Merge #180: musig: add test vectors for applying multiple tweaks

510b61a musig: add test vectors for applying multiple tweaks (Jonas Nick)

Pull request description:

ACKs for top commit:
  real-or-random:
    utACK 510b61a
  robot-dreams:
    utACK 510b61a

Tree-SHA512: 5fed7e01f23c0c7d1526bd9f89c5f385ad95ab1f0331df6e5bc7710e4d9f4f3860a5fd63adb7adda0a57e5fcf6204ccb941232ceb26eae44cb74f0916963d674

Author: real-or-random

src/modules/musig/tests_impl.h

@@ -1143,7 +1143,7 @@ void musig_test_vectors_noncegen(void) {
     }
 }
 
-void musig_test_vectors_sign_helper(secp256k1_musig_keyagg_cache *keyagg_cache, int *fin_nonce_parity, unsigned char *sig, const unsigned char *secnonce_bytes, const unsigned char *agg_pubnonce_ser, const unsigned char *sk, const unsigned char *msg, const unsigned char *tweak, int xonly_tweak, const secp256k1_pubkey *adaptor, const unsigned char **pk_ser, int signer_pos) {
+void musig_test_vectors_sign_helper(secp256k1_musig_keyagg_cache *keyagg_cache, int *fin_nonce_parity, unsigned char *sig, const unsigned char *secnonce_bytes, const unsigned char *agg_pubnonce_ser, const unsigned char *sk, const unsigned char *msg, const unsigned char tweak[][32], const int *is_xonly_t, int n_tweaks, const secp256k1_pubkey *adaptor, const unsigned char **pk_ser, int signer_pos) {
     secp256k1_keypair signer_keypair;
     secp256k1_musig_secnonce secnonce;
     secp256k1_xonly_pubkey pk[3];
@@ -1163,11 +1163,11 @@ void musig_test_vectors_sign_helper(secp256k1_musig_keyagg_cache *keyagg_cache,
         pk_ptr[i] = &pk[i];
     }
     CHECK(secp256k1_musig_pubkey_agg(ctx, NULL, &agg_pk, keyagg_cache, pk_ptr, 3) == 1);
-    if (tweak != NULL) {
-        if (xonly_tweak) {
-            CHECK(secp256k1_musig_pubkey_xonly_tweak_add(ctx, NULL, keyagg_cache, tweak) == 1);
+    for (i = 0; i < n_tweaks; i++) {
+        if (is_xonly_t[i]) {
+            CHECK(secp256k1_musig_pubkey_xonly_tweak_add(ctx, NULL, keyagg_cache, tweak[i]) == 1);
         } else {
-            CHECK(secp256k1_musig_pubkey_ec_tweak_add(ctx, NULL, keyagg_cache, tweak) == 1);
+            CHECK(secp256k1_musig_pubkey_ec_tweak_add(ctx, NULL, keyagg_cache, tweak[i]) == 1);
         }
     }
     memcpy(&secnonce.data[0], secp256k1_musig_secnonce_magic, 4);
@@ -1247,7 +1247,7 @@ void musig_test_vectors_sign(void) {
             0x20, 0xA1, 0x81, 0x85, 0x5F, 0xD8, 0xBD, 0xB7,
             0xF1, 0x27, 0xBB, 0x12, 0x40, 0x3B, 0x4D, 0x3B,
         };
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, 0, NULL, pk, 0);
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, NULL, 0, NULL, pk, 0);
         /* TODO: remove when test vectors are not expected to change anymore */
         /* int k, l; */
         /* printf("const unsigned char sig_expected[32] = {\n"); */
@@ -1276,7 +1276,7 @@ void musig_test_vectors_sign(void) {
             0x81, 0x38, 0xDA, 0xEC, 0x5C, 0xB2, 0x0A, 0x35,
             0x7C, 0xEC, 0xA7, 0xC8, 0x42, 0x42, 0x95, 0xEA,
         };
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, 0, NULL, pk, 1);
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, NULL, 0, NULL, pk, 1);
         /* Check that the description of the test vector is correct */
         CHECK(musig_test_pk_parity(&keyagg_cache) == 0);
         CHECK(musig_test_is_second_pk(&keyagg_cache, sk));
@@ -1292,7 +1292,7 @@ void musig_test_vectors_sign(void) {
             0xE6, 0xA7, 0xF7, 0xFB, 0xE1, 0x5C, 0xDC, 0xAF,
             0xA4, 0xA3, 0xD1, 0xBC, 0xAA, 0xBC, 0x75, 0x17,
         };
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, 0, NULL, pk, 2);
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, NULL, 0, NULL, pk, 2);
         /* Check that the description of the test vector is correct */
         CHECK(musig_test_pk_parity(&keyagg_cache) == 1);
         CHECK(fin_nonce_parity == 0);
@@ -1307,13 +1307,14 @@ void musig_test_vectors_sign(void) {
             0x15, 0x97, 0xF9, 0x60, 0x3D, 0x3A, 0xB0, 0x5B,
             0x49, 0x13, 0x64, 0x17, 0x75, 0xE1, 0x37, 0x5B,
         };
-        const unsigned char tweak[32] = {
+        const unsigned char tweak[1][32] = {{
             0xE8, 0xF7, 0x91, 0xFF, 0x92, 0x25, 0xA2, 0xAF,
             0x01, 0x02, 0xAF, 0xFF, 0x4A, 0x9A, 0x72, 0x3D,
             0x96, 0x12, 0xA6, 0x82, 0xA2, 0x5E, 0xBE, 0x79,
             0x80, 0x2B, 0x26, 0x3C, 0xDF, 0xCD, 0x83, 0xBB,
-        };
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, 1, NULL, pk, 2);
+        }};
+        int is_xonly_t[1] = { 1 };
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, is_xonly_t, 1, NULL, pk, 2);
 
         CHECK(musig_test_pk_parity(&keyagg_cache) == 1);
         CHECK(!musig_test_is_second_pk(&keyagg_cache, sk));
@@ -1328,19 +1329,91 @@ void musig_test_vectors_sign(void) {
             0x19, 0x5C, 0x1D, 0x4B, 0x52, 0xE6, 0x3E, 0xCD,
             0x7B, 0xC5, 0x99, 0x16, 0x44, 0xE4, 0x4D, 0xDD,
         };
-        const unsigned char tweak[32] = {
+        const unsigned char tweak[1][32] = {{
             0xE8, 0xF7, 0x91, 0xFF, 0x92, 0x25, 0xA2, 0xAF,
             0x01, 0x02, 0xAF, 0xFF, 0x4A, 0x9A, 0x72, 0x3D,
             0x96, 0x12, 0xA6, 0x82, 0xA2, 0x5E, 0xBE, 0x79,
             0x80, 0x2B, 0x26, 0x3C, 0xDF, 0xCD, 0x83, 0xBB,
-        };
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, 0, NULL, pk, 2);
+        }};
+        int is_xonly_t[1] = { 0 };
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, is_xonly_t, 1, NULL, pk, 2);
 
         CHECK(musig_test_pk_parity(&keyagg_cache) == 1);
         CHECK(!musig_test_is_second_pk(&keyagg_cache, sk));
         CHECK(fin_nonce_parity == 0);
         CHECK(memcmp(sig, sig_expected, 32) == 0);
     }
+    {
+       /* This is a test that includes an ordinary and an x-only public key tweak. */
+        const unsigned char sig_expected[32] = {
+            0xC3, 0xA8, 0x29, 0xA8, 0x14, 0x80, 0xE3, 0x6E,
+            0xC3, 0xAB, 0x05, 0x29, 0x64, 0x50, 0x9A, 0x94,
+            0xEB, 0xF3, 0x42, 0x10, 0x40, 0x3D, 0x16, 0xB2,
+            0x26, 0xA6, 0xF1, 0x6E, 0xC8, 0x5B, 0x73, 0x57,
+        };
+
+        const unsigned char tweak[2][32] = {
+            {
+                0xE8, 0xF7, 0x91, 0xFF, 0x92, 0x25, 0xA2, 0xAF,
+                0x01, 0x02, 0xAF, 0xFF, 0x4A, 0x9A, 0x72, 0x3D,
+                0x96, 0x12, 0xA6, 0x82, 0xA2, 0x5E, 0xBE, 0x79,
+                0x80, 0x2B, 0x26, 0x3C, 0xDF, 0xCD, 0x83, 0xBB,
+            },
+            {
+                0xAE, 0x2E, 0xA7, 0x97, 0xCC, 0x0F, 0xE7, 0x2A,
+                0xC5, 0xB9, 0x7B, 0x97, 0xF3, 0xC6, 0x95, 0x7D,
+                0x7E, 0x41, 0x99, 0xA1, 0x67, 0xA5, 0x8E, 0xB0,
+                0x8B, 0xCA, 0xFF, 0xDA, 0x70, 0xAC, 0x04, 0x55,
+            },
+        };
+        int is_xonly_t[2] = { 0, 1 };
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, is_xonly_t, 2, NULL, pk, 2);
+        CHECK(musig_test_pk_parity(&keyagg_cache) == 0);
+        CHECK(!musig_test_is_second_pk(&keyagg_cache, sk));
+        CHECK(fin_nonce_parity == 0);
+        CHECK(memcmp(sig, sig_expected, 32) == 0);
+    }
+    {
+       /* This is a test with four tweaks: x-only, ordinary, x-only, ordinary. */
+        const unsigned char sig_expected[32] = {
+            0x8C, 0x44, 0x73, 0xC6, 0xA3, 0x82, 0xBD, 0x3C,
+            0x4A, 0xD7, 0xBE, 0x59, 0x81, 0x8D, 0xA5, 0xED,
+            0x7C, 0xF8, 0xCE, 0xC4, 0xBC, 0x21, 0x99, 0x6C,
+            0xFD, 0xA0, 0x8B, 0xB4, 0x31, 0x6B, 0x8B, 0xC7,
+        };
+        const unsigned char tweak[4][32] = {
+            {
+                0xE8, 0xF7, 0x91, 0xFF, 0x92, 0x25, 0xA2, 0xAF,
+                0x01, 0x02, 0xAF, 0xFF, 0x4A, 0x9A, 0x72, 0x3D,
+                0x96, 0x12, 0xA6, 0x82, 0xA2, 0x5E, 0xBE, 0x79,
+                0x80, 0x2B, 0x26, 0x3C, 0xDF, 0xCD, 0x83, 0xBB,
+            },
+            {
+                0xAE, 0x2E, 0xA7, 0x97, 0xCC, 0x0F, 0xE7, 0x2A,
+                0xC5, 0xB9, 0x7B, 0x97, 0xF3, 0xC6, 0x95, 0x7D,
+                0x7E, 0x41, 0x99, 0xA1, 0x67, 0xA5, 0x8E, 0xB0,
+                0x8B, 0xCA, 0xFF, 0xDA, 0x70, 0xAC, 0x04, 0x55,
+            },
+            {
+                0xF5, 0x2E, 0xCB, 0xC5, 0x65, 0xB3, 0xD8, 0xBE,
+                0xA2, 0xDF, 0xD5, 0xB7, 0x5A, 0x4F, 0x45, 0x7E,
+                0x54, 0x36, 0x98, 0x09, 0x32, 0x2E, 0x41, 0x20,
+                0x83, 0x16, 0x26, 0xF2, 0x90, 0xFA, 0x87, 0xE0,
+            },
+            {
+                0x19, 0x69, 0xAD, 0x73, 0xCC, 0x17, 0x7F, 0xA0,
+                0xB4, 0xFC, 0xED, 0x6D, 0xF1, 0xF7, 0xBF, 0x99,
+                0x07, 0xE6, 0x65, 0xFD, 0xE9, 0xBA, 0x19, 0x6A,
+                0x74, 0xFE, 0xD0, 0xA3, 0xCF, 0x5A, 0xEF, 0x9D,
+            },
+        };
+        int is_xonly_t[4] = { 1, 0, 1, 0 };
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, tweak, is_xonly_t, 4, NULL, pk, 2);
+        CHECK(musig_test_pk_parity(&keyagg_cache) == 0);
+        CHECK(!musig_test_is_second_pk(&keyagg_cache, sk));
+        CHECK(fin_nonce_parity == 1);
+        CHECK(memcmp(sig, sig_expected, 32) == 0);
+    }
     {
        /* This is a test that includes an adaptor. */
         const unsigned char sig_expected[32] = {
@@ -1357,7 +1430,7 @@ void musig_test_vectors_sign(void) {
         };
         secp256k1_pubkey pub_adaptor;
         CHECK(secp256k1_ec_pubkey_create(ctx, &pub_adaptor, sec_adaptor) == 1);
-        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, 0, &pub_adaptor, pk, 2);
+        musig_test_vectors_sign_helper(&keyagg_cache, &fin_nonce_parity, sig, secnonce, agg_pubnonce, sk, msg, NULL, NULL, 0, &pub_adaptor, pk, 2);
 
         CHECK(musig_test_pk_parity(&keyagg_cache) == 1);
         CHECK(!musig_test_is_second_pk(&keyagg_cache, sk));