From 488ed32f2ada1d1dd108fc245d025c4d5f252783 Mon Sep 17 00:00:00 2001 From: Cory Fields Date: Fri, 9 Jan 2015 16:39:12 -0500 Subject: [PATCH 1/3] 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. --- src/ecwrapper.cpp | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/src/ecwrapper.cpp b/src/ecwrapper.cpp index c29390eb9..33dd9a9a2 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& 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) From dad7764a9dedb1143b6ea8bfd37f71f7ff72f518 Mon Sep 17 00:00:00 2001 From: Cory Fields Date: Fri, 9 Jan 2015 20:52:55 -0500 Subject: [PATCH 2/3] depends: bump openssl to 1.0.1k --- depends/packages/openssl.mk | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/depends/packages/openssl.mk b/depends/packages/openssl.mk index ad64494c1..32eb1e653 100644 --- a/depends/packages/openssl.mk +++ b/depends/packages/openssl.mk @@ -1,8 +1,8 @@ package=openssl -$(package)_version=1.0.1j +$(package)_version=1.0.1k $(package)_download_path=https://www.openssl.org/source $(package)_file_name=$(package)-$($(package)_version).tar.gz -$(package)_sha256_hash=1b60ca8789ba6f03e8ef20da2293b8dc131c39d83814e775069f02d26354edf3 +$(package)_sha256_hash=8f9faeaebad088e772f4ef5e38252d472be4d878c6b3a2718c10a4fcebe7a41c define $(package)_set_vars $(package)_config_env=AR="$($(package)_ar)" RANLIB="$($(package)_ranlib)" CC="$($(package)_cc)" From 8dccba6a45db0466370726ed462b9da2eae43bce Mon Sep 17 00:00:00 2001 From: Cory Fields Date: Fri, 9 Jan 2015 22:06:08 -0500 Subject: [PATCH 3/3] fail immediately on an empty signature --- src/ecwrapper.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/ecwrapper.cpp b/src/ecwrapper.cpp index 33dd9a9a2..0236e90c1 100644 --- a/src/ecwrapper.cpp +++ b/src/ecwrapper.cpp @@ -117,6 +117,9 @@ bool CECKey::SetPubKey(const unsigned char* pubkey, size_t size) { } bool CECKey::Verify(const uint256 &hash, const std::vector& vchSig) { + if (vchSig.empty()) + return false; + // 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();