sipa
diff --git a/‎.gitignore‎
Lines changed: 1 addition & 1 deletion b/‎.gitignore‎
Lines changed: 1 addition & 1 deletion
diff --git a/‎.travis.yml‎
Lines changed: 8 additions & 6 deletions b/‎.travis.yml‎
Lines changed: 8 additions & 6 deletions
diff --git a/‎Makefile.am‎
Lines changed: 7 additions & 2 deletions b/‎Makefile.am‎
Lines changed: 7 additions & 2 deletions
diff --git a/‎README.md‎
Lines changed: 14 additions & 3 deletions b/‎README.md‎
Lines changed: 14 additions & 3 deletions
diff --git a/‎configure.ac‎
Lines changed: 114 additions & 32 deletions b/‎configure.ac‎
Lines changed: 114 additions & 32 deletions
diff --git a/‎contrib/lax_der_parsing.c‎
Lines changed: 3 additions & 3 deletions b/‎contrib/lax_der_parsing.c‎
Lines changed: 3 additions & 3 deletions
@@ -1,9 +1,9 @@
 bench_inv
 bench_ecdh
 bench_ecmult
+bench_schnorrsig
 bench_sign
 bench_verify
-bench_schnorr_verify
 bench_recover
 bench_internal
 tests
 
@@ -11,25 +11,27 @@ cache:
   - 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
+    - FIELD=auto  BIGNUM=auto  SCALAR=auto  ENDOMORPHISM=no  STATICPRECOMPUTATION=yes  ECMULTGENPRECISION=auto  ASM=no  BUILD=check  EXTRAFLAGS=  HOST=  ECDH=no  RECOVERY=no  EXPERIMENTAL=no  JNI=no JNI=no SCHNORRSIG=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
   matrix:
     - SCALAR=32bit    RECOVERY=yes
-    - SCALAR=32bit    FIELD=32bit       ECDH=yes  EXPERIMENTAL=yes
+    - SCALAR=32bit    FIELD=32bit       ECDH=yes  EXPERIMENTAL=yes   SCHNORRSIG=yes
     - SCALAR=64bit
-    - FIELD=64bit     RECOVERY=yes
+    - FIELD=64bit     RECOVERY=yes      EXPERIMENTAL=yes             SCHNORRSIG=yes
     - FIELD=64bit     ENDOMORPHISM=yes
-    - FIELD=64bit     ENDOMORPHISM=yes  ECDH=yes EXPERIMENTAL=yes
+    - FIELD=64bit     ENDOMORPHISM=yes  ECDH=yes EXPERIMENTAL=yes    SCHNORRSIG=yes
     - FIELD=64bit                       ASM=x86_64
     - FIELD=64bit     ENDOMORPHISM=yes  ASM=x86_64
     - FIELD=32bit     ENDOMORPHISM=yes
     - BIGNUM=no
-    - BIGNUM=no       ENDOMORPHISM=yes RECOVERY=yes EXPERIMENTAL=yes
+    - BIGNUM=no       ENDOMORPHISM=yes RECOVERY=yes EXPERIMENTAL=yes SCHNORRSIG=yes
     - BIGNUM=no       STATICPRECOMPUTATION=no
     - BUILD=distcheck
     - EXTRAFLAGS=CPPFLAGS=-DDETERMINISTIC
     - EXTRAFLAGS=CFLAGS=-O0
     - BUILD=check-java JNI=yes ECDH=yes EXPERIMENTAL=yes
+    - ECMULTGENPRECISION=2
+    - ECMULTGENPRECISION=8
 matrix:
   fast_finish: true
   include:
@@ -65,4 +67,4 @@ before_script: ./autogen.sh
 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 $BUILD
+ - ./configure --enable-experimental=$EXPERIMENTAL --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-scalar=$SCALAR --enable-ecmult-static-precomputation=$STATICPRECOMPUTATION --with-ecmult-gen-precision=$ECMULTGENPRECISION --enable-module-ecdh=$ECDH --enable-module-recovery=$RECOVERY --enable-module-schnorrsig=$SCHNORRSIG --enable-jni=$JNI $EXTRAFLAGS $USE_HOST && make -j2 $BUILD
@@ -8,6 +8,7 @@ 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
@@ -150,11 +151,11 @@ 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)
@@ -177,6 +178,10 @@ if ENABLE_MODULE_ECDH
 include src/modules/ecdh/Makefile.am.include
 endif
 
+if ENABLE_MODULE_SCHNORRSIG
+include src/modules/schnorrsig/Makefile.am.include
+endif
+
 if ENABLE_MODULE_RECOVERY
 include src/modules/recovery/Makefile.am.include
 endif
@@ -45,8 +45,10 @@ 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
+  * 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 (private key) is known, preventing even an attacker with control over the private key used to control the data internally.
 
 Build steps
@@ -57,5 +59,14 @@ 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
@@ -85,42 +85,42 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
     ])
 
 AC_ARG_ENABLE(benchmark,
-    AS_HELP_STRING([--enable-benchmark],[compile benchmark (default is yes)]),
+    AS_HELP_STRING([--enable-benchmark],[compile benchmark [default=yes]]),
     [use_benchmark=$enableval],
     [use_benchmark=yes])
 
 AC_ARG_ENABLE(coverage,
-    AS_HELP_STRING([--enable-coverage],[enable compiler flags to support kcov coverage analysis]),
+    AS_HELP_STRING([--enable-coverage],[enable compiler flags to support kcov coverage analysis [default=no]]),
     [enable_coverage=$enableval],
     [enable_coverage=no])
 
 AC_ARG_ENABLE(tests,
-    AS_HELP_STRING([--enable-tests],[compile tests (default is yes)]),
+    AS_HELP_STRING([--enable-tests],[compile tests [default=yes]]),
     [use_tests=$enableval],
     [use_tests=yes])
 
 AC_ARG_ENABLE(openssl_tests,
-    AS_HELP_STRING([--enable-openssl-tests],[enable OpenSSL tests, if OpenSSL is available (default is auto)]),
+    AS_HELP_STRING([--enable-openssl-tests],[enable OpenSSL tests [default=auto]]),
     [enable_openssl_tests=$enableval],
     [enable_openssl_tests=auto])
 
 AC_ARG_ENABLE(experimental,
-    AS_HELP_STRING([--enable-experimental],[allow experimental configure options (default is no)]),
+    AS_HELP_STRING([--enable-experimental],[allow experimental configure options [default=no]]),
     [use_experimental=$enableval],
     [use_experimental=no])
 
 AC_ARG_ENABLE(exhaustive_tests,
-    AS_HELP_STRING([--enable-exhaustive-tests],[compile exhaustive tests (default is yes)]),
+    AS_HELP_STRING([--enable-exhaustive-tests],[compile exhaustive tests [default=yes]]),
     [use_exhaustive_tests=$enableval],
     [use_exhaustive_tests=yes])
 
 AC_ARG_ENABLE(endomorphism,
-    AS_HELP_STRING([--enable-endomorphism],[enable endomorphism (default is no)]),
+    AS_HELP_STRING([--enable-endomorphism],[enable endomorphism [default=no]]),
     [use_endomorphism=$enableval],
     [use_endomorphism=no])
 
 AC_ARG_ENABLE(ecmult_static_precomputation,
-    AS_HELP_STRING([--enable-ecmult-static-precomputation],[enable precomputed ecmult table for signing (default is yes)]),
+    AS_HELP_STRING([--enable-ecmult-static-precomputation],[enable precomputed ecmult table for signing [default=auto]]),
     [use_ecmult_static_precomputation=$enableval],
     [use_ecmult_static_precomputation=auto])
 
@@ -129,34 +129,61 @@ AC_ARG_ENABLE(module_ecdh,
     [enable_module_ecdh=$enableval],
     [enable_module_ecdh=no])
 
+AC_ARG_ENABLE(module_schnorrsig,
+    AS_HELP_STRING([--enable-module-schnorrsig],[enable schnorrsig module (experimental)]),
+    [enable_module_schnorrsig=$enableval],
+    [enable_module_schnorrsig=no])
+
 AC_ARG_ENABLE(module_recovery,
-    AS_HELP_STRING([--enable-module-recovery],[enable ECDSA pubkey recovery module (default is no)]),
+    AS_HELP_STRING([--enable-module-recovery],[enable ECDSA pubkey recovery module [default=no]]),
     [enable_module_recovery=$enableval],
     [enable_module_recovery=no])
 
+AC_ARG_ENABLE(external_default_callbacks,
+    AS_HELP_STRING([--enable-external-default-callbacks],[enable external default callback functions [default=no]]),
+    [use_external_default_callbacks=$enableval],
+    [use_external_default_callbacks=no])
+
 AC_ARG_ENABLE(jni,
-    AS_HELP_STRING([--enable-jni],[enable libsecp256k1_jni (default is no)]),
+    AS_HELP_STRING([--enable-jni],[enable libsecp256k1_jni [default=no]]),
     [use_jni=$enableval],
     [use_jni=no])
 
 AC_ARG_WITH([field], [AS_HELP_STRING([--with-field=64bit|32bit|auto],
-[Specify Field Implementation. Default is auto])],[req_field=$withval], [req_field=auto])
+[finite field implementation to use [default=auto]])],[req_field=$withval], [req_field=auto])
 
 AC_ARG_WITH([bignum], [AS_HELP_STRING([--with-bignum=gmp|no|auto],
-[Specify Bignum Implementation. Default is auto])],[req_bignum=$withval], [req_bignum=auto])
+[bignum implementation to use [default=auto]])],[req_bignum=$withval], [req_bignum=auto])
 
 AC_ARG_WITH([scalar], [AS_HELP_STRING([--with-scalar=64bit|32bit|auto],
-[Specify scalar implementation. Default is auto])],[req_scalar=$withval], [req_scalar=auto])
-
-AC_ARG_WITH([asm], [AS_HELP_STRING([--with-asm=x86_64|arm|no|auto]
-[Specify assembly optimizations to use. Default is auto (experimental: arm)])],[req_asm=$withval], [req_asm=auto])
+[scalar implementation to use [default=auto]])],[req_scalar=$withval], [req_scalar=auto])
+
+AC_ARG_WITH([asm], [AS_HELP_STRING([--with-asm=x86_64|arm|no|auto],
+[assembly optimizations to use (experimental: arm) [default=auto]])],[req_asm=$withval], [req_asm=auto])
+
+AC_ARG_WITH([ecmult-window], [AS_HELP_STRING([--with-ecmult-window=SIZE|auto],
+[window size for ecmult precomputation for verification, specified as integer in range [2..24].]
+[Larger values result in possibly better performance at the cost of an exponentially larger precomputed table.]
+[The table will store 2^(SIZE-2) * 64 bytes of data but can be larger in memory due to platform-specific padding and alignment.]
+[If the endomorphism optimization is enabled, two tables of this size are used instead of only one.]
+["auto" is a reasonable setting for desktop machines (currently 15). [default=auto]]
+)],
+[req_ecmult_window=$withval], [req_ecmult_window=auto])
+
+AC_ARG_WITH([ecmult-gen-precision], [AS_HELP_STRING([--with-ecmult-gen-precision=2|4|8|auto],
+[Precision bits to tune the precomputed table size for signing.]
+[The size of the table is 32kB for 2 bits, 64kB for 4 bits, 512kB for 8 bits of precision.]
+[A larger table size usually results in possible faster signing.]
+["auto" is a reasonable setting for desktop machines (currently 4). [default=auto]]
+)],
+[req_ecmult_gen_precision=$withval], [req_ecmult_gen_precision=auto])
 
 AC_CHECK_TYPES([__int128])
 
 if test x"$enable_coverage" = x"yes"; then
     AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code])
     CFLAGS="$CFLAGS -O0 --coverage"
-    LDFLAGS="--coverage"
+    LDFLAGS="$LDFLAGS --coverage"
 else
     CFLAGS="$CFLAGS -O3"
 fi
@@ -387,6 +414,44 @@ case $set_scalar in
   ;;
 esac
 
+#set ecmult window size
+if test x"$req_ecmult_window" = x"auto"; then
+  set_ecmult_window=15
+else
+  set_ecmult_window=$req_ecmult_window
+fi
+
+error_window_size=['window size for ecmult precomputation not an integer in range [2..24] or "auto"']
+case $set_ecmult_window in
+''|*[[!0-9]]*)
+  # no valid integer
+  AC_MSG_ERROR($error_window_size)
+  ;;
+*)
+  if test "$set_ecmult_window" -lt 2 -o "$set_ecmult_window" -gt 24 ; then
+    # not in range
+    AC_MSG_ERROR($error_window_size)
+  fi
+  AC_DEFINE_UNQUOTED(ECMULT_WINDOW_SIZE, $set_ecmult_window, [Set window size for ecmult precomputation])
+  ;;
+esac
+
+#set ecmult gen precision
+if test x"$req_ecmult_gen_precision" = x"auto"; then
+  set_ecmult_gen_precision=4
+else
+  set_ecmult_gen_precision=$req_ecmult_gen_precision
+fi
+
+case $set_ecmult_gen_precision in
+2|4|8)
+  AC_DEFINE_UNQUOTED(ECMULT_GEN_PREC_BITS, $set_ecmult_gen_precision, [Set ecmult gen precision bits])
+  ;;
+*)
+  AC_MSG_ERROR(['ecmult gen precision not 2, 4, 8 or "auto"'])
+  ;;
+esac
+
 if test x"$use_tests" = x"yes"; then
   SECP_OPENSSL_CHECK
   if test x"$has_openssl_ec" = x"yes"; then
@@ -452,6 +517,10 @@ if test x"$enable_module_ecdh" = x"yes"; then
   AC_DEFINE(ENABLE_MODULE_ECDH, 1, [Define this symbol to enable the ECDH module])
 fi
 
+if test x"$enable_module_schnorrsig" = x"yes"; then
+  AC_DEFINE(ENABLE_MODULE_SCHNORRSIG, 1, [Define this symbol to enable the schnorrsig module])
+fi
+
 if test x"$enable_module_recovery" = x"yes"; then
   AC_DEFINE(ENABLE_MODULE_RECOVERY, 1, [Define this symbol to enable the ECDSA pubkey recovery module])
 fi
@@ -462,16 +531,24 @@ if test x"$use_external_asm" = x"yes"; then
   AC_DEFINE(USE_EXTERNAL_ASM, 1, [Define this symbol if an external (non-inline) assembly implementation is used])
 fi
 
+if test x"$use_external_default_callbacks" = x"yes"; then
+  AC_DEFINE(USE_EXTERNAL_DEFAULT_CALLBACKS, 1, [Define this symbol if an external implementation of the default callbacks is used])
+fi
+
 if test x"$enable_experimental" = x"yes"; then
   AC_MSG_NOTICE([******])
   AC_MSG_NOTICE([WARNING: experimental build])
   AC_MSG_NOTICE([Experimental features do not have stable APIs or properties, and may not be safe for production use.])
   AC_MSG_NOTICE([Building ECDH module: $enable_module_ecdh])
+  AC_MSG_NOTICE([Building schnorrsig module: $enable_module_schnorrsig])
   AC_MSG_NOTICE([******])
 else
   if test x"$enable_module_ecdh" = x"yes"; then
     AC_MSG_ERROR([ECDH module is experimental. Use --enable-experimental to allow.])
   fi
+  if test x"$enable_module_schnorrsig" = x"yes"; then
+    AC_MSG_ERROR([schnorrsig module is experimental. Use --enable-experimental to allow.])
+  fi
   if test x"$set_asm" = x"arm"; then
     AC_MSG_ERROR([ARM assembly optimization is experimental. Use --enable-experimental to allow.])
   fi
@@ -490,6 +567,7 @@ AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$use_exhaustive_tests" != x"no"])
 AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"])
 AM_CONDITIONAL([USE_ECMULT_STATIC_PRECOMPUTATION], [test x"$set_precomp" = x"yes"])
 AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"])
+AM_CONDITIONAL([ENABLE_MODULE_SCHNORRSIG], [test x"$enable_module_schnorrsig" = x"yes"])
 AM_CONDITIONAL([ENABLE_MODULE_RECOVERY], [test x"$enable_module_recovery" = x"yes"])
 AM_CONDITIONAL([USE_JNI], [test x"$use_jni" = x"yes"])
 AM_CONDITIONAL([USE_EXTERNAL_ASM], [test x"$use_external_asm" = x"yes"])
@@ -504,21 +582,25 @@ AC_OUTPUT
 
 echo
 echo "Build Options:"
-echo "  with endomorphism   = $use_endomorphism"
-echo "  with ecmult precomp = $set_precomp"
-echo "  with jni            = $use_jni"
-echo "  with benchmarks     = $use_benchmark"
-echo "  with coverage       = $enable_coverage"
-echo "  module ecdh         = $enable_module_ecdh"
-echo "  module recovery     = $enable_module_recovery"
+echo "  with endomorphism       = $use_endomorphism"
+echo "  with ecmult precomp     = $set_precomp"
+echo "  with external callbacks = $use_external_default_callbacks"
+echo "  with jni                = $use_jni"
+echo "  with benchmarks         = $use_benchmark"
+echo "  with coverage           = $enable_coverage"
+echo "  module ecdh             = $enable_module_ecdh"
+echo "  module recovery         = $enable_module_recovery"
+echo "  module schnorrsig       = $enable_module_schnorrsig"
 echo
-echo "  asm                 = $set_asm"
-echo "  bignum              = $set_bignum"
-echo "  field               = $set_field"
-echo "  scalar              = $set_scalar"
+echo "  asm                     = $set_asm"
+echo "  bignum                  = $set_bignum"
+echo "  field                   = $set_field"
+echo "  scalar                  = $set_scalar"
+echo "  ecmult window size      = $set_ecmult_window"
+echo "  ecmult gen prec. bits   = $set_ecmult_gen_precision"
 echo
-echo "  CC                  = $CC"
-echo "  CFLAGS              = $CFLAGS"
-echo "  CPPFLAGS            = $CPPFLAGS"
-echo "  LDFLAGS             = $LDFLAGS"
+echo "  CC                      = $CC"
+echo "  CFLAGS                  = $CFLAGS"
+echo "  CPPFLAGS                = $CPPFLAGS"
+echo "  LDFLAGS                 = $LDFLAGS"
 echo
@@ -32,7 +32,7 @@ int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
-        if (pos + lenbyte > inputlen) {
+        if (lenbyte > inputlen - pos) {
             return 0;
         }
         pos += lenbyte;
@@ -51,7 +51,7 @@ int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
-        if (pos + lenbyte > inputlen) {
+        if (lenbyte > inputlen - pos) {
             return 0;
         }
         while (lenbyte > 0 && input[pos] == 0) {
@@ -89,7 +89,7 @@ int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_
     lenbyte = input[pos++];
     if (lenbyte & 0x80) {
         lenbyte -= 0x80;
-        if (pos + lenbyte > inputlen) {
+        if (lenbyte > inputlen - pos) {
             return 0;
         }
         while (lenbyte > 0 && input[pos] == 0) {