Merge pull request #6954

6e18268 Switch to libsecp256k1-based validation for ECDSA (Pieter Wuille)

Author: laanwj

doc/release-notes.md

@@ -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
 =================
 

src/Makefile.am

@@ -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

src/bitcoin-tx.cpp

@@ -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,