int(* secp256k1_ecdh_hash_function)(unsigned char *output, const unsigned char *x32, const unsigned char *y32, void *data)
A pointer to a function that hashes an EC point to obtain an ECDH secret.
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdh(const secp256k1_context *ctx, unsigned char *output, const secp256k1_pubkey *pubkey, const unsigned char *seckey, secp256k1_ecdh_hash_function hashfp, void *data) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4)
Compute an EC Diffie-Hellman secret in constant time.