Update src/secp256k1 subtree

Author: sipa

src/secp256k1/.gitignore

@@ -9,6 +9,7 @@ bench_internal
 tests
 exhaustive_tests
 gen_context
+valgrind_ctime_test
 *.exe
 *.so
 *.a

src/secp256k1/.travis.yml

@@ -1,18 +1,23 @@
 language: c
-os: linux
+os:
+  - linux
+  - osx
+
+dist: bionic
+# Valgrind currently supports upto macOS 10.13, the latest xcode of that version is 10.1
+osx_image: xcode10.1
 addons:
   apt:
-    packages: libgmp-dev
+    packages:
+      - libgmp-dev
+      - valgrind
+      - libtool-bin
 compiler:
   - clang
   - gcc
-cache:
-  directories:
-  - src/java/guava/
 env:
   global:
-    - FIELD=auto  BIGNUM=auto  SCALAR=auto  ENDOMORPHISM=no  STATICPRECOMPUTATION=yes  ASM=no  BUILD=check  EXTRAFLAGS=  HOST=  ECDH=no  RECOVERY=no  EXPERIMENTAL=no  JNI=no
-    - GUAVA_URL=https://search.maven.org/remotecontent?filepath=com/google/guava/guava/18.0/guava-18.0.jar GUAVA_JAR=src/java/guava/guava-18.0.jar
+    - FIELD=auto  BIGNUM=auto  SCALAR=auto  ENDOMORPHISM=no  STATICPRECOMPUTATION=yes  ECMULTGENPRECISION=auto  ASM=no  BUILD=check  EXTRAFLAGS=  HOST=  ECDH=no  RECOVERY=no  EXPERIMENTAL=no CTIMETEST=yes BENCH=yes ITERS=2
   matrix:
     - SCALAR=32bit    RECOVERY=yes
     - SCALAR=32bit    FIELD=32bit       ECDH=yes  EXPERIMENTAL=yes
@@ -26,43 +31,78 @@ env:
     - BIGNUM=no
     - BIGNUM=no       ENDOMORPHISM=yes RECOVERY=yes EXPERIMENTAL=yes
     - BIGNUM=no       STATICPRECOMPUTATION=no
-    - BUILD=distcheck
-    - EXTRAFLAGS=CPPFLAGS=-DDETERMINISTIC
-    - EXTRAFLAGS=CFLAGS=-O0
-    - BUILD=check-java JNI=yes ECDH=yes EXPERIMENTAL=yes
+    - BUILD=distcheck CTIMETEST= BENCH=
+    - CPPFLAGS=-DDETERMINISTIC
+    - CFLAGS=-O0 CTIMETEST=
+    - ECMULTGENPRECISION=2
+    - ECMULTGENPRECISION=8
+    - VALGRIND=yes ENDOMORPHISM=yes BIGNUM=no ASM=x86_64 EXPERIMENTAL=yes ECDH=yes  RECOVERY=yes EXTRAFLAGS="--disable-openssl-tests" CPPFLAGS=-DVALGRIND BUILD=
+    - VALGRIND=yes                  BIGNUM=no ASM=x86_64 EXPERIMENTAL=yes ECDH=yes  RECOVERY=yes EXTRAFLAGS="--disable-openssl-tests" CPPFLAGS=-DVALGRIND BUILD=
 matrix:
   fast_finish: true
   include:
     - compiler: clang
+      os: linux
       env: HOST=i686-linux-gnu ENDOMORPHISM=yes
       addons:
         apt:
           packages:
             - gcc-multilib
             - libgmp-dev:i386
+            - valgrind
+            - libtool-bin
+            - libc6-dbg:i386
     - compiler: clang
       env: HOST=i686-linux-gnu
+      os: linux
       addons:
         apt:
           packages:
             - gcc-multilib
+            - valgrind
+            - libtool-bin
+            - libc6-dbg:i386
     - compiler: gcc
       env: HOST=i686-linux-gnu ENDOMORPHISM=yes
+      os: linux
       addons:
         apt:
           packages:
             - gcc-multilib
+            - valgrind
+            - libtool-bin
+            - libc6-dbg:i386
     - compiler: gcc
+      os: linux
       env: HOST=i686-linux-gnu
       addons:
         apt:
           packages:
             - gcc-multilib
             - libgmp-dev:i386
-before_install: mkdir -p `dirname $GUAVA_JAR`
-install: if [ ! -f $GUAVA_JAR ]; then wget $GUAVA_URL -O $GUAVA_JAR; fi
+            - valgrind
+            - libtool-bin
+            - libc6-dbg:i386
+
+# We use this to install macOS dependencies instead of the built in `homebrew` plugin,
+# because in xcode earlier than 11 they have a bug requiring updating the system which overall takes ~8 minutes.
+# https://travis-ci.community/t/macos-build-fails-because-of-homebrew-bundle-unknown-command/7296
+before_install:
+ - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then HOMEBREW_NO_AUTO_UPDATE=1 brew install gmp valgrind gcc@9; fi
+
 before_script: ./autogen.sh
+
+# travis auto terminates jobs that go for 10 minutes without printing to stdout, but travis_wait doesn't work well with forking programs like valgrind (https://docs.travis-ci.com/user/common-build-problems/#build-times-out-because-no-output-was-received https://github.com/bitcoin-core/secp256k1/pull/750#issuecomment-623476860)
 script:
- - if [ -n "$HOST" ]; then export USE_HOST="--host=$HOST"; fi
- - if [ "x$HOST" = "xi686-linux-gnu" ]; then export CC="$CC -m32"; fi
- - ./configure --enable-experimental=$EXPERIMENTAL --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-scalar=$SCALAR --enable-ecmult-static-precomputation=$STATICPRECOMPUTATION --enable-module-ecdh=$ECDH --enable-module-recovery=$RECOVERY --enable-jni=$JNI $EXTRAFLAGS $USE_HOST && make -j2 $BUILD
+  - function keep_alive() { while true; do echo -en "\a"; sleep 60; done }
+  - keep_alive &
+  - ./contrib/travis.sh
+  - kill %keep_alive
+
+after_script:
+    - cat ./tests.log
+    - cat ./exhaustive_tests.log
+    - cat ./valgrind_ctime_test.log
+    - cat ./bench.log
+    - $CC --version
+    - valgrind --version

src/secp256k1/Makefile.am

@@ -1,13 +1,8 @@
 ACLOCAL_AMFLAGS = -I build-aux/m4
 
 lib_LTLIBRARIES = libsecp256k1.la
-if USE_JNI
-JNI_LIB = libsecp256k1_jni.la
-noinst_LTLIBRARIES = $(JNI_LIB)
-else
-JNI_LIB =
-endif
 include_HEADERS = include/secp256k1.h
+include_HEADERS += include/secp256k1_preallocated.h
 noinst_HEADERS =
 noinst_HEADERS += src/scalar.h
 noinst_HEADERS += src/scalar_4x64.h
@@ -39,8 +34,6 @@ noinst_HEADERS += src/field_5x52.h
 noinst_HEADERS += src/field_5x52_impl.h
 noinst_HEADERS += src/field_5x52_int128_impl.h
 noinst_HEADERS += src/field_5x52_asm_impl.h
-noinst_HEADERS += src/java/org_bitcoin_NativeSecp256k1.h
-noinst_HEADERS += src/java/org_bitcoin_Secp256k1Context.h
 noinst_HEADERS += src/util.h
 noinst_HEADERS += src/scratch.h
 noinst_HEADERS += src/scratch_impl.h
@@ -74,16 +67,19 @@ endif
 
 libsecp256k1_la_SOURCES = src/secp256k1.c
 libsecp256k1_la_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/include -I$(top_srcdir)/src $(SECP_INCLUDES)
-libsecp256k1_la_LIBADD = $(JNI_LIB) $(SECP_LIBS) $(COMMON_LIB)
+libsecp256k1_la_LIBADD = $(SECP_LIBS) $(COMMON_LIB)
 
-libsecp256k1_jni_la_SOURCES  = src/java/org_bitcoin_NativeSecp256k1.c src/java/org_bitcoin_Secp256k1Context.c
-libsecp256k1_jni_la_CPPFLAGS = -DSECP256K1_BUILD $(JNI_INCLUDES)
+if VALGRIND_ENABLED
+libsecp256k1_la_CPPFLAGS += -DVALGRIND
+endif
 
 noinst_PROGRAMS =
 if USE_BENCHMARK
 noinst_PROGRAMS += bench_verify bench_sign bench_internal bench_ecmult
 bench_verify_SOURCES = src/bench_verify.c
 bench_verify_LDADD = libsecp256k1.la $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB)
+# SECP_TEST_INCLUDES are only used here for CRYPTO_CPPFLAGS
+bench_verify_CPPFLAGS = -DSECP256K1_BUILD $(SECP_TEST_INCLUDES)
 bench_sign_SOURCES = src/bench_sign.c
 bench_sign_LDADD = libsecp256k1.la $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB)
 bench_internal_SOURCES = src/bench_internal.c
@@ -99,6 +95,12 @@ if USE_TESTS
 noinst_PROGRAMS += tests
 tests_SOURCES = src/tests.c
 tests_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/src -I$(top_srcdir)/include $(SECP_INCLUDES) $(SECP_TEST_INCLUDES)
+if VALGRIND_ENABLED
+tests_CPPFLAGS += -DVALGRIND
+noinst_PROGRAMS += valgrind_ctime_test
+valgrind_ctime_test_SOURCES = src/valgrind_ctime_test.c
+valgrind_ctime_test_LDADD = libsecp256k1.la $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB)
+endif
 if !ENABLE_COVERAGE
 tests_CPPFLAGS += -DVERIFY
 endif
@@ -119,42 +121,12 @@ exhaustive_tests_LDFLAGS = -static
 TESTS += exhaustive_tests
 endif
 
-JAVAROOT=src/java
-JAVAORG=org/bitcoin
-JAVA_GUAVA=$(srcdir)/$(JAVAROOT)/guava/guava-18.0.jar
-CLASSPATH_ENV=CLASSPATH=$(JAVA_GUAVA)
-JAVA_FILES= \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1.java \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1Test.java \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1Util.java \
-  $(JAVAROOT)/$(JAVAORG)/Secp256k1Context.java
-
-if USE_JNI
-
-$(JAVA_GUAVA):
-	@echo Guava is missing. Fetch it via: \
-	wget https://search.maven.org/remotecontent?filepath=com/google/guava/guava/18.0/guava-18.0.jar -O $(@)
-	@false
-
-.stamp-java: $(JAVA_FILES)
-	@echo   Compiling $^
-	$(AM_V_at)$(CLASSPATH_ENV) javac $^
-	@touch $@
-
-if USE_TESTS
-
-check-java: libsecp256k1.la $(JAVA_GUAVA) .stamp-java
-	$(AM_V_at)java -Djava.library.path="./:./src:./src/.libs:.libs/" -cp "$(JAVA_GUAVA):$(JAVAROOT)" $(JAVAORG)/NativeSecp256k1Test
-
-endif
-endif
-
 if USE_ECMULT_STATIC_PRECOMPUTATION
-CPPFLAGS_FOR_BUILD +=-I$(top_srcdir)
+CPPFLAGS_FOR_BUILD +=-I$(top_srcdir) -I$(builddir)/src
 
 gen_context_OBJECTS = gen_context.o
 gen_context_BIN = gen_context$(BUILD_EXEEXT)
-gen_%.o: src/gen_%.c
+gen_%.o: src/gen_%.c src/libsecp256k1-config.h
 	$(CC_FOR_BUILD) $(CPPFLAGS_FOR_BUILD) $(CFLAGS_FOR_BUILD) -c $< -o $@
 
 $(gen_context_BIN): $(gen_context_OBJECTS)
@@ -168,10 +140,10 @@ $(bench_ecmult_OBJECTS): src/ecmult_static_context.h
 src/ecmult_static_context.h: $(gen_context_BIN)
 	./$(gen_context_BIN)
 
-CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h $(JAVAROOT)/$(JAVAORG)/*.class .stamp-java
+CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h
 endif
 
-EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h $(JAVA_FILES)
+EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h
 
 if ENABLE_MODULE_ECDH
 include src/modules/ecdh/Makefile.am.include

src/secp256k1/README.md

@@ -3,17 +3,22 @@ libsecp256k1
 
 [![Build Status](https://travis-ci.org/bitcoin-core/secp256k1.svg?branch=master)](https://travis-ci.org/bitcoin-core/secp256k1)
 
-Optimized C library for EC operations on curve secp256k1.
+Optimized C library for ECDSA signatures and secret/public key operations on curve secp256k1.
 
-This library is a work in progress and is being used to research best practices. Use at your own risk.
+This library is intended to be the highest quality publicly available library for cryptography on the secp256k1 curve. However, the primary focus of its development has been for usage in the Bitcoin system and usage unlike Bitcoin's may be less well tested, verified, or suffer from a less well thought out interface. Correct usage requires some care and consideration that the library is fit for your application's purpose.
 
 Features:
 * secp256k1 ECDSA signing/verification and key generation.
-* Adding/multiplying private/public keys.
-* Serialization/parsing of private keys, public keys, signatures.
-* Constant time, constant memory access signing and pubkey generation.
-* Derandomized DSA (via RFC6979 or with a caller provided function.)
+* Additive and multiplicative tweaking of secret/public keys.
+* Serialization/parsing of secret keys, public keys, signatures.
+* Constant time, constant memory access signing and public key generation.
+* Derandomized ECDSA (via RFC6979 or with a caller provided function.)
 * Very efficient implementation.
+* Suitable for embedded systems.
+* Optional module for public key recovery.
+* Optional module for ECDH key exchange (experimental).
+
+Experimental features have not received enough scrutiny to satisfy the standard of quality of this library but are made available for testing and review by the community. The APIs of these features should not be considered stable.
 
 Implementation details
 ----------------------
@@ -23,11 +28,12 @@ Implementation details
   * Extensive testing infrastructure.
   * Structured to facilitate review and analysis.
   * Intended to be portable to any system with a C89 compiler and uint64_t support.
+  * No use of floating types.
   * Expose only higher level interfaces to minimize the API surface and improve application security. ("Be difficult to use insecurely.")
 * Field operations
   * Optimized implementation of arithmetic modulo the curve's field size (2^256 - 0x1000003D1).
     * Using 5 52-bit limbs (including hand-optimized assembly for x86_64, by Diederik Huys).
-    * Using 10 26-bit limbs.
+    * Using 10 26-bit limbs (including hand-optimized assembly for 32-bit ARM, by Wladimir J. van der Laan).
   * Field inverses and square roots using a sliding window over blocks of 1s (by Peter Dettman).
 * Scalar operations
   * Optimized implementation without data-dependent branches of arithmetic modulo the curve's order.
@@ -45,9 +51,11 @@ Implementation details
   * Optionally (off by default) use secp256k1's efficiently-computable endomorphism to split the P multiplicand into 2 half-sized ones.
 * Point multiplication for signing
   * Use a precomputed table of multiples of powers of 16 multiplied with the generator, so general multiplication becomes a series of additions.
-  * Access the table with branch-free conditional moves so memory access is uniform.
-  * No data-dependent branches
-  * The precomputed tables add and eventually subtract points for which no known scalar (private key) is known, preventing even an attacker with control over the private key used to control the data internally.
+  * Intended to be completely free of timing sidechannels for secret-key operations (on reasonable hardware/toolchains)
+    * Access the table with branch-free conditional moves so memory access is uniform.
+    * No data-dependent branches
+  * Optional runtime blinding which attempts to frustrate differential power analysis.
+  * The precomputed tables add and eventually subtract points for which no known scalar (secret key) is known, preventing even an attacker with control over the secret key used to control the data internally.
 
 Build steps
 -----------
@@ -57,5 +65,40 @@ libsecp256k1 is built using autotools:
     $ ./autogen.sh
     $ ./configure
     $ make
-    $ ./tests
+    $ make check
     $ sudo make install  # optional
+
+Exhaustive tests
+-----------
+
+    $ ./exhaustive_tests
+
+With valgrind, you might need to increase the max stack size:
+
+    $ valgrind --max-stackframe=2500000 ./exhaustive_tests
+
+Test coverage
+-----------
+
+This library aims to have full coverage of the reachable lines and branches.
+
+To create a test coverage report, configure with `--enable-coverage` (use of GCC is necessary):
+
+    $ ./configure --enable-coverage
+
+Run the tests:
+
+    $ make check
+
+To create a report, `gcovr` is recommended, as it includes branch coverage reporting:
+
+    $ gcovr --exclude 'src/bench*' --print-summary
+
+To create a HTML report with coloured and annotated source code:
+
+    $ gcovr --exclude 'src/bench*' --html --html-details -o coverage.html
+
+Reporting a vulnerability
+------------
+
+See [SECURITY.md](SECURITY.md)

src/secp256k1/SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+To report security issues send an email to [email protected] (not for support).
+
+The following keys may be used to communicate sensitive information to developers:
+
+| Name | Fingerprint |
+|------|-------------|
+| Pieter Wuille | 133E AC17 9436 F14A 5CF1  B794 860F EB80 4E66 9320 |
+| Andrew Poelstra | 699A 63EF C17A D3A9 A34C  FFC0 7AD0 A91C 40BD 0091 |
+| Tim Ruffing | 09E0 3F87 1092 E40E 106E  902B 33BC 86AB 80FF 5516 |
+
+You can import a key by running the following command with that individual’s fingerprint: `gpg --recv-keys "<fingerprint>"` Ensure that you put quotes around fingerprints containing spaces.