Update libsecp256k1 subtree to latest upstream master

3 files changed, 52 insertions, 32 deletions

diff --git a/src/secp256k1/include/secp256k1.h b/src/secp256k1/include/secp256k1.h
index 2178c8e2d6..d368488af2 100644
--- a/src/secp256k1/include/secp256k1.h
+++ b/src/secp256k1/include/secp256k1.h
@@ -11,7 +11,7 @@ extern "C" {
  *
  * 1. Context pointers go first, followed by output arguments, combined
  *    output/input arguments, and finally input-only arguments.
- * 2. Array lengths always immediately the follow the argument whose length
+ * 2. Array lengths always immediately follow the argument whose length
  *    they describe, even if this violates rule 1.
  * 3. Within the OUT/OUTIN/IN groups, pointers to data that is typically generated
  *    later go first. This means: signatures, public nonces, secret nonces,
@@ -452,7 +452,14 @@ SECP256K1_API int secp256k1_ecdsa_signature_serialize_compact(
  *           0: incorrect or unparseable signature
  *  Args:    ctx:       a secp256k1 context object, initialized for verification.
  *  In:      sig:       the signature being verified (cannot be NULL)
- *           msg32:     the 32-byte message hash being verified (cannot be NULL)
+ *           msghash32: the 32-byte message hash being verified (cannot be NULL).
+ *                      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)
  *
  * To avoid accepting malleable signatures, only ECDSA signatures in lower-S
@@ -467,7 +474,7 @@ SECP256K1_API int secp256k1_ecdsa_signature_serialize_compact(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify(
     const secp256k1_context* ctx,
     const secp256k1_ecdsa_signature *sig,
-    const unsigned char *msg32,
+    const unsigned char *msghash32,
     const secp256k1_pubkey *pubkey
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
 
@@ -532,12 +539,12 @@ 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:      msg32:  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 (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)
  *
  * The created signature is always in lower-S form. See
  * secp256k1_ecdsa_signature_normalize for more details.
@@ -545,7 +552,7 @@ SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_def
 SECP256K1_API int secp256k1_ecdsa_sign(
     const secp256k1_context* ctx,
     secp256k1_ecdsa_signature *sig,
-    const unsigned char *msg32,
+    const unsigned char *msghash32,
     const unsigned char *seckey,
     secp256k1_nonce_function noncefp,
     const void *ndata
@@ -626,7 +633,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate(
  *                  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)
- *  In:      tweak: pointer to a 32-byte tweak. If the tweak is invalid according to
+ *  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).
@@ -634,7 +641,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_add(
     const secp256k1_context* ctx,
     unsigned char *seckey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Same as secp256k1_ec_seckey_tweak_add, but DEPRECATED. Will be removed in
@@ -642,7 +649,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_add(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
     const secp256k1_context* ctx,
     unsigned char *seckey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Tweak a public key by adding tweak times the generator to it.
@@ -654,7 +661,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
  *                  (cannot be NULL).
  *  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).
- *  In:      tweak: pointer to a 32-byte tweak. If the tweak is invalid according to
+ *  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).
@@ -662,7 +669,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
     const secp256k1_context* ctx,
     secp256k1_pubkey *pubkey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Tweak a secret key by multiplying it by a tweak.
@@ -673,7 +680,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
  *                  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)
- *  In:      tweak: pointer to a 32-byte tweak. If the tweak is invalid according to
+ *  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).
@@ -681,7 +688,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_mul(
     const secp256k1_context* ctx,
     unsigned char *seckey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Same as secp256k1_ec_seckey_tweak_mul, but DEPRECATED. Will be removed in
@@ -689,7 +696,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_mul(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
     const secp256k1_context* ctx,
     unsigned char *seckey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Tweak a public key by multiplying it by a tweak value.
@@ -699,7 +706,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
  *                  (cannot be NULL).
  *  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).
- *  In:      tweak: pointer to a 32-byte tweak. If the tweak is invalid according to
+ *  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).
@@ -707,7 +714,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul(
     const secp256k1_context* ctx,
     secp256k1_pubkey *pubkey,
-    const unsigned char *tweak
+    const unsigned char *tweak32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
 /** Updates the context randomization to protect against side-channel leakage.
diff --git a/src/secp256k1/include/secp256k1_extrakeys.h b/src/secp256k1/include/secp256k1_extrakeys.h
index 0c5dff2c94..6fc7b290f8 100644
--- a/src/secp256k1/include/secp256k1_extrakeys.h
+++ b/src/secp256k1/include/secp256k1_extrakeys.h
@@ -165,6 +165,19 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_create(
     const unsigned char *seckey
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
 
+/** Get the secret key from a keypair.
+ *
+ *  Returns: 0 if the arguments are invalid. 1 otherwise.
+ *  Args:   ctx: pointer to a context object (cannot be NULL)
+ *  Out: seckey: pointer to a 32-byte buffer for the secret key (cannot be NULL)
+ *  In: keypair: pointer to a keypair (cannot be NULL)
+ */
+SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_sec(
+    const secp256k1_context* ctx,
+    unsigned char *seckey,
+    const secp256k1_keypair *keypair
+) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
+
 /** Get the public key from a keypair.
  *
  *  Returns: 0 if the arguments are invalid. 1 otherwise.
diff --git a/src/secp256k1/include/secp256k1_recovery.h b/src/secp256k1/include/secp256k1_recovery.h
index f8ccaecd3d..aa16532ce8 100644
--- a/src/secp256k1/include/secp256k1_recovery.h
+++ b/src/secp256k1/include/secp256k1_recovery.h
@@ -71,17 +71,17 @@ SECP256K1_API int secp256k1_ecdsa_recoverable_signature_serialize_compact(
  *
  *  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:      msg32:  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 (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)
  */
 SECP256K1_API int secp256k1_ecdsa_sign_recoverable(
     const secp256k1_context* ctx,
     secp256k1_ecdsa_recoverable_signature *sig,
-    const unsigned char *msg32,
+    const unsigned char *msghash32,
     const unsigned char *seckey,
     secp256k1_nonce_function noncefp,
     const void *ndata
@@ -91,16 +91,16 @@ SECP256K1_API int secp256k1_ecdsa_sign_recoverable(
  *
  *  Returns: 1: public key successfully recovered (which guarantees a correct signature).
  *           0: otherwise.
- *  Args:    ctx:        pointer to a context object, initialized for verification (cannot be NULL)
- *  Out:     pubkey:     pointer to the recovered public key (cannot be NULL)
- *  In:      sig:        pointer to initialized signature that supports pubkey recovery (cannot be NULL)
- *           msg32:      the 32-byte message hash assumed to be signed (cannot be NULL)
+ *  Args:    ctx:       pointer to a context object, initialized for verification (cannot be NULL)
+ *  Out:     pubkey:    pointer to the recovered public key (cannot be NULL)
+ *  In:      sig:       pointer to initialized signature that supports pubkey recovery (cannot be NULL)
+ *           msghash32: the 32-byte message hash assumed to be signed (cannot be NULL)
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_recover(
     const secp256k1_context* ctx,
     secp256k1_pubkey *pubkey,
     const secp256k1_ecdsa_recoverable_signature *sig,
-    const unsigned char *msg32
+    const unsigned char *msghash32
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
 
 #ifdef __cplusplus