Merge pull request #5506

7873633 Squashed 'src/secp256k1/' changes from bccaf86..50cc6ab (Pieter Wuille)
1a9576d Use libsecp256k1's RFC6979 implementation (Pieter Wuille)

1 files changed, 21 insertions, 24 deletions

diff --git a/src/key.cpp b/src/key.cpp
index 2235c271d1..d8319db1a3 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -6,7 +6,6 @@
 
 #include "arith_uint256.h"
 #include "crypto/hmac_sha512.h"
-#include "crypto/rfc6979_hmac_sha256.h"
 #include "eccryptoverify.h"
 #include "pubkey.h"
 #include "random.h"
@@ -74,23 +73,28 @@ CPubKey CKey::GetPubKey() const {
     return result;
 }
 
+extern "C"
+{
+static int secp256k1_nonce_function_test_case(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, unsigned int attempt, const void *data)
+{
+    const uint32_t *test_case = static_cast<const uint32_t*>(data);
+    uint256 nonce;
+    secp256k1_nonce_function_rfc6979(nonce.begin(), msg32, key32, attempt, NULL);
+    nonce = ArithToUint256(UintToArith256(nonce) + *test_case);
+    memcpy(nonce32, nonce.begin(), 32);
+    return 1;
+}
+}
+
 bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, uint32_t test_case) const {
     if (!fValid)
         return false;
     vchSig.resize(72);
-    RFC6979_HMAC_SHA256 prng(begin(), 32, (unsigned char*)&hash, 32);
-    do {
-        uint256 nonce;
-        prng.Generate((unsigned char*)&nonce, 32);
-        nonce = ArithToUint256(UintToArith256(nonce) + test_case);
-        int nSigLen = 72;
-        int ret = secp256k1_ecdsa_sign((const unsigned char*)&hash, (unsigned char*)&vchSig[0], &nSigLen, begin(), (unsigned char*)&nonce);
-        nonce = uint256();
-        if (ret) {
-            vchSig.resize(nSigLen);
-            return true;
-        }
-    } while(true);
+    int nSigLen = 72;
+    int ret = secp256k1_ecdsa_sign(hash.begin(), (unsigned char*)&vchSig[0], &nSigLen, begin(), test_case == 0 ? secp256k1_nonce_function_rfc6979 : secp256k1_nonce_function_test_case, test_case == 0 ? NULL : &test_case);
+    assert(ret);
+    vchSig.resize(nSigLen);
+    return true;
 }
 
 bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
@@ -101,7 +105,7 @@ bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
     std::string str = "Bitcoin key verification\n";
     GetRandBytes(rnd, sizeof(rnd));
     uint256 hash;
-    CHash256().Write((unsigned char*)str.data(), str.size()).Write(rnd, sizeof(rnd)).Finalize((unsigned char*)&hash);
+    CHash256().Write((unsigned char*)str.data(), str.size()).Write(rnd, sizeof(rnd)).Finalize(hash.begin());
     std::vector<unsigned char> vchSig;
     Sign(hash, vchSig);
     return pubkey.Verify(hash, vchSig);
@@ -112,15 +116,8 @@ bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig)
         return false;
     vchSig.resize(65);
     int rec = -1;
-    RFC6979_HMAC_SHA256 prng(begin(), 32, (unsigned char*)&hash, 32);
-    do {
-        uint256 nonce;
-        prng.Generate((unsigned char*)&nonce, 32);
-        int ret = secp256k1_ecdsa_sign_compact((const unsigned char*)&hash, &vchSig[1], begin(), (unsigned char*)&nonce, &rec);
-        nonce = uint256();
-        if (ret)
-            break;
-    } while(true);
+    int ret = secp256k1_ecdsa_sign_compact(hash.begin(), &vchSig[1], begin(), secp256k1_nonce_function_rfc6979, NULL, &rec);
+    assert(ret);
     assert(rec != -1);
     vchSig[0] = 27 + rec + (fCompressed ? 4 : 0);
     return true;