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author | Cory Fields <cory-nospam-@coryfields.com> | 2015-01-09 16:39:12 -0500 |
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committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2015-01-10 08:10:29 +0100 |
commit | ace39db7644d5cb6bb8f99a465c5635b090e9ca5 (patch) | |
tree | a9fa14d5c0fc8d0d7b0a92e754f396788769f74a /src/ecwrapper.cpp | |
parent | 263b65ebf0ce0beae5622a533234c8f897aec4e1 (diff) | |
download | bitcoin-ace39db7644d5cb6bb8f99a465c5635b090e9ca5.tar.xz |
consensus: guard against openssl's new strict DER checks
New versions of OpenSSL will reject non-canonical DER signatures. However,
it'll happily decode them. Decode then re-encode before verification in order
to ensure that it is properly consumed.
Github-Pull: #5634
Rebased-From: 488ed32f2ada1d1dd108fc245d025c4d5f252783
Diffstat (limited to 'src/ecwrapper.cpp')
-rw-r--r-- | src/ecwrapper.cpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/src/ecwrapper.cpp b/src/ecwrapper.cpp index 5ce7e61294..be33913d0d 100644 --- a/src/ecwrapper.cpp +++ b/src/ecwrapper.cpp @@ -117,10 +117,20 @@ bool CECKey::SetPubKey(const unsigned char* pubkey, size_t size) { } bool CECKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) { - // -1 = error, 0 = bad sig, 1 = good - if (ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], vchSig.size(), pkey) != 1) + // New versions of OpenSSL will reject non-canonical DER signatures. de/re-serialize first. + unsigned char *norm_der = NULL; + ECDSA_SIG *norm_sig = ECDSA_SIG_new(); + const unsigned char* sigptr = &vchSig[0]; + d2i_ECDSA_SIG(&norm_sig, &sigptr, vchSig.size()); + int derlen = i2d_ECDSA_SIG(norm_sig, &norm_der); + ECDSA_SIG_free(norm_sig); + if (derlen <= 0) return false; - return true; + + // -1 = error, 0 = bad sig, 1 = good + bool ret = ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), norm_der, derlen, pkey) == 1; + OPENSSL_free(norm_der); + return ret; } bool CECKey::Recover(const uint256 &hash, const unsigned char *p64, int rec) |