED_delete_ext removes the extension in |x| at index |loc| and
// returns the removed extension, or NULL if |loc| was out of bounds. If
// non-NULL, the caller must release the result with |X509_EXTENSION_free|.
OPENSSL_EXPORT X509_EXTENSION *X509_REVOKED_delete_ext(X509_REVOKED *x,
                                                       int loc);

// X509_REVOKED_add_ext adds a copy of |ex| to |x|. It returns one on success
// and zero on failure. The caller retains ownership of |ex| and can release it
// independently of |x|.
//
// The new extension is inserted at index |loc|, shifting extensions to the
// right. If |loc| is -1 or out of bounds, the new extension is appended to the
// list.
OPENSSL_EXPORT int X509_REVOKED_add_ext(X509_REVOKED *x,
                                        const X509_EXTENSION *ex, int loc);

// X509_REVOKED_get_ext_d2i behaves like |X509V3_get_d2i| but looks for the
// extension in |revoked|'s extension list.
//
// WARNING: This function is difficult to use correctly. See the documentation
// for |X509V3_get_d2i| for details.
OPENSSL_EXPORT void *X509_REVOKED_get_ext_d2i(const X509_REVOKED *revoked,
                                              int nid, int *out_critical,
                                              int *out_idx);

// X509_REVOKED_add1_ext_i2d behaves like |X509V3_add1_i2d| but adds the
// extension to |x|'s extension list.
//
// WARNING: This function may return zero or -1 on error. The caller must also
// ensure |value|'s type matches |nid|. See the documentation for
// |X509V3_add1_i2d| for details.
OPENSSL_EXPORT int X509_REVOKED_add1_ext_i2d(X509_REVOKED *x, int nid,
                                             void *value, int crit,
                                             unsigned long flags);


// Certificate requests.
//
// An |X509_REQ| represents a PKCS #10 certificate request (RFC 2986). These are
// also referred to as certificate signing requests or CSRs. CSRs are a common
// format used to request a certificate from a CA.
//
// Although an |X509_REQ| is a mutable object, mutating an |X509_REQ| can give
// incorrect results. Callers typically obtain |X509_REQ|s by parsing some input
// with |d2i_X509_REQ|, etc. Such objects carry information such as the
// serialized CertificationRequestInfo, which will become inconsistent when
// mutated.
//
// Instead, mutation functions should only be used when issuing new CRLs, as
// described in a later section.

// X509_REQ is an |ASN1_ITEM| whose ASN.1 type is CertificateRequest (RFC 2986)
// and C type is |X509_REQ*|.
DECLARE_ASN1_ITEM(X509_REQ)

// X509_REQ_dup returns a newly-allocated copy of |req|, or NULL on error. This
// function works by serializing the structure, so if |req| is incomplete, it
// may fail.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |req| was
// mutated.
OPENSSL_EXPORT X509_REQ *X509_REQ_dup(X509_REQ *req);

// X509_REQ_free releases memory associated with |req|.
OPENSSL_EXPORT void X509_REQ_free(X509_REQ *req);

// d2i_X509_REQ parses up to |len| bytes from |*inp| as a DER-encoded
// CertificateRequest (RFC 2986), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_REQ *d2i_X509_REQ(X509_REQ **out, const uint8_t **inp,
                                      long len);

// i2d_X509_REQ marshals |req| as a CertificateRequest (RFC 2986), as described
// in |i2d_SAMPLE|.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |req| was
// mutated.
OPENSSL_EXPORT int i2d_X509_REQ(X509_REQ *req, uint8_t **outp);

// X509_REQ_VERSION_1 is the version constant for |X509_REQ| objects. No other
// versions are defined.
#define X509_REQ_VERSION_1 0

// X509_REQ_get_version returns the numerical value of |req|'s version. This
// will always be |X509_REQ_VERSION_1| for valid CSRs. For compatibility,
// |d2i_X509_REQ| also accepts some invalid version numbers, in which case this
// function may return other values.
OPENSSL_EXPORT long X509_REQ_get_version(const X509_REQ *req);

// X509_REQ_get_subject_name returns |req|'s subject name. Note this function is
// not const-correct for legacy reasons.
OPENSSL_EXPORT X509_NAME *X509_REQ_get_subject_name(const X509_REQ *req);

// X509_REQ_get_pubkey returns |req|'s public key as an |EVP_PKEY|, or NULL if
// the public key was unsupported or could not be decoded. This function returns
// a reference to the |EVP_PKEY|. The caller must release the result with
// |EVP_PKEY_free| when done.
OPENSSL_EXPORT EVP_PKEY *X509_REQ_get_pubkey(X509_REQ *req);

// X509_REQ_get0_pubkey is like |X509_REQ_get_pubkey|, but directly returns the
// reference to |req|. The caller must not free the result after use.
OPENSSL_EXPORT EVP_PKEY *X509_REQ_get0_pubkey(X509_REQ *req);

// X509_REQ_check_private_key returns one if |req|'s public key matches |pkey|
// and zero otherwise.
OPENSSL_EXPORT int X509_REQ_check_private_key(X509_REQ *req,
                                              const EVP_PKEY *pkey);

// X509_REQ_get_attr_count returns the number of attributes in |req|.
OPENSSL_EXPORT int X509_REQ_get_attr_count(const X509_REQ *req);

// X509_REQ_get_attr returns the attribute at index |loc| in |req|, or NULL if
// out of bounds.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_REQ_get_attr(const X509_REQ *req, int loc);

// X509_REQ_get_attr_by_NID returns the index of the attribute in |req| of type
// |nid|, or a negative number if not found. If found, callers can use
// |X509_REQ_get_attr| to look up the attribute by index.
//
// If |lastpos| is non-negative, it begins searching at |lastpos| + 1. Callers
// can thus loop over all matching attributes by first passing -1 and then
// passing the previously-returned value until no match is returned.
OPENSSL_EXPORT int X509_REQ_get_attr_by_NID(const X509_REQ *req, int nid,
                                            int lastpos);

// X509_REQ_get_attr_by_OBJ behaves like |X509_REQ_get_attr_by_NID| but looks
// for attributes of type |obj|.
OPENSSL_EXPORT int X509_REQ_get_attr_by_OBJ(const X509_REQ *req,
                                            const ASN1_OBJECT *obj,
                                            int lastpos);

// X509_REQ_extension_nid returns one if |nid| is a supported CSR attribute type
// for carrying extensions and zero otherwise. The supported types are
// |NID_ext_req| (pkcs-9-at-extensionRequest from RFC 2985) and |NID_ms_ext_req|
// (a Microsoft szOID_CERT_EXTENSIONS variant).
OPENSSL_EXPORT int X509_REQ_extension_nid(int nid);

// X509_REQ_get_extensions decodes the list of requested extensions in |req| and
// returns a newly-allocated |STACK_OF(X509_EXTENSION)| containing the result.
// It returns NULL on error, or if |req| did not request extensions.
//
// CSRs do not store extensions directly. Instead there are attribute types
// which are defined to hold extensions. See |X509_REQ_extension_nid|. This
// function supports both pkcs-9-at-extensionRequest from RFC 2985 and the
// Microsoft szOID_CERT_EXTENSIONS variant. If both are present,
// pkcs-9-at-extensionRequest is preferred.
OPENSSL_EXPORT STACK_OF(X509_EXTENSION) *X509_REQ_get_extensions(X509_REQ *req);

// X509_REQ_get0_signature sets |*out_sig| and |*out_alg| to the signature and
// signature algorithm of |req|, respectively. Either output pointer may be NULL
// to ignore the value.
OPENSSL_EXPORT void X509_REQ_get0_signature(const X509_REQ *req,
                                            const ASN1_BIT_STRING **out_sig,
                                            const X509_ALGOR **out_alg);

// X509_REQ_get_signature_nid returns the NID corresponding to |req|'s signature
// algorithm, or |NID_undef| if the signature algorithm does not correspond to
// a known NID.
OPENSSL_EXPORT int X509_REQ_get_signature_nid(const X509_REQ *req);

// X509_REQ_verify checks that |req| has a valid signature by |pkey|. It returns
// one if the signature is valid and zero otherwise.
OPENSSL_EXPORT int X509_REQ_verify(X509_REQ *req, EVP_PKEY *pkey);


// Issuing certificate requests.
//
// An |X509_REQ| object may also represent an incomplete CSR. Callers may
// construct empty |X509_REQ| objects, fill in fields individually, and finally
// sign the result. The following functions may be used for this purpose.

// X509_REQ_new returns a newly-allocated, empty |X509_REQ| object, or NULL on
// error. This object may be filled in and then signed to construct a CSR.
OPENSSL_EXPORT X509_REQ *X509_REQ_new(void);

// X509_REQ_set_version sets |req|'s version to |version|, which should be
// |X509_REQ_VERSION_1|. It returns one on success and zero on error.
//
// The only defined CSR version is |X509_REQ_VERSION_1|, so there is no need to
// call this function.
OPENSSL_EXPORT int X509_REQ_set_version(X509_REQ *req, long version);

// X509_REQ_set_subject_name sets |req|'s subject to a copy of |name|. It
// returns one on success and zero on error.
OPENSSL_EXPORT int X509_REQ_set_subject_name(X509_REQ *req, X509_NAME *name);

// X509_REQ_set_pubkey sets |req|'s public key to |pkey|. It returns one on
// success and zero on error. This function does not take ownership of |pkey|
// and internally copies and updates reference counts as needed.
OPENSSL_EXPORT int X509_REQ_set_pubkey(X509_REQ *req, EVP_PKEY *pkey);

// X509_REQ_delete_attr removes the attribute at index |loc| in |req|. It
// returns the removed attribute to the caller, or NULL if |loc| was out of
// bounds. If non-NULL, the caller must release the result with
// |X509_ATTRIBUTE_free| when done. It is also safe, but not necessary, to call
// |X509_ATTRIBUTE_free| if the result is NULL.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_REQ_delete_attr(X509_REQ *req, int loc);

// X509_REQ_add1_attr appends a copy of |attr| to |req|'s list of attributes. It
// returns one on success and zero on error.
OPENSSL_EXPORT int X509_REQ_add1_attr(X509_REQ *req,
                                      const X509_ATTRIBUTE *attr);

// X509_REQ_add1_attr_by_OBJ appends a new attribute to |req| with type |obj|.
// It returns one on success and zero on error. The value is determined by
// |X509_ATTRIBUTE_set1_data|.
//
// WARNING: The interpretation of |attrtype|, |data|, and |len| is complex and
// error-prone. See |X509_ATTRIBUTE_set1_data| for details.
OPENSSL_EXPORT int X509_REQ_add1_attr_by_OBJ(X509_REQ *req,
                                             const ASN1_OBJECT *obj,
                                             int attrtype,
                                             const unsigned char *data,
                                             int len);

// X509_REQ_add1_attr_by_NID behaves like |X509_REQ_add1_attr_by_OBJ| except the
// attribute type is determined by |nid|.
OPENSSL_EXPORT int X509_REQ_add1_attr_by_NID(X509_REQ *req, int nid,
                                             int attrtype,
                                             const unsigned char *data,
                                             int len);

// X509_REQ_add1_attr_by_txt behaves like |X509_REQ_add1_attr_by_OBJ| except the
// attribute type is determined by calling |OBJ_txt2obj| with |attrname|.
OPENSSL_EXPORT int X509_REQ_add1_attr_by_txt(X509_REQ *req,
                                             const char *attrname, int attrtype,
                                             const unsigned char *data,
                                             int len);

// X509_REQ_add_extensions_nid adds an attribute to |req| of type |nid|, to
// request the certificate extensions in |exts|. It returns one on success and
// zero on error. |nid| should be |NID_ext_req| or |NID_ms_ext_req|.
OPENSSL_EXPORT int X509_REQ_add_extensions_nid(
    X509_REQ *req, const STACK_OF(X509_EXTENSION) *exts, int nid);

// X509_REQ_add_extensions behaves like |X509_REQ_add_extensions_nid|, using the
// standard |NID_ext_req| for the attribute type.
OPENSSL_EXPORT int X509_REQ_add_extensions(
    X509_REQ *req, const STACK_OF(X509_EXTENSION) *exts);

// X509_REQ_sign signs |req| with |pkey| and replaces the signature algorithm
// and signature fields. It returns the length of the signature on success and
// zero on error. This function uses digest algorithm |md|, or |pkey|'s default
// if NULL. Other signing parameters use |pkey|'s defaults. To customize them,
// use |X509_REQ_sign_ctx|.
OPENSSL_EXPORT int X509_REQ_sign(X509_REQ *req, EVP_PKEY *pkey,
                                 const EVP_MD *md);

// X509_REQ_sign_ctx signs |req| with |ctx| and replaces the signature algorithm
// and signature fields. It returns the length of the signature on success and
// zero on error. The signature algorithm and parameters come from |ctx|, which
// must have been initialized with |EVP_DigestSignInit|. The caller should
// configure the corresponding |EVP_PKEY_CTX| before calling this function.
//
// On success or failure, this function mutates |ctx| and resets it to the empty
// state. Caller should not rely on its contents after the function returns.
OPENSSL_EXPORT int X509_REQ_sign_ctx(X509_REQ *req, EVP_MD_CTX *ctx);

// i2d_re_X509_REQ_tbs serializes the CertificationRequestInfo (see RFC 2986)
// portion of |req|, as described in |i2d_SAMPLE|.
//
// This function re-encodes the CertificationRequestInfo and may not reflect
// |req|'s original encoding. It may be used to manually generate a signature
// for a new certificate request.
OPENSSL_EXPORT int i2d_re_X509_REQ_tbs(X509_REQ *req, uint8_t **outp);

// X509_REQ_set1_signature_algo sets |req|'s signature algorithm to |algo| and
// returns one on success or zero on error.
OPENSSL_EXPORT int X509_REQ_set1_signature_algo(X509_REQ *req,
                                                const X509_ALGOR *algo);

// X509_REQ_set1_signature_value sets |req|'s signature to a copy of the
// |sig_len| bytes pointed by |sig|. It returns one on success and zero on
// error.
//
// Due to a specification error, PKCS#10 certificate requests store signatures
// in ASN.1 BIT STRINGs, but signature algorithms return byte strings rather
// than bit strings. This function creates a BIT STRING containing a whole
// number of bytes, with the bit order matching the DER encoding. This matches
// the encoding used by all X.509 signature algorithms.
OPENSSL_EXPORT int X509_REQ_set1_signature_value(X509_REQ *req,
                                                 const uint8_t *sig,
                                                 size_t sig_len);


// Names.
//
// An |X509_NAME| represents an X.509 Name structure (RFC 5280). X.509 names are
// a complex, hierarchical structure over a collection of attributes. Each name
// is sequence of relative distinguished names (RDNs), decreasing in
// specificity. For example, the first RDN may specify the country, while the
// next RDN may specify a locality. Each RDN is, itself, a set of attributes.
// Having more than one attribute in an RDN is uncommon, but possible. Within an
// RDN, attributes have the same level in specificity. Attribute types are
// OBJECT IDENTIFIERs. This determines the ASN.1 type of the value, which is
// commonly a string but may be other types.
//
// The |X509_NAME| representation flattens this two-level structure into a
// single list of attributes. Each attribute is stored in an |X509_NAME_ENTRY|,
// with also maintains the index of the RDN it is part of, accessible via
// |X509_NAME_ENTRY_set|. This can be used to recover the two-level structure.
//
// X.509 names are largely vestigial. Historically, DNS names were parsed out of
// the subject's common name attribute, but this is deprecated and has since
// moved to the subject alternative name extension. In modern usage, X.509 names
// are primarily opaque identifiers to link a certificate with its issuer.

DEFINE_STACK_OF(X509_NAME_ENTRY)
DEFINE_STACK_OF(X509_NAME)

// X509_NAME is an |ASN1_ITEM| whose ASN.1 type is X.509 Name (RFC 5280) and C
// type is |X509_NAME*|.
DECLARE_ASN1_ITEM(X509_NAME)

// X509_NAME_new returns a new, empty |X509_NAME_new|, or NULL on
// error.
OPENSSL_EXPORT X509_NAME *X509_NAME_new(void);

// X509_NAME_free releases memory associated with |name|.
OPENSSL_EXPORT void X509_NAME_free(X509_NAME *name);

// d2i_X509_NAME parses up to |len| bytes from |*inp| as a DER-encoded X.509
// Name (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_NAME *d2i_X509_NAME(X509_NAME **out, const uint8_t **inp,
                                        long len);

// i2d_X509_NAME marshals |in| as a DER-encoded X.509 Name (RFC 5280), as
// described in |i2d_SAMPLE|.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |in| was
// mutated.
OPENSSL_EXPORT int i2d_X509_NAME(X509_NAME *in, uint8_t **outp);

// X509_NAME_dup returns a newly-allocated copy of |name|, or NULL on error.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |name| was
// mutated.
OPENSSL_EXPORT X509_NAME *X509_NAME_dup(X509_NAME *name);

// X509_NAME_cmp compares |a| and |b|'s canonicalized forms. It returns zero if
// they are equal, one if |a| sorts after |b|, -1 if |b| sorts after |a|, and -2
// on error.
//
// TODO(https://crbug.com/boringssl/407): This function is const, but it is not
// always thread-safe, notably if |name| was mutated.
//
// TODO(https://crbug.com/boringssl/355): The -2 return is very inconvenient to
// pass to a sorting function. Can we make this infallible? In the meantime,
// prefer to use this function only for equality checks rather than comparisons.
// Although even the library itself passes this to a sorting function.
OPENSSL_EXPORT int X509_NAME_cmp(const X509_NAME *a, const X509_NAME *b);

// X509_NAME_get0_der sets |*out_der| and |*out_der_len|
//
// Avoid this function and prefer |i2d_X509_NAME|. It is one of the reasons
// these functions are not consistently thread-safe or const-correct. Depending
// on the resolution of https://crbug.com/boringssl/407, this function may be
// removed or cause poor performance.
OPENSSL_EXPORT int X509_NAME_get0_der(X509_NAME *name, const uint8_t **out_der,
                                      size_t *out_der_len);

// X509_NAME_set makes a copy of |name|. On success, it frees |*xn|, sets |*xn|
// to the copy, and returns one. Otherwise, it returns zero.
//
// TODO(https://crbug.com/boringssl/407): This function should be const and
// thread-safe but is currently neither in some cases, notably if |name| was
// mutated.
OPENSSL_EXPORT int X509_NAME_set(X509_NAME **xn, X509_NAME *name);

// X509_NAME_entry_count returns the number of entries in |name|.
OPENSSL_EXPORT int X509_NAME_entry_count(const X509_NAME *name);

// X509_NAME_get_index_by_NID returns the zero-based index of the first
// attribute in |name| with type |nid|, or -1 if there is none. |nid| should be
// one of the |NID_*| constants. If |lastpos| is non-negative, it begins
// searching at |lastpos+1|. To search all attributes, pass in -1, not zero.
//
// Indices from this function refer to |X509_NAME|'s flattened representation.
OPENSSL_EXPORT int X509_NAME_get_index_by_NID(const X509_NAME *name, int nid,
                                              int lastpos);

// X509_NAME_get_index_by_OBJ behaves like |X509_NAME_get_index_by_NID| but
// looks for attributes with type |obj|.
OPENSSL_EXPORT int X509_NAME_get_index_by_OBJ(const X509_NAME *name,
                                              const ASN1_OBJECT *obj,
                                              int lastpos);

// X509_NAME_get_entry returns the attribute in |name| at index |loc|, or NULL
// if |loc| is out of range. |loc| is interpreted using |X509_NAME|'s flattened
// representation. This function returns a non-const pointer for OpenSSL
// compatibility, but callers should not mutate the result. Doing so will break
// internal invariants in the library.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_get_entry(const X509_NAME *name,
                                                    int loc);

// X509_NAME_delete_entry removes and returns the attribute in |name| at index
// |loc|, or NULL if |loc| is out of range. |loc| is interpreted using
// |X509_NAME|'s flattened representation. If the attribute is found, the caller
// is responsible for releasing the result with |X509_NAME_ENTRY_free|.
//
// This function will internally update RDN indices (see |X509_NAME_ENTRY_set|)
// so they continue to be consecutive.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_delete_entry(X509_NAME *name,
                                                       int loc);

// X509_NAME_add_entry adds a copy of |entry| to |name| and returns one on
// success or zero on error. If |loc| is -1, the entry is appended to |name|.
// Otherwise, it is inserted at index |loc|. If |set| is -1, the entry is added
// to the previous entry's RDN. If it is 0, the entry becomes a singleton RDN.
// If 1, it is added to next entry's RDN.
//
// This function will internally update RDN indices (see |X509_NAME_ENTRY_set|)
// so they continue to be consecutive.
OPENSSL_EXPORT int X509_NAME_add_entry(X509_NAME *name,
                                       const X509_NAME_ENTRY *entry, int loc,
                                       int set);

// X509_NAME_add_entry_by_OBJ adds a new entry to |name| and returns one on
// success or zero on error. The entry's attribute type is |obj|. The entry's
// attribute value is determined by |type|, |bytes|, and |len|, as in
// |X509_NAME_ENTRY_set_data|. The entry's position is determined by |loc| and
// |set| as in |X509_NAME_add_entry|.
OPENSSL_EXPORT int X509_NAME_add_entry_by_OBJ(X509_NAME *name,
                                              const ASN1_OBJECT *obj, int type,
                                              const uint8_t *bytes,
                                              ossl_ssize_t len, int loc,
                                              int set);

// X509_NAME_add_entry_by_NID behaves like |X509_NAME_add_entry_by_OBJ| but sets
// the entry's attribute type to |nid|, which should be one of the |NID_*|
// constants.
OPENSSL_EXPORT int X509_NAME_add_entry_by_NID(X509_NAME *name, int nid,
                                              int type, const uint8_t *bytes,
                                              ossl_ssize_t len, int loc,
                                              int set);

// X509_NAME_add_entry_by_txt behaves like |X509_NAME_add_entry_by_OBJ| but sets
// the entry's attribute type to |field|, which is passed to |OBJ_txt2obj|.
OPENSSL_EXPORT int X509_NAME_add_entry_by_txt(X509_NAME *name,
                                              const char *field, int type,
                                              const uint8_t *bytes,
                                              ossl_ssize_t len, int loc,
                                              int set);

// X509_NAME_ENTRY is an |ASN1_ITEM| whose ASN.1 type is AttributeTypeAndValue
// (RFC 5280) and C type is |X509_NAME_ENTRY*|.
DECLARE_ASN1_ITEM(X509_NAME_ENTRY)

// X509_NAME_ENTRY_new returns a new, empty |X509_NAME_ENTRY_new|, or NULL on
// error.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_ENTRY_new(void);

// X509_NAME_ENTRY_free releases memory associated with |entry|.
OPENSSL_EXPORT void X509_NAME_ENTRY_free(X509_NAME_ENTRY *entry);

// d2i_X509_NAME_ENTRY parses up to |len| bytes from |*inp| as a DER-encoded
// AttributeTypeAndValue (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_NAME_ENTRY *d2i_X509_NAME_ENTRY(X509_NAME_ENTRY **out,
                                                    const uint8_t **inp,
                                                    long len);

// i2d_X509_NAME_ENTRY marshals |in| as a DER-encoded AttributeTypeAndValue (RFC
// 5280), as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_NAME_ENTRY(const X509_NAME_ENTRY *in,
                                       uint8_t **outp);

// X509_NAME_ENTRY_dup returns a newly-allocated copy of |entry|, or NULL on
// error.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_ENTRY_dup(
    const X509_NAME_ENTRY *entry);

// X509_NAME_ENTRY_get_object returns |entry|'s attribute type. This function
// returns a non-const pointer for OpenSSL compatibility, but callers should not
// mutate the result. Doing so will break internal invariants in the library.
OPENSSL_EXPORT ASN1_OBJECT *X509_NAME_ENTRY_get_object(
    const X509_NAME_ENTRY *entry);

// X509_NAME_ENTRY_set_object sets |entry|'s attribute type to |obj|. It returns
// one on success and zero on error.
OPENSSL_EXPORT int X509_NAME_ENTRY_set_object(X509_NAME_ENTRY *entry,
                                              const ASN1_OBJECT *obj);

// X509_NAME_ENTRY_get_data returns |entry|'s attribute value, represented as an
// |ASN1_STRING|. This value may have any ASN.1 type, so callers must check the
// type before interpreting the contents. This function returns a non-const
// pointer for OpenSSL compatibility, but callers should not mutate the result.
// Doing so will break internal invariants in the library.
//
// TODO(https://crbug.com/boringssl/412): Although the spec says any ASN.1 type
// is allowed, we currently only allow an ad-hoc set of types. Additionally, it
// is unclear if some types can even be represented by this function.
OPENSSL_EXPORT ASN1_STRING *X509_NAME_ENTRY_get_data(
    const X509_NAME_ENTRY *entry);

// X509_NAME_ENTRY_set_data sets |entry|'s value to |len| bytes from |bytes|. It
// returns one on success and zero on error. If |len| is -1, |bytes| must be a
// NUL-terminated C string and the length is determined by |strlen|. |bytes| is
// converted to an ASN.1 type as follows:
//
// If |type| is a |MBSTRING_*| constant, the value is an ASN.1 string. The
// string is determined by decoding |bytes| in the encoding specified by |type|,
// and then re-encoding it in a form appropriate for |entry|'s attribute type.
// See |ASN1_STRING_set_by_NID| for details.
//
// Otherwise, the value is an |ASN1_STRING| with type |type| and value |bytes|.
// See |ASN1_STRING| for how to format ASN.1 types as an |ASN1_STRING|. If
// |type| is |V_ASN1_UNDEF| the previous |ASN1_STRING| type is reused.
OPENSSL_EXPORT int X509_NAME_ENTRY_set_data(X509_NAME_ENTRY *entry, int type,
                                            const uint8_t *bytes,
                                            ossl_ssize_t len);

// X509_NAME_ENTRY_set returns the zero-based index of the RDN which contains
// |entry|. Consecutive entries with the same index are part of the same RDN.
OPENSSL_EXPORT int X509_NAME_ENTRY_set(const X509_NAME_ENTRY *entry);

// X509_NAME_ENTRY_create_by_OBJ creates a new |X509_NAME_ENTRY| with attribute
// type |obj|. The attribute value is determined from |type|, |bytes|, and |len|
// as in |X509_NAME_ENTRY_set_data|. It returns the |X509_NAME_ENTRY| on success
// and NULL on error.
//
// If |out| is non-NULL and |*out| is NULL, it additionally sets |*out| to the
// result on success. If both |out| and |*out| are non-NULL, it updates the
// object at |*out| instead of allocating a new one.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_ENTRY_create_by_OBJ(
    X509_NAME_ENTRY **out, const ASN1_OBJECT *obj, int type,
    const uint8_t *bytes, ossl_ssize_t len);

// X509_NAME_ENTRY_create_by_NID behaves like |X509_NAME_ENTRY_create_by_OBJ|
// except the attribute type is |nid|, which should be one of the |NID_*|
// constants.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_ENTRY_create_by_NID(
    X509_NAME_ENTRY **out, int nid, int type, const uint8_t *bytes,
    ossl_ssize_t len);

// X509_NAME_ENTRY_create_by_txt behaves like |X509_NAME_ENTRY_create_by_OBJ|
// except the attribute type is |field|, which is passed to |OBJ_txt2obj|.
OPENSSL_EXPORT X509_NAME_ENTRY *X509_NAME_ENTRY_create_by_txt(
    X509_NAME_ENTRY **out, const char *field, int type, const uint8_t *bytes,
    ossl_ssize_t len);


// Public keys.
//
// X.509 encodes public keys as SubjectPublicKeyInfo (RFC 5280), sometimes
// referred to as SPKI. These are represented in this library by |X509_PUBKEY|.

// X509_PUBKEY is an |ASN1_ITEM| whose ASN.1 type is SubjectPublicKeyInfo and C
// type is |X509_PUBKEY*|.
DECLARE_ASN1_ITEM(X509_PUBKEY)

// X509_PUBKEY_new returns a newly-allocated, empty |X509_PUBKEY| object, or
// NULL on error.
OPENSSL_EXPORT X509_PUBKEY *X509_PUBKEY_new(void);

// X509_PUBKEY_free releases memory associated with |key|.
OPENSSL_EXPORT void X509_PUBKEY_free(X509_PUBKEY *key);

// d2i_X509_PUBKEY parses up to |len| bytes from |*inp| as a DER-encoded
// SubjectPublicKeyInfo, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT X509_PUBKEY *d2i_X509_PUBKEY(X509_PUBKEY **out,
                                            const uint8_t **inp, long len);

// i2d_X509_PUBKEY marshals |key| as a DER-encoded SubjectPublicKeyInfo, as
// described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_PUBKEY(const X509_PUBKEY *key, uint8_t **outp);

// X509_PUBKEY_set serializes |pkey| into a newly-allocated |X509_PUBKEY|
// structure. On success, it frees |*x| if non-NULL, then sets |*x| to the new
// object, and returns one. Otherwise, it returns zero.
OPENSSL_EXPORT int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey);

// X509_PUBKEY_get decodes the public key in |key| and returns an |EVP_PKEY| on
// success, or NULL on error or unrecognized algorithm. The caller must release
// the result with |EVP_PKEY_free| when done. The |EVP_PKEY| is cached in |key|,
// so callers must not mutate the result.
OPENSSL_EXPORT EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key);

// X509_PUBKEY_set0_param sets |pub| to a key with AlgorithmIdentifier
// determined by |obj|, |param_type|, and |param_value|, and an encoded
// public key of |key|. On success, it gives |pub| ownership of all the other
// parameters and returns one. Otherwise, it returns zero. |key| must have been
// allocated by |OPENSSL_malloc|. |obj| and, if applicable, |param_value| must
// not be freed after a successful call, and must have been allocated in a
// manner compatible with |ASN1_OBJECT_free| or |ASN1_STRING_free|.
//
// |obj|, |param_type|, and |param_value| are interpreted as in
// |X509_ALGOR_set0|. See |X509_ALGOR_set0| for details.
OPENSSL_EXPORT int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *obj,
                                          int param_type, void *param_value,
                                          uint8_t *key, int key_len);

// X509_PUBKEY_get0_param outputs fields of |pub| and returns one. If |out_obj|
// is not NULL, it sets |*out_obj| to AlgorithmIdentifier's OID. If |out_key|
// is not NULL, it sets |*out_key| and |*out_key_len| to the encoded public key.
// If |out_alg| is not NULL, it sets |*out_alg| to the AlgorithmIdentifier.
//
// All pointers outputted by this function are internal to |pub| and must not be
// freed by the caller. Additionally, although some outputs are non-const,
// callers must not mutate the resulting objects.
//
// Note: X.509 SubjectPublicKeyInfo structures store the encoded public key as a
// BIT STRING. |*out_key| and |*out_key_len| will silently pad the key with zero
// bits if |pub| did not contain a whole number of bytes. Use
// |X509_PUBKEY_get0_public_key| to preserve this information.
OPENSSL_EXPORT int X509_PUBKEY_get0_param(ASN1_OBJECT **out_obj,
                                          const uint8_t **out_key,
                                          int *out_key_len,
                                          X509_ALGOR **out_alg,
                                          X509_PUBKEY *pub);

// X509_PUBKEY_get0_public_key returns |pub|'s encoded public key.
OPENSSL_EXPORT const ASN1_BIT_STRING *X509_PUBKEY_get0_public_key(
    const X509_PUBKEY *pub);


// Extensions.
//
// X.509 certificates and CRLs may contain a list of extensions (RFC 5280).
// Extensions have a type, specified by an object identifier (|ASN1_OBJECT|) and
// a byte string value, which should a DER-encoded structure whose type is
// determined by the extension type. This library represents extensions with the
// |X509_EXTENSION| type.

// X509_EXTENSION is an |ASN1_ITEM| whose ASN.1 type is X.509 Extension (RFC
// 5280) and C type is |X509_EXTENSION*|.
DECLARE_ASN1_ITEM(X509_EXTENSION)

// X509_EXTENSION_new returns a newly-allocated, empty |X509_EXTENSION| object
// or NULL on error.
OPENSSL_EXPORT X509_EXTENSION *X509_EXTENSION_new(void);

// X509_EXTENSION_free releases memory associated with |ex|.
OPENSSL_EXPORT void X509_EXTENSION_free(X509_EXTENSION *ex);

// d2i_X509_EXTENSION parses up to |len| bytes from |*inp| as a DER-encoded
// X.509 Extension (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_EXTENSION *d2i_X509_EXTENSION(X509_EXTENSION **out,
                                                  const uint8_t **inp,
                                                  long len);

// i2d_X509_EXTENSION marshals |ex| as a DER-encoded X.509 Extension (RFC
// 5280), as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_EXTENSION(const X509_EXTENSION *ex, uint8_t **outp);

// X509_EXTENSION_dup returns a newly-allocated copy of |ex|, or NULL on error.
// This function works by serializing the structure, so if |ex| is incomplete,
// it may fail.
OPENSSL_EXPORT X509_EXTENSION *X509_EXTENSION_dup(const X509_EXTENSION *ex);

// X509_EXTENSION_create_by_NID creates a new |X509_EXTENSION| with type |nid|,
// value |data|, and critical bit |crit|. It returns an |X509_EXTENSION| on
// success, and NULL on error. |nid| should be a |NID_*| constant.
//
// If |ex| and |*ex| are both non-NULL, |*ex| is used to hold the result,
// otherwise a new object is allocated. If |ex| is non-NULL and |*ex| is NULL,
// the function sets |*ex| to point to the newly allocated result, in addition
// to returning the result.
OPENSSL_EXPORT X509_EXTENSION *X509_EXTENSION_create_by_NID(
    X509_EXTENSION **ex, int nid, int crit, const ASN1_OCTET_STRING *data);

// X509_EXTENSION_create_by_OBJ behaves like |X509_EXTENSION_create_by_NID|, but
// the extension type is determined by an |ASN1_OBJECT|.
OPENSSL_EXPORT X509_EXTENSION *X509_EXTENSION_create_by_OBJ(
    X509_EXTENSION **ex, const ASN1_OBJECT *obj, int crit,
    const ASN1_OCTET_STRING *data);

// X509_EXTENSION_get_object returns |ex|'s extension type. This function
// returns a non-const pointer for OpenSSL compatibility, but callers should not
// mutate the result.
OPENSSL_EXPORT ASN1_OBJECT *X509_EXTENSION_get_object(const X509_EXTENSION *ex);

// X509_EXTENSION_get_data returns |ne|'s extension value. This function returns
// a non-const pointer for OpenSSL compatibility, but callers should not mutate
// the result.
OPENSSL_EXPORT ASN1_OCTET_STRING *X509_EXTENSION_get_data(
    const X509_EXTENSION *ne);

// X509_EXTENSION_get_critical returns one if |ex| is critical and zero
// otherwise.
OPENSSL_EXPORT int X509_EXTENSION_get_critical(const X509_EXTENSION *ex);

// X509_EXTENSION_set_object sets |ex|'s extension type to |obj|. It returns one
// on success and zero on error.
OPENSSL_EXPORT int X509_EXTENSION_set_object(X509_EXTENSION *ex,
                                             const ASN1_OBJECT *obj);

// X509_EXTENSION_set_critical sets |ex| to critical if |crit| is non-zero and
// to non-critical if |crit| is zero.
OPENSSL_EXPORT int X509_EXTENSION_set_critical(X509_EXTENSION *ex, int crit);

// X509_EXTENSION_set_data set's |ex|'s extension value to a copy of |data|. It
// returns one on success and zero on error.
OPENSSL_EXPORT int X509_EXTENSION_set_data(X509_EXTENSION *ex,
                                           const ASN1_OCTET_STRING *data);


// Extension lists.
//
// The following functions manipulate lists of extensions. Most of them have
// corresponding functions on the containing |X509|, |X509_CRL|, or
// |X509_REVOKED|.

DEFINE_STACK_OF(X509_EXTENSION)
typedef STACK_OF(X509_EXTENSION) X509_EXTENSIONS;

// X509_EXTENSIONS is an |ASN1_ITEM| whose ASN.1 type is SEQUENCE of Extension
// (RFC 5280) and C type is |STACK_OF(X509_EXTENSION)*|.
DECLARE_ASN1_ITEM(X509_EXTENSIONS)

// d2i_X509_EXTENSIONS parses up to |len| bytes from |*inp| as a DER-encoded
// SEQUENCE OF Extension (RFC 5280), as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_EXTENSIONS *d2i_X509_EXTENSIONS(X509_EXTENSIONS **out,
                                                    const uint8_t **inp,
                                                    long len);

// i2d_X509_EXTENSIONS marshals |alg| as a DER-encoded SEQUENCE OF Extension
// (RFC 5280), as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_EXTENSIONS(const X509_EXTENSIONS *alg,
                                       uint8_t **outp);

// X509v3_get_ext_count returns the number of extensions in |x|.
OPENSSL_EXPORT int X509v3_get_ext_count(const STACK_OF(X509_EXTENSION) *x);

// X509v3_get_ext_by_NID returns the index of the first extension in |x| with
// type |nid|, or a negative number if not found. If found, callers can use
// |X509v3_get_ext| to look up the extension by index.
//
// If |lastpos| is non-negative, it begins searching at |lastpos| + 1. Callers
// can thus loop over all matching extensions by first passing -1 and then
// passing the previously-returned value until no match is returned.
OPENSSL_EXPORT int X509v3_get_ext_by_NID(const STACK_OF(X509_EXTENSION) *x,
                                         int nid, int lastpos);

// X509v3_get_ext_by_OBJ behaves like |X509v3_get_ext_by_NID| but looks for
// extensions matching |obj|.
OPENSSL_EXPORT int X509v3_get_ext_by_OBJ(const STACK_OF(X509_EXTENSION) *x,
                                         const ASN1_OBJECT *obj, int lastpos);

// X509v3_get_ext_by_critical returns the index of the first extension in |x|
// whose critical bit matches |crit|, or a negative number if no such extension
// was found.
//
// If |lastpos| is non-negative, it begins searching at |lastpos| + 1. Callers
// can thus loop over all matching extensions by first passing -1 and then
// passing the previously-returned value until no match is returned.
OPENSSL_EXPORT int X509v3_get_ext_by_critical(const STACK_OF(X509_EXTENSION) *x,
                                              int crit, int lastpos);

// X509v3_get_ext returns the extension in |x| at index |loc|, or NULL if |loc|
// is out of bounds. This function returns a non-const pointer for OpenSSL
// compatibility, but callers should not mutate the result.
OPENSSL_EXPORT X509_EXTENSION *X509v3_get_ext(const STACK_OF(X509_EXTENSION) *x,
                                              int loc);

// X509v3_delete_ext removes the extension in |x| at index |loc| and returns the
// removed extension, or NULL if |loc| was out of bounds. If an extension was
// returned, the caller must release it with |X509_EXTENSION_free|.
OPENSSL_EXPORT X509_EXTENSION *X509v3_delete_ext(STACK_OF(X509_EXTENSION) *x,
                                                 int loc);

// X509v3_add_ext adds a copy of |ex| to the extension list in |*x|. If |*x| is
// NULL, it allocates a new |STACK_OF(X509_EXTENSION)| to hold the copy and sets
// |*x| to the new list. It returns |*x| on success and NULL on error. The
// caller retains ownership of |ex| and can release it independently of |*x|.
//
// The new extension is inserted at index |loc|, shifting extensions to the
// right. If |loc| is -1 or out of bounds, the new extension is appended to the
// list.
OPENSSL_EXPORT STACK_OF(X509_EXTENSION) *X509v3_add_ext(
    STACK_OF(X509_EXTENSION) **x, const X509_EXTENSION *ex, int loc);


// Algorithm identifiers.
//
// An |X509_ALGOR| represents an AlgorithmIdentifier structure, used in X.509
// to represent signature algorithms and public key algorithms.

DEFINE_STACK_OF(X509_ALGOR)

// X509_ALGOR is an |ASN1_ITEM| whose ASN.1 type is AlgorithmIdentifier and C
// type is |X509_ALGOR*|.
DECLARE_ASN1_ITEM(X509_ALGOR)

// X509_ALGOR_new returns a newly-allocated, empty |X509_ALGOR| object, or NULL
// on error.
OPENSSL_EXPORT X509_ALGOR *X509_ALGOR_new(void);

// X509_ALGOR_dup returns a newly-allocated copy of |alg|, or NULL on error.
// This function works by serializing the structure, so if |alg| is incomplete,
// it may fail.
OPENSSL_EXPORT X509_ALGOR *X509_ALGOR_dup(const X509_ALGOR *alg);

// X509_ALGOR_free releases memory associated with |alg|.
OPENSSL_EXPORT void X509_ALGOR_free(X509_ALGOR *alg);

// d2i_X509_ALGOR parses up to |len| bytes from |*inp| as a DER-encoded
// AlgorithmIdentifier, as described in |d2i_SAMPLE_with_reuse|.
OPENSSL_EXPORT X509_ALGOR *d2i_X509_ALGOR(X509_ALGOR **out, const uint8_t **inp,
                                          long len);

// i2d_X509_ALGOR marshals |alg| as a DER-encoded AlgorithmIdentifier, as
// described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_ALGOR(const X509_ALGOR *alg, uint8_t **outp);

// X509_ALGOR_set0 sets |alg| to an AlgorithmIdentifier with algorithm |obj| and
// parameter determined by |param_type| and |param_value|. It returns one on
// success and zero on error. This function takes ownership of |obj| and
// |param_value| on success.
//
// If |param_type| is |V_ASN1_UNDEF|, the parameter is omitted. If |param_type|
// is zero, the parameter is left unchanged. Otherwise, |param_type| and
// |param_value| are interpreted as in |ASN1_TYPE_set|.
//
// Note omitting the parameter (|V_ASN1_UNDEF|) and encoding an explicit NULL
// value (|V_ASN1_NULL|) are different. Some algorithms require one and some the
// other. Consult the relevant specification before calling this function. The
// correct parameter for an RSASSA-PKCS1-v1_5 signature is |V_ASN1_NULL|. The
// correct one for an ECDSA or Ed25519 signature is |V_ASN1_UNDEF|.
OPENSSL_EXPORT int X509_ALGOR_set0(X509_ALGOR *alg, ASN1_OBJECT *obj,
                                   int param_type, void *param_value);

// X509_ALGOR_get0 sets |*out_obj| to the |alg|'s algorithm. If |alg|'s
// parameter is omitted, it sets |*out_param_type| and |*out_param_value| to
// |V_ASN1_UNDEF| and NULL. Otherwise, it sets |*out_param_type| and
// |*out_param_value| to the parameter, using the same representation as
// |ASN1_TYPE_set0|. See |ASN1_TYPE_set0| and |ASN1_TYPE| for details.
//
// Callers that require the parameter in serialized form should, after checking
// for |V_ASN1_UNDEF|, use |ASN1_TYPE_set1| and |d2i_ASN1_TYPE|, rather than
// inspecting |*out_param_value|.
//
// Each of |out_obj|, |out_param_type|, and |out_param_value| may be NULL to
// ignore the output. If |out_param_type| is NULL, |out_param_value| is ignored.
//
// WARNING: If |*out_param_type| is set to |V_ASN1_UNDEF|, OpenSSL and older
// revisions of BoringSSL leave |*out_param_value| unset rather than setting it
// to NULL. Callers that support both OpenSSL and BoringSSL should not assume
// |*out_param_value| is uniformly initialized.
OPENSSL_EXPORT void X509_ALGOR_get0(const ASN1_OBJECT **out_obj,
                                    int *out_param_type,
                                    const void **out_param_value,
                                    const X509_ALGOR *alg);

// X509_ALGOR_set_md sets |alg| to the hash function |md|. Note this
// AlgorithmIdentifier represents the hash function itself, not a signature
// algorithm that uses |md|.
OPENSSL_EXPORT void X509_ALGOR_set_md(X509_ALGOR *alg, const EVP_MD *md);

// X509_ALGOR_cmp returns zero if |a| and |b| are equal, and some non-zero value
// otherwise. Note this function can only be used for equality checks, not an
// ordering.
OPENSSL_EXPORT int X509_ALGOR_cmp(const X509_ALGOR *a, const X509_ALGOR *b);


// Attributes.
//
// Unlike certificates and CRLs, CSRs use a separate Attribute structure (RFC
// 2985, RFC 2986) for extensibility. This is represented by the library as
// |X509_ATTRIBUTE|.

DEFINE_STACK_OF(X509_ATTRIBUTE)

// X509_ATTRIBUTE is an |ASN1_ITEM| whose ASN.1 type is Attribute (RFC 2986) and
// C type is |X509_ATTRIBUTE*|.
DECLARE_ASN1_ITEM(X509_ATTRIBUTE)

// X509_ATTRIBUTE_new returns a newly-allocated, empty |X509_ATTRIBUTE| object,
// or NULL on error. |X509_ATTRIBUTE_set1_*| may be used to finish initializing
// it.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_new(void);

// X509_ATTRIBUTE_dup returns a newly-allocated copy of |attr|, or NULL on
// error. This function works by serializing the structure, so if |attr| is
// incomplete, it may fail.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_dup(const X509_ATTRIBUTE *attr);

// X509_ATTRIBUTE_free releases memory associated with |attr|.
OPENSSL_EXPORT void X509_ATTRIBUTE_free(X509_ATTRIBUTE *attr);

// d2i_X509_ATTRIBUTE parses up to |len| bytes from |*inp| as a DER-encoded
// Attribute (RFC 2986), as described in |d2i_SAMPLE|.
OPENSSL_EXPORT X509_ATTRIBUTE *d2i_X509_ATTRIBUTE(X509_ATTRIBUTE **out,
                                                  const uint8_t **inp,
                                                  long len);

// i2d_X509_ATTRIBUTE marshals |alg| as a DER-encoded Attribute (RFC 2986), as
// described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_ATTRIBUTE(const X509_ATTRIBUTE *alg,
                                      uint8_t **outp);

// X509_ATTRIBUTE_create returns a newly-allocated |X509_ATTRIBUTE|, or NULL on
// error. The attribute has type |nid| and contains a single value determined by
// |attrtype| and |value|, which are interpreted as in |ASN1_TYPE_set|. Note
// this function takes ownership of |value|.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_create(int nid, int attrtype,
                                                     void *value);

// X509_ATTRIBUTE_create_by_NID returns a newly-allocated |X509_ATTRIBUTE| of
// type |nid|, or NULL on error. The value is determined as in
// |X509_ATTRIBUTE_set1_data|.
//
// If |attr| is non-NULL, the resulting |X509_ATTRIBUTE| is also written to
// |*attr|. If |*attr| was non-NULL when the function was called, |*attr| is
// reused instead of creating a new object.
//
// WARNING: The interpretation of |attrtype|, |data|, and |len| is complex and
// error-prone. See |X509_ATTRIBUTE_set1_data| for details.
//
// WARNING: The object reuse form is deprecated and may be removed in the
// future. It also currently incorrectly appends to the reused object's value
// set rather than overwriting it.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_create_by_NID(
    X509_ATTRIBUTE **attr, int nid, int attrtype, const void *data, int len);

// X509_ATTRIBUTE_create_by_OBJ behaves like |X509_ATTRIBUTE_create_by_NID|
// except the attribute's type is determined by |obj|.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_create_by_OBJ(
    X509_ATTRIBUTE **attr, const ASN1_OBJECT *obj, int attrtype,
    const void *data, int len);

// X509_ATTRIBUTE_create_by_txt behaves like |X509_ATTRIBUTE_create_by_NID|
// except the attribute's type is determined by calling |OBJ_txt2obj| with
// |attrname|.
OPENSSL_EXPORT X509_ATTRIBUTE *X509_ATTRIBUTE_create_by_txt(
    X509_ATTRIBUTE **attr, const char *attrname, int type,
    const unsigned char *bytes, int len);

// X509_ATTRIBUTE_set1_object sets |attr|'s type to |obj|. It returns one on
// success and zero on error.
OPENSSL_EXPORT int X509_ATTRIBUTE_set1_object(X509_ATTRIBUTE *attr,
                                              const ASN1_OBJECT *obj);

// X509_ATTRIBUTE_set1_data appends a value to |attr|'s value set and returns
// one on success or zero on error. The value is determined as follows:
//
// If |attrtype| is a |MBSTRING_*| constant, the value is an ASN.1 string. The
// string is determined by decoding |len| bytes from |data| in the encoding
// specified by |attrtype|, and then re-encoding it in a form appropriate for
// |attr|'s type. If |len| is -1, |strlen(data)| is used instead. See
// |ASN1_STRING_set_by_NID| for details.
//
// Otherwise, if |len| is not -1, the value is an ASN.1 string. |attrtype| is an
// |ASN1_STRING| type value and the |len| bytes from |data| are copied as the
// type-specific representation of |ASN1_STRING|. See |ASN1_STRING| for details.
//
// WARNING: If this form is used to construct a negative INTEGER or ENUMERATED,
// |attrtype| includes the |V_ASN1_NEG| flag for |ASN1_STRING|, but the function
// forgets to clear the flag for |ASN1_TYPE|. This matches OpenSSL but is
// probably a bug. For now, do not use this form with negative values.
//
// Otherwise, if |len| is -1, the value is constructed by passing |attrtype| and
// |data| to |ASN1_TYPE_set1|. That is, |attrtype| is an |ASN1_TYPE| type value,
// and |data| is cast to the corresponding pointer type.
//
// WARNING: Despite the name, this function appends to |attr|'s value set,
// rather than overwriting it. To overwrite the value set, create a new
// |X509_ATTRIBUTE| with |X509_ATTRIBUTE_new|.
//
// WARNING: If using the |MBSTRING_*| form, pass a length rather than relying on
// |strlen|. In particular, |strlen| will not behave correctly if the input is
// |MBSTRING_BMP| or |MBSTRING_UNIV|.
//
// WARNING: This function currently misinterprets |V_ASN1_OTHER| as an
// |MBSTRING_*| constant. This matches OpenSSL but means it is impossible to
// construct a value with a non-universal tag.
OPENSSL_EXPORT int X509_ATTRIBUTE_set1_data(X509_ATTRIBUTE *attr, int attrtype,
                                            const void *data, int len);

// X509_ATTRIBUTE_get0_data returns the |idx|th value of |attr| in a
// type-specific representation to |attrtype|, or NULL if out of bounds or the
// type does not match. |attrtype| is one of the type values in |ASN1_TYPE|. On
// match, the return value uses the same representation as |ASN1_TYPE_set0|. See
// |ASN1_TYPE| for details.
OPENSSL_EXPORT void *X509_ATTRIBUTE_get0_data(X509_ATTRIBUTE *attr, int idx,
                                              int attrtype, void *unused);

// X509_ATTRIBUTE_count returns the number of values in |attr|.
OPENSSL_EXPORT int X509_ATTRIBUTE_count(const X509_ATTRIBUTE *attr);

// X509_ATTRIBUTE_get0_object returns the type of |attr|.
OPENSSL_EXPORT ASN1_OBJECT *X509_ATTRIBUTE_get0_object(X509_ATTRIBUTE *attr);

// X509_ATTRIBUTE_get0_type returns the |idx|th value in |attr|, or NULL if out
// of bounds. Note this function returns one of |attr|'s values, not the type.
OPENSSL_EXPORT ASN1_TYPE *X509_ATTRIBUTE_get0_type(X509_ATTRIBUTE *attr,
                                                   int idx);


// SignedPublicKeyAndChallenge structures.
//
// The SignedPublicKeyAndChallenge (SPKAC) is a legacy structure to request
// certificates, primarily in the legacy <keygen> HTML tag. An SPKAC structure
// is represented by a |NETSCAPE_SPKI| structure.
//
// The structure is described in
// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/keygen

// A Netscape_spki_st, or |NETSCAPE_SPKI|, represents a
// SignedPublicKeyAndChallenge structure. Although this structure contains a
// |spkac| field of type |NETSCAPE_SPKAC|, these are misnamed. The SPKAC is the
// entire structure, not the signed portion.
struct Netscape_spki_st {
  NETSCAPE_SPKAC *spkac;
  X509_ALGOR *sig_algor;
  ASN1_BIT_STRING *signature;
} /* NETSCAPE_SPKI */;

// NETSCAPE_SPKI is an |ASN1_ITEM| whose ASN.1 type is
// SignedPublicKeyAndChallenge and C type is |NETSCAPE_SPKI*|.
DECLARE_ASN1_ITEM(NETSCAPE_SPKI)

// NETSCAPE_SPKI_new returns a newly-allocated, empty |NETSCAPE_SPKI| object, or
// NULL on error.
OPENSSL_EXPORT NETSCAPE_SPKI *NETSCAPE_SPKI_new(void);

// NETSCAPE_SPKI_free releases memory associated with |spki|.
OPENSSL_EXPORT void NETSCAPE_SPKI_free(NETSCAPE_SPKI *spki);

// d2i_NETSCAPE_SPKI parses up to |len| bytes from |*inp| as a DER-encoded
// SignedPublicKeyAndChallenge structure, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT NETSCAPE_SPKI *d2i_NETSCAPE_SPKI(NETSCAPE_SPKI **out,
                                                const uint8_t **inp, long len);

// i2d_NETSCAPE_SPKI marshals |spki| as a DER-encoded
// SignedPublicKeyAndChallenge structure, as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_NETSCAPE_SPKI(const NETSCAPE_SPKI *spki, uint8_t **outp);

// NETSCAPE_SPKI_verify checks that |spki| has a valid signature by |pkey|. It
// returns one if the signature is valid and zero otherwise.
OPENSSL_EXPORT int NETSCAPE_SPKI_verify(NETSCAPE_SPKI *spki, EVP_PKEY *pkey);

// NETSCAPE_SPKI_b64_decode decodes |len| bytes from |str| as a base64-encoded
// SignedPublicKeyAndChallenge structure. It returns a newly-allocated
// |NETSCAPE_SPKI| structure with the result, or NULL on error. If |len| is 0 or
// negative, the length is calculated with |strlen| and |str| must be a
// NUL-terminated C string.
OPENSSL_EXPORT NETSCAPE_SPKI *NETSCAPE_SPKI_b64_decode(const char *str,
                                                       ossl_ssize_t len);

// NETSCAPE_SPKI_b64_encode encodes |spki| as a base64-encoded
// SignedPublicKeyAndChallenge structure. It returns a newly-allocated
// NUL-terminated C string with the result, or NULL on error. The caller must
// release the memory with |OPENSSL_free| when done.
OPENSSL_EXPORT char *NETSCAPE_SPKI_b64_encode(NETSCAPE_SPKI *spki);

// NETSCAPE_SPKI_get_pubkey decodes and returns the public key in |spki| as an
// |EVP_PKEY|, or NULL on error. The caller takes ownership of the resulting
// pointer and must call |EVP_PKEY_free| when done.
OPENSSL_EXPORT EVP_PKEY *NETSCAPE_SPKI_get_pubkey(NETSCAPE_SPKI *spki);

// NETSCAPE_SPKI_set_pubkey sets |spki|'s public key to |pkey|. It returns one
// on success or zero on error. This function does not take ownership of |pkey|,
// so the caller may continue to manage its lifetime independently of |spki|.
OPENSSL_EXPORT int NETSCAPE_SPKI_set_pubkey(NETSCAPE_SPKI *spki,
                                            EVP_PKEY *pkey);

// NETSCAPE_SPKI_sign signs |spki| with |pkey| and replaces the signature
// algorithm and signature fields. It returns the length of the signature on
// success and zero on error. This function uses digest algorithm |md|, or
// |pkey|'s default if NULL. Other signing parameters use |pkey|'s defaults.
OPENSSL_EXPORT int NETSCAPE_SPKI_sign(NETSCAPE_SPKI *spki, EVP_PKEY *pkey,
                                      const EVP_MD *md);

// A Netscape_spkac_st, or |NETSCAPE_SPKAC|, represents a PublicKeyAndChallenge
// structure. This type is misnamed. The full SPKAC includes the signature,
// which is represented with the |NETSCAPE_SPKI| type.
struct Netscape_spkac_st {
  X509_PUBKEY *pubkey;
  ASN1_IA5STRING *challenge;
} /* NETSCAPE_SPKAC */;

// NETSCAPE_SPKAC is an |ASN1_ITEM| whose ASN.1 type is PublicKeyAndChallenge
// and C type is |NETSCAPE_SPKAC*|.
DECLARE_ASN1_ITEM(NETSCAPE_SPKAC)

// NETSCAPE_SPKAC_new returns a newly-allocated, empty |NETSCAPE_SPKAC| object,
// or NULL on error.
OPENSSL_EXPORT NETSCAPE_SPKAC *NETSCAPE_SPKAC_new(void);

// NETSCAPE_SPKAC_free releases memory associated with |spkac|.
OPENSSL_EXPORT void NETSCAPE_SPKAC_free(NETSCAPE_SPKAC *spkac);

// d2i_NETSCAPE_SPKAC parses up to |len| bytes from |*inp| as a DER-encoded
// PublicKeyAndChallenge structure, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT NETSCAPE_SPKAC *d2i_NETSCAPE_SPKAC(NETSCAPE_SPKAC **out,
                                                  const uint8_t **inp,
                                                  long len);

// i2d_NETSCAPE_SPKAC marshals |spkac| as a DER-encoded PublicKeyAndChallenge
// structure, as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_NETSCAPE_SPKAC(const NETSCAPE_SPKAC *spkac,
                                      uint8_t **outp);


// RSASSA-PSS Parameters.
//
// In X.509, RSASSA-PSS signatures and keys use a complex parameter structure,
// defined in RFC 4055. The following functions are provided for compatibility
// with some OpenSSL APIs relating to this. Use of RSASSA-PSS in X.509 is
// discouraged. The parameters structure is very complex, and it takes more
// bytes to merely encode parameters than an entire P-256 ECDSA signature.

// An rsa_pss_params_st, aka |RSA_PSS_PARAMS|, represents a parsed
// RSASSA-PSS-params structure, as defined in (RFC 4055).
struct rsa_pss_params_st {
  X509_ALGOR *hashAlgorithm;
  X509_ALGOR *maskGenAlgorithm;
  ASN1_INTEGER *saltLength;
  ASN1_INTEGER *trailerField;
  // OpenSSL caches the MGF hash on |RSA_PSS_PARAMS| in some cases. None of the
  // cases apply to BoringSSL, so this is always NULL, but Node expects the
  // field to be present.
  X509_ALGOR *maskHash;
} /* RSA_PSS_PARAMS */;

// RSA_PSS_PARAMS is an |ASN1_ITEM| whose ASN.1 type is RSASSA-PSS-params (RFC
// 4055) and C type is |RSA_PSS_PARAMS*|.
DECLARE_ASN1_ITEM(RSA_PSS_PARAMS)

// RSA_PSS_PARAMS_new returns a new, empty |RSA_PSS_PARAMS|, or NULL on error.
OPENSSL_EXPORT RSA_PSS_PARAMS *RSA_PSS_PARAMS_new(void);

// RSA_PSS_PARAMS_free releases memory associated with |params|.
OPENSSL_EXPORT void RSA_PSS_PARAMS_free(RSA_PSS_PARAMS *params);

// d2i_RSA_PSS_PARAMS parses up to |len| bytes from |*inp| as a DER-encoded
// RSASSA-PSS-params (RFC 4055), as described in |d2i_SAMPLE|.
OPENSSL_EXPORT RSA_PSS_PARAMS *d2i_RSA_PSS_PARAMS(RSA_PSS_PARAMS **out,
                                                  const uint8_t **inp,
                                                  long len);

// i2d_RSA_PSS_PARAMS marshals |in| as a DER-encoded RSASSA-PSS-params (RFC
// 4055), as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_RSA_PSS_PARAMS(const RSA_PSS_PARAMS *in, uint8_t **outp);


// PKCS#8 private keys.
//
// The |PKCS8_PRIV_KEY_INFO| type represents a PKCS#8 PrivateKeyInfo (RFC 5208)
// structure. This is analogous to SubjectPublicKeyInfo and uses the same
// AlgorithmIdentifiers, but carries private keys and is not part of X.509
// itself.
//
// TODO(davidben): Do these functions really belong in this header?

// PKCS8_PRIV_KEY_INFO is an |ASN1_ITEM| whose ASN.1 type is PrivateKeyInfo and
// C type is |PKCS8_PRIV_KEY_INFO*|.
DECLARE_ASN1_ITEM(PKCS8_PRIV_KEY_INFO)

// PKCS8_PRIV_KEY_INFO_new returns a newly-allocated, empty
// |PKCS8_PRIV_KEY_INFO| object, or NULL on error.
OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *PKCS8_PRIV_KEY_INFO_new(void);

// PKCS8_PRIV_KEY_INFO_free releases memory associated with |key|.
OPENSSL_EXPORT void PKCS8_PRIV_KEY_INFO_free(PKCS8_PRIV_KEY_INFO *key);

// d2i_PKCS8_PRIV_KEY_INFO parses up to |len| bytes from |*inp| as a DER-encoded
// PrivateKeyInfo, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *d2i_PKCS8_PRIV_KEY_INFO(
    PKCS8_PRIV_KEY_INFO **out, const uint8_t **inp, long len);

// i2d_PKCS8_PRIV_KEY_INFO marshals |key| as a DER-encoded PrivateKeyInfo, as
// described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_PKCS8_PRIV_KEY_INFO(const PKCS8_PRIV_KEY_INFO *key,
                                           uint8_t **outp);

// EVP_PKCS82PKEY returns |p8| as a newly-allocated |EVP_PKEY|, or NULL if the
// key was unsupported or could not be decoded. The caller must release the
// result with |EVP_PKEY_free| when done.
//
// Use |EVP_parse_private_key| instead.
OPENSSL_EXPORT EVP_PKEY *EVP_PKCS82PKEY(const PKCS8_PRIV_KEY_INFO *p8);

// EVP_PKEY2PKCS8 encodes |pkey| as a PKCS#8 PrivateKeyInfo (RFC 5208),
// represented as a newly-allocated |PKCS8_PRIV_KEY_INFO|, or NULL on error. The
// caller must release the result with |PKCS8_PRIV_KEY_INFO_free| when done.
//
// Use |EVP_marshal_private_key| instead.
OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(const EVP_PKEY *pkey);


// Algorithm and octet string pairs.
//
// The |X509_SIG| type represents an ASN.1 SEQUENCE type of an
// AlgorithmIdentifier and an OCTET STRING. Although named |X509_SIG|, there is
// no type in X.509 which matches this format. The two common types which do are
// DigestInfo (RFC 2315 and RFC 8017), and EncryptedPrivateKeyInfo (RFC 5208).

// X509_SIG is an |ASN1_ITEM| whose ASN.1 type is the SEQUENCE described above
// and C type is |X509_SIG*|.
DECLARE_ASN1_ITEM(X509_SIG)

// X509_SIG_new returns a newly-allocated, empty |X509_SIG| object, or NULL on
// error.
OPENSSL_EXPORT X509_SIG *X509_SIG_new(void);

// X509_SIG_free releases memory associated with |key|.
OPENSSL_EXPORT void X509_SIG_free(X509_SIG *key);

// d2i_X509_SIG parses up to |len| bytes from |*inp| as a DER-encoded algorithm
// and octet string pair, as described in |d2i_SAMPLE|.
OPENSSL_EXPORT X509_SIG *d2i_X509_SIG(X509_SIG **out, const uint8_t **inp,
                                      long len);

// i2d_X509_SIG marshals |sig| as a DER-encoded algorithm
// and octet string pair, as described in |i2d_SAMPLE|.
OPENSSL_EXPORT int i2d_X509_SIG(const X509_SIG *sig, uint8_t **outp);

// X509_SIG_get0 sets |*out_alg| and |*out_digest| to non-owning pointers to
// |sig|'s algorithm and digest fields, respectively. Either |out_alg| and
// |out_digest| may be NULL to skip those fields.
OPENSSL_EXPORT void X509_SIG_get0(const X509_SIG *sig,
                                  const X509_ALGOR **out_alg,
                                  const ASN1_OCTET_STRING **out_digest);

// X509_SIG_getm behaves like |X509_SIG_get0| but returns mutable pointers.
OPENSSL_EXPORT void X509_SIG_getm(X509_SIG *sig, X509_ALGOR **out_alg,
                                  ASN1_OCTET_STRING **out_digest);


// Printing functions.
//
// The following functions output human-readable representations of
// X.509-related structures. They should only be used for debugging or logging
// and not parsed programmatically. In many cases, the outputs are ambiguous, so
// attempting to parse them can lead to string injection vulnerabilities.

// The following flags control |X509_print_ex| and |X509_REQ_print_ex|.

// X509_FLAG_COMPAT disables all flags. It additionally causes names to be
// printed with a 16-byte indent.
#define X509_FLAG_COMPAT 0

// X509_FLAG_NO_HEADER skips a header identifying the type of object printed.
#define X509_FLAG_NO_HEADER 1L

// X509_FLAG_NO_VERSION skips printing the X.509 version number.
#define X509_FLAG_NO_VERSION (1L << 1)

// X509_FLAG_NO_SERIAL skips printing the serial number. It is ignored in
// |X509_REQ_print_fp|.
#define X509_FLAG_NO_SERIAL (1L << 2)

// X509_FLAG_NO_SIGNAME skips printing the signature algorithm in the
// TBSCertificate. It is ignored in |X509_REQ_print_fp|.
#define X509_FLAG_NO_SIGNAME (1L << 3)

// X509_FLAG_NO_ISSUER skips printing the issuer.
#define X509_FLAG_NO_ISSUER (1L << 4)

// X509_FLAG_NO_VALIDITY skips printing the notBefore and notAfter times. It is
// ignored in |X509_REQ_print_fp|.
#define X509_FLAG_NO_VALIDITY (1L << 5)

// X509_FLAG_NO_SUBJECT skips printing the subject.
#define X509_FLAG_NO_SUBJECT (1L << 6)

// X509_FLAG_NO_PUBKEY skips printing the public key.
#define X509_FLAG_NO_PUBKEY (1L << 7)

// X509_FLAG_NO_EXTENSIONS skips printing the extension list. It is ignored in
// |X509_REQ_print_fp|. CSRs instead have attributes, which is controlled by
// |X509_FLAG_NO_ATTRIBUTES|.
#define X509_FLAG_NO_EXTENSIONS (1L << 8)

// X509_FLAG_NO_SIGDUMP skips printing the signature and outer signature
// algorithm.
#define X509_FLAG_NO_SIGDUMP (1L << 9)

// X509_FLAG_NO_AUX skips printing auxiliary properties. (See |d2i_X509_AUX| and
// related functions.)
#define X509_FLAG_NO_AUX (1L << 10)

// X509_FLAG_NO_ATTRIBUTES skips printing CSR attributes. It does nothing for
// certificates and CRLs.
#define X509_FLAG_NO_ATTRIBUTES (1L << 11)

// X509_FLAG_NO_IDS skips printing the issuerUniqueID and subjectUniqueID in a
// certificate. It is ignored in |X509_REQ_print_fp|.
#define X509_FLAG_NO_IDS (1L << 12)

// X509_print_ex writes a human-readable representation of |x| to |bp|. It
// returns one on success and zero on error. |nmflags| is the flags parameter
// for |X509_NAME_print_ex| when printing the subject and issuer. |cflag| should
// be some combination of the |X509_FLAG_*| constants.
OPENSSL_EXPORT int X509_print_ex(BIO *bp, X509 *x, unsigned long nmflag,
                                 unsigned long cflag);

// X509_print_ex_fp behaves like |X509_print_ex| but writes to |fp|.
OPENSSL_EXPORT int X509_print_ex_fp(FILE *fp, X509 *x, unsigned long nmflag,
                                    unsigned long cflag);

// X509_print calls |X509_print_ex| with |XN_FLAG_COMPAT| and |X509_FLAG_COMPAT|
// flags.
OPENSSL_EXPORT int X509_print(BIO *bp, X509 *x);

// X509_print_fp behaves like |X509_print| but writes to |fp|.
OPENSSL_EXPORT int X509_print_fp(FILE *fp, X509 *x);

// X509_CRL_print writes a human-readable representation of |x| to |bp|. It
// returns one on success and zero on error.
OPENSSL_EXPORT int X509_CRL_print(BIO *bp, X509_CRL *x);

// X509_CRL_print_fp behaves like |X509_CRL_print| but writes to |fp|.
OPENSSL_EXPORT int X509_CRL_print_fp(FILE *fp, X509_CRL *x);

// X509_REQ_print_ex writes a human-readable representation of |x| to |bp|. It
// returns one on success and zero on error. |nmflags| is the flags parameter
// for |X509_NAME_print_ex|, when printing the subject. |cflag| should be some
// combination of the |X509_FLAG_*| constants.
OPENSSL_EXPORT int X509_REQ_print_ex(BIO *bp, X509_REQ *x, unsigned long nmflag,
                                     unsigned long cflag);

// X509_REQ_print calls |X509_REQ_print_ex| with |XN_FLAG_COMPAT| and
// |X509_FLAG_COMPAT| flags.
OPENSSL_EXPORT int X509_REQ_print(BIO *bp, X509_REQ *req);

// X509_REQ_print_fp behaves like |X509_REQ_print| but writes to |fp|.
OPENSSL_EXPORT int X509_REQ_print_fp(FILE *fp, X509_REQ *req);

// The following flags are control |X509_NAME_print_ex|. They must not collide
// with |ASN1_STRFLGS_*|.
//
// TODO(davidben): This is far, far too many options and most of them are
// useless. Trim this down.

// XN_FLAG_COMPAT prints with |X509_NAME_print|'s format and return value
// convention.
#define XN_FLAG_COMPAT 0

// XN_FLAG_SEP_MASK determines the separators to use between attributes.
#define XN_FLAG_SEP_MASK (0xf << 16)

// XN_FLAG_SEP_COMMA_PLUS separates RDNs with "," and attributes within an RDN
// with "+", as in RFC 2253.
#define XN_FLAG_SEP_COMMA_PLUS (1 << 16)

// XN_FLAG_SEP_CPLUS_SPC behaves like |XN_FLAG_SEP_COMMA_PLUS| but adds spaces
// between the separators.
#define XN_FLAG_SEP_CPLUS_SPC (2 << 16)

// XN_FLAG_SEP_SPLUS_SPC separates RDNs with "; " and attributes within an RDN
// with " + ".
#define XN_FLAG_SEP_SPLUS_SPC (3 << 16)

// XN_FLAG_SEP_MULTILINE prints each attribute on one line.
#define XN_FLAG_SEP_MULTILINE (4 << 16)

// XN_FLAG_DN_REV prints RDNs in reverse, from least significant to most
// significant, as RFC 2253.
#define XN_FLAG_DN_REV (1 << 20)

// XN_FLAG_FN_MASK determines how attribute types are displayed.
#define XN_FLAG_FN_MASK (0x3 << 21)

// XN_FLAG_FN_SN uses the attribute type's short name, when available.
#define XN_FLAG_FN_SN 0

// XN_FLAG_SPC_EQ wraps the "=" operator with spaces when printing attributes.
#define XN_FLAG_SPC_EQ (1 << 23)

// XN_FLAG_DUMP_UNKNOWN_FIELDS causes unknown attribute types to be printed in
// hex, as in RFC 2253.
#define XN_FLAG_DUMP_UNKNOWN_FIELDS (1 << 24)

// XN_FLAG_RFC2253 prints like RFC 2253.
#define XN_FLAG_RFC2253                                             \
  (ASN1_STRFLGS_RFC2253 | XN_FLAG_SEP_COMMA_PLUS | XN_FLAG_DN_REV | \
   XN_FLAG_FN_SN | XN_FLAG_DUMP_UNKNOWN_FIELDS)

// XN_FLAG_ONELINE prints a one-line representation of the name.
#define XN_FLAG_ONELINE                                                    \
  (ASN1_STRFLGS_RFC2253 | ASN1_STRFLGS_ESC_QUOTE | XN_FLAG_SEP_CPLUS_SPC | \
   XN_FLAG_SPC_EQ | XN_FLAG_FN_SN)

// X509_NAME_print_ex writes a human-readable representation of |nm| to |out|.
// Each line of output is indented by |indent| spaces. It returns the number of
// bytes written on success, and -1 on error. If |out| is NULL, it returns the
// number of bytes it would have written but does not write anything. |flags|
// should be some combination of |XN_FLAG_*| and |ASN1_STRFLGS_*| values and
// determines the output. If unsure, use |XN_FLAG_RFC2253|.
//
// If |flags| is |XN_FLAG_COMPAT|, or zero, this function calls
// |X509_NAME_print| instead. In that case, it returns one on success, rather
// than the output length.
OPENSSL_EXPORT int X509_NAME_print_ex(BIO *out, const X509_NAME *nm, int indent,
                                      unsigned long flags);

// X509_NAME_print prints a human-readable representation of |name| to |bp|. It
// returns one on success and zero on error. |obase| is ignored.
//
// This function outputs a legacy format that does not correctly handle string
// encodings and other cases. Prefer |X509_NAME_print_ex| if printing a name for
// debugging purposes.
OPENSSL_EXPORT int X509_NAME_print(BIO *bp, const X509_NAME *name, int obase);

// X509_NAME_oneline writes a human-readable representation to |name| to a
// buffer as a NUL-terminated C string.
//
// If |buf| is NULL, returns a newly-allocated buffer containing the result on
// success, or NULL on error. The buffer must be released with |OPENSSL_free|
// when done.
//
// If |buf| is non-NULL, at most |size| bytes of output are written to |buf|
// instead. |size| includes the trailing NUL. The function then returns |buf| on
// success or NULL on error. If the output does not fit in |size| bytes, the
// output is silently truncated at an attribute boundary.
//
// This function outputs a legacy format that does not correctly handle string
// encodings and other cases. Prefer |X509_NAME_print_ex| if printing a name for
// debugging purposes.
OPENSSL_EXPORT char *X509_NAME_oneline(const X509_NAME *name, char *buf,
                                       int size);

// X509_NAME_print_ex_fp behaves like |X509_NAME_print_ex| but writes to |fp|.
OPENSSL_EXPORT int X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm,
                                         int indent, unsigned long flags);

// X509_signature_dump writes a human-readable representation of |sig| to |bio|,
// indented with |indent| spaces. It returns one on success and zero on error.
OPENSSL_EXPORT int X509_signature_dump(BIO *bio, const ASN1_STRING *sig,
                                       int indent);

// X509_signature_print writes a human-readable representation of |alg| and
// |sig| to |bio|. It returns one on success and zero on error.
OPENSSL_EXPORT int X509_signature_print(BIO *bio, const X509_ALGOR *alg,
                                        const ASN1_STRING *sig);


// Convenience functions.

// X509_pubkey_digest hashes the contents of the BIT STRING in |x509|'s
// subjectPublicKeyInfo field with |md| and writes the result to |out|.
// |EVP_MD_CTX_size| bytes are written, which is at most |EVP_MAX_MD_SIZE|. If
// |out_len| is not NULL, |*out_len| is set to the number of bytes written. This
// function returns one on success and zero on error.
//
// This hash omits the BIT STRING tag, length, and number of unused bits. It
// also omits the AlgorithmIdentifier which describes the key type. It
// corresponds to the OCSP KeyHash definition and is not suitable for other
// purposes.
OPENSSL_EXPORT int X509_pubkey_digest(const X509 *x509, const EVP_MD *md,
                                      uint8_t *out, unsigned *out_len);

// X509_digest hashes |x509|'s DER encoding with |md| and writes the result to
// |out|. |EVP_MD_CTX_size| bytes are written, which is at most
// |EVP_MAX_MD_SIZE|. If |out_len| is not NULL, |*out_len| is set to the number
// of bytes written. This function returns one on success and zero on error.
// Note this digest covers the entire certificate, not just the signed portion.
OPENSSL_EXPORT int X509_digest(const X509 *x509, const EVP_MD *md, uint8_t *out,
                               unsigned *out_len);

// X509_CRL_digest hashes |crl|'s DER encoding with |md| and writes the result
// to |out|. |EVP_MD_CTX_size| bytes are written, which is at most
// |EVP_MAX_MD_SIZE|. If |out_len| is not NULL, |*out_len| is set to the number
// of bytes written. This function returns one on success and zero on error.
// Note this digest covers the entire CRL, not just the signed portion.
OPENSSL_EXPORT int X509_CRL_digest(const X509_CRL *crl, const EVP_MD *md,
                                   uint8_t *out, unsigned *out_len);

// X509_REQ_digest hashes |req|'s DER encoding with |md| and writes the result
// to |out|. |EVP_MD_CTX_size| bytes are written, which is at most
// |EVP_MAX_MD_SIZE|. If |out_len| is not NULL, |*out_len| is set to the number
// of bytes written. This function returns one on success and zero on error.
// Note this digest covers the entire certificate request, not just the signed
// portion.
OPENSSL_EXPORT int X509_REQ_digest(const X509_REQ *req, const EVP_MD *md,
                                   uint8_t *out, unsigned *out_len);

// X509_NAME_digest hashes |name|'s DER encoding with |md| and writes the result
// to |out|. |EVP_MD_CTX_size| bytes are written, which is at most
// |EVP_MAX_MD_SIZE|. If |out_len| is not NULL, |*out_len| is set to the number
// of bytes written. This function returns one on success and zero on error.
OPENSSL_EXPORT int X509_NAME_digest(const X509_NAME *name, const EVP_MD *md,
                                    uint8_t *out, unsigned *out_len);

// The following functions behave like the corresponding unsuffixed |d2i_*|
// functions, but read the result from |bp| instead. Callers using these
// functions with memory |BIO|s to parse structures already in memory should use
// |d2i_*| instead.
OPENSSL_EXPORT X509 *d2i_X509_bio(BIO *bp, X509 **x509);
OPENSSL_EXPORT X509_CRL *d2i_X509_CRL_bio(BIO *bp, X509_CRL **crl);
OPENSSL_EXPORT X509_REQ *d2i_X509_REQ_bio(BIO *bp, X509_REQ **req);
OPENSSL_EXPORT RSA *d2i_RSAPrivateKey_bio(BIO *bp, RSA **rsa);
OPENSSL_EXPORT RSA *d2i_RSAPublicKey_bio(BIO *bp, RSA **rsa);
OPENSSL_EXPORT RSA *d2i_RSA_PUBKEY_bio(BIO *bp, RSA **rsa);
OPENSSL_EXPORT DSA *d2i_DSA_PUBKEY_bio(BIO *bp, DSA **dsa);
OPENSSL_EXPORT DSA *d2i_DSAPrivateKey_bio(BIO *bp, DSA **dsa);
OPENSSL_EXPORT EC_KEY *d2i_EC_PUBKEY_bio(BIO *bp, EC_KEY **eckey);
OPENSSL_EXPORT EC_KEY *d2i_ECPrivateKey_bio(BIO *bp, EC_KEY **eckey);
OPENSSL_EXPORT X509_SIG *d2i_PKCS8_bio(BIO *bp, X509_SIG **p8);
OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *d2i_PKCS8_PRIV_KEY_INFO_bio(
    BIO *bp, PKCS8_PRIV_KEY_INFO **p8inf);
OPENSSL_EXPORT EVP_PKEY *d2i_PUBKEY_bio(BIO *bp, EVP_PKEY **a);
OPENSSL_EXPORT DH *d2i_DHparams_bio(BIO *bp, DH **dh);

// d2i_PrivateKey_bio behaves like |d2i_AutoPrivateKey|, but reads from |bp|
// instead.
OPENSSL_EXPORT EVP_PKEY *d2i_PrivateKey_bio(BIO *bp, EVP_PKEY **a);

// The following functions behave like the corresponding unsuffixed |i2d_*|
// functions, but write the result to |bp|. They return one on success and zero
// on error. Callers using them with memory |BIO|s to encode structures to
// memory should use |i2d_*| directly instead.
OPENSSL_EXPORT int i2d_X509_bio(BIO *bp, X509 *x509);
OPENSSL_EXPORT int i2d_X509_CRL_bio(BIO *bp, X509_CRL *crl);
OPENSSL_EXPORT int i2d_X509_REQ_bio(BIO *bp, X509_REQ *req);
OPENSSL_EXPORT int i2d_RSAPrivateKey_bio(BIO *bp, RSA *rsa);
OPENSSL_EXPORT int i2d_RSAPublicKey_bio(BIO *bp, RSA *rsa);
OPENSSL_EXPORT int i2d_RSA_PUBKEY_bio(BIO *bp, RSA *rsa);
OPENSSL_EXPORT int i2d_DSA_PUBKEY_bio(BIO *bp, DSA *dsa);
OPENSSL_EXPORT int i2d_DSAPrivateKey_bio(BIO *bp, DSA *dsa);
OPENSSL_EXPORT int i2d_EC_PUBKEY_bio(BIO *bp, EC_KEY *eckey);
OPENSSL_EXPORT int i2d_ECPrivateKey_bio(BIO *bp, EC_KEY *eckey);
OPENSSL_EXPORT int i2d_PKCS8_bio(BIO *bp, X509_SIG *p8);
OPENSSL_EXPORT int i2d_PKCS8_PRIV_KEY_INFO_bio(BIO *bp,
                                               PKCS8_PRIV_KEY_INFO *p8inf);
OPENSSL_EXPORT int i2d_PrivateKey_bio(BIO *bp, EVP_PKEY *pkey);
OPENSSL_EXPORT int i2d_PUBKEY_bio(BIO *bp, EVP_PKEY *pkey);
OPENSSL_EXPORT int i2d_DHparams_bio(BIO *bp, const DH *dh);

// i2d_PKCS8PrivateKeyInfo_bio encodes |key| as a PKCS#8 PrivateKeyInfo
// structure (see |EVP_marshal_private_key|) and writes the result to |bp|. It
// returns one on success and zero on error.
OPENSSL_EXPORT int i2d_PKCS8PrivateKeyInfo_bio(BIO *bp, EVP_PKEY *key);

// The following functions behave like the corresponding |d2i_*_bio| functions,
// but read from |fp| instead.
OPENSSL_EXPORT X509 *d2i_X509_fp(FILE *fp, X509 **x509);
OPENSSL_EXPORT X509_CRL *d2i_X509_CRL_fp(FILE *fp, X509_CRL **crl);
OPENSSL_EXPORT X509_REQ *d2i_X509_REQ_fp(FILE *fp, X509_REQ **req);
OPENSSL_EXPORT RSA *d2i_RSAPrivateKey_fp(FILE *fp, RSA **rsa);
OPENSSL_EXPORT RSA *d2i_RSAPublicKey_fp(FILE *fp, RSA **rsa);
OPENSSL_EXPORT RSA *d2i_RSA_PUBKEY_fp(FILE *fp, RSA **rsa);
OPENSSL_EXPORT DSA *d2i_DSA_PUBKEY_fp(FILE *fp, DSA **dsa);
OPENSSL_EXPORT DSA *d2i_DSAPrivateKey_fp(FILE *fp, DSA **dsa);
OPENSSL_EXPORT EC_KEY *d2i_EC_PUBKEY_fp(FILE *fp, EC_KEY **eckey);
OPENSSL_EXPORT EC_KEY *d2i_ECPrivateKey_fp(FILE *fp, EC_KEY **eckey);
OPENSSL_EXPORT X509_SIG *d2i_PKCS8_fp(FILE *fp, X509_SIG **p8);
OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *d2i_PKCS8_PRIV_KEY_INFO_fp(
    FILE *fp, PKCS8_PRIV_KEY_INFO **p8inf);
OPENSSL_EXPORT EVP_PKEY *d2i_PrivateKey_fp(FILE *fp, EVP_PKEY **a);
OPENSSL_EXPORT EVP_PKEY *d2i_PUBKEY_fp(FILE *fp, EVP_PKEY **a);

// The following functions behave like the corresponding |i2d_*_bio| functions,
// but write to |fp| instead.
OPENSSL_EXPORT int i2d_X509_fp(FILE *fp, X509 *x509);
OPENSSL_EXPORT int i2d_X509_CRL_fp(FILE *fp, X509_CRL *crl);
OPENSSL_EXPORT int i2d_X509_REQ_fp(FILE *fp, X509_REQ *req);
OPENSSL_EXPORT int i2d_RSAPrivateKey_fp(FILE *fp, RSA *rsa);
OPENSSL_EXPORT int i2d_RSAPublicKey_fp(FILE *fp, RSA *rsa);
OPENSSL_EXPORT int i2d_RSA_PUBKEY_fp(FILE *fp, RSA *rsa);
OPENSSL_EXPORT int i2d_DSA_PUBKEY_fp(FILE *fp, DSA *dsa);
OPENSSL_EXPORT int i2d_DSAPrivateKey_fp(FILE *fp, DSA *dsa);
OPENSSL_EXPORT int i2d_EC_PUBKEY_fp(FILE *fp, EC_KEY *eckey);
OPENSSL_EXPORT int i2d_ECPrivateKey_fp(FILE *fp, EC_KEY *eckey);
OPENSSL_EXPORT int i2d_PKCS8_fp(FILE *fp, X509_SIG *p8);
OPENSSL_EXPORT int i2d_PKCS8_PRIV_KEY_INFO_fp(FILE *fp,
                                              PKCS8_PRIV_KEY_INFO *p8inf);
OPENSSL_EXPORT int i2d_PKCS8PrivateKeyInfo_fp(FILE *fp, EVP_PKEY *key);
OPENSSL_EXPORT int i2d_PrivateKey_fp(FILE *fp, EVP_PKEY *pkey);
OPENSSL_EXPORT int i2d_PUBKEY_fp(FILE *fp, EVP_PKEY *pkey);

// X509_find_by_issuer_and_serial returns the first |X509| in |sk| whose issuer
// and serial are |name| and |serial|, respectively. If no match is found, it
// returns NULL.
OPENSSL_EXPORT X509 *X509_find_by_issuer_and_serial(const STACK_OF(X509) *sk,
                                                    X509_NAME *name,
                                                    const ASN1_INTEGER *serial);

// X509_find_by_subject returns the first |X509| in |sk| whose subject is
// |name|. If no match is found, it returns NULL.
OPENSSL_EXPORT X509 *X509_find_by_subject(const STACK_OF(X509) *sk,
                                          X509_NAME *name);

// X509_cmp_time compares |s| against |*t|. On success, it returns a negative
// number if |s| <= |*t| and a positive number if |s| > |*t|. On error, it
// returns zero. If |t| is NULL, it uses the current time instead of |*t|.
//
// WARNING: Unlike most comparison functions, this function returns zero on
// error, not equality.
OPENSSL_EXPORT int X509_cmp_time(const ASN1_TIME *s, const time_t *t);

// X509_cmp_time_posix compares |s| against |t|. On success, it returns a
// negative number if |s| <= |t| and a positive number if |s| > |t|. On error,
// it returns zero.
//
// WARNING: Unlike most comparison functions, this function returns zero on
// error, not equality.
OPENSSL_EXPORT int X509_cmp_time_posix(const ASN1_TIME *s, int64_t t);

// X509_cmp_current_time behaves like |X509_cmp_time| but compares |s| against
// the current time.
OPENSSL_EXPORT int X509_cmp_current_time(const ASN1_TIME *s);

// X509_time_adj calls |X509_time_adj_ex| with |offset_day| equal to zero.
OPENSSL_EXPORT ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec,
                                        const time_t *t);

// X509_time_adj_ex behaves like |ASN1_TIME_adj|, but adds an offset to |*t|. If
// |t| is NULL, it uses the current time instead of |*t|.
OPENSSL_EXPORT ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, int offset_day,
                                           long offset_sec, const time_t *t);

// X509_gmtime_adj behaves like |X509_time_adj_ex| but adds |offset_sec| to the
// current time.
OPENSSL_EXPORT ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long offset_sec);

// X509_issuer_name_cmp behaves like |X509_NAME_cmp|, but compares |a| and |b|'s
// issuer names.
OPENSSL_EXPORT int X509_issuer_name_cmp(const X509 *a, const X509 *b);

// X509_subject_name_cmp behaves like |X509_NAME_cmp|, but compares |a| and
// |b|'s subject names.
OPENSSL_EXPORT int X509_subject_name_cmp(const X509 *a, const X509 *b);

// X509_CRL_cmp behaves like |X509_NAME_cmp|, but compares |a| and |b|'s
// issuer names.
//
// WARNING: This function is misnamed. It does not compare other parts of the
// CRL, only the issuer fields using |X509_NAME_cmp|.
OPENSSL_EXPORT int X509_CRL_cmp(const X509_CRL *a, const X509_CRL *b);


// ex_data functions.
//
// See |ex_data.h| for details.

OPENSSL_EXPORT int X509_get_ex_new_index(long argl, void *argp,
                                         CRYPTO_EX_unused *unused,
                                         CRYPTO_EX_dup *dup_unused,
                                         CRYPTO_EX_free *free_func);
OPENSSL_EXPORT int X509_set_ex_data(X509 *r, int idx, void *arg);
OPENSSL_EXPORT void *X509_get_ex_data(X509 *r, int idx);

OPENSSL_EXPORT int X509_STORE_CTX_get_ex_new_index(long argl, void *argp,
                                                   CRYPTO_EX_unused *unused,
                                                   CRYPTO_EX_dup *dup_unused,
                                                   CRYPTO_EX_free *free_func);
OPENSSL_EXPORT int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx,
                                              void *data);
OPENSSL_EXPORT void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx);


// Hashing and signing ASN.1 structures.

// ASN1_digest serializes |data| with |i2d| and then hashes the result with
// |type|. On success, it returns one, writes the digest to |md|, and sets
// |*len| to the digest length if non-NULL. On error, it returns zero.
//
// |EVP_MD_CTX_size| bytes are written, which is at most |EVP_MAX_MD_SIZE|. The
// buffer must have sufficient space for this output.
OPENSSL_EXPORT int ASN1_digest(i2d_of_void *i2d, const EVP_MD *type, char *data,
                               unsigned char *md, unsigned int *len);

// ASN1_item_digest serializes |data| with |it| and then hashes the result with
// |type|. On success, it returns one, writes the digest to |md|, and sets
// |*len| to the digest length if non-NULL. On error, it returns zero.
//
// |EVP_MD_CTX_size| bytes are written, which is at most |EVP_MAX_MD_SIZE|. The
// buffer must have sufficient space for this output.
//
// WARNING: |data| must be a pointer with the same type as |it|'s corresponding
// C type. Using the wrong type is a potentially exploitable memory error.
OPENSSL_EXPORT int ASN1_item_digest(const ASN1_ITEM *it, const EVP_MD *type,
                                    void *data, unsigned char *md,
                                    unsigned int *len);

// ASN1_item_verify serializes |data| with |it| and then verifies |signature| is
// a valid signature for the result with |algor1| and |pkey|. It returns one on
// success and zero on error. The signature and algorithm are interpreted as in
// X.509.
//
// WARNING: |data| must be a pointer with the same type as |it|'s corresponding
// C type. Using the wrong type is a potentially exploitable memory error.
OPENSSL_EXPORT int ASN1_item_verify(const ASN1_ITEM *it,
                                    const X509_ALGOR *algor1,
                                    const ASN1_BIT_STRING *signature,
                                    void *data, EVP_PKEY *pkey);

// ASN1_item_sign serializes |data| with |it| and then signs the result with
// the private key |pkey|. It returns the length of the signature on success and
// zero on error. On success, it writes the signature to |signature| and the
// signature algorithm to each of |algor1| and |algor2|. Either of |algor1| or
// |algor2| may be NULL to ignore them. This function uses digest algorithm
// |md|, or |pkey|'s default if NULL. Other signing parameters use |pkey|'s
// defaults. To customize them, use |ASN1_item_sign_ctx|.
//
// WARNING: |data| must be a pointer with the same type as |it|'s corresponding
// C type. Using the wrong type is a potentially exploitable memory error.
OPENSSL_EXPORT int ASN1_item_sign(const ASN1_ITEM *it, X509_ALGOR *algor1,
                                  X509_ALGOR *algor2,
                                  ASN1_BIT_STRING *signature, void *data,
                                  EVP_PKEY *pkey, const EVP_MD *type);

// ASN1_item_sign_ctx behaves like |ASN1_item_sign| except the signature is
// signed with |ctx|, |ctx|, which must have been initialized with
// |EVP_DigestSignInit|. The caller should configure the corresponding
// |EVP_PKEY_CTX| with any additional parameters before calling this function.
//
// On success or failure, this function mutates |ctx| and resets it to the empty
// state. Caller should not rely on its contents after the function returns.
//
// WARNING: |data| must be a pointer with the same type as |it|'s corresponding
// C type. Using the wrong type is a potentially exploitable memory error.
OPENSSL_EXPORT int ASN1_item_sign_ctx(const ASN1_ITEM *it, X509_ALGOR *algor1,
                                      X509_ALGOR *algor2,
                                      ASN1_BIT_STRING *signature, void *asn,
                                      EVP_MD_CTX *ctx);


// X.509 information.
//
// |X509_INFO| is the return type for |PEM_X509_INFO_read_bio|, defined in
// <openssl/pem.h>. It is used to store a certificate, CRL, or private key. This
// type is defined in this header for OpenSSL compatibility.

struct private_key_st {
  EVP_PKEY *dec_pkey;
} /* X509_PKEY */;

struct X509_info_st {
  X509 *x509;
  X509_CRL *crl;
  X509_PKEY *x_pkey;

  EVP_CIPHER_INFO enc_cipher;
  int enc_len;
  char *enc_data;
} /* X509_INFO */;

DEFINE_STACK_OF(X509_INFO)

// X509_INFO_free releases memory associated with |info|.
OPENSSL_EXPORT void X509_INFO_free(X509_INFO *info);


// Deprecated functions.

// X509_get_notBefore returns |x509|'s notBefore time. Note this function is not
// const-correct for legacy reasons. Use |X509_get0_notBefore| or
// |X509_getm_notBefore| instead.
OPENSSL_EXPORT ASN1_TIME *X509_get_notBefore(const X509 *x509);

// X509_get_notAfter returns |x509|'s notAfter time. Note this function is not
// const-correct for legacy reasons. Use |X509_get0_notAfter| or
// |X509_getm_notAfter| instead.
OPENSSL_EXPORT ASN1_TIME *X509_get_notAfter(const X509 *x509);

// X509_set_notBefore calls |X509_set1_notBefore|. Use |X509_set1_notBefore|
// instead.
OPENSSL_EXPORT int X509_set_notBefore(X509 *x509, const ASN1_TIME *tm);

// X509_set_notAfter calls |X509_set1_notAfter|. Use |X509_set1_notAfter|
// instead.
OPENSSL_EXPORT int X509_set_notAfter(X509 *x509, const ASN1_TIME *tm);

// X509_CRL_get_lastUpdate returns a mutable pointer to |crl|'s thisUpdate time.
// The OpenSSL API refers to this field as lastUpdate.
//
// Use |X509_CRL_get0_lastUpdate| or |X509_CRL_set1_lastUpdate| instead.
OPENSSL_EXPORT ASN1_TIME *X509_CRL_get_lastUpdate(X509_CRL *crl);

// X509_CRL_get_nextUpdate returns a mutable pointer to |crl|'s nextUpdate time,
// or NULL if |crl| has none. Use |X509_CRL_get0_nextUpdate| or
// |X509_CRL_set1_nextUpdate| instead.
OPENSSL_EXPORT ASN1_TIME *X509_CRL_get_nextUpdate(X509_CRL *crl);

// X509_extract_key is a legacy alias to |X509_get_pubkey|. Use
// |X509_get_pubkey| instead.
#define X509_extract_key(x) X509_get_pubkey(x)

// X509_REQ_extract_key is a legacy alias for |X509_REQ_get_pubkey|.
#define X509_REQ_extract_key(a) X509_REQ_get_pubkey(a)

// X509_name_cmp is a legacy alias for |X509_NAME_cmp|.
#define X509_name_cmp(a, b) X509_NAME_cmp((a), (b))

// The following symbols are deprecated aliases to |X509_CRL_set1_*|.
#define X509_CRL_set_lastUpdate X509_CRL_set1_lastUpdate
#define X509_CRL_set_nextUpdate X509_CRL_set1_nextUpdate

// X509_get_serialNumber returns a mutable pointer to |x509|'s serial number.
// Prefer |X509_get0_serialNumber|.
OPENSSL_EXPORT ASN1_INTEGER *X509_get_serialNumber(X509 *x509);

// X509_NAME_get_text_by_OBJ finds the first attribute with type |obj| in
// |name|. If found, it writes the value's UTF-8 representation to |buf|.
// followed by a NUL byte, and returns the number of bytes in the output,
// excluding the NUL byte. This is unlike OpenSSL which returns the raw
// ASN1_STRING data. The UTF-8 encoding of the |ASN1_STRING| may not contain a 0
// codepoint.
//
// This function writes at most |len| bytes, including the NUL byte.  If |buf|
// is NULL, it writes nothing and returns the number of bytes in the
// output, excluding the NUL byte that would be required for the full UTF-8
// output.
//
// This function may return -1 if an error occurs for any reason, including the
// value not being a recognized string type, |len| being of insufficient size to
// hold the full UTF-8 encoding and NUL byte, memory allocation failures, an
// object with type |obj| not existing in |name|, or if the UTF-8 encoding of
// the string contains a zero byte.
OPENSSL_EXPORT int X509_NAME_get_text_by_OBJ(const X509_NAME *name,
                                             const ASN1_OBJECT *obj, char *buf,
                                             int len);

// X509_NAME_get_text_by_NID behaves like |X509_NAME_get_text_by_OBJ| except it
// finds an attribute of type |nid|, which should be one of the |NID_*|
// constants.
OPENSSL_EXPORT int X509_NAME_get_text_by_NID(const X509_NAME *name, int nid,
                                             char *buf, int len);

// X509_STORE_CTX_get0_parent_ctx returns NULL.
OPENSSL_EXPORT X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(
    X509_STORE_CTX *ctx);

// X509_LOOKUP_free releases memory associated with |ctx|. This function should
// never be used outside the library. No function in the public API hands
// ownership of an |X509_LOOKUP| to the caller.
//
// TODO(davidben): Unexport this function after rust-openssl is fixed to no
// longer call it.
OPENSSL_EXPORT void X509_LOOKUP_free(X509_LOOKUP *ctx);

// X509_STORE_CTX_cleanup resets |ctx| to the empty state.
//
// This function is a remnant of when |X509_STORE_CTX| was stack-allocated and
// should not be used. If releasing |ctx|, call |X509_STORE_CTX_free|. If
// reusing |ctx| for a new verification, release the old one and create a new
// one.
OPENSSL_EXPORT void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx);


// Private structures.

struct X509_algor_st {
  ASN1_OBJECT *algorithm;
  ASN1_TYPE *parameter;
} /* X509_ALGOR */;


// Functions below this point have not yet been organized into sections.

#define X509_FILETYPE_PEM 1
#define X509_FILETYPE_ASN1 2
#define X509_FILETYPE_DEFAULT 3

#define X509v3_KU_DIGITAL_SIGNATURE 0x0080
#define X509v3_KU_NON_REPUDIATION 0x0040
#define X509v3_KU_KEY_ENCIPHERMENT 0x0020
#define X509v3_KU_DATA_ENCIPHERMENT 0x0010
#define X509v3_KU_KEY_AGREEMENT 0x0008
#define X509v3_KU_KEY_CERT_SIGN 0x0004
#define X509v3_KU_CRL_SIGN 0x0002
#define X509v3_KU_ENCIPHER_ONLY 0x0001
#define X509v3_KU_DECIPHER_ONLY 0x8000
#define X509v3_KU_UNDEF 0xffff

// This stuff is certificate "auxiliary info"
// it contains details which are useful in certificate
// stores and databases. When used this is tagged onto
// the end of the certificate itself

DECLARE_STACK_OF(DIST_POINT)
DECLARE_STACK_OF(GENERAL_NAME)

// This is used for a table of trust checking functions

struct x509_trust_st {
  int trust;
  int flags;
  int (*check_trust)(struct x509_trust_st *, X509 *, int);
  char *name;
  int arg1;
  void *arg2;
} /* X509_TRUST */;

DEFINE_STACK_OF(X509_TRUST)

// standard trust ids

#define X509_TRUST_DEFAULT (-1)  // Only valid in purpose settings

#define X509_TRUST_COMPAT 1
#define X509_TRUST_SSL_CLIENT 2
#define X509_TRUST_SSL_SERVER 3
#define X509_TRUST_EMAIL 4
#define X509_TRUST_OBJECT_SIGN 5
#define X509_TRUST_OCSP_SIGN 6
#define X509_TRUST_OCSP_REQUEST 7
#define X509_TRUST_TSA 8

// Keep these up to date! (hidden)

#define X509_TRUST_MIN 1
#define X509_TRUST_MAX 8


// trust_flags values

#define X509_TRUST_DYNAMIC 1
#define X509_TRUST_DYNAMIC_NAME 2

// check_trust return codes

#define X509_TRUST_TRUSTED 1
#define X509_TRUST_REJECTED 2
#define X509_TRUST_UNTRUSTED 3

DECLARE_STACK_OF(GENERAL_NAMES)

// X509_verify_cert_error_string returns |err| as a human-readable string, where
// |err| should be one of the |X509_V_*| values. If |err| is unknown, it returns
// a default description.
OPENSSL_EXPORT const char *X509_verify_cert_error_string(long err);

OPENSSL_EXPORT const char *X509_get_default_cert_area(void);
OPENSSL_EXPORT const char *X509_get_default_cert_dir(void);
OPENSSL_EXPORT const char *X509_get_default_cert_file(void);
OPENSSL_EXPORT const char *X509_get_default_cert_dir_env(void);
OPENSSL_EXPORT const char *X509_get_default_cert_file_env(void);
OPENSSL_EXPORT const char *X509_get_default_private_dir(void);


OPENSSL_EXPORT int X509_TRUST_set(int *t, int trust);

OPENSSL_EXPORT unsigned long X509_issuer_name_hash(X509 *a);

OPENSSL_EXPORT unsigned long X509_subject_name_hash(X509 *x);

OPENSSL_EXPORT unsigned long X509_issuer_name_hash_old(X509 *a);
OPENSSL_EXPORT unsigned long X509_subject_name_hash_old(X509 *x);

OPENSSL_EXPORT int X509_cmp(const X509 *a, const X509 *b);
OPENSSL_EXPORT unsigned long X509_NAME_hash(X509_NAME *x);
OPENSSL_EXPORT unsigned long X509_NAME_hash_old(X509_NAME *x);

OPENSSL_EXPORT int X509_CRL_match(const X509_CRL *a, const X509_CRL *b);

// X509_verify_cert attempts to discover and validate a certificate chain based
// on parameters in |ctx|. |ctx| usually includes a target certificate to be
// verified, a set of certificates serving as trust anchors, a list of
// non-trusted certificates that may be helpful for chain construction, flags,
// and various other optional components such as callback functions. A
// certificate chain is built up starting from the target certificate and ending
// in a trust anchor. The chain is built up iteratively, looking up in turn a
// certificate with suitable key usage that matches as an issuer of the current
// "subject" certificate.
//
// NOTE:
//   1. Applications rarely call this function directly, but it is used
//      internally for certificate validation.
//   2. |X509_verify_cert| and other related functions call
//      |sk_X509_OBJECT_sort| internally, which rearranges the certificate
//      ordering. There will be cases where two certs have an identical
//      |subject| and |X509_OBJECT_cmp| will return 0, but one is a valid cert
//      and the other is invalid.
//      Due to https://github.com/openssl/openssl/issues/18708, certificate
//      verification could fail if an invalid cert is checked before the valid
//      cert. What we do with sorting behavior when certs are identical is
//      considered "unstable" and certain sorting expectations shouldn't be
//      depended on.
OPENSSL_EXPORT int X509_verify_cert(X509_STORE_CTX *ctx);

OPENSSL_EXPORT int X509_check_trust(X509 *x, int id, int flags);
OPENSSL_EXPORT int X509_TRUST_get_count(void);
OPENSSL_EXPORT X509_TRUST *X509_TRUST_get0(int idx);
OPENSSL_EXPORT int X509_TRUST_get_by_id(int id);
OPENSSL_EXPORT int X509_TRUST_add(int id, int flags,
                                  int (*ck)(X509_TRUST *, X509 *, int),
                                  const char *name, int arg1, void *arg2);
OPENSSL_EXPORT void X509_TRUST_cleanup(void);
OPENSSL_EXPORT int X509_TRUST_get_flags(const X509_TRUST *xp);
OPENSSL_EXPORT char *X509_TRUST_get0_name(const X509_TRUST *xp);
OPENSSL_EXPORT int X509_TRUST_get_trust(const X509_TRUST *xp);


/*
SSL_CTX -> X509_STORE
                -> X509_LOOKUP
                        ->X509_LOOKUP_METHOD
                -> X509_LOOKUP
                        ->X509_LOOKUP_METHOD

SSL	-> X509_STORE_CTX
                ->X509_STORE

The X509_STORE holds the tables etc for verification stuff.
A X509_STORE_CTX is used while validating a single certificate.
The X509_STORE has X509_LOOKUPs for looking up certs.
The X509_STORE then calls a function to actually verify the
certificate chain.
*/

#define X509_LU_NONE 0
#define X509_LU_X509 1
#define X509_LU_CRL 2
#define X509_LU_PKEY 3

DEFINE_STACK_OF(X509_LOOKUP)
DEFINE_STACK_OF(X509_OBJECT)
DEFINE_STACK_OF(X509_VERIFY_PARAM)

typedef int (*X509_STORE_CTX_verify_cb)(int, X509_STORE_CTX *);
typedef int (*X509_STORE_CTX_get_issuer_fn)(X509 **issuer, X509_STORE_CTX *ctx,
                                            X509 *x);
typedef int (*X509_STORE_CTX_get_crl_fn)(X509_STORE_CTX *ctx, X509_CRL **crl,
                                         X509 *x);
typedef int (*X509_STORE_CTX_check_crl_fn)(X509_STORE_CTX *ctx, X509_CRL *crl);

OPENSSL_EXPORT int X509_STORE_set_depth(X509_STORE *store, int depth);

OPENSSL_EXPORT void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth);

#define X509_STORE_CTX_set_app_data(ctx, data) \
  X509_STORE_CTX_set_ex_data(ctx, 0, data)
#define X509_STORE_CTX_get_app_data(ctx) X509_STORE_CTX_get_ex_data(ctx, 0)

#define X509_L_FILE_LOAD 1
#define X509_L_ADD_DIR 2

#define X509_LOOKUP_load_file(x, name, type) \
  X509_LOOKUP_ctrl((x), X509_L_FILE_LOAD, (name), (long)(type), NULL)

#define X509_LOOKUP_add_dir(x, name, type) \
  X509_LOOKUP_ctrl((x), X509_L_ADD_DIR, (name), (long)(type), NULL)

#define X509_V_OK 0
#define X509_V_ERR_UNSPECIFIED 1

#define X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT 2
#define X509_V_ERR_UNABLE_TO_GET_CRL 3
#define X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE 4
#define X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE 5
#define X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY 6
#define X509_V_ERR_CERT_SIGNATURE_FAILURE 7
#define X509_V_ERR_CRL_SIGNATURE_FAILURE 8
#define X509_V_ERR_CERT_NOT_YET_VALID 9
#define X509_V_ERR_CERT_HAS_EXPIRED 10
#define X509_V_ERR_CRL_NOT_YET_VALID 11
#define X509_V_ERR_CRL_HAS_EXPIRED 12
#define X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD 13
#define X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD 14
#define X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD 15
#define X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD 16
#define X509_V_ERR_OUT_OF_MEM 17
#define X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT 18
#define X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN 19
#define X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY 20
#define X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE 21
#define X509_V_ERR_CERT_CHAIN_TOO_LONG 22
#define X509_V_ERR_CERT_REVOKED 23
#define X509_V_ERR_INVALID_CA 24
#define X509_V_ERR_PATH_LENGTH_EXCEEDED 25
#define X509_V_ERR_INVALID_PURPOSE 26
#define X509_V_ERR_CERT_UNTRUSTED 27
#define X509_V_ERR_CERT_REJECTED 28
// These are 'informational' when looking for issuer cert
#define X509_V_ERR_SUBJECT_ISSUER_MISMATCH 29
#define X509_V_ERR_AKID_SKID_MISMATCH 30
#define X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH 31
#define X509_V_ERR_KEYUSAGE_NO_CERTSIGN 32

#define X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER 33
#define X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION 34
#define X509_V_ERR_KEYUSAGE_NO_CRL_SIGN 35
#define X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION 36
#define X509_V_ERR_INVALID_NON_CA 37
#define X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED 38
#define X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE 39
#define X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED 40

#define X509_V_ERR_INVALID_EXTENSION 41
#define X509_V_ERR_INVALID_POLICY_EXTENSION 42
#define X509_V_ERR_NO_EXPLICIT_POLICY 43
#define X509_V_ERR_DIFFERENT_CRL_SCOPE 44
#define X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE 45

#define X509_V_ERR_UNNESTED_RESOURCE 46

#define X509_V_ERR_PERMITTED_VIOLATION 47
#define X509_V_ERR_EXCLUDED_VIOLATION 48
#define X509_V_ERR_SUBTREE_MINMAX 49
#define X509_V_ERR_APPLICATION_VERIFICATION 50
#define X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE 51
#define X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX 52
#define X509_V_ERR_UNSUPPORTED_NAME_SYNTAX 53
#define X509_V_ERR_CRL_PATH_VALIDATION_ERROR 54

// The following indicate Host, email and IP check errors
#define X509_V_ERR_HOSTNAME_MISMATCH 62
#define X509_V_ERR_EMAIL_MISMATCH 63
#define X509_V_ERR_IP_ADDRESS_MISMATCH 64

// X509_V_ERR_INVALID_CALL indicates a caller error.
#define X509_V_ERR_INVALID_CALL 65
// X509_V_ERR_STORE_LOOKUP indicates an issuer lookup error.
#define X509_V_ERR_STORE_LOOKUP 66

#define X509_V_ERR_NAME_CONSTRAINTS_WITHOUT_SANS 67

// Certificate verify flags

// X509_V_FLAG_CB_ISSUER_CHECK sends issuer+subject checks to |verify_cb|.
#define X509_V_FLAG_CB_ISSUER_CHECK 0x1
// X509_V_FLAG_USE_CHECK_TIME uses check time instead of current time.
#define X509_V_FLAG_USE_CHECK_TIME 0x2
// X509_V_FLAG_CRL_CHECK enables lookup CRLs for the leaf certificate.
#define X509_V_FLAG_CRL_CHECK 0x4
// X509_V_FLAG_CRL_CHECK_ALL enables lookup CRLs for whole chain.
#define X509_V_FLAG_CRL_CHECK_ALL 0x8
// X509_V_FLAG_IGNORE_CRITICAL ignores unhandled critical extensions.
#define X509_V_FLAG_IGNORE_CRITICAL 0x10
// X509_V_FLAG_X509_STRICT does nothing as its functionality has been enabled by
// default. In OpenSSL, enabling this disables workarounds for some broken
// certificates and makes the verification strictly apply X509 rules.
#define X509_V_FLAG_X509_STRICT 0x00
// X509_V_FLAG_ALLOW_PROXY_CERTS does nothing as proxy certificate support has
// been removed. Proxy certificate support has been removed from AWS-LC.
#define X509_V_FLAG_ALLOW_PROXY_CERTS 0x40
// X509_V_FLAG_POLICY_CHECK enables policy checking.
#define X509_V_FLAG_POLICY_CHECK 0x80
// X509_V_FLAG_EXPLICIT_POLICY enables the policy variable:
// require-explicit-policy
#define X509_V_FLAG_EXPLICIT_POLICY 0x100
// X509_V_FLAG_INHIBIT_ANY enables the policy variable: inhibit-any-policy
#define X509_V_FLAG_INHIBIT_ANY 0x200
// X509_V_FLAG_INHIBIT_MAP enables the policy variable: inhibit-policy-mapping
#define X509_V_FLAG_INHIBIT_MAP 0x400
// X509_V_FLAG_NOTIFY_POLICY notifies the callback that the policy is OK
#define X509_V_FLAG_NOTIFY_POLICY 0x800
// X509_V_FLAG_EXTENDED_CRL_SUPPORT causes all verifications to fail. Extended
// CRL features have been removed.
#define X509_V_FLAG_EXTENDED_CRL_SUPPORT 0x1000
// X509_V_FLAG_USE_DELTAS causes all verifications to fail. Delta CRL support
// has been removed.
#define X509_V_FLAG_USE_DELTAS 0x2000
// X509_V_FLAG_CHECK_SS_SIGNATURE enables checking the self signed CA signature.
#define X509_V_FLAG_CHECK_SS_SIGNATURE 0x4000
// X509_V_FLAG_TRUSTED_FIRST flag causes chain construction to look for issuers
// in the trust store before looking at the untrusted certificates provided.
// This is ON by default in both AWS-LC and OpenSSL.
#define X509_V_FLAG_TRUSTED_FIRST 0x8000

// X509_V_FLAG_PARTIAL_CHAIN allows partial chains if at least one certificate
// is in the trusted store.
#define X509_V_FLAG_PARTIAL_CHAIN 0x80000

// X509_V_FLAG_NO_ALT_CHAINS suppresses checking for alternative chains. If the
// initial chain is not trusted, do not attempt to build an alternative chain.
// Alternate chain checking was introduced in 1.0.2b. Setting this flag will
// force the behaviour to match that of previous versions.
#define X509_V_FLAG_NO_ALT_CHAINS 0x100000

// X509_V_FLAG_NO_CHECK_TIME disables all time checks in certificate
// verification.
#define X509_V_FLAG_NO_CHECK_TIME 0x200000

#define X509_VP_FLAG_DEFAULT 0x1
#define X509_VP_FLAG_OVERWRITE 0x2
#define X509_VP_FLAG_RESET_FLAGS 0x4
#define X509_VP_FLAG_LOCKED 0x8
#define X509_VP_FLAG_ONCE 0x10

// Internal use: mask of policy related options (hidden)

#define X509_V_FLAG_POLICY_MASK                             \
  (X509_V_FLAG_POLICY_CHECK | X509_V_FLAG_EXPLICIT_POLICY | \
   X509_V_FLAG_INHIBIT_ANY | X509_V_FLAG_INHIBIT_MAP)

// X509_OBJECT_new allocates an |X509_OBJECT| on the heap.
OPENSSL_EXPORT X509_OBJECT *X509_OBJECT_new(void);

// X509_OBJECT_free frees an |X509_OBJECT| from the heap.
OPENSSL_EXPORT void X509_OBJECT_free(X509_OBJECT *a);

// X509_OBJECT_new returns a newly-allocated, empty |X509_OBJECT| or NULL on
// error.
OPENSSL_EXPORT X509_OBJECT *X509_OBJECT_new(void);

// X509_OBJECT_free releases memory associated with |obj|.
OPENSSL_EXPORT void X509_OBJECT_free(X509_OBJECT *obj);

// X509_OBJECT_get_type returns the type of |obj|, which will be one of the
// |X509_LU_*| constants.
OPENSSL_EXPORT int X509_OBJECT_get_type(const X509_OBJECT *obj);

// X509_OBJECT_get0_X509 returns |obj| as a certificate, or NULL if |obj| is not
// a certificate.
OPENSSL_EXPORT X509 *X509_OBJECT_get0_X509(const X509_OBJECT *obj);

// X509_OBJECT_get0_X509_CRL returns the |X509_CRL| associated with |a|
OPENSSL_EXPORT X509_CRL *X509_OBJECT_get0_X509_CRL(const X509_OBJECT *a);

// X509_OBJECT_set1_X509 sets |obj| on |a| and uprefs |obj|. As with other set1
// methods, |a| does not take ownership of |obj|; the caller is responsible for
// managing freeing |obj| when appropriate.
OPENSSL_EXPORT int X509_OBJECT_set1_X509(X509_OBJECT *a, X509 *obj);

// X509_OBJECT_set1_X509_CRL sets CRL |obj| on |a| and uprefs |obj|. As with
// other set1 methods, |a| does not take ownership of |obj|; the caller is
// responsible for managing freeing |obj| when appropriate.
OPENSSL_EXPORT int X509_OBJECT_set1_X509_CRL(X509_OBJECT *a, X509_CRL *obj);

// X509_STORE_lock takes a write lock on |v|. return 1 on success, 0 on failure.
//
// Avoid operations on the X509_STORE or a X509_STORE_CTX containing it while
// it is locked; many |X509_STORE_*| functions take this lock internally which
// will cause a deadlock when called on a locked store.
OPENSSL_EXPORT int X509_STORE_lock(X509_STORE *v);

// X509_STORE_unlock releases a lock on |v|. return 1 on success, 0 on failure
OPENSSL_EXPORT int X509_STORE_unlock(X509_STORE *v);

// X509_STORE_new returns a newly-allocated |X509_STORE|, or NULL on error.
OPENSSL_EXPORT X509_STORE *X509_STORE_new(void);

// X509_STORE_up_ref adds one to the reference count of |store| and returns one.
OPENSSL_EXPORT int X509_STORE_up_ref(X509_STORE *store);

// X509_STORE_free releases memory associated with |store|.
OPENSSL_EXPORT void X509_STORE_free(X509_STORE *store);

OPENSSL_EXPORT STACK_OF(X509_OBJECT) *X509_STORE_get0_objects(X509_STORE *st);
OPENSSL_EXPORT STACK_OF(X509) *X509_STORE_get1_certs(X509_STORE_CTX *st,
                                                     X509_NAME *nm);
OPENSSL_EXPORT STACK_OF(X509_CRL) *X509_STORE_get1_crls(X509_STORE_CTX *st,
                                                        X509_NAME *nm);
OPENSSL_EXPORT int X509_STORE_set_flags(X509_STORE *ctx, unsigned long flags);
OPENSSL_EXPORT int X509_STORE_set_purpose(X509_STORE *ctx, int purpose);
OPENSSL_EXPORT int X509_STORE_set_trust(X509_STORE *ctx, int trust);
OPENSSL_EXPORT int X509_STORE_set1_param(X509_STORE *ctx,
                                         X509_VERIFY_PARAM *pm);

// X509_STORE_get0_param returns |store|'s default verification parameters. This
// object is mutable and may be modified by the caller.
//
// TODO(crbug.com/boringssl/441): Discuss the semantics of this notion of
// "default".
OPENSSL_EXPORT X509_VERIFY_PARAM *X509_STORE_get0_param(X509_STORE *store);

// X509_STORE_set_verify_cb acts like |X509_STORE_CTX_set_verify_cb| but sets
// the verify callback for any |X509_STORE_CTX| created from this |X509_STORE|
//
// Do not use this funciton. see |X509_STORE_CTX_set_verify_cb|.
OPENSSL_EXPORT void X509_STORE_set_verify_cb(
    X509_STORE *ctx, X509_STORE_CTX_verify_cb verify_cb);
#define X509_STORE_set_verify_cb_func(ctx, func) \
  X509_STORE_set_verify_cb((ctx), (func))
OPENSSL_EXPORT X509_STORE_CTX_verify_cb
X509_STORE_get_verify_cb(X509_STORE *ctx);
OPENSSL_EXPORT void X509_STORE_set_get_issuer(
    X509_STORE *ctx, X509_STORE_CTX_get_issuer_fn get_issuer);
OPENSSL_EXPORT X509_STORE_CTX_get_issuer_fn
X509_STORE_get_get_issuer(X509_STORE *ctx);
OPENSSL_EXPORT void X509_STORE_set_get_crl(X509_STORE *ctx,
                                           X509_STORE_CTX_get_crl_fn get_crl);
OPENSSL_EXPORT X509_STORE_CTX_get_crl_fn
X509_STORE_get_get_crl(X509_STORE *ctx);
OPENSSL_EXPORT void X509_STORE_set_check_crl(
    X509_STORE *ctx, X509_STORE_CTX_check_crl_fn check_crl);
OPENSSL_EXPORT X509_STORE_CTX_check_crl_fn
X509_STORE_get_check_crl(X509_STORE *ctx);

OPENSSL_EXPORT X509_STORE_CTX *X509_STORE_CTX_new(void);

OPENSSL_EXPORT int X509_STORE_CTX_get1_issuer(X509 **issuer,
                                              X509_STORE_CTX *ctx, X509 *x);

// X509_STORE_CTX_free releases memory associated with |ctx|.
OPENSSL_EXPORT void X509_STORE_CTX_free(X509_STORE_CTX *ctx);

OPENSSL_EXPORT int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store,
                                       X509 *x509, STACK_OF(X509) *chain);

// X509_STORE_CTX_set0_trusted_stack configures |ctx| to trust the certificates
// in |sk|. |sk| must remain valid for the duration of |ctx|.
//
// WARNING: This function differs from most |set0| functions in that it does not
// take ownership of its input. The caller is required to ensure the lifetimes
// are consistent.
OPENSSL_EXPORT void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx,
                                                      STACK_OF(X509) *sk);

// X509_STORE_CTX_trusted_stack is a deprecated alias for
// |X509_STORE_CTX_set0_trusted_stack|.
OPENSSL_EXPORT void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx,
                                                 STACK_OF(X509) *sk);

// X509_STORE_CTX_get0_store returns the |X509_STORE| that |ctx| uses.
OPENSSL_EXPORT X509_STORE *X509_STORE_CTX_get0_store(X509_STORE_CTX *ctx);

// X509_STORE_CTX_get0_cert returns the leaf certificate that |ctx| is
// verifying.
OPENSSL_EXPORT X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx);

OPENSSL_EXPORT X509_LOOKUP *X509_STORE_add_lookup(X509_STORE *v,
                                                  X509_LOOKUP_METHOD *m);

OPENSSL_EXPORT X509_LOOKUP_METHOD *X509_LOOKUP_hash_dir(void);
OPENSSL_EXPORT X509_LOOKUP_METHOD *X509_LOOKUP_file(void);

OPENSSL_EXPORT int X509_STORE_add_cert(X509_STORE *ctx, X509 *x);
OPENSSL_EXPORT int X509_STORE_add_crl(X509_STORE *ctx, X509_CRL *x);

OPENSSL_EXPORT int X509_LOOKUP_ctrl(X509_LOOKUP *ctx, int cmd, const char *argc,
                                    long argl, char **ret);

OPENSSL_EXPORT int X509_load_cert_file(X509_LOOKUP *ctx, const char *file,
                                       int type);
OPENSSL_EXPORT int X509_load_crl_file(X509_LOOKUP *ctx, const char *file,
                                      int type);
OPENSSL_EXPORT int X509_load_cert_crl_file(X509_LOOKUP *ctx, const char *file,
                                           int type);

OPENSSL_EXPORT int X509_STORE_load_locations(X509_STORE *ctx, const char *file,
                                             const char *dir);
OPENSSL_EXPORT int X509_STORE_set_default_paths(X509_STORE *ctx);
OPENSSL_EXPORT int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx);
OPENSSL_EXPORT void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int s);
OPENSSL_EXPORT int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx);
OPENSSL_EXPORT X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx);
OPENSSL_EXPORT X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx);
OPENSSL_EXPORT X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx);

// X509_STORE_CTX_get_chain returns the pointer to the verified chain if
// verification was successful. If unsuccessful it may return null or a partial
// chain. The reference count is not incremented and must not be freed.
OPENSSL_EXPORT STACK_OF(X509) *X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx);

// X509_STORE_CTX_get0_chain behaves like |X509_STORE_CTX_get_chain|.
OPENSSL_EXPORT STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx);

// X509_STORE_CTX_get1_chain behaves like |X509_STORE_CTX_get0_chain| and also
// increments the reference counter. The |STACK_OF(X509)| must be freed with
// |sk_X509_pop_free|
OPENSSL_EXPORT STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx);
OPENSSL_EXPORT void X509_STORE_CTX_set_cert(X509_STORE_CTX *c, X509 *x);
OPENSSL_EXPORT void X509_STORE_CTX_set_chain(X509_STORE_CTX *c,
                                             STACK_OF(X509) *sk);
OPENSSL_EXPORT STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(
    X509_STORE_CTX *ctx);
OPENSSL_EXPORT void X509_STORE_CTX_set0_crls(X509_STORE_CTX *c,
                                             STACK_OF(X509_CRL) *sk);
OPENSSL_EXPORT int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose);
OPENSSL_EXPORT int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust);
OPENSSL_EXPORT int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx,
                                                  int def_purpose, int purpose,
                                                  int trust);
OPENSSL_EXPORT void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx,
                                             unsigned long flags);

// X509_STORE_CTX_set_time configures certificate verification to use |t|
// instead of the current time. |flags| is ignored and should be zero.
OPENSSL_EXPORT void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx,
                                            unsigned long flags, time_t t);

// X509_STORE_CTX_set_time_posix configures certificate verification to use |t|
// instead of the current time. |t| is interpreted as a POSIX timestamp in
// seconds. |flags| is ignored and should be zero.
OPENSSL_EXPORT void X509_STORE_CTX_set_time_posix(X509_STORE_CTX *ctx,
                                                  unsigned long flags,
                                                  int64_t t);

// X509_STORE_CTX_set_verify_cb configures a callback function for |ctx| that is
// called multiple times during |X509_verify_cert|. The callback returns zero to
// fail verification and non-zero to proceed. Typically, it will return |ok|,
// which preserves the default behavior. Returning one when |ok| is zero will
// proceed past some error. The callback may inspect |ctx| and the error queue
// to attempt to determine the current stage of certificate verification, but
// this is often unreliable.
//
// WARNING: Do not use this function. It is extremely fragile and unpredictable.
// This callback exposes implementation details of certificate verification,
// which change as the library evolves. Attempting to use it for security checks
// can introduce vulnerabilities if making incorrect assumptions about when the
// callback is called. Additionally, overriding |ok| may leave |ctx| in an
// inconsistent state and break invariants.
//
// Instead, customize certificate verification by configuring options on the
// |X509_STORE_CTX| before verification, or applying additional checks after
// |X509_verify_cert| completes successfully.
OPENSSL_EXPORT void X509_STORE_CTX_set_verify_cb(
    X509_STORE_CTX *ctx, int (*verify_cb)(int ok, X509_STORE_CTX *ctx));

// X509_STORE_CTX_get0_param returns |ctx|'s verification parameters. This
// object is mutable and may be modified by the caller.
OPENSSL_EXPORT X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(
    X509_STORE_CTX *ctx);

// X509_STORE_CTX_set0_param returns |ctx|'s verification parameters to |param|
// and takes ownership of |param|. After this function returns, the caller
// should not free |param|.
//
// TODO(crbug.com/boringssl/441): The bug notes some odd interactions with
// the different notions of default. Discuss this.
OPENSSL_EXPORT void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx,
                                              X509_VERIFY_PARAM *param);

OPENSSL_EXPORT int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx,
                                              const char *name);

// X509_STORE_get_by_subject is an alias to |X509_STORE_CTX_get_by_subject| in
// OpenSSL 1.1.1.
#define X509_STORE_get_by_subject X509_STORE_CTX_get_by_subject

// X509_STORE_CTX_get_by_subject tries to find an object of a given type, which
// may be |X509_LU_X509| or |X509_LU_CRL|, and the subject name from the store
// in |vs|. If found and |ret| is not NULL, it increments the reference count
// and stores the object in |ret|.
OPENSSL_EXPORT int X509_STORE_CTX_get_by_subject(X509_STORE_CTX *vs, int type,
                                                 X509_NAME *name,
                                                 X509_OBJECT *ret);

// X509_VERIFY_PARAM functions

// X509_VERIFY_PARAM_new returns a newly-allocated |X509_VERIFY_PARAM|, or NULL
// on error.
OPENSSL_EXPORT X509_VERIFY_PARAM *X509_VERIFY_PARAM_new(void);

// X509_VERIFY_PARAM_free releases memory associated with |param|.
OPENSSL_EXPORT void X509_VERIFY_PARAM_free(X509_VERIFY_PARAM *param);

OPENSSL_EXPORT int X509_VERIFY_PARAM_inherit(X509_VERIFY_PARAM *to,
                                             const X509_VERIFY_PARAM *from);
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1(X509_VERIFY_PARAM *to,
                                          const X509_VERIFY_PARAM *from);
OPENSSL_EXPORT int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param,
                                               unsigned long flags);
OPENSSL_EXPORT int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
                                                 unsigned long flags);
OPENSSL_EXPORT unsigned long X509_VERIFY_PARAM_get_flags(
    X509_VERIFY_PARAM *param);
OPENSSL_EXPORT int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param,
                                                 int purpose);
OPENSSL_EXPORT int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param,
                                               int trust);
OPENSSL_EXPORT void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param,
                                                int depth);

// X509_VERIFY_PARAM_set_time configures certificate verification to use |t|
// instead of the current time.
OPENSSL_EXPORT void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param,
                                               time_t t);

// X509_VERIFY_PARAM_set_time_posix configures certificate verification to use
// |t| instead of the current time. |t| is interpreted as a POSIX timestamp in
// seconds.
OPENSSL_EXPORT void X509_VERIFY_PARAM_set_time_posix(X509_VERIFY_PARAM *param,
                                                     int64_t t);

// X509_VERIFY_PARAM_add0_policy adds |policy| to the user-initial-policy-set
// (see Section 6.1.1 of RFC 5280). On success, it takes ownership of
// |policy| and returns one. Otherwise, it returns zero and the caller retains
// owneship of |policy|.
OPENSSL_EXPORT int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
                                                 ASN1_OBJECT *policy);

// X509_VERIFY_PARAM_set1_policies sets the user-initial-policy-set (see
// Section 6.1.1 of RFC 5280) to a copy of |policies|. It returns one on success
// and zero on error.
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1_policies(
    X509_VERIFY_PARAM *param, const STACK_OF(ASN1_OBJECT) *policies);

// X509_VERIFY_PARAM_set1_host configures |param| to check for the DNS name
// specified by |name| and clears any previously specified hostname. If |name|
// is NULL or empty, the list of hostnames is cleared and name checks are not
// performed on the peer certificate. It returns one on success and zero on
// error.
// |namelen| should be set to the length of |name|. It may be zero if |name| is
// NUL-terminated, but this is only maintained for backwards compatibility with
// OpenSSL.
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
                                               const char *name,
                                               size_t namelen);

// X509_VERIFY_PARAM_add1_host |name| to the list of names checked by
// |param|. If any configured DNS name matches the certificate, verification
// succeeds. Any previous names set via |X509_VERIFY_PARAM_set1_host| or
// |X509_VERIFY_PARAM_add1_host| are retained, no change is made if |name| is
// NULL or empty. When multiple names are configured, the peer is considered
// verified when any name matches. It returns one on success and zero on error.
// |namelen| should be set to the length of |name|. It may be zero if |name| is
// NUL-terminated, but this is only maintained for backwards compatibility with
// OpenSSL.
OPENSSL_EXPORT int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
                                               const char *name,
                                               size_t name_len);

// X509_VERIFY_PARAM_set_hostflags sets the name-checking flags on |param| to
// |flags|. |flags| should be a combination of |X509_CHECK_FLAG_*| constants.
OPENSSL_EXPORT void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
                                                    unsigned int flags);

OPENSSL_EXPORT char *X509_VERIFY_PARAM_get0_peername(X509_VERIFY_PARAM *);

// X509_VERIFY_PARAM_set1_email configures |param| to check for the email
// address specified by |email|. It returns one on success and zero on error.
// |emaillen| should be set to the length of |email|. It may be zero if |email|
// is NUL-terminated, but this is only maintained for backwards compatibility
// with OpenSSL.
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
                                                const char *email,
                                                size_t emaillen);

// X509_VERIFY_PARAM_set1_ip configures |param| to check for the IP address
// specified by |ip|. It returns one on success and zero on error. The IP
// address is specified in its binary representation. |ip_len| must be 4 for an
// IPv4 address and 16 for an IPv6 address.
// NOTE:|iplen| MUST be set to the length of |ip|.
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
                                             const unsigned char *ip,
                                             size_t iplen);

// X509_VERIFY_PARAM_set1_ip_asc decodes |ipasc| as the ASCII representation of
// an IPv4 or IPv6 address, and configures |param| to check for it. It returns
// one on success and zero on error.
// |ipasc| MUST be a NUL-terminal ASCII string: dotted decimal quad for IPv4 and
// colon-separated hexadecimal for IPv6. The condensed "::" notation is
// supported for IPv6 addresses.
OPENSSL_EXPORT int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param,
                                                 const char *ipasc);

OPENSSL_EXPORT int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);

// X509_VERIFY_PARAM_lookup returns a pre-defined |X509_VERIFY_PARAM| named by
// |name|, or NULL if no such name is defined.
OPENSSL_EXPORT const X509_VERIFY_PARAM *X509_VERIFY_PARAM_lookup(
    const char *name);

// Forward reference
struct v3_ext_method;
struct v3_ext_ctx;

// Useful typedefs

typedef struct v3_ext_method X509V3_EXT_METHOD;

typedef void *(*X509V3_EXT_NEW)(void);
typedef void (*X509V3_EXT_FREE)(void *);
typedef void *(*X509V3_EXT_D2I)(void *, const unsigned char **, long);
typedef int (*X509V3_EXT_I2D)(void *, unsigned char **);
typedef STACK_OF(CONF_VALUE) *(*X509V3_EXT_I2V)(const X509V3_EXT_METHOD *method,
                                                void *ext,
                                                STACK_OF(CONF_VALUE) *extlist);
typedef void *(*X509V3_EXT_V2I)(const X509V3_EXT_METHOD *method,
                                const X509V3_CTX *ctx,
                                const STACK_OF(CONF_VALUE) *values);
typedef char *(*X509V3_EXT_I2S)(const X509V3_EXT_METHOD *method, void *ext);
typedef void *(*X509V3_EXT_S2I)(const X509V3_EXT_METHOD *method,
                                const X509V3_CTX *ctx, const char *str);
typedef int (*X509V3_EXT_I2R)(const X509V3_EXT_METHOD *method, void *ext,
                              BIO *out, int indent);
typedef void *(*X509V3_EXT_R2I)(const X509V3_EXT_METHOD *method,
                                const X509V3_CTX *ctx, const char *str);

// V3 extension structure

struct v3_ext_method {
  int ext_nid;
  int ext_flags;

  // it determines how values of this extension are allocated, released, parsed,
  // and marshalled. This must be non-NULL.
  ASN1_ITEM_EXP *it;

  // The following functions are ignored in favor of |it|. They are retained in
  // the struct only for source compatibility with existing struct definitions.
  //
  // Only OCSP nonce extensions currently rely on these functions with AWS-LC.
  // This is to maintain backwards compatibility with how OCSP nonce extensions
  // are handled in OpenSSL. This can't be easily removed because OpenSSL
  // considers the OCSP nonce to be "special".
  // |X509V3_EXT_add| enforces |it| to be non-NULL, so external users are not
  // allowed to use the following functions.
  X509V3_EXT_NEW ext_new;
  X509V3_EXT_FREE ext_free;
  X509V3_EXT_D2I d2i;
  X509V3_EXT_I2D i2d;

  // The following pair is used for string extensions
  X509V3_EXT_I2S i2s;
  X509V3_EXT_S2I s2i;

  // The following pair is used for multi-valued extensions
  X509V3_EXT_I2V i2v;
  X509V3_EXT_V2I v2i;

  // The following are used for raw extensions
  X509V3_EXT_I2R i2r;
  X509V3_EXT_R2I r2i;

  void *usr_data;  // Any extension specific data
};

DEFINE_STACK_OF(X509V3_EXT_METHOD)

// ext_flags values

#define X509V3_EXT_CTX_DEP 0x2
#define X509V3_EXT_MULTILINE 0x4

struct BASIC_CONSTRAINTS_st {
  int ca;
  ASN1_INTEGER *pathlen;
};


typedef struct otherName_st {
  ASN1_OBJECT *type_id;
  ASN1_TYPE *value;
} OTHERNAME;

typedef struct EDIPartyName_st {
  ASN1_STRING *nameAssigner;
  ASN1_STRING *partyName;
} EDIPARTYNAME;

typedef struct GENERAL_NAME_st {
#define GEN_OTHERNAME 0
#define GEN_EMAIL 1
#define GEN_DNS 2
#define GEN_X400 3
#define GEN_DIRNAME 4
#define GEN_EDIPARTY 5
#define GEN_URI 6
#define GEN_IPADD 7
#define GEN_RID 8

  int type;
  union {
    char *ptr;
    OTHERNAME *otherName;  // otherName
    ASN1_IA5STRING *rfc822Name;
    ASN1_IA5STRING *dNSName;
    ASN1_STRING *x400Address;
    X509_NAME *directoryName;
    EDIPARTYNAME *ediPartyName;
    ASN1_IA5STRING *uniformResourceIdentifier;
    ASN1_OCTET_STRING *iPAddress;
    ASN1_OBJECT *registeredID;

    // Old names
    ASN1_OCTET_STRING *ip;  // iPAddress
    X509_NAME *dirn;        // dirn
    ASN1_IA5STRING *ia5;    // rfc822Name, dNSName, uniformResourceIdentifier
    ASN1_OBJECT *rid;       // registeredID
  } d;
} GENERAL_NAME;

DEFINE_STACK_OF(GENERAL_NAME)

typedef STACK_OF(GENERAL_NAME) GENERAL_NAMES;

DEFINE_STACK_OF(GENERAL_NAMES)

typedef struct ACCESS_DESCRIPTION_st {
  ASN1_OBJECT *method;
  GENERAL_NAME *location;
} ACCESS_DESCRIPTION;

DEFINE_STACK_OF(ACCESS_DESCRIPTION)

typedef STACK_OF(ACCESS_DESCRIPTION) AUTHORITY_INFO_ACCESS;

typedef STACK_OF(ASN1_OBJECT) EXTENDED_KEY_USAGE;

typedef struct DIST_POINT_NAME_st {
  int type;
  union {
    GENERAL_NAMES *fullname;
    STACK_OF(X509_NAME_ENTRY) *relativename;
  } name;
  // If relativename then this contains the full distribution point name
  X509_NAME *dpname;
} DIST_POINT_NAME;
// CRLDP_ALL_REASONS is an alias for all existing reasons
#define CRLDP_ALL_REASONS 0x807f

#define CRL_REASON_NONE (-1)
#define CRL_REASON_UNSPECIFIED 0
#define CRL_REASON_KEY_COMPROMISE 1
#define CRL_REASON_CA_COMPROMISE 2
#define CRL_REASON_AFFILIATION_CHANGED 3
#define CRL_REASON_SUPERSEDED 4
#define CRL_REASON_CESSATION_OF_OPERATION 5
#define CRL_REASON_CERTIFICATE_HOLD 6
#define CRL_REASON_REMOVE_FROM_CRL 8
#define CRL_REASON_PRIVILEGE_WITHDRAWN 9
#define CRL_REASON_AA_COMPROMISE 10

struct DIST_POINT_st {
  DIST_POINT_NAME *distpoint;
  ASN1_BIT_STRING *reasons;
  GENERAL_NAMES *CRLissuer;
};

typedef STACK_OF(DIST_POINT) CRL_DIST_POINTS;

DEFINE_STACK_OF(DIST_POINT)

struct AUTHORITY_KEYID_st {
  ASN1_OCTET_STRING *keyid;
  GENERAL_NAMES *issuer;
  ASN1_INTEGER *serial;
};

typedef struct NOTICEREF_st {
  ASN1_STRING *organization;
  STACK_OF(ASN1_INTEGER) *noticenos;
} NOTICEREF;

typedef struct USERNOTICE_st {
  NOTICEREF *noticeref;
  ASN1_STRING *exptext;
} USERNOTICE;

typedef struct POLICYQUALINFO_st {
  ASN1_OBJECT *pqualid;
  union {
    ASN1_IA5STRING *cpsuri;
    USERNOTICE *usernotice;
    ASN1_TYPE *other;
  } d;
} POLICYQUALINFO;

DEFINE_STACK_OF(POLICYQUALINFO)

typedef struct POLICYINFO_st {
  ASN1_OBJECT *policyid;
  STACK_OF(POLICYQUALINFO) *qualifiers;
} POLICYINFO;

typedef STACK_OF(POLICYINFO) CERTIFICATEPOLICIES;

DEFINE_STACK_OF(POLICYINFO)

typedef struct POLICY_MAPPING_st {
  ASN1_OBJECT *issuerDomainPolicy;
  ASN1_OBJECT *subjectDomainPolicy;
} POLICY_MAPPING;

DEFINE_STACK_OF(POLICY_MAPPING)

typedef STACK_OF(POLICY_MAPPING) POLICY_MAPPINGS;

typedef struct GENERAL_SUBTREE_st {
  GENERAL_NAME *base;
  ASN1_INTEGER *minimum;
  ASN1_INTEGER *maximum;
} GENERAL_SUBTREE;

DEFINE_STACK_OF(GENERAL_SUBTREE)

struct NAME_CONSTRAINTS_st {
  STACK_OF(GENERAL_SUBTREE) *permittedSubtrees;
  STACK_OF(GENERAL_SUBTREE) *excludedSubtrees;
};

typedef struct POLICY_CONSTRAINTS_st {
  ASN1_INTEGER *requireExplicitPolicy;
  ASN1_INTEGER *inhibitPolicyMapping;
} POLICY_CONSTRAINTS;

struct ISSUING_DIST_POINT_st {
  DIST_POINT_NAME *distpoint;
  ASN1_BOOLEAN onlyuser;
  ASN1_BOOLEAN onlyCA;
  ASN1_BIT_STRING *onlysomereasons;
  ASN1_BOOLEAN indirectCRL;
  ASN1_BOOLEAN onlyattr;
};

// X509_PURPOSE stuff

#define EXFLAG_BCONS 0x1
#define EXFLAG_KUSAGE 0x2
#define EXFLAG_XKUSAGE 0x4
#define EXFLAG_NSCERT 0x8

#define EXFLAG_CA 0x10
// EXFLAG_SI indicates the certificate is self-issued, i.e. its subject and
// issuer names match.
#define EXFLAG_SI 0x20
#define EXFLAG_V1 0x40
#define EXFLAG_INVALID 0x80
#define EXFLAG_SET 0x100
#define EXFLAG_CRITICAL 0x200
// EXFLAG_SS indicates the certificate is likely self-signed. That is, if it is
// self-issued, its authority key identifer (if any) matches itself, and its key
// usage extension (if any) allows certificate signatures. The signature itself
// is not checked in computing this bit.
#define EXFLAG_SS 0x2000

#define KU_DIGITAL_SIGNATURE 0x0080
#define KU_NON_REPUDIATION 0x0040
#define KU_KEY_ENCIPHERMENT 0x0020
#define KU_DATA_ENCIPHERMENT 0x0010
#define KU_KEY_AGREEMENT 0x0008
#define KU_KEY_CERT_SIGN 0x0004
#define KU_CRL_SIGN 0x0002
#define KU_ENCIPHER_ONLY 0x0001
#define KU_DECIPHER_ONLY 0x8000

#define NS_SSL_CLIENT 0x80
#define NS_SSL_SERVER 0x40
#define NS_SMIME 0x20
#define NS_OBJSIGN 0x10
#define NS_SSL_CA 0x04
#define NS_SMIME_CA 0x02
#define NS_OBJSIGN_CA 0x01
#define NS_ANY_CA (NS_SSL_CA | NS_SMIME_CA | NS_OBJSIGN_CA)

#define XKU_SSL_SERVER 0x1
#define XKU_SSL_CLIENT 0x2
#define XKU_SMIME 0x4
#define XKU_CODE_SIGN 0x8
#define XKU_SGC 0x10
#define XKU_OCSP_SIGN 0x20
#define XKU_TIMESTAMP 0x40
#define XKU_DVCS 0x80
#define XKU_ANYEKU 0x100

#define X509_PURPOSE_DYNAMIC 0x1
#define X509_PURPOSE_DYNAMIC_NAME 0x2

typedef struct x509_purpose_st {
  int purpose;
  int trust;  // Default trust ID
  int flags;
  int (*check_purpose)(const struct x509_purpose_st *, const X509 *, int);
  char *name;
  char *sname;
  void *usr_data;
} X509_PURPOSE;

#define X509_PURPOSE_SSL_CLIENT 1
#define X509_PURPOSE_SSL_SERVER 2
#define X509_PURPOSE_NS_SSL_SERVER 3
#define X509_PURPOSE_SMIME_SIGN 4
#define X509_PURPOSE_SMIME_ENCRYPT 5
#define X509_PURPOSE_CRL_SIGN 6
#define X509_PURPOSE_ANY 7
#define X509_PURPOSE_OCSP_HELPER 8
#define X509_PURPOSE_TIMESTAMP_SIGN 9

#define X509_PURPOSE_MIN 1
#define X509_PURPOSE_MAX 9

DEFINE_STACK_OF(X509_PURPOSE)

DECLARE_ASN1_FUNCTIONS_const(BASIC_CONSTRAINTS)

// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(AUTHORITY_KEYID)

// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(GENERAL_NAME)
OPENSSL_EXPORT GENERAL_NAME *GENERAL_NAME_dup(GENERAL_NAME *a);

// i2v_GENERAL_NAME serializes |gen| as a |CONF_VALUE|. If |ret| is non-NULL, it
// appends the value to |ret| and returns |ret| on success or NULL on error. If
// it returns NULL, the caller is still responsible for freeing |ret|. If |ret|
// is NULL, it returns a newly-allocated |STACK_OF(CONF_VALUE)| containing the
// result. |method| is ignored.
//
// Do not use this function. This is an internal implementation detail of the
// human-readable print functions. If extracting a SAN list from a certificate,
// look at |gen| directly.
OPENSSL_EXPORT STACK_OF(CONF_VALUE) *i2v_GENERAL_NAME(
    const X509V3_EXT_METHOD *method, const GENERAL_NAME *gen,
    STACK_OF(CONF_VALUE) *ret);

// GENERAL_NAME_print prints a human-readable representation of |gen| to |out|.
// It returns one on success and zero on error.
//
// TODO(davidben): Actually, it just returns one and doesn't check for I/O or
// allocation errors. But it should return zero on error.
OPENSSL_EXPORT int GENERAL_NAME_print(BIO *out, const GENERAL_NAME *gen);

// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(GENERAL_NAMES)

// i2v_GENERAL_NAMES serializes |gen| as a list of |CONF_VALUE|s. If |ret| is
// non-NULL, it appends the values to |ret| and returns |ret| on success or NULL
// on error. If it returns NULL, the caller is still responsible for freeing
// |ret|. If |ret| is NULL, it returns a newly-allocated |STACK_OF(CONF_VALUE)|
// containing the results. |method| is ignored.
//
// Do not use this function. This is an internal implementation detail of the
// human-readable print functions. If extracting a SAN list from a certificate,
// look at |gen| directly.
OPENSSL_EXPORT STACK_OF(CONF_VALUE) *i2v_GENERAL_NAMES(
    const X509V3_EXT_METHOD *method, const GENERAL_NAMES *gen,
    STACK_OF(CONF_VALUE) *extlist);
OPENSSL_EXPORT GENERAL_NAMES *v2i_GENERAL_NAMES(
    const X509V3_EXT_METHOD *method, const X509V3_CTX *ctx,
    const STACK_OF(CONF_VALUE) *nval);

DECLARE_ASN1_FUNCTIONS_const(OTHERNAME)
DECLARE_ASN1_FUNCTIONS_const(EDIPARTYNAME)
OPENSSL_EXPORT void GENERAL_NAME_set0_value(GENERAL_NAME *a, int type,
                                            void *value);
OPENSSL_EXPORT void *GENERAL_NAME_get0_value(const GENERAL_NAME *a, int *ptype);
OPENSSL_EXPORT int GENERAL_NAME_set0_othername(GENERAL_NAME *gen,
                                               ASN1_OBJECT *oid,
                                               ASN1_TYPE *value);
OPENSSL_EXPORT int GENERAL_NAME_get0_otherName(const GENERAL_NAME *gen,
                                               ASN1_OBJECT **poid,
                                               ASN1_TYPE **pvalue);

// i2s_ASN1_OCTET_STRING returns a human-readable representation of |oct| as a
// newly-allocated, NUL-terminated string, or NULL on error. |method| is
// ignored. The caller must release the result with |OPENSSL_free| when done.
OPENSSL_EXPORT char *i2s_ASN1_OCTET_STRING(const X509V3_EXT_METHOD *method,
                                           const ASN1_OCTET_STRING *oct);

OPENSSL_EXPORT ASN1_OCTET_STRING *s2i_ASN1_OCTET_STRING(
    const X509V3_EXT_METHOD *method, const X509V3_CTX *ctx, const char *str);

DECLARE_ASN1_FUNCTIONS_const(EXTENDED_KEY_USAGE)
OPENSSL_EXPORT int i2a_ACCESS_DESCRIPTION(BIO *bp, const ACCESS_DESCRIPTION *a);

DECLARE_ASN1_FUNCTIONS_const(CERTIFICATEPOLICIES)
DECLARE_ASN1_FUNCTIONS_const(POLICYINFO)
DECLARE_ASN1_FUNCTIONS_const(POLICYQUALINFO)
DECLARE_ASN1_FUNCTIONS_const(USERNOTICE)
DECLARE_ASN1_FUNCTIONS_const(NOTICEREF)

// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(CRL_DIST_POINTS)
// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(DIST_POINT)
// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(DIST_POINT_NAME)
// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(ISSUING_DIST_POINT)

OPENSSL_EXPORT int DIST_POINT_set_dpname(DIST_POINT_NAME *dpn,
                                         X509_NAME *iname);

OPENSSL_EXPORT int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc);

// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(ACCESS_DESCRIPTION)
// TODO(https://crbug.com/boringssl/407): This is not const because it contains
// an |X509_NAME|.
DECLARE_ASN1_FUNCTIONS(AUTHORITY_INFO_ACCESS)

DECLARE_ASN1_ITEM(POLICY_MAPPING)
DECLARE_ASN1_ALLOC_FUNCTIONS(POLICY_MAPPING)
DECLARE_ASN1_ITEM(POLICY_MAPPINGS)

DECLARE_ASN1_ITEM(GENERAL_SUBTREE)
DECLARE_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)

DECLARE_ASN1_ITEM(NAME_CONSTRAINTS)
DECLARE_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)

DECLARE_ASN1_ALLOC_FUNCTIONS(POLICY_CONSTRAINTS)
DECLARE_ASN1_ITEM(POLICY_CONSTRAINTS)

OPENSSL_EXPORT GENERAL_NAME *a2i_GENERAL_NAME(GENERAL_NAME *out,
                                              const X509V3_EXT_METHOD *method,
                                              const X509V3_CTX *ctx, int gen_type,
                                              const char *value, int is_nc);

OPENSSL_EXPORT GENERAL_NAME *v2i_GENERAL_NAME(const X509V3_EXT_METHOD *method,
                                              const X509V3_CTX *ctx,
                                              const CONF_VALUE *cnf);
OPENSSL_EXPORT GENERAL_NAME *v2i_GENERAL_NAME_ex(
    GENERAL_NAME *out, const X509V3_EXT_METHOD *method, const X509V3_CTX *ctx,
    const CONF_VALUE *cnf, int is_nc);
OPENSSL_EXPORT void X509V3_conf_free(CONF_VALUE *val);


// Deprecated config-based extension creation.
//
// The following functions allow specifying X.509 extensions using OpenSSL's
// config file syntax, from the OpenSSL command-line tool. They are retained,
// for now, for compatibility with legacy software but may be removed in the
// future. Construct the extensions using the typed C APIs instead.
//
// Callers should especially avoid these functions if passing in non-constant
// values. They use ad-hoc, string-based formats which are prone to injection
// vulnerabilities. For a CA, this means using them risks misissuance.
//
// These functions are not safe to use with untrusted inputs. The string formats
// may implicitly reference context information and, in OpenSSL (though not
// BoringSSL), one even allows reading arbitrary files. Many formats can also
// produce far larger outputs than their inputs, so untrusted inputs may lead to
// denial-of-service attacks. Finally, the parsers see much less testing and
// review than most of the library and may have bugs including memory leaks or
// crashes.

// v3_ext_ctx, aka |X509V3_CTX|, contains additional context information for
// constructing extensions. Some string formats reference additional values in
// these objects. It must be initialized with |X509V3_set_ctx| or
// |X509V3_set_ctx_test| before use.
struct v3_ext_ctx {
  int flags;
  const X509 *issuer_cert;
  const X509 *subject_cert;
  const X509_REQ *subject_req;
  const X509_CRL *crl;
  const CONF *db;
};

#define X509V3_CTX_TEST 0x1

// X509V3_set_ctx initializes |ctx| with the specified objects. Some string
// formats will reference fields in these objects. Each object may be NULL to
// omit it, in which case those formats cannot be used. |flags| should be zero,
// unless called via |X509V3_set_ctx_test|.
//
// |issuer|, |subject|, |req|, and |crl|, if non-NULL, must outlive |ctx|.
OPENSSL_EXPORT void X509V3_set_ctx(X509V3_CTX *ctx, const X509 *issuer,
                                   const X509 *subject, const X509_REQ *req,
                                   const X509_CRL *crl, int flags);

// X509V3_set_ctx_test calls |X509V3_set_ctx| without any reference objects and
// mocks out some features that use them. The resulting extensions may be
// incomplete and should be discarded. This can be used to partially validate
// syntax.
//
// TODO(davidben): Can we remove this?
#define X509V3_set_ctx_test(ctx) \
  X509V3_set_ctx(ctx, NULL, NULL, NULL, NULL, X509V3_CTX_TEST)

// X509V3_set_nconf sets |ctx| to use |conf| as the config database. |ctx| must
// have previously been initialized by |X509V3_set_ctx| or
// |X509V3_set_ctx_test|. Some string formats will reference sections in |conf|.
// |conf| may be NULL, in which case these formats cannot be used. If non-NULL,
// |conf| must outlive |ctx|.
OPENSSL_EXPORT void X509V3_set_nconf(X509V3_CTX *ctx, const CONF *conf);

// X509V3_set_ctx_nodb calls |X509V3_set_nconf| with no config database.
#define X509V3_set_ctx_nodb(ctx) X509V3_set_nconf(ctx, NULL)

// X509V3_EXT_nconf constructs an extension of type specified by |name|, and
// value specified by |value|. It returns a newly-allocated |X509_EXTENSION|
// object on success, or NULL on error. |conf| and |ctx| specify additional
// information referenced by some formats. Either |conf| or |ctx| may be NULL,
// in which case features which use it will be disabled.
//
// If non-NULL, |ctx| must be initialized with |X509V3_set_ctx| or
// |X509V3_set_ctx_test|.
//
// Both |conf| and |ctx| provide a |CONF| object. When |ctx| is non-NULL, most
// features use the |ctx| copy, configured with |X509V3_set_ctx|, but some use
// |conf|. Callers should ensure the two match to avoid surprisingly behavior.
OPENSSL_EXPORT X509_EXTENSION *X509V3_EXT_nconf(const CONF *conf,
                                                const X509V3_CTX *ctx,
                                                const char *name,
                                                const char *value);

// X509V3_EXT_nconf_nid behaves like |X509V3_EXT_nconf|, except the extension
// type is specified as a NID.
OPENSSL_EXPORT X509_EXTENSION *X509V3_EXT_nconf_nid(const CONF *conf,
                                                    const X509V3_CTX *ctx,
                                                    int ext_nid,
                                                    const char *value);

// X509V3_EXT_conf_nid calls |X509V3_EXT_nconf_nid|. |conf| must be NULL.
//
// TODO(davidben): This and |X509V3_EXT_conf| are the only exposed instance of
// |LHASH| in our public headers. cryptography.io wraps this function so we
// cannot replace the type with a dummy struct.
OPENSSL_EXPORT X509_EXTENSION *X509V3_EXT_conf_nid(LHASH_OF(CONF_VALUE) *conf,
                                                   const X509V3_CTX *ctx,
                                                   int ext_nid,
                                                   const char *value);

// X509V3_EXT_conf calls |X509V3_EXT_nconf|. |conf| must be NULL.
//
// NOTE: This is only provided for compatibility. See |X509V3_EXT_nconf|
// instead.
OPENSSL_EXPORT X509_EXTENSION *X509V3_EXT_conf(LHASH_OF(CONF_VALUE) *conf,
                                               X509V3_CTX *ctx,
                                               const char *name,
                                               const char *value);


// X509V3_EXT_add_nconf_sk looks up the section named |section| in |conf|. For
// each |CONF_VALUE| in the section, it constructs an extension as in
// |X509V3_EXT_nconf|, taking |name| and |value| from the |CONF_VALUE|. Each new
// extension is appended to |*sk|. If |*sk| is non-NULL, and at least one
// extension is added, it sets |*sk| to a newly-allocated
// |STACK_OF(X509_EXTENSION)|. It returns one on success and zero on error.
OPENSSL_EXPORT int X509V3_EXT_add_nconf_sk(const CONF *conf,
                                           const X509V3_CTX *ctx,
                                           const char *section,
                                           STACK_OF(X509_EXTENSION) **sk);

// X509V3_EXT_add_nconf adds extensions to |cert| as in
// |X509V3_EXT_add_nconf_sk|. It returns one on success and zero on error.
OPENSSL_EXPORT int X509V3_EXT_add_nconf(const CONF *conf, const X509V3_CTX *ctx,
                                        const char *section, X509 *cert);

// X509V3_EXT_REQ_add_nconf adds extensions to |req| as in
// |X509V3_EXT_add_nconf_sk|. It returns one on success and zero on error.
OPENSSL_EXPORT int X509V3_EXT_REQ_add_nconf(const CONF *conf,
                                            const X509V3_CTX *ctx,
                                            const char *section, X509_REQ *req);

// X509V3_EXT_CRL_add_nconf adds extensions to |crl| as in
// |X509V3_EXT_add_nconf_sk|. It returns one on success and zero on error.
OPENSSL_EXPORT int X509V3_EXT_CRL_add_nconf(const CONF *conf,
                                            const X509V3_CTX *ctx,
                                            const char *section, X509_CRL *crl);


OPENSSL_EXPORT char *i2s_ASN1_INTEGER(const X509V3_EXT_METHOD *meth,
                                      const ASN1_INTEGER *aint);
OPENSSL_EXPORT ASN1_INTEGER *s2i_ASN1_INTEGER(const X509V3_EXT_METHOD *meth,
                                              const char *value);
OPENSSL_EXPORT char *i2s_ASN1_ENUMERATED(const X509V3_EXT_METHOD *meth,
                                         const ASN1_ENUMERATED *aint);

// X509V3_EXT_add registers |ext| as a custom extension for the extension type
// |ext->ext_nid|. |ext| must be valid for the remainder of the address space's
// lifetime. It returns one on success and zero on error.
//
// WARNING: This function modifies global state. If other code in the same
// address space also registers an extension with type |ext->ext_nid|, the two
// registrations will conflict. Which registration takes effect is undefined. If
// the two registrations use incompatible in-memory representations, code
// expecting the other registration will then cast a type to the wrong type,
// resulting in a potentially exploitable memory error. This conflict can also
// occur if BoringSSL later adds support for |ext->ext_nid|, with a different
// in-memory representation than the one expected by |ext|.
//
// This function, additionally, is not thread-safe and cannot be called
// concurrently with any other BoringSSL function.
//
// As a result, it is impossible to safely use this function. Registering a
// custom extension has no impact on certificate verification so, instead,
// callers should simply handle the custom extension with the byte-based
// |X509_EXTENSION| APIs directly. Registering |ext| with the library has little
// practical value.
OPENSSL_EXPORT OPENSSL_DEPRECATED int X509V3_EXT_add(X509V3_EXT_METHOD *ext);

// X509V3_EXT_add_list calls |X509V3_EXT_add| on |&extlist[0]|, |&extlist[1]|,
// and so on, until some |extlist[i]->ext_nid| is -1. It returns one on success
// and zero on error.
//
// WARNING: Do not use this function. See |X509V3_EXT_add|.
OPENSSL_EXPORT int X509V3_EXT_add_list(X509V3_EXT_METHOD *extlist);

// X509V3_EXT_add_alias registers a custom extension with NID |nid_to|. The
// corresponding ASN.1 type is copied from |nid_from|. It returns one on success
// and zero on error.
//
// WARNING: Do not use this function. See |X509V3_EXT_add|.
OPENSSL_EXPORT OPENSSL_DEPRECATED int X509V3_EXT_add_alias(int nid_to,
                                                           int nid_from);

// X509V3_EXT_cleanup removes all custom extensions registered with
// |X509V3_EXT_add*|.
//
// WARNING: This function modifies global state and will impact custom
// extensions registered by any code in the same address space. It,
// additionally, is not thread-safe and cannot be called concurrently with any
// other BoringSSL function.
//
// Instead of calling this function, allow memory from custom extensions to be
// released on process exit, along with other global program state.
OPENSSL_EXPORT void X509V3_EXT_cleanup(void);

OPENSSL_EXPORT const X509V3_EXT_METHOD *X509V3_EXT_get(
    const X509_EXTENSION *ext);
OPENSSL_EXPORT const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid);
OPENSSL_EXPORT int X509V3_add_standard_extensions(void);
OPENSSL_EXPORT STACK_OF(CONF_VALUE) *X509V3_parse_list(const char *line);

// X509V3_EXT_d2i decodes |ext| and returns a pointer to a newly-allocated
// structure, with type dependent on the type of the extension. It returns NULL
// if |ext| is an unsupported extension or if there was a syntax error in the
// extension. The caller should cast the return value to the expected type and
// free the structure when done.
//
// WARNING: Casting the return value to the wrong type is a potentially
// exploitable memory error, so callers must not use this function before
// checking |ext| is of a known type.
OPENSSL_EXPORT void *X509V3_EXT_d2i(const X509_EXTENSION *ext);

// X509V3_get_d2i finds and decodes the extension in |extensions| of type |nid|.
// If found, it decodes it and returns a newly-allocated structure, with type
// dependent on |nid|. If the extension is not found or on error, it returns
// NULL. The caller may distinguish these cases using the |out_critical| value.
//
// If |out_critical| is not NULL, this function sets |*out_critical| to one if
// the extension is found and critical, zero if it is found and not critical, -1
// if it is not found, and -2 if there is an invalid duplicate extension. Note
// this function may set |*out_critical| to one or zero and still return NULL if
// the extension is found but has a syntax error.
//
// If |out_idx| is not NULL, this function looks for the first occurrence of the
// extension after |*out_idx|. It then sets |*out_idx| to the index of the
// extension, or -1 if not found. If |out_idx| is non-NULL, duplicate extensions
// are not treated as an error. Callers, however, should not rely on this
// behavior as it may be removed in the future. Duplicate extensions are
// forbidden in RFC 5280.
//
// WARNING: This function is difficult to use correctly. Callers should pass a
// non-NULL |out_critical| and check both the return value and |*out_critical|
// to handle errors. If the return value is NULL and |*out_critical| is not -1,
// there was an error. Otherwise, the function succeeded and but may return NULL
// for a missing extension. Callers should pass NULL to |out_idx| so that
// duplicate extensions are handled correctly.
//
// Additionally, casting the return value to the wrong type is a potentially
// exploitable memory error, so callers must ensure the cast and |nid| match.
OPENSSL_EXPORT void *X509V3_get_d2i(const STACK_OF(X509_EXTENSION) *extensions,
                                    int nid, int *out_critical, int *out_idx);

// X509V3_EXT_free casts |ext_data| into the type that corresponds to |nid| and
// releases memory associated with it. It returns one on success and zero if
// |nid| is not a known extension.
//
// WARNING: Casting |ext_data| to the wrong type is a potentially exploitable
// memory error, so callers must ensure |ext_data|'s type matches |nid|.
//
// TODO(davidben): OpenSSL upstream no longer exposes this function. Remove it?
OPENSSL_EXPORT int X509V3_EXT_free(int nid, void *ext_data);

// X509V3_EXT_i2d casts |ext_struc| into the type that corresponds to
// |ext_nid|, serializes it, and returns a newly-allocated |X509_EXTENSION|
// object containing the serialization, or NULL on error. The |X509_EXTENSION|
// has OID |ext_nid| and is critical if |crit| is one.
//
// WARNING: Casting |ext_struc| to the wrong type is a potentially exploitable
// memory error, so callers must ensure |ext_struct|'s type matches |ext_nid|.
OPENSSL_EXPORT X509_EXTENSION *X509V3_EXT_i2d(int ext_nid, int crit,
                                              void *ext_struc);

// The following constants control the behavior of |X509V3_add1_i2d| and related
// functions.

// X509V3_ADD_OP_MASK can be ANDed with the flags to determine how duplicate
// extensions are processed.
#define X509V3_ADD_OP_MASK 0xfL

// X509V3_ADD_DEFAULT causes the function to fail if the extension was already
// present.
#define X509V3_ADD_DEFAULT 0L

// X509V3_ADD_APPEND causes the function to unconditionally appended the new
// extension to to the extensions list, even if there is a duplicate.
#define X509V3_ADD_APPEND 1L

// X509V3_ADD_REPLACE causes the function to replace the existing extension, or
// append if it is not present.
#define X509V3_ADD_REPLACE 2L

// X509V3_ADD_REPLACE_EXISTING causes the function to replace the existing extension and
// fail if it is not present.
#define X509V3_ADD_REPLACE_EXISTING 3L

// X509V3_ADD_KEEP_EXISTING causes the function to succeed without replacing the
// extension if already present.
#define X509V3_ADD_KEEP_EXISTING 4L

// X509V3_ADD_DELETE causes the function to remove the matching extension. No
// new extension is added. If there is no matching extension, the function
// fails. The |value| parameter is ignored in this mode.
#define X509V3_ADD_DELETE 5L

// X509V3_ADD_SILENT may be ORed into one of the values above to indicate the
// function should not add to the error queue on duplicate or missing extension.
// The function will continue to return zero in those cases, and it will
// continue to return -1 and add to the error queue on other errors.
#define X509V3_ADD_SILENT 0x10

// X509V3_add1_i2d casts |value| to the type that corresponds to |nid|,
// serializes it, and appends it to the extension list in |*x|. If |*x| is NULL,
// it will set |*x| to a newly-allocated |STACK_OF(X509_EXTENSION)| as needed.
// The |crit| parameter determines whether the new extension is critical.
// |flags| may be some combination of the |X509V3_ADD_*| constants to control
// the function's behavior on duplicate extension.
//
// This function returns one on success, zero if the operation failed due to a
// missing or duplicate extension, and -1 on other errors.
//
// WARNING: Casting |value| to the wrong type is a potentially exploitable
// memory error, so callers must ensure |value|'s type matches |nid|.
OPENSSL_EXPORT int X509V3_add1_i2d(STACK_OF(X509_EXTENSION) **x, int nid,
                                   void *value, int crit, unsigned long flags);

#define X509V3_EXT_UNKNOWN_MASK (0xfL << 16)

// X509V3_EXT_DEFAULT causes unknown extensions or syntax errors to return
// failure.
#define X509V3_EXT_DEFAULT 0
// X509V3_EXT_ERROR_UNKNOWN causes unknown extensions or syntax errors to print
// as "<Not Supported>" or "<Parse Error>", respectively.
#define X509V3_EXT_ERROR_UNKNOWN (1L << 16)
// X509V3_EXT_PARSE_UNKNOWN is deprecated and behaves like
// |X509V3_EXT_DUMP_UNKNOWN|.
#define X509V3_EXT_PARSE_UNKNOWN (2L << 16)
// X509V3_EXT_DUMP_UNKNOWN causes unknown extensions to be displayed as a
// hexdump.
#define X509V3_EXT_DUMP_UNKNOWN (3L << 16)

OPENSSL_EXPORT void X509V3_EXT_val_prn(BIO *out,
                                       const STACK_OF(CONF_VALUE) *val,
                                       int indent, int ml);
OPENSSL_EXPORT int X509V3_EXT_print(BIO *out, const X509_EXTENSION *ext,
                                    unsigned long flag, int indent);
OPENSSL_EXPORT int X509V3_EXT_print_fp(FILE *out, const X509_EXTENSION *ext,
                                       int flag, int indent);

// X509V3_extensions_print prints |title|, followed by a human-readable
// representation of |exts| to |out|. It returns one on success and zero on
// error. The output is indented by |indent| spaces. |flag| is one of the
// |X509V3_EXT_*| constants and controls printing of unknown extensions and
// syntax errors.
OPENSSL_EXPORT int X509V3_extensions_print(BIO *out, const char *title,
                                           const STACK_OF(X509_EXTENSION) *exts,
                                           unsigned long flag, int indent);

OPENSSL_EXPORT int X509_check_ca(X509 *x);
OPENSSL_EXPORT int X509_check_purpose(X509 *x, int id, int ca);
OPENSSL_EXPORT int X509_supported_extension(const X509_EXTENSION *ex);
OPENSSL_EXPORT int X509_PURPOSE_set(int *p, int purpose);
OPENSSL_EXPORT int X509_check_issued(X509 *issuer, X509 *subject);
OPENSSL_EXPORT int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid);

OPENSSL_EXPORT uint32_t X509_get_extension_flags(X509 *x);
OPENSSL_EXPORT uint32_t X509_get_key_usage(X509 *x);
OPENSSL_EXPORT uint32_t X509_get_extended_key_usage(X509 *x);

// X509_get0_subject_key_id returns |x509|'s subject key identifier, if present.
// (See RFC 5280, section 4.2.1.2.) It returns NULL if the extension is not
// present or if some extension in |x509| was invalid.
//
// Note that decoding an |X509| object will not check for invalid extensions. To
// detect the error case, call |X509_get_extensions_flags| and check the
// |EXFLAG_INVALID| bit.
OPENSSL_EXPORT const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x509);

// X509_get0_authority_key_id returns keyIdentifier of |x509|'s authority key
// identifier, if the extension and field are present. (See RFC 5280,
// section 4.2.1.1.) It returns NULL if the extension is not present, if it is
// present but lacks a keyIdentifier field, or if some extension in |x509| was
// invalid.
//
// Note that decoding an |X509| object will not check for invalid extensions. To
// detect the error case, call |X509_get_extensions_flags| and check the
// |EXFLAG_INVALID| bit.
OPENSSL_EXPORT const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x509);

// X509_get0_authority_issuer returns the authorityCertIssuer of |x509|'s
// authority key identifier, if the extension and field are present. (See
// RFC 5280, section 4.2.1.1.) It returns NULL if the extension is not present,
// if it is present but lacks a authorityCertIssuer field, or if some extension
// in |x509| was invalid.
//
// Note that decoding an |X509| object will not check for invalid extensions. To
// detect the error case, call |X509_get_extensions_flags| and check the
// |EXFLAG_INVALID| bit.
OPENSSL_EXPORT const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x509);

// X509_get0_authority_serial returns the authorityCertSerialNumber of |x509|'s
// authority key identifier, if the extension and field are present. (See
// RFC 5280, section 4.2.1.1.) It returns NULL if the extension is not present,
// if it is present but lacks a authorityCertSerialNumber field, or if some
// extension in |x509| was invalid.
//
// Note that decoding an |X509| object will not check for invalid extensions. To
// detect the error case, call |X509_get_extensions_flags| and check the
// |EXFLAG_INVALID| bit.
OPENSSL_EXPORT const ASN1_INTEGER *X509_get0_authority_serial(X509 *x509);

OPENSSL_EXPORT int X509_PURPOSE_get_count(void);
OPENSSL_EXPORT X509_PURPOSE *X509_PURPOSE_get0(int idx);
OPENSSL_EXPORT int X509_PURPOSE_get_by_sname(const char *sname);
OPENSSL_EXPORT int X509_PURPOSE_get_by_id(int id);
OPENSSL_EXPORT int X509_PURPOSE_add(int id, int trust, int flags,
                                    int (*ck)(const X509_PURPOSE *,
                                              const X509 *, int),
                                    const char *name, const char *sname,
                                    void *arg);
OPENSSL_EXPORT char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp);
OPENSSL_EXPORT char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp);
OPENSSL_EXPORT int X509_PURPOSE_get_trust(const X509_PURPOSE *xp);
OPENSSL_EXPORT void X509_PURPOSE_cleanup(void);
OPENSSL_EXPORT int X509_PURPOSE_get_id(const X509_PURPOSE *);

OPENSSL_EXPORT STACK_OF(OPENSSL_STRING) *X509_get1_email(X509 *x);
OPENSSL_EXPORT STACK_OF(OPENSSL_STRING) *X509_REQ_get1_email(X509_REQ *x);
OPENSSL_EXPORT void X509_email_free(STACK_OF(OPENSSL_STRING) *sk);
OPENSSL_EXPORT STACK_OF(OPENSSL_STRING) *X509_get1_ocsp(X509 *x);


// X509_check_* functions
//
// See https://www.openssl.org/docs/manmaster/man3/X509_check_host.html
// for more details.

// X509_CHECK_FLAG_NO_WILDCARDS disables wildcard matching for dnsName fields
// and common name. This only applies to |X509_check_host|.
#define X509_CHECK_FLAG_NO_WILDCARDS 0x2

// X509_CHECK_FLAG_NEVER_CHECK_SUBJECT skips the subject common name fallback
// if subjectAltNames is missing.
#define X509_CHECK_FLAG_NEVER_CHECK_SUBJECT 0x20

// X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS does nothing, but is necessary in
// OpenSSL to enable standard wildcard matching. In AWS-LC, this behavior is
// always enabled. This only applies to |X509_check_host| in OpenSSL.
#define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0

// X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT is deprecated and does nothing.
// Enabling this in OpenSSL considers the subject DN even if the certificate
// contains at least one subject alternative name of the right type; the
// default is to ignore the subject DN when at least one corresponding subject
// alternative names is present.
#define X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT 0

// X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS is deprecated and does nothing.
// This only applies to |X509_check_host|. When used in OpenSSL, it allows a
// "*" that constitutes the complete label of a DNS name (e.g.
// "*.example.com") to match more than one label in |chk|.
#define X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS 0

// X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS is deprecated and does nothing.
// This only applies to |X509_check_host|. When used in OpenSSL, it
// restricts name values which start with ".", that would otherwise match
// any sub-domain in the peer certificate, to only match direct child
// sub-domains.
#define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0

// X509_check_host checks if |x| has a Common Name or Subject Alternate name
// that matches the |chk| string up to |chklen|. If |chklen| is 0
// X509_check_host will calculate the length using strlen. It is encouraged to
// always pass in the length of |chk| and rely on higher level parsing to ensure
// strlen is not called on a string that does not contain a null terminator.
// If a match is found X509_check_host returns 1, if |peername| is not null
// it is updated to point to the matching name in |x|.
OPENSSL_EXPORT int X509_check_host(X509 *x, const char *chk, size_t chklen,
                                   unsigned int flags, char **peername);

// X509_check_email checks if the email address in |x| matches |chk| string up
// to |chklen|. If |chklen| is 0 X509_check_email will calculate the length
// using strlen. It is encouraged to always pass in the length of |chk| and rely
// on higher level parsing to ensure strlen is not called on a string that does
// not contain a null terminator. If the certificate matches X509_check_email
// returns 1.
OPENSSL_EXPORT int X509_check_email(X509 *x, const char *chk, size_t chklen,
                                    unsigned int flags);

// X509_check_ip checks if the IPv4 or IPv6 address in |x| matches |chk| up
// to |chklen|. X509_check_ip does not attempt to determine the length of |chk|
// if 0 is passed in for |chklen|. If the certificate matches X509_check_ip
// returns 1.
OPENSSL_EXPORT int X509_check_ip(X509 *x, const unsigned char *chk,
                                 size_t chklen, unsigned int flags);
OPENSSL_EXPORT int X509_check_ip_asc(X509 *x, const char *ipasc,
                                     unsigned int flags);

OPENSSL_EXPORT ASN1_OCTET_STRING *a2i_IPADDRESS(const char *ipasc);
OPENSSL_EXPORT ASN1_OCTET_STRING *a2i_IPADDRESS_NC(const char *ipasc);


#if defined(__cplusplus)
}  // extern C
#endif

#if !defined(BORINGSSL_NO_CXX)
extern "C++" {

BSSL_NAMESPACE_BEGIN

BORINGSSL_MAKE_DELETER(ACCESS_DESCRIPTION, ACCESS_DESCRIPTION_free)
BORINGSSL_MAKE_DELETER(AUTHORITY_KEYID, AUTHORITY_KEYID_free)
BORINGSSL_MAKE_DELETER(BASIC_CONSTRAINTS, BASIC_CONSTRAINTS_free)
// TODO(davidben): Move this to conf.h and rename to CONF_VALUE_free.
BORINGSSL_MAKE_DELETER(CONF_VALUE, X509V3_conf_free)
BORINGSSL_MAKE_DELETER(DIST_POINT, DIST_POINT_free)
BORINGSSL_MAKE_DELETER(GENERAL_NAME, GENERAL_NAME_free)
BORINGSSL_MAKE_DELETER(GENERAL_SUBTREE, GENERAL_SUBTREE_free)
BORINGSSL_MAKE_DELETER(NAME_CONSTRAINTS, NAME_CONSTRAINTS_free)
BORINGSSL_MAKE_DELETER(NETSCAPE_SPKI, NETSCAPE_SPKI_free)
BORINGSSL_MAKE_DELETER(POLICY_MAPPING, POLICY_MAPPING_free)
BORINGSSL_MAKE_DELETER(POLICYINFO, POLICYINFO_free)
BORINGSSL_MAKE_DELETER(RSA_PSS_PARAMS, RSA_PSS_PARAMS_free)
BORINGSSL_MAKE_DELETER(X509, X509_free)
BORINGSSL_MAKE_UP_REF(X509, X509_up_ref)
BORINGSSL_MAKE_DELETER(X509_ALGOR, X509_ALGOR_free)
BORINGSSL_MAKE_DELETER(X509_ATTRIBUTE, X509_ATTRIBUTE_free)
BORINGSSL_MAKE_DELETER(X509_CRL, X509_CRL_free)
BORINGSSL_MAKE_UP_REF(X509_CRL, X509_CRL_up_ref)
BORINGSSL_MAKE_DELETER(X509_EXTENSION, X509_EXTENSION_free)
BORINGSSL_MAKE_DELETER(X509_INFO, X509_INFO_free)
BORINGSSL_MAKE_DELETER(X509_LOOKUP, X509_LOOKUP_free)
BORINGSSL_MAKE_DELETER(X509_NAME, X509_NAME_free)
BORINGSSL_MAKE_DELETER(X509_NAME_ENTRY, X509_NAME_ENTRY_free)
BORINGSSL_MAKE_DELETER(X509_OBJECT, X509_OBJECT_free)
BORINGSSL_MAKE_DELETER(X509_PUBKEY, X509_PUBKEY_free)
BORINGSSL_MAKE_DELETER(X509_REQ, X509_REQ_free)
BORINGSSL_MAKE_DELETER(X509_REVOKED, X509_REVOKED_free)
BORINGSSL_MAKE_DELETER(X509_SIG, X509_SIG_free)
BORINGSSL_MAKE_DELETER(X509_STORE, X509_STORE_free)
BORINGSSL_MAKE_UP_REF(X509_STORE, X509_STORE_up_ref)
BORINGSSL_MAKE_DELETER(X509_STORE_CTX, X509_STORE_CTX_free)
BORINGSSL_MAKE_DELETER(X509_VERIFY_PARAM, X509_VERIFY_PARAM_free)

BSSL_NAMESPACE_END

}  // extern C++
#endif  // !BORINGSSL_NO_CXX

#define X509_R_AKID_MISMATCH 100
#define X509_R_BAD_PKCS7_VERSION 101
#define X509_R_BAD_X509_FILETYPE 102
#define X509_R_BASE64_DECODE_ERROR 103
#define X509_R_CANT_CHECK_DH_KEY 104
#define X509_R_CERT_ALREADY_IN_HASH_TABLE 105
#define X509_R_CRL_ALREADY_DELTA 106
#define X509_R_CRL_VERIFY_FAILURE 107
#define X509_R_IDP_MISMATCH 108
#define X509_R_INVALID_BIT_STRING_BITS_LEFT 109
#define X509_R_INVALID_DIRECTORY 110
#define X509_R_INVALID_FIELD_NAME 111
#define X509_R_INVALID_PSS_PARAMETERS 112
#define X509_R_INVALID_TRUST 113
#define X509_R_ISSUER_MISMATCH 114
#define X509_R_KEY_TYPE_MISMATCH 115
#define X509_R_KEY_VALUES_MISMATCH 116
#define X509_R_LOADING_CERT_DIR 117
#define X509_R_LOADING_DEFAULTS 118
#define X509_R_NEWER_CRL_NOT_NEWER 119
#define X509_R_NOT_PKCS7_SIGNED_DATA 120
#define X509_R_NO_CERTIFICATES_INCLUDED 121
#define X509_R_NO_CERT_SET_FOR_US_TO_VERIFY 122
#define X509_R_NO_CRLS_INCLUDED 123
#define X509_R_NO_CRL_NUMBER 124
#define X509_R_PUBLIC_KEY_DECODE_ERROR 125
#define X509_R_PUBLIC_KEY_ENCODE_ERROR 126
#define X509_R_SHOULD_RETRY 127
#define X509_R_UNKNOWN_KEY_TYPE 128
#define X509_R_UNKNOWN_NID 129
#define X509_R_UNKNOWN_PURPOSE_ID 130
#define X509_R_UNKNOWN_TRUST_ID 131
#define X509_R_UNSUPPORTED_ALGORITHM 132
#define X509_R_WRONG_LOOKUP_TYPE 133
#define X509_R_WRONG_TYPE 134
#define X509_R_NAME_TOO_LONG 135
#define X509_R_INVALID_PARAMETER 136
#define X509_R_SIGNATURE_ALGORITHM_MISMATCH 137
#define X509_R_DELTA_CRL_WITHOUT_CRL_NUMBER 138
#define X509_R_INVALID_FIELD_FOR_VERSION 139
#define X509_R_INVALID_VERSION 140
#define X509_R_NO_CERTIFICATE_FOUND 141
#define X509_R_NO_CERTIFICATE_OR_CRL_FOUND 142
#define X509_R_NO_CRL_FOUND 143
#define X509_R_INVALID_POLICY_EXTENSION 144
#define X509_R_UNKNOWN_SIGID_ALGS 145

#endif  // OPENSSL_HEADER_X509_H