Merge commits 'd7ec49a6 9a5a87e aa5d34a 2a3a97c ' into temp-merge-976

Also remove remaining uses of ecmult context in secp-zkp and update API tests
accordingly.

Author: jonasnick

.gitattributes

@@ -0,0 +1 @@
+src/ecmult_static_pre_g.h linguist-generated

.gitignore

@@ -11,6 +11,7 @@ bench_internal
 tests
 exhaustive_tests
 gen_context
+gen_ecmult_static_pre_g
 valgrind_ctime_test
 *.exe
 *.so

Makefile.am

@@ -129,12 +129,19 @@ exhaustive_tests_LDFLAGS = -static
 TESTS += exhaustive_tests
 endif
 
+EXTRA_PROGRAMS = gen_ecmult_static_pre_g
+gen_ecmult_static_pre_g_SOURCES = src/gen_ecmult_static_pre_g.c
+# See Automake manual, Section "Errors with distclean"
+src/ecmult_static_pre_g.h:
+	$(MAKE) $(AM_MAKEFLAGS) gen_ecmult_static_pre_g$(EXEEXT)
+	./gen_ecmult_static_pre_g$(EXEEXT)
+
 if USE_ECMULT_STATIC_PRECOMPUTATION
 CPPFLAGS_FOR_BUILD +=-I$(top_srcdir) -I$(builddir)/src
 
 gen_context_OBJECTS = gen_context.o
 gen_context_BIN = gen_context$(BUILD_EXEEXT)
-gen_%.o: src/gen_%.c src/libsecp256k1-config.h
+$(gen_context_OBJECTS): src/gen_context.c src/libsecp256k1-config.h
 	$(CC_FOR_BUILD) $(DEFS) $(CPPFLAGS_FOR_BUILD) $(SECP_CFLAGS_FOR_BUILD) $(CFLAGS_FOR_BUILD) -c $< -o $@
 
 $(gen_context_BIN): $(gen_context_OBJECTS)
@@ -151,7 +158,7 @@ src/ecmult_static_context.h: $(gen_context_BIN)
 CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h
 endif
 
-EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h
+EXTRA_DIST = autogen.sh src/gen_context.c src/ecmult_static_pre_g.h src/basic-config.h
 
 if ENABLE_MODULE_ECDH
 include src/modules/ecdh/Makefile.am.include

ci/linux-debian.Dockerfile

@@ -14,7 +14,7 @@ RUN apt-get install --no-install-recommends --no-upgrade -y \
         make automake libtool pkg-config dpkg-dev valgrind qemu-user \
         gcc clang llvm libc6-dbg \
         g++ \
-        gcc-i686-linux-gnu libc6-dev-i386-cross libc6-dbg:i386 libubsan1:i386 libasan5:i386 \
+        gcc-i686-linux-gnu libc6-dev-i386-cross libc6-dbg:i386 libubsan1:i386 libasan6:i386 \
         gcc-s390x-linux-gnu libc6-dev-s390x-cross libc6-dbg:s390x \
         gcc-arm-linux-gnueabihf libc6-dev-armhf-cross libc6-dbg:armhf \
         gcc-aarch64-linux-gnu libc6-dev-arm64-cross libc6-dbg:arm64 \

configure.ac

@@ -217,6 +217,8 @@ 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-1) * 64 bytes of data but can be larger in memory due to platform-specific padding and alignment.]
+[A window size larger than 15 will require you delete the prebuilt ecmult_static_pre_g.h file so that it can be rebuilt.]
+[For very large window sizes, use "make -j 1" to reduce memory use during compilation.]
 ["auto" is a reasonable setting for desktop machines (currently 15). [default=auto]]
 )],
 [req_ecmult_window=$withval], [req_ecmult_window=auto])

include/secp256k1.h

@@ -226,7 +226,7 @@ SECP256K1_API secp256k1_context* secp256k1_context_create(
  *  memory allocation entirely, see the functions in secp256k1_preallocated.h.
  *
  *  Returns: a newly created context object.
- *  Args:    ctx: an existing context to copy (cannot be NULL)
+ *  Args:    ctx: an existing context to copy
  */
 SECP256K1_API secp256k1_context* secp256k1_context_clone(
     const secp256k1_context* ctx
@@ -247,7 +247,7 @@ SECP256K1_API secp256k1_context* secp256k1_context_clone(
  */
 SECP256K1_API void secp256k1_context_destroy(
     secp256k1_context* ctx
-);
+) SECP256K1_ARG_NONNULL(1);
 
 /** Set a callback function to be called when an illegal argument is passed to
  *  an API call. It will only trigger for violations that are mentioned
@@ -278,11 +278,11 @@ SECP256K1_API void secp256k1_context_destroy(
  *  fails. In this case, the corresponding default handler will be called with
  *  the data pointer argument set to NULL.
  *
- *  Args: ctx:  an existing context object (cannot be NULL)
+ *  Args: ctx:  an existing context object.
  *  In:   fun:  a pointer to a function to call when an illegal argument is
  *              passed to the API, taking a message and an opaque pointer.
  *              (NULL restores the default handler.)
- *        data: the opaque pointer to pass to fun above.
+ *        data: the opaque pointer to pass to fun above, must be NULL for the default handler.
  *
  *  See also secp256k1_context_set_error_callback.
  */
@@ -302,12 +302,12 @@ SECP256K1_API void secp256k1_context_set_illegal_callback(
  *  for that). After this callback returns, anything may happen, including
  *  crashing.
  *
- *  Args: ctx:  an existing context object (cannot be NULL)
+ *  Args: ctx:  an existing context object.
  *  In:   fun:  a pointer to a function to call when an internal error occurs,
  *              taking a message and an opaque pointer (NULL restores the
  *              default handler, see secp256k1_context_set_illegal_callback
  *              for details).
- *        data: the opaque pointer to pass to fun above.
+ *        data: the opaque pointer to pass to fun above, must be NULL for the default handler.
  *
  *  See also secp256k1_context_set_illegal_callback.
  */
@@ -320,7 +320,7 @@ SECP256K1_API void secp256k1_context_set_error_callback(
 /** Create a secp256k1 scratch space object.
  *
  *  Returns: a newly created scratch space.
- *  Args: ctx:  an existing context object (cannot be NULL)
+ *  Args: ctx:  an existing context object.
  *  In:   size: amount of memory to be available as scratch space. Some extra
  *              (<100 bytes) will be allocated for extra accounting.
  */
@@ -480,16 +480,16 @@ SECP256K1_API int secp256k1_ecdsa_signature_serialize_compact(
  *  Returns: 1: correct signature
  *           0: incorrect or unparseable signature
  *  Args:    ctx:       a secp256k1 context object, initialized for verification.
- *  In:      sig:       the signature being verified (cannot be NULL)
- *           msghash32: the 32-byte message hash being verified (cannot be NULL).
+ *  In:      sig:       the signature being verified.
+ *           msghash32: the 32-byte message hash being verified.
  *                      The verifier must make sure to apply a cryptographic
  *                      hash function to the message by itself and not accept an
  *                      msghash32 value directly. Otherwise, it would be easy to
  *                      create a "valid" signature without knowledge of the
  *                      secret key. See also
  *                      https://bitcoin.stackexchange.com/a/81116/35586 for more
  *                      background on this topic.
- *           pubkey:    pointer to an initialized public key to verify with (cannot be NULL)
+ *           pubkey:    pointer to an initialized public key to verify with.
  *
  * To avoid accepting malleable signatures, only ECDSA signatures in lower-S
  * form are accepted.
@@ -515,8 +515,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify(
  *                or copy if the input was already normalized. (can be NULL if
  *                you're only interested in whether the input was already
  *                normalized).
- *  In:   sigin:  a pointer to a signature to check/normalize (cannot be NULL,
- *                can be identical to sigout)
+ *  In:   sigin:  a pointer to a signature to check/normalize (can be identical to sigout)
  *
  *  With ECDSA a third-party can forge a second distinct signature of the same
  *  message, given a single initial signature, but without knowing the key. This
@@ -568,12 +567,16 @@ SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_def
  *
  *  Returns: 1: signature created
  *           0: the nonce generation function failed, or the secret key was invalid.
- *  Args:    ctx:       pointer to a context object, initialized for signing (cannot be NULL)
- *  Out:     sig:       pointer to an array where the signature will be placed (cannot be NULL)
- *  In:      msghash32: the 32-byte message hash being signed (cannot be NULL)
- *           seckey:    pointer to a 32-byte secret key (cannot be NULL)
- *           noncefp:   pointer to a nonce generation function. If NULL, secp256k1_nonce_function_default is used
- *           ndata:     pointer to arbitrary data used by the nonce generation function (can be NULL)
+ *  Args:    ctx:       pointer to a context object, initialized for signing.
+ *  Out:     sig:       pointer to an array where the signature will be placed.
+ *  In:      msghash32: the 32-byte message hash being signed.
+ *           seckey:    pointer to a 32-byte secret key.
+ *           noncefp:   pointer to a nonce generation function. If NULL,
+ *                      secp256k1_nonce_function_default is used.
+ *           ndata:     pointer to arbitrary data used by the nonce generation function
+ *                      (can be NULL). If it is non-NULL and
+ *                      secp256k1_nonce_function_default is used, then ndata must be a
+ *                      pointer to 32-bytes of additional data.
  *
  * The created signature is always in lower-S form. See
  * secp256k1_ecdsa_signature_normalize for more details.
@@ -596,8 +599,8 @@ SECP256K1_API int secp256k1_ecdsa_sign(
  *
  *  Returns: 1: secret key is valid
  *           0: secret key is invalid
- *  Args:    ctx: pointer to a context object (cannot be NULL)
- *  In:      seckey: pointer to a 32-byte secret key (cannot be NULL)
+ *  Args:    ctx: pointer to a context object.
+ *  In:      seckey: pointer to a 32-byte secret key.
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(
     const secp256k1_context* ctx,
@@ -606,11 +609,11 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(
 
 /** Compute the public key for a secret key.
  *
- *  Returns: 1: secret was valid, public key stores
- *           0: secret was invalid, try again
- *  Args:   ctx:        pointer to a context object, initialized for signing (cannot be NULL)
- *  Out:    pubkey:     pointer to the created public key (cannot be NULL)
- *  In:     seckey:     pointer to a 32-byte secret key (cannot be NULL)
+ *  Returns: 1: secret was valid, public key stores.
+ *           0: secret was invalid, try again.
+ *  Args:    ctx:    pointer to a context object, initialized for signing.
+ *  Out:     pubkey: pointer to the created public key.
+ *  In:      seckey: pointer to a 32-byte secret key.
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create(
     const secp256k1_context* ctx,
@@ -626,8 +629,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create(
  *  In/Out: seckey: pointer to the 32-byte secret key to be negated. If the
  *                  secret key is invalid according to
  *                  secp256k1_ec_seckey_verify, this function returns 0 and
- *                  seckey will be set to some unspecified value. (cannot be
- *                  NULL)
+ *                  seckey will be set to some unspecified value.
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_negate(
     const secp256k1_context* ctx,
@@ -645,7 +647,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_negate(
  *
  *  Returns: 1 always
  *  Args:   ctx:        pointer to a context object
- *  In/Out: pubkey:     pointer to the public key to be negated (cannot be NULL)
+ *  In/Out: pubkey:     pointer to the public key to be negated.
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate(
     const secp256k1_context* ctx,
@@ -657,15 +659,15 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate(
  *  Returns: 0 if the arguments are invalid or the resulting secret key would be
  *           invalid (only when the tweak is the negation of the secret key). 1
  *           otherwise.
- *  Args:    ctx:   pointer to a context object (cannot be NULL).
+ *  Args:    ctx:   pointer to a context object.
  *  In/Out: seckey: pointer to a 32-byte secret key. If the secret key is
  *                  invalid according to secp256k1_ec_seckey_verify, this
  *                  function returns 0. seckey will be set to some unspecified
- *                  value if this function returns 0. (cannot be NULL)
+ *                  value if this function returns 0.
  *  In:    tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to
  *                  secp256k1_ec_seckey_verify, this function returns 0. For
  *                  uniformly random 32-byte arrays the chance of being invalid
- *                  is negligible (around 1 in 2^128) (cannot be NULL).
+ *                  is negligible (around 1 in 2^128).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_add(
     const secp256k1_context* ctx,
@@ -686,14 +688,13 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
  *  Returns: 0 if the arguments are invalid or the resulting public key would be
  *           invalid (only when the tweak is the negation of the corresponding
  *           secret key). 1 otherwise.
- *  Args:    ctx:   pointer to a context object initialized for validation
- *                  (cannot be NULL).
+ *  Args:    ctx:   pointer to a context object initialized for validation.
  *  In/Out: pubkey: pointer to a public key object. pubkey will be set to an
- *                  invalid value if this function returns 0 (cannot be NULL).
+ *                  invalid value if this function returns 0.
  *  In:    tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to
  *                  secp256k1_ec_seckey_verify, this function returns 0. For
  *                  uniformly random 32-byte arrays the chance of being invalid
- *                  is negligible (around 1 in 2^128) (cannot be NULL).
+ *                  is negligible (around 1 in 2^128).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
     const secp256k1_context* ctx,
@@ -704,15 +705,15 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
 /** Tweak a secret key by multiplying it by a tweak.
  *
  *  Returns: 0 if the arguments are invalid. 1 otherwise.
- *  Args:   ctx:    pointer to a context object (cannot be NULL).
+ *  Args:   ctx:    pointer to a context object.
  *  In/Out: seckey: pointer to a 32-byte secret key. If the secret key is
  *                  invalid according to secp256k1_ec_seckey_verify, this
  *                  function returns 0. seckey will be set to some unspecified
- *                  value if this function returns 0. (cannot be NULL)
+ *                  value if this function returns 0.
  *  In:    tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to
  *                  secp256k1_ec_seckey_verify, this function returns 0. For
  *                  uniformly random 32-byte arrays the chance of being invalid
- *                  is negligible (around 1 in 2^128) (cannot be NULL).
+ *                  is negligible (around 1 in 2^128).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_mul(
     const secp256k1_context* ctx,
@@ -731,14 +732,13 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
 /** Tweak a public key by multiplying it by a tweak value.
  *
  *  Returns: 0 if the arguments are invalid. 1 otherwise.
- *  Args:    ctx:   pointer to a context object initialized for validation
- *                  (cannot be NULL).
+ *  Args:    ctx:   pointer to a context object initialized for validation.
  *  In/Out: pubkey: pointer to a public key object. pubkey will be set to an
- *                  invalid value if this function returns 0 (cannot be NULL).
+ *                  invalid value if this function returns 0.
  *  In:    tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to
  *                  secp256k1_ec_seckey_verify, this function returns 0. For
  *                  uniformly random 32-byte arrays the chance of being invalid
- *                  is negligible (around 1 in 2^128) (cannot be NULL).
+ *                  is negligible (around 1 in 2^128).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul(
     const secp256k1_context* ctx,
@@ -749,7 +749,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul(
 /** Updates the context randomization to protect against side-channel leakage.
  *  Returns: 1: randomization successfully updated or nothing to randomize
  *           0: error
- *  Args:    ctx:       pointer to a context object (cannot be NULL)
+ *  Args:    ctx:       pointer to a context object.
  *  In:      seed32:    pointer to a 32-byte random seed (NULL resets to initial state)
  *
  * While secp256k1 code is written to be constant-time no matter what secret
@@ -780,18 +780,17 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_context_randomize(
  *
  *  Returns: 1: the sum of the public keys is valid.
  *           0: the sum of the public keys is not valid.
- *  Args:   ctx:        pointer to a context object
- *  Out:    out:        pointer to a public key object for placing the resulting public key
- *                      (cannot be NULL)
- *  In:     ins:        pointer to array of pointers to public keys (cannot be NULL)
- *          n:          the number of public keys to add together (must be at least 1)
+ *  Args:   ctx:        pointer to a context object.
+ *  Out:    out:        pointer to a public key object for placing the resulting public key.
+ *  In:     ins:        pointer to array of pointers to public keys.
+ *          n:          the number of public keys to add together (must be at least 1).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_combine(
     const secp256k1_context* ctx,
     secp256k1_pubkey *out,
     const secp256k1_pubkey * const * ins,
     size_t n
-) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
+) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Compute a tagged hash as defined in BIP-340.
  *

include/secp256k1_ecdh.h

@@ -37,14 +37,15 @@ SECP256K1_API extern const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_func
  *
  *  Returns: 1: exponentiation was successful
  *           0: scalar was invalid (zero or overflow) or hashfp returned 0
- *  Args:    ctx:        pointer to a context object (cannot be NULL)
- *  Out:     output:     pointer to an array to be filled by hashfp
- *  In:      pubkey:     a pointer to a secp256k1_pubkey containing an
- *                       initialized public key
- *           seckey:     a 32-byte scalar with which to multiply the point
- *           hashfp:     pointer to a hash function. If NULL, secp256k1_ecdh_hash_function_sha256 is used
- *                       (in which case, 32 bytes will be written to output)
+ *  Args:    ctx:        pointer to a context object.
+ *  Out:     output:     pointer to an array to be filled by hashfp.
+ *  In:      pubkey:     a pointer to a secp256k1_pubkey containing an initialized public key.
+ *           seckey:     a 32-byte scalar with which to multiply the point.
+ *           hashfp:     pointer to a hash function. If NULL,
+ *                       secp256k1_ecdh_hash_function_sha256 is used
+ *                       (in which case, 32 bytes will be written to output).
  *           data:       arbitrary data pointer that is passed through to hashfp
+ *                       (can be NULL for secp256k1_ecdh_hash_function_sha256).
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdh(
   const secp256k1_context* ctx,