test: add simple BIP-352 test with mixed plain/taproot inputs

src/modules/silentpayments/tests_impl.h

@@ -0,0 +1,117 @@
+/***********************************************************************
+ * Distributed under the MIT software license, see the accompanying    *
+ * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
+ ***********************************************************************/
+
+#ifndef SECP256K1_MODULE_SILENTPAYMENTS_TESTS_H
+#define SECP256K1_MODULE_SILENTPAYMENTS_TESTS_H
+
+#include "../../../include/secp256k1_silentpayments.h"
+
+void run_silentpayments_tests(void) {
+    /* BIP-352 test vector
+     * "Single recipient: taproot input with odd y-value and non-taproot input" */
+    unsigned char outpoint_lowest[36] = {
+        0x16,0x9e,0x1e,0x83,0xe9,0x30,0x85,0x33,0x91,0xbc,0x6f,0x35,0xf6,0x05,0xc6,0x75,
+        0x4c,0xfe,0xad,0x57,0xcf,0x83,0x87,0x63,0x9d,0x3b,0x40,0x96,0xc5,0x4f,0x18,0xf4,
+        0x00,0x00,0x00,0x00
+    };
+    unsigned char input_privkey_plain0[32] = {
+        0x8d,0x47,0x51,0xf6,0xe8,0xa3,0x58,0x68,0x80,0xfb,0x66,0xc1,0x9a,0xe2,0x77,0x96,
+        0x9b,0xd5,0xaa,0x06,0xf6,0x1c,0x4e,0xe2,0xf1,0xe2,0x48,0x6e,0xfd,0xf6,0x66,0xd3
+    };
+    unsigned char input_privkey_taproot0[32] = {
+        0x1d,0x37,0x78,0x7c,0x2b,0x71,0x16,0xee,0x98,0x3e,0x9f,0x9c,0x13,0x26,0x9d,0xf2,
+        0x90,0x91,0xb3,0x91,0xc0,0x4d,0xb9,0x42,0x39,0xe0,0xd2,0xbc,0x21,0x82,0xc3,0xbf
+    };
+    const unsigned char* input_privkeys_plain[1];
+    const unsigned char* input_privkeys_taproot[1];
+    unsigned char input_pubkey_plain0[33] = {0x03,
+        0xe0,0xec,0x4f,0x64,0xb3,0xfa,0x2e,0x46,0x3c,0xcf,0xcf,0x4e,0x85,0x6e,0x37,0xd5,
+        0xe1,0xe2,0x02,0x75,0xbc,0x89,0xec,0x1d,0xef,0x9e,0xb0,0x98,0xef,0xf1,0xf8,0x5d
+    };
+    unsigned char input_pubkey_xonly0[32] = {
+        0x8c,0x8d,0x23,0xd4,0x76,0x4f,0xef,0xfc,0xd5,0xe7,0x2e,0x38,0x08,0x02,0x54,0x0f,
+        0xa0,0xf8,0x8e,0x3d,0x62,0xad,0x5e,0x0b,0x47,0x95,0x5f,0x74,0xd7,0xb2,0x83,0xc4
+    };
+    const secp256k1_pubkey* input_pubkeys_plain[1];
+    const secp256k1_xonly_pubkey* input_pubkeys_xonly[1];
+    unsigned char receiver_scan_privkey[32] = {
+        0x0f,0x69,0x4e,0x06,0x80,0x28,0xa7,0x17,0xf8,0xaf,0x6b,0x94,0x11,0xf9,0xa1,0x33,
+        0xdd,0x35,0x65,0x25,0x87,0x14,0xcc,0x22,0x65,0x94,0xb3,0x4d,0xb9,0x0c,0x1f,0x2c
+    };
+    unsigned char receiver_scan_pubkey[33] = {0x02,
+        0x20,0xbc,0xfa,0xc5,0xb9,0x9e,0x04,0xad,0x1a,0x06,0xdd,0xfb,0x01,0x6e,0xe1,0x35,
+        0x82,0x60,0x9d,0x60,0xb6,0x29,0x1e,0x98,0xd0,0x1a,0x9b,0xc9,0xa1,0x6c,0x96,0xd4
+    };
+    unsigned char receiver_spend_privkey[32] = {
+        0x9d,0x6a,0xd8,0x55,0xce,0x34,0x17,0xef,0x84,0xe8,0x36,0x89,0x2e,0x5a,0x56,0x39,
+        0x2b,0xfb,0xa0,0x5f,0xa5,0xd9,0x7c,0xce,0xa3,0x0e,0x26,0x6f,0x54,0x0e,0x08,0xb3
+    };
+    unsigned char receiver_spend_pubkey[33] = {0x02,
+        0x5c,0xc9,0x85,0x6d,0x6f,0x83,0x75,0x35,0x0e,0x12,0x39,0x78,0xda,0xac,0x20,0x0c,
+        0x26,0x0c,0xb5,0xb5,0xae,0x83,0x10,0x6c,0xab,0x90,0x48,0x4d,0xcd,0x8f,0xcf,0x36
+    };
+    unsigned char output_expected[32] = {
+        0x35,0x93,0x58,0xf5,0x9e,0xe9,0xe9,0xee,0xc3,0xf0,0x0b,0xdf,0x48,0x82,0x57,0x0f,
+        0xd5,0xc1,0x82,0xe4,0x51,0xaa,0x26,0x50,0xb7,0x88,0x54,0x4a,0xff,0x01,0x2a,0x3a
+    };
+    unsigned char privkey_tweak_expected[32] = {
+        0xa2,0xf9,0xdd,0x05,0xd1,0xd3,0x98,0x34,0x7c,0x88,0x5d,0x9c,0x61,0xa6,0x4d,0x18,
+        0xa2,0x64,0xde,0x6d,0x49,0xce,0xa4,0x32,0x6b,0xaf,0xc2,0x79,0x1d,0x62,0x7f,0xa7
+    };
+
+    unsigned char shared_secret_sender[33];
+    unsigned char shared_secret_receiver[33];
+    secp256k1_pubkey public_keys_sum;
+    unsigned char private_keys_sum[32];
+    unsigned char input_hash1[32];
+    unsigned char input_hash2[32];
+    secp256k1_xonly_pubkey output_expected_xonly_obj;
+    secp256k1_xonly_pubkey output_calculated_xonly_obj;
+    unsigned char output_calculated[32];
+    unsigned char privkey_calculated[32];
+    unsigned char privkey_expected[32];
+
+    /* convert raw key material into secp256k1 objects where necessary */
+    secp256k1_pubkey input_pubkey_plain_obj, receiver_scan_pubkey_obj, receiver_spend_pubkey_obj;
+    secp256k1_xonly_pubkey input_pubkey_xonly_obj;
+    CHECK(secp256k1_ec_pubkey_parse(CTX, &input_pubkey_plain_obj, input_pubkey_plain0, 33));
+    CHECK(secp256k1_ec_pubkey_parse(CTX, &receiver_scan_pubkey_obj, receiver_scan_pubkey, 33));
+    CHECK(secp256k1_ec_pubkey_parse(CTX, &receiver_spend_pubkey_obj, receiver_spend_pubkey, 33));
+    CHECK(secp256k1_xonly_pubkey_parse(CTX, &input_pubkey_xonly_obj, input_pubkey_xonly0));
+    CHECK(secp256k1_xonly_pubkey_parse(CTX, &output_expected_xonly_obj, output_expected));
+    input_pubkeys_plain[0] = &input_pubkey_plain_obj;
+    input_pubkeys_xonly[0] = &input_pubkey_xonly_obj;
+
+    /* create shared secret from sender and receiver perspective, and check that they match */
+    input_privkeys_plain[0] = input_privkey_plain0;
+    input_privkeys_taproot[0] = input_privkey_taproot0;
+    CHECK(secp256k1_silentpayments_create_private_tweak_data(CTX, private_keys_sum, input_hash1,
+        input_privkeys_plain, 1, input_privkeys_taproot, 1, outpoint_lowest));
+    CHECK(secp256k1_silentpayments_create_shared_secret(CTX, shared_secret_sender,
+        &receiver_scan_pubkey_obj, private_keys_sum, input_hash1));
+
+    CHECK(secp256k1_silentpayments_create_public_tweak_data(CTX, &public_keys_sum, input_hash2,
+        input_pubkeys_plain, 1, input_pubkeys_xonly, 1, outpoint_lowest));
+    CHECK(secp256k1_silentpayments_create_shared_secret(CTX, shared_secret_receiver,
+        &public_keys_sum, receiver_scan_privkey, input_hash2));
+
+    CHECK(secp256k1_memcmp_var(input_hash1, input_hash2, 32) == 0);
+    CHECK(secp256k1_memcmp_var(shared_secret_sender, shared_secret_receiver, 33) == 0);
+
+    /* check that calculated silent payments output matches */
+    CHECK(secp256k1_silentpayments_create_output_pubkey(CTX, &output_calculated_xonly_obj, NULL,
+        shared_secret_sender, &receiver_spend_pubkey_obj, 0));
+    CHECK(secp256k1_xonly_pubkey_serialize(CTX, output_calculated, &output_calculated_xonly_obj));
+    CHECK(secp256k1_memcmp_var(output_calculated, output_expected, 32) == 0);
+
+    /* check that calculated silent payment output spending private key matches */
+    memcpy(privkey_expected, receiver_spend_privkey, 32);
+    CHECK(secp256k1_ec_seckey_tweak_add(CTX, privkey_expected, privkey_tweak_expected));
+    CHECK(secp256k1_silentpayments_create_output_seckey(CTX, privkey_calculated,
+        shared_secret_receiver, receiver_spend_privkey, 0, NULL));
+    CHECK(secp256k1_memcmp_var(privkey_calculated, privkey_expected, 32) == 0);
+}
+
+#endif

src/tests.c

@@ -7285,6 +7285,10 @@ static void run_ecdsa_wycheproof(void) {
 # include "modules/ellswift/tests_impl.h"
 #endif
 
+#ifdef ENABLE_MODULE_SILENTPAYMENTS
+# include "modules/silentpayments/tests_impl.h"
+#endif
+
 static void run_secp256k1_memczero_test(void) {
     unsigned char buf1[6] = {1, 2, 3, 4, 5, 6};
     unsigned char buf2[sizeof(buf1)];
@@ -7633,6 +7637,10 @@ int main(int argc, char **argv) {
     run_ellswift_tests();
 #endif
 
+#ifdef ENABLE_MODULE_SILENTPAYMENTS
+    run_silentpayments_tests();
+#endif
+
     /* util tests */
     run_secp256k1_memczero_test();
     run_secp256k1_byteorder_tests();