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| author | Cory Fields <cory-nospam-@coryfields.com> | 2015-01-09 16:39:12 -0500 |
|---|---|---|
| committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2015-01-10 08:31:14 +0100 |
| commit | b8e81b7ccd4490155e3345fc73346ff8c3a77524 (patch) | |
| tree | 71dbcf161b27b84554d3a1811cc1c55f36e537b8 | |
| parent | 0a94661e8db94e84ecbf1ea45a51fb3c7fb77283 (diff) | |
| download | bitcoin-b8e81b7ccd4490155e3345fc73346ff8c3a77524.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
| -rw-r--r-- | src/key.cpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/src/key.cpp b/src/key.cpp index 5b261bb285..e5943af79a 100644 --- a/src/key.cpp +++ b/src/key.cpp @@ -227,10 +227,20 @@ public: } bool 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 SignCompact(const uint256 &hash, unsigned char *p64, int &rec) { |