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Merge pull request #6954

6e18268 Switch to libsecp256k1-based validation for ECDSA (Pieter Wuille)
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laanwj committed Nov 16, 2015
2 parents dafefb7 + 6e18268 commit e54ebbf6009716a7abcd4d8d3f7bd910e88decdc
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@@ -190,6 +190,21 @@ calculating the target.
A more detailed documentation about keeping traffic low can be found in
[/doc/reducetraffic.md](/doc/reducetraffic.md).
+Signature validation using libsecp256k1
+---------------------------------------
+
+ECDSA signatures inside Bitcoin transactions now use validation using
+[https://github.com/bitcoin/secp256k1](libsecp256k1) instead of OpenSSL.
+
+Depending on the platform, this means a significant speedup for raw signature
+validation speed. The advantage is largest on x86_64, where validation is over
+five times faster. In practice, this translates to a raw reindexing and new
+block validation times that are less than half of what it was before.
+
+Libsecp256k1 has undergone very extensive testing and validation.
+
+A side effect of this change is that libconsensus no longer depends on OpenSSL.
+
0.12.0 Change log
=================
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@@ -104,8 +104,6 @@ BITCOIN_CORE_H = \
consensus/validation.h \
core_io.h \
core_memusage.h \
- eccryptoverify.h \
- ecwrapper.h \
hash.h \
httprpc.h \
httpserver.h \
@@ -272,8 +270,6 @@ libbitcoin_common_a_SOURCES = \
compressor.cpp \
core_read.cpp \
core_write.cpp \
- eccryptoverify.cpp \
- ecwrapper.cpp \
hash.cpp \
key.cpp \
keystore.cpp \
@@ -404,8 +400,6 @@ libbitcoinconsensus_la_SOURCES = \
crypto/sha1.cpp \
crypto/sha256.cpp \
crypto/sha512.cpp \
- eccryptoverify.cpp \
- ecwrapper.cpp \
hash.cpp \
primitives/transaction.cpp \
pubkey.cpp \
@@ -420,8 +414,8 @@ if GLIBC_BACK_COMPAT
endif
libbitcoinconsensus_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined $(RELDFLAGS)
-libbitcoinconsensus_la_LIBADD = $(CRYPTO_LIBS)
-libbitcoinconsensus_la_CPPFLAGS = $(AM_CPPFLAGS) $(CRYPTO_CFLAGS) -I$(builddir)/obj -DBUILD_BITCOIN_INTERNAL
+libbitcoinconsensus_la_LIBADD = $(LIBSECP256K1)
+libbitcoinconsensus_la_CPPFLAGS = $(AM_CPPFLAGS) -I$(builddir)/obj -I$(srcdir)/secp256k1/include -DBUILD_BITCOIN_INTERNAL
libbitcoinconsensus_la_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
endif
View
@@ -477,9 +477,15 @@ static void MutateTxSign(CMutableTransaction& tx, const string& flagStr)
class Secp256k1Init
{
+ ECCVerifyHandle globalVerifyHandle;
+
public:
- Secp256k1Init() { ECC_Start(); }
- ~Secp256k1Init() { ECC_Stop(); }
+ Secp256k1Init() {
+ ECC_Start();
+ }
+ ~Secp256k1Init() {
+ ECC_Stop();
+ }
};
static void MutateTx(CMutableTransaction& tx, const string& command,
View
@@ -1,68 +0,0 @@
-// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#include "eccryptoverify.h"
-
-namespace {
-
-int CompareBigEndian(const unsigned char *c1, size_t c1len, const unsigned char *c2, size_t c2len) {
- while (c1len > c2len) {
- if (*c1)
- return 1;
- c1++;
- c1len--;
- }
- while (c2len > c1len) {
- if (*c2)
- return -1;
- c2++;
- c2len--;
- }
- while (c1len > 0) {
- if (*c1 > *c2)
- return 1;
- if (*c2 > *c1)
- return -1;
- c1++;
- c2++;
- c1len--;
- }
- return 0;
-}
-
-/** Order of secp256k1's generator minus 1. */
-const unsigned char vchMaxModOrder[32] = {
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,
- 0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,
- 0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x40
-};
-
-/** Half of the order of secp256k1's generator minus 1. */
-const unsigned char vchMaxModHalfOrder[32] = {
- 0x7F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0x5D,0x57,0x6E,0x73,0x57,0xA4,0x50,0x1D,
- 0xDF,0xE9,0x2F,0x46,0x68,0x1B,0x20,0xA0
-};
-
-const unsigned char vchZero[1] = {0};
-} // anon namespace
-
-namespace eccrypto {
-
-bool Check(const unsigned char *vch) {
- return vch &&
- CompareBigEndian(vch, 32, vchZero, 0) > 0 &&
- CompareBigEndian(vch, 32, vchMaxModOrder, 32) <= 0;
-}
-
-bool CheckSignatureElement(const unsigned char *vch, int len, bool half) {
- return vch &&
- CompareBigEndian(vch, len, vchZero, 0) > 0 &&
- CompareBigEndian(vch, len, half ? vchMaxModHalfOrder : vchMaxModOrder, 32) <= 0;
-}
-
-} // namespace eccrypto
View
@@ -1,21 +0,0 @@
-// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#ifndef BITCOIN_ECCRYPTOVERIFY_H
-#define BITCOIN_ECCRYPTOVERIFY_H
-
-#include <vector>
-#include <cstdlib>
-
-class uint256;
-
-namespace eccrypto {
-
-bool Check(const unsigned char *vch);
-bool CheckSignatureElement(const unsigned char *vch, int len, bool half);
-
-} // eccrypto namespace
-
-#endif // BITCOIN_ECCRYPTOVERIFY_H
View
@@ -1,218 +0,0 @@
-// Copyright (c) 2009-2014 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#include "ecwrapper.h"
-
-#include "serialize.h"
-#include "uint256.h"
-
-#include <openssl/bn.h>
-#include <openssl/ecdsa.h>
-#include <openssl/obj_mac.h>
-
-namespace {
-
-class ecgroup_order
-{
-public:
- static const EC_GROUP* get()
- {
- static const ecgroup_order wrapper;
- return wrapper.pgroup;
- }
-
-private:
- ecgroup_order()
- : pgroup(EC_GROUP_new_by_curve_name(NID_secp256k1))
- {
- }
-
- ~ecgroup_order()
- {
- EC_GROUP_free(pgroup);
- }
-
- EC_GROUP* pgroup;
-};
-
-/**
- * Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields
- * recid selects which key is recovered
- * if check is non-zero, additional checks are performed
- */
-int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check)
-{
- if (!eckey) return 0;
-
- int ret = 0;
- BN_CTX *ctx = NULL;
-
- BIGNUM *x = NULL;
- BIGNUM *e = NULL;
- BIGNUM *order = NULL;
- BIGNUM *sor = NULL;
- BIGNUM *eor = NULL;
- BIGNUM *field = NULL;
- EC_POINT *R = NULL;
- EC_POINT *O = NULL;
- EC_POINT *Q = NULL;
- BIGNUM *rr = NULL;
- BIGNUM *zero = NULL;
- int n = 0;
- int i = recid / 2;
-
- const EC_GROUP *group = EC_KEY_get0_group(eckey);
- if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; }
- BN_CTX_start(ctx);
- order = BN_CTX_get(ctx);
- if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; }
- x = BN_CTX_get(ctx);
- if (!BN_copy(x, order)) { ret=-1; goto err; }
- if (!BN_mul_word(x, i)) { ret=-1; goto err; }
- if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; }
- field = BN_CTX_get(ctx);
- if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; }
- if (BN_cmp(x, field) >= 0) { ret=0; goto err; }
- if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
- if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; }
- if (check)
- {
- if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
- if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; }
- if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; }
- }
- if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
- n = EC_GROUP_get_degree(group);
- e = BN_CTX_get(ctx);
- if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; }
- if (8*msglen > n) BN_rshift(e, e, 8-(n & 7));
- zero = BN_CTX_get(ctx);
- if (!BN_zero(zero)) { ret=-1; goto err; }
- if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; }
- rr = BN_CTX_get(ctx);
- if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; }
- sor = BN_CTX_get(ctx);
- if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; }
- eor = BN_CTX_get(ctx);
- if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; }
- if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; }
- if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; }
-
- ret = 1;
-
-err:
- if (ctx) {
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- }
- if (R != NULL) EC_POINT_free(R);
- if (O != NULL) EC_POINT_free(O);
- if (Q != NULL) EC_POINT_free(Q);
- return ret;
-}
-
-} // anon namespace
-
-CECKey::CECKey() {
- pkey = EC_KEY_new();
- assert(pkey != NULL);
- int result = EC_KEY_set_group(pkey, ecgroup_order::get());
- assert(result);
-}
-
-CECKey::~CECKey() {
- EC_KEY_free(pkey);
-}
-
-void CECKey::GetPubKey(std::vector<unsigned char> &pubkey, bool fCompressed) {
- EC_KEY_set_conv_form(pkey, fCompressed ? POINT_CONVERSION_COMPRESSED : POINT_CONVERSION_UNCOMPRESSED);
- int nSize = i2o_ECPublicKey(pkey, NULL);
- assert(nSize);
- assert(nSize <= 65);
- pubkey.clear();
- pubkey.resize(nSize);
- unsigned char *pbegin(begin_ptr(pubkey));
- int nSize2 = i2o_ECPublicKey(pkey, &pbegin);
- assert(nSize == nSize2);
-}
-
-bool CECKey::SetPubKey(const unsigned char* pubkey, size_t size) {
- return o2i_ECPublicKey(&pkey, &pubkey, size) != NULL;
-}
-
-bool CECKey::Verify(const uint256 &hash, const std::vector<unsigned char>& 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();
- const unsigned char* sigptr = &vchSig[0];
- assert(norm_sig);
- if (d2i_ECDSA_SIG(&norm_sig, &sigptr, vchSig.size()) == NULL)
- {
- /* As of OpenSSL 1.0.0p d2i_ECDSA_SIG frees and nulls the pointer on
- * error. But OpenSSL's own use of this function redundantly frees the
- * result. As ECDSA_SIG_free(NULL) is a no-op, and in the absence of a
- * clear contract for the function behaving the same way is more
- * conservative.
- */
- ECDSA_SIG_free(norm_sig);
- return false;
- }
- int derlen = i2d_ECDSA_SIG(norm_sig, &norm_der);
- ECDSA_SIG_free(norm_sig);
- if (derlen <= 0)
- return false;
-
- // -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)
-{
- if (rec<0 || rec>=3)
- return false;
- ECDSA_SIG *sig = ECDSA_SIG_new();
- BN_bin2bn(&p64[0], 32, sig->r);
- BN_bin2bn(&p64[32], 32, sig->s);
- bool ret = ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), rec, 0) == 1;
- ECDSA_SIG_free(sig);
- return ret;
-}
-
-bool CECKey::TweakPublic(const unsigned char vchTweak[32]) {
- bool ret = true;
- BN_CTX *ctx = BN_CTX_new();
- BN_CTX_start(ctx);
- BIGNUM *bnTweak = BN_CTX_get(ctx);
- BIGNUM *bnOrder = BN_CTX_get(ctx);
- BIGNUM *bnOne = BN_CTX_get(ctx);
- const EC_GROUP *group = EC_KEY_get0_group(pkey);
- EC_GROUP_get_order(group, bnOrder, ctx); // what a grossly inefficient way to get the (constant) group order...
- BN_bin2bn(vchTweak, 32, bnTweak);
- if (BN_cmp(bnTweak, bnOrder) >= 0)
- ret = false; // extremely unlikely
- EC_POINT *point = EC_POINT_dup(EC_KEY_get0_public_key(pkey), group);
- BN_one(bnOne);
- EC_POINT_mul(group, point, bnTweak, point, bnOne, ctx);
- if (EC_POINT_is_at_infinity(group, point))
- ret = false; // ridiculously unlikely
- EC_KEY_set_public_key(pkey, point);
- EC_POINT_free(point);
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- return ret;
-}
-
-bool CECKey::SanityCheck()
-{
- const EC_GROUP *pgroup = ecgroup_order::get();
- if(pgroup == NULL)
- return false;
- // TODO Is there more EC functionality that could be missing?
- return true;
-}
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