f fix tagged hash by setting and add test

BlockstreamResearch · Feb 5, 2019 · 950054e · 950054e
1 parent c5e9fa2
commit 950054e
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diff --git a/src/modules/musig/main_impl.h b/src/modules/musig/main_impl.h
@@ -42,6 +42,7 @@ static void secp256k1_musig_sha256_init_tagged(secp256k1_sha256 *sha) {
     sha->s[5] = 0xaca1a22ful;
     sha->s[6] = 0x6f43b801ul;
     sha->s[7] = 0x85ce27cdul;
+    sha->bytes = 64;
 }
 
 /* Compute r = SHA256(ell, idx). The four bytes of idx are serialized least significant byte first. */

diff --git a/src/modules/musig/tests_impl.h b/src/modules/musig/tests_impl.h
@@ -713,6 +713,7 @@ void sha256_tag_test(void) {
     secp256k1_sha256 sha;
     secp256k1_sha256 sha_tagged;
     unsigned char buf[32];
+    unsigned char buf2[32];
     size_t i;
 
     secp256k1_sha256_initialize(&sha);
@@ -731,6 +732,11 @@ void sha256_tag_test(void) {
     for (i = 0; i < 8; i++) {
         CHECK(sha_tagged.s[i] == sha.s[i]);
     }
+    secp256k1_sha256_write(&sha, buf, 32);
+    secp256k1_sha256_write(&sha_tagged, buf, 32);
+    secp256k1_sha256_finalize(&sha, buf);
+    secp256k1_sha256_finalize(&sha_tagged, buf2);
+    CHECK(memcmp(buf, buf2, 32) == 0);
 }
 
 void run_musig_tests(void) {