Prepare 2.2.0

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rustls-pemfile"
-version = "2.1.3"
+version = "2.2.0"
 edition = "2018"
 license = "Apache-2.0 OR ISC OR MIT"
 readme = "README.md"

README.md

@@ -8,6 +8,30 @@ poor and doing so doesn't address a meaningful threat model.
 [![Crate](https://img.shields.io/crates/v/rustls-pemfile.svg)](https://crates.io/crates/rustls-pemfile)
 [![Documentation](https://docs.rs/rustls-pemfile/badge.svg)](https://docs.rs/rustls-pemfile/)
 
+# See also: rustls-pki-types
+
+The main function of this crate has been incorporated into
+[rustls-pki-types](https://crates.io/crates/rustls-pki-types). 2.2.0 maintains the
+existing public API for this crate, on top of this new implementation. This drops
+the dependency on the `base64` crate, and allows for constant-time decoding of private keys.
+
+This crate will continue to exist in its current form, but it is somewhat unlikely that the
+API will be extended from its current state.
+
+Should you wish to migrate to using the new [`rustls-pki-types` PEM APIs](https://docs.rs/rustls-pki-types/latest/rustls_pki_types/pem/trait.PemObject.html)
+directly, here is a rough cheat-sheet:
+
+| *Use case* | *Replace* |
+|---|---|
+| File stream to `CertificateDer` iterator |`rustls_pemfile::certs(io::BufRead)` <br>  ➡️ <br> `CertificateDer::pem_reader_iter(io::Read)` |
+| File stream to one `PrivateKeyDer` | `rustls_pemfile::private_key(io::BufRead)` <br> ➡️  <br> `PrivateKeyDer::from_pem_reader(io::Read)` |
+| File stream to one `CertificateSigningRequestDer` | `rustls_pemfile::csr(io::BufRead)` <br> ➡️  <br> `CertificateSigningRequestDer::from_pem_reader(io::Read)` |
+| File stream to `CertificateRevocationListDer` iterator |`rustls_pemfile::crls(io::BufRead)` <br>  ➡️ <br> `CertificateRevocationListDer::pem_reader_iter(io::Read)` |
+| File stream to `PrivatePkcs1KeyDer` iterator |`rustls_pemfile::rsa_private_keys(io::BufRead)` <br>  ➡️ <br> `PrivatePkcs1KeyDer::pem_reader_iter(io::Read)` |
+| File stream to `PrivatePkcs8KeyDer` iterator |`rustls_pemfile::pkcs8_private_keys(io::BufRead)` <br>  ➡️ <br> `PrivatePkcs8KeyDer::pem_reader_iter(io::Read)` |
+| File stream to `PrivateSec1KeyDer` iterator |`rustls_pemfile::ec_private_keys(io::BufRead)` <br>  ➡️ <br> `PrivateSec1KeyDer::pem_reader_iter(io::Read)` |
+| File stream to `SubjectPublicKeyInfoDer` iterator |`rustls_pemfile::public_keys(io::BufRead)` <br>  ➡️ <br> `SubjectPublicKeyInfoDer::pem_reader_iter(io::Read)` |
+
 # Changelog
 
 The detailed list of changes in each release can be found at