Update the secp256k1 subtree to the latest upstream version

1 files changed, 28 insertions, 4 deletions

diff --git a/src/secp256k1/include/secp256k1_ecdh.h b/src/secp256k1/include/secp256k1_ecdh.h
index 88492dc1a4..df5fde235c 100644
--- a/src/secp256k1/include/secp256k1_ecdh.h
+++ b/src/secp256k1/include/secp256k1_ecdh.h
@@ -7,21 +7,45 @@
 extern "C" {
 #endif
 
+/** A pointer to a function that applies hash function to a point
+ *
+ *  Returns: 1 if a point was successfully hashed. 0 will cause ecdh to fail
+ *  Out:    output:     pointer to an array to be filled by the function
+ *  In:     x:          pointer to a 32-byte x coordinate
+ *          y:          pointer to a 32-byte y coordinate
+ *          data:       Arbitrary data pointer that is passed through
+ */
+typedef int (*secp256k1_ecdh_hash_function)(
+  unsigned char *output,
+  const unsigned char *x,
+  const unsigned char *y,
+  void *data
+);
+
+/** An implementation of SHA256 hash function that applies to compressed public key. */
+SECP256K1_API extern const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_sha256;
+
+/** A default ecdh hash function (currently equal to secp256k1_ecdh_hash_function_sha256). */
+SECP256K1_API extern const secp256k1_ecdh_hash_function secp256k1_ecdh_hash_function_default;
+
 /** Compute an EC Diffie-Hellman secret in constant time
  *  Returns: 1: exponentiation was successful
  *           0: scalar was invalid (zero or overflow)
  *  Args:    ctx:        pointer to a context object (cannot be NULL)
- *  Out:     result:     a 32-byte array which will be populated by an ECDH
- *                       secret computed from the point and scalar
+ *  Out:     output:     pointer to an array to be filled by the function
  *  In:      pubkey:     a pointer to a secp256k1_pubkey containing an
  *                       initialized public key
  *           privkey:    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
+ *           data:       Arbitrary data pointer that is passed through
  */
 SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdh(
   const secp256k1_context* ctx,
-  unsigned char *result,
+  unsigned char *output,
   const secp256k1_pubkey *pubkey,
-  const unsigned char *privkey
+  const unsigned char *privkey,
+  secp256k1_ecdh_hash_function hashfp,
+  void *data
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
 
 #ifdef __cplusplus