Merge bitcoin/bitcoin#21573: Update libsecp256k1 subtree to latest master

5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb libsecp256k1 no longer has --with-bignum= configure option (Pieter Wuille)
bdca9bcb6c9379707d09c63f02326884befbefb2 Squashed 'src/secp256k1/' changes from 3967d96bf1..efad3506a8 (Pieter Wuille)
cabb5661234f8d832dbc3b65bf80b0acc02db0a0 Disable certain false positive warnings for libsecp256k1 msvc build (Pieter Wuille)

Pull request description:

  This updates our src/secp256k1 subtree to the latest upstream master. The changes include:

  * The introduction of safegcd-based modular inverses, reducing ECDSA signing time by 25%-30% and ECDSA verification time by 15%-17%.
    * [Original paper](https://gcd.cr.yp.to/papers.html) by Daniel J. Bernstein and Bo-Yin Yang
    * [Implementation](https://github.com/bitcoin-core/secp256k1/pull/767) by Peter Dettman; [final](https://github.com/bitcoin-core/secp256k1/pull/831) version
    * [Explanation](https://github.com/bitcoin-core/secp256k1/blob/master/doc/safegcd_implementation.md) of the algorithm using Python snippets
    * [Analysis](https://github.com/sipa/safegcd-bounds) of the maximum number of iterations the algorithm needs
    * [Formal proof in Coq](https://medium.com/blockstream/a-formal-proof-of-safegcd-bounds-695e1735a348) by Russell O'Connor, for a high-level equivalent algorithm
  * Removal of libgmp as an (optional) dependency (which wasn't used in the Bitcoin Core build)
  * CI changes (Travis -> Cirrus)
  * Build system improvements

ACKs for top commit:
  laanwj:
    Tested ACK 5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb

Tree-SHA512: ad8ac3746264d279556a4aa7efdde3733e114fdba8856dd53218588521f04d83950366f5c1ea8fd56329b4c7fe08eedf8e206f8f26dbe3f0f81852e138655431

1 files changed, 12 insertions, 12 deletions

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