BlockstreamResearch · jonasnick · Jul 20, 2023 · Oct 25, 2022 · Nov 21, 2022 · Dec 5, 2022
diff --git a/.cirrus.yml b/.cirrus.yml
@@ -1,6 +1,7 @@
 env:
   ### compiler options
   HOST:
+  WRAPPER_CMD:
   # Specific warnings can be disabled with -Wno-error=foo.
   # -pedantic-errors is not equivalent to -Werror=pedantic and thus not implied by -Werror according to the GCC manual.
   WERROR_CFLAGS: -Werror -pedantic-errors
@@ -41,6 +42,8 @@ cat_logs_snippet: &CAT_LOGS
   always:
     cat_tests_log_script:
       - cat tests.log || true
+    cat_noverify_tests_log_script:
+      - cat noverify_tests.log || true
     cat_exhaustive_tests_log_script:
       - cat exhaustive_tests.log || true
     cat_valgrind_ctime_test_log_script:

diff --git a/.gitignore b/.gitignore
@@ -47,8 +47,6 @@ coverage.*.html
 *.gcno
 *.gcov
 
-src/libsecp256k1-config.h
-src/libsecp256k1-config.h.in
 build-aux/ar-lib
 build-aux/config.guess
 build-aux/config.sub
@@ -63,7 +61,6 @@ build-aux/m4/ltversion.m4
 build-aux/missing
 build-aux/compile
 build-aux/test-driver
-src/stamp-h1
 libsecp256k1.pc
 contrib/gh-pr-create.sh
 

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,29 +3,40 @@ Instead, it is the changelog of the upstream library [libsecp256k1](https://gith
 
 # Changelog
 
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
 ## [0.2.0] - 2022-12-12
 
-### Added
+#### Added
+ - Added usage examples for common use cases in a new `examples/` directory.
  - Added `secp256k1_selftest`, to be used in conjunction with `secp256k1_context_static`.
+ - Added support for 128-bit wide multiplication on MSVC for x86_64 and arm64, giving roughly a 20% speedup on those platforms.
 
-### Changed
- - Enabled modules schnorrsig, extrakeys and ECDH by default in `./configure`.
+#### Changed
+ - Enabled modules `schnorrsig`, `extrakeys` and `ecdh` by default in `./configure`.
+ - The `secp256k1_nonce_function_rfc6979` nonce function, used by default by `secp256k1_ecdsa_sign`, now reduces the message hash modulo the group order to match the specification. This only affects improper use of ECDSA signing API.
 
-### Deprecated
+#### Deprecated
  - Deprecated context flags `SECP256K1_CONTEXT_VERIFY` and `SECP256K1_CONTEXT_SIGN`. Use `SECP256K1_CONTEXT_NONE` instead.
  - Renamed `secp256k1_context_no_precomp` to `secp256k1_context_static`.
+ - Module `schnorrsig`: renamed `secp256k1_schnorrsig_sign` to `secp256k1_schnorrsig_sign32`.
 
-### ABI Compatibility
+#### ABI Compatibility
 
 Since this is the first release, we do not compare application binary interfaces.
-However, there are unreleased versions of libsecp256k1 that are *not* ABI compatible with this version.
+However, there are earlier unreleased versions of libsecp256k1 that are *not* ABI compatible with this version.
 
 ## [0.1.0] - 2013-03-05 to 2021-12-25
 
 This version was in fact never released.
 The number was given by the build system since the introduction of autotools in Jan 2014 (ea0fe5a5bf0c04f9cc955b2966b614f5f378c6f6).
 Therefore, this version number does not uniquely identify a set of source files.
+
+[unreleased]: https://github.com/bitcoin-core/secp256k1/compare/v0.2.0...HEAD
+[0.2.0]: https://github.com/bitcoin-core/secp256k1/compare/423b6d19d373f1224fd671a982584d7e7900bc93..v0.2.0
+[0.1.0]: https://github.com/bitcoin-core/secp256k1/commit/423b6d19d373f1224fd671a982584d7e7900bc93
diff --git a/Makefile.am b/Makefile.am
@@ -75,7 +75,7 @@ noinst_HEADERS += examples/random.h
 PRECOMPUTED_LIB = libsecp256k1_precomputed.la
 noinst_LTLIBRARIES = $(PRECOMPUTED_LIB)
 libsecp256k1_precomputed_la_SOURCES =  src/precomputed_ecmult.c src/precomputed_ecmult_gen.c
-libsecp256k1_precomputed_la_CPPFLAGS = $(SECP_INCLUDES)
+libsecp256k1_precomputed_la_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 
 if USE_EXTERNAL_ASM
 COMMON_LIB = libsecp256k1_common.la
@@ -94,7 +94,7 @@ endif
 endif
 
 libsecp256k1_la_SOURCES = src/secp256k1.c
-libsecp256k1_la_CPPFLAGS = $(SECP_INCLUDES)
+libsecp256k1_la_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 libsecp256k1_la_LIBADD = $(SECP_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
 libsecp256k1_la_LDFLAGS = -no-undefined -version-info $(LIB_VERSION_CURRENT):$(LIB_VERSION_REVISION):$(LIB_VERSION_AGE)
 
@@ -107,37 +107,43 @@ if USE_BENCHMARK
 noinst_PROGRAMS += bench bench_internal bench_ecmult
 bench_SOURCES = src/bench.c
 bench_LDADD = libsecp256k1.la $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB)
+bench_CPPFLAGS = $(SECP_CONFIG_DEFINES)
 bench_internal_SOURCES = src/bench_internal.c
 bench_internal_LDADD = $(SECP_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
-bench_internal_CPPFLAGS = $(SECP_INCLUDES)
+bench_internal_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 bench_ecmult_SOURCES = src/bench_ecmult.c
 bench_ecmult_LDADD = $(SECP_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
-bench_ecmult_CPPFLAGS = $(SECP_INCLUDES)
+bench_ecmult_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 endif
 
 TESTS =
 if USE_TESTS
-noinst_PROGRAMS += tests
-tests_SOURCES = src/tests.c
-tests_CPPFLAGS = $(SECP_INCLUDES) $(SECP_TEST_INCLUDES)
+TESTS += noverify_tests
+noinst_PROGRAMS += noverify_tests
+noverify_tests_SOURCES = src/tests.c
+noverify_tests_CPPFLAGS = $(SECP_INCLUDES) $(SECP_TEST_INCLUDES) $(SECP_CONFIG_DEFINES)
+noverify_tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
+noverify_tests_LDFLAGS = -static
 if VALGRIND_ENABLED
-tests_CPPFLAGS += -DVALGRIND
+noverify_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) $(COMMON_LIB)
 endif
 if !ENABLE_COVERAGE
-tests_CPPFLAGS += -DVERIFY
-endif
-tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
-tests_LDFLAGS = -static
 TESTS += tests
+noinst_PROGRAMS += tests
+tests_SOURCES  = $(noverify_tests_SOURCES)
+tests_CPPFLAGS = $(noverify_tests_CPPFLAGS) -DVERIFY
+tests_LDADD    = $(noverify_tests_LDADD)
+tests_LDFLAGS  = $(noverify_tests_LDFLAGS)
+endif
 endif
 
 if USE_EXHAUSTIVE_TESTS
 noinst_PROGRAMS += exhaustive_tests
 exhaustive_tests_SOURCES = src/tests_exhaustive.c
-exhaustive_tests_CPPFLAGS = $(SECP_INCLUDES)
+exhaustive_tests_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 if !ENABLE_COVERAGE
 exhaustive_tests_CPPFLAGS += -DVERIFY
 endif
@@ -197,11 +203,11 @@ EXTRA_PROGRAMS = precompute_ecmult precompute_ecmult_gen
 CLEANFILES = $(EXTRA_PROGRAMS)
 
 precompute_ecmult_SOURCES = src/precompute_ecmult.c
-precompute_ecmult_CPPFLAGS = $(SECP_INCLUDES)
+precompute_ecmult_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 precompute_ecmult_LDADD = $(SECP_LIBS) $(COMMON_LIB)
 
 precompute_ecmult_gen_SOURCES = src/precompute_ecmult_gen.c
-precompute_ecmult_gen_CPPFLAGS = $(SECP_INCLUDES)
+precompute_ecmult_gen_CPPFLAGS = $(SECP_INCLUDES) $(SECP_CONFIG_DEFINES)
 precompute_ecmult_gen_LDADD = $(SECP_LIBS) $(COMMON_LIB)
 
 # See Automake manual, Section "Errors with distclean".

diff --git a/build-aux/m4/bitcoin_secp.m4 b/build-aux/m4/bitcoin_secp.m4
@@ -20,7 +20,7 @@ if test x"$has_valgrind" != x"yes"; then
     #if defined(NVALGRIND)
     #  error "Valgrind does not support this platform."
     #endif
-  ]])], [has_valgrind=yes; AC_DEFINE(HAVE_VALGRIND,1,[Define this symbol if valgrind is installed, and it supports the host platform])])
+  ]])], [has_valgrind=yes])
 fi
 AC_MSG_RESULT($has_valgrind)
 ])

diff --git a/ci/cirrus.sh b/ci/cirrus.sh
@@ -1,7 +1,6 @@
 #!/bin/sh
 
-set -e
-set -x
+set -eux
 
 export LC_ALL=C
 
@@ -11,15 +10,21 @@ print_environment() {
     set +x
     # There are many ways to print variable names and their content. This one
     # does not rely on bash.
-    for i in WERROR_CFLAGS MAKEFLAGS BUILD \
+    for var in WERROR_CFLAGS MAKEFLAGS BUILD \
             ECMULTWINDOW ECMULTGENPRECISION ASM WIDEMUL WITH_VALGRIND EXTRAFLAGS \
             EXPERIMENTAL ECDH RECOVERY SCHNORRSIG \
             ECDSA_S2C GENERATOR RANGEPROOF WHITELIST MUSIG ECDSAADAPTOR BPPP \
             SECP256K1_TEST_ITERS BENCH SECP256K1_BENCH_ITERS CTIMETEST\
             EXAMPLES \
-            WRAPPER_CMD CC AR NM HOST
+            HOST WRAPPER_CMD \
+            CC CFLAGS CPPFLAGS AR NM
     do
-        eval 'printf "%s %s " "$i=\"${'"$i"'}\""'
+        eval "isset=\${$var+x}"
+        if [ -n "$isset" ]; then
+            eval "val=\${$var}"
+            # shellcheck disable=SC2154
+            printf '%s="%s" ' "$var" "$val"
+        fi
     done
     echo "$0"
     set -x
@@ -37,7 +42,7 @@ esac
 
 env >> test_env.log
 
-if [ -n "$CC" ]; then
+if [ -n "${CC+x}" ]; then
     # The MSVC compiler "cl" doesn't understand "-v"
     $CC -v || true
 fi

diff --git a/configure.ac b/configure.ac
@@ -273,7 +273,7 @@ fi
 AM_CONDITIONAL([VALGRIND_ENABLED],[test "$enable_valgrind" = "yes"])
 
 if test x"$enable_coverage" = x"yes"; then
-    AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code])
+    SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DCOVERAGE=1"
     SECP_CFLAGS="-O0 --coverage $SECP_CFLAGS"
     LDFLAGS="--coverage $LDFLAGS"
 else
@@ -285,13 +285,13 @@ fi
 
 AC_MSG_CHECKING([for __builtin_popcount])
 AC_LINK_IFELSE([AC_LANG_SOURCE([[void myfunc() {__builtin_popcount(0);}]])],
-    [ AC_MSG_RESULT([yes]);AC_DEFINE(HAVE_BUILTIN_POPCOUNT,1,[Define this symbol if __builtin_popcount is available]) ],
+    [ AC_MSG_RESULT([yes]); SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DHAVE_BUILTIN_POPCOUNT=1"],
     [ AC_MSG_RESULT([no])
     ])
 
 AC_MSG_CHECKING([for  __builtin_clzll])
 AC_LINK_IFELSE([AC_LANG_SOURCE([[void myfunc() { __builtin_clzll(1);}]])],
-    [ AC_MSG_RESULT([yes]);AC_DEFINE(HAVE_BUILTIN_CLZLL,1,[Define this symbol if  __builtin_clzll is available]) ],
+    [ AC_MSG_RESULT([yes]); SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DHAVE_BUILTIN_CLZLL=1"],
     [ AC_MSG_RESULT([no])
     ])
 
@@ -327,7 +327,7 @@ enable_external_asm=no
 
 case $set_asm in
 x86_64)
-  AC_DEFINE(USE_ASM_X86_64, 1, [Define this symbol to enable x86_64 assembly optimizations])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_ASM_X86_64=1"
   ;;
 arm)
   enable_external_asm=yes
@@ -340,20 +340,20 @@ no)
 esac
 
 if test x"$enable_external_asm" = x"yes"; then
-  AC_DEFINE(USE_EXTERNAL_ASM, 1, [Define this symbol if an external (non-inline) assembly implementation is used])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_EXTERNAL_ASM=1"
 fi
 
 
 # Select wide multiplication implementation
 case $set_widemul in
 int128_struct)
-  AC_DEFINE(USE_FORCE_WIDEMUL_INT128_STRUCT, 1, [Define this symbol to force the use of the structure for simulating (unsigned) int128 based wide multiplication])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_FORCE_WIDEMUL_INT128_STRUCT=1"
   ;;
 int128)
-  AC_DEFINE(USE_FORCE_WIDEMUL_INT128, 1, [Define this symbol to force the use of the (unsigned) __int128 based wide multiplication implementation])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_FORCE_WIDEMUL_INT128=1"
   ;;
 int64)
-  AC_DEFINE(USE_FORCE_WIDEMUL_INT64, 1, [Define this symbol to force the use of the (u)int64_t based wide multiplication implementation])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_FORCE_WIDEMUL_INT64=1"
   ;;
 auto)
   ;;
@@ -380,7 +380,7 @@ case $set_ecmult_window in
     # not in range
     AC_MSG_ERROR($error_window_size)
   fi
-  AC_DEFINE_UNQUOTED(ECMULT_WINDOW_SIZE, $set_ecmult_window, [Set window size for ecmult precomputation])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DECMULT_WINDOW_SIZE=$set_ecmult_window"
   ;;
 esac
 
@@ -393,7 +393,7 @@ fi
 
 case $set_ecmult_gen_precision in
 2|4|8)
-  AC_DEFINE_UNQUOTED(ECMULT_GEN_PREC_BITS, $set_ecmult_gen_precision, [Set ecmult gen precision bits])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DECMULT_GEN_PREC_BITS=$set_ecmult_gen_precision"
   ;;
 *)
   AC_MSG_ERROR(['ecmult gen precision not 2, 4, 8 or "auto"'])
@@ -418,65 +418,65 @@ SECP_CFLAGS="$SECP_CFLAGS $WERROR_CFLAGS"
 # tested first.
 
 if test x"$enable_module_ecdh" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_ECDH, 1, [Define this symbol to enable the ECDH module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_ECDH=1"
 fi
 
 if test x"$enable_module_musig" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_MUSIG, 1, [Define this symbol to enable the MuSig module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_MUSIG=1"
   enable_module_schnorrsig=yes
 fi
 
 if test x"$enable_module_recovery" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_RECOVERY, 1, [Define this symbol to enable the ECDSA pubkey recovery module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_RECOVERY=1"
 fi
 
 if test x"$enable_module_whitelist" = x"yes"; then
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_WHITELIST=1"
   enable_module_rangeproof=yes
-  AC_DEFINE(ENABLE_MODULE_WHITELIST, 1, [Define this symbol to enable the key whitelisting module])
 fi
 
 if test x"$enable_module_surjectionproof" = x"yes"; then
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_SURJECTIONPROOF=1"
   enable_module_rangeproof=yes
-  AC_DEFINE(ENABLE_MODULE_SURJECTIONPROOF, 1, [Define this symbol to enable the surjection proof module])
 fi
 
 if test x"$enable_module_rangeproof" = x"yes"; then
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_RANGEPROOF=1"
   enable_module_generator=yes
-  AC_DEFINE(ENABLE_MODULE_RANGEPROOF, 1, [Define this symbol to enable the Pedersen / zero knowledge range proof module])
 fi
 
 if test x"$enable_module_bppp" = x"yes"; then
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_BPPP=1"
   enable_module_generator=yes
-  AC_DEFINE(ENABLE_MODULE_BPPP, 1, [Define this symbol to enable the Bulletproofs++ module])
 fi
 
 if test x"$enable_module_generator" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_GENERATOR, 1, [Define this symbol to enable the NUMS generator module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_GENERATOR=1"
 fi
 
 if test x"$enable_module_schnorrsig" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_SCHNORRSIG, 1, [Define this symbol to enable the schnorrsig module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_SCHNORRSIG=1"
   enable_module_extrakeys=yes
 fi
 
 if test x"$enable_module_extrakeys" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_EXTRAKEYS, 1, [Define this symbol to enable the extrakeys module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_EXTRAKEYS=1"
 fi
 
 if test x"$enable_module_ecdsa_s2c" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_ECDSA_S2C, 1, [Define this symbol to enable the ECDSA sign-to-contract module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_ECDSA_S2C=1"
 fi
 
 if test x"$enable_external_default_callbacks" = x"yes"; then
-  AC_DEFINE(USE_EXTERNAL_DEFAULT_CALLBACKS, 1, [Define this symbol if an external implementation of the default callbacks is used])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_EXTERNAL_DEFAULT_CALLBACKS=1"
 fi
 
 if test x"$use_reduced_surjection_proof_size" = x"yes"; then
-  AC_DEFINE(USE_REDUCED_SURJECTION_PROOF_SIZE, 1, [Define this symbol to reduce SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS to 16, disabling parsing and verification])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DUSE_REDUCED_SURJECTION_PROOF_SIZE=1"
 fi
 
 if test x"$enable_module_ecdsa_adaptor" = x"yes"; then
-  AC_DEFINE(ENABLE_MODULE_ECDSA_ADAPTOR, 1, [Define this symbol to enable the ECDSA adaptor module])
+  SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DENABLE_MODULE_ECDSA_ADAPTOR=1"
 fi
 
 ###
@@ -526,13 +526,13 @@ fi
 ### Generate output
 ###
 
-AC_CONFIG_HEADERS([src/libsecp256k1-config.h])
 AC_CONFIG_FILES([Makefile libsecp256k1.pc])
 AC_SUBST(SECP_INCLUDES)
 AC_SUBST(SECP_LIBS)
 AC_SUBST(SECP_TEST_LIBS)
 AC_SUBST(SECP_TEST_INCLUDES)
 AC_SUBST(SECP_CFLAGS)
+AC_SUBST(SECP_CONFIG_DEFINES)
 AM_CONDITIONAL([ENABLE_COVERAGE], [test x"$enable_coverage" = x"yes"])
 AM_CONDITIONAL([USE_TESTS], [test x"$enable_tests" != x"no"])
 AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$enable_exhaustive_tests" != x"no"])