Line data    Source code

       1             : #include "fd_secp256k1.h"
       2             : 
       3             : #include <secp256k1.h>
       4             : #include <secp256k1_recovery.h>
       5             : 
       6             : void *
       7             : fd_secp256k1_recover( void *       public_key,
       8             :                       void const * msg_hash,
       9             :                       void const * sig,
      10       60765 :                       int          recovery_id ) {
      11       60765 :   secp256k1_ecdsa_recoverable_signature recoverable_sig;
      12       60765 :   secp256k1_pubkey internal_public_key;
      13       60765 :   uchar serialized_public_key[ 65 ];
      14       60765 :   size_t public_key_len = 65;
      15             : 
      16             :   /* Avoid panic in secp256k1_ecdsa_recoverable_signature_parse_compact
      17             :      https://github.com/bitcoin-core/secp256k1/blob/v0.5.0/src/modules/recovery/main_impl.h#L46
      18             :      ARG_CHECK(recid >= 0 && recid <= 3); */
      19       60765 :   if ( FD_UNLIKELY( !(recovery_id >= 0 && recovery_id <= 3) ) ) {
      20             :     /* COV: the callers do the same check */
      21          48 :     return NULL;
      22          48 :   }
      23             : 
      24       60717 :   if( FD_UNLIKELY( !secp256k1_ecdsa_recoverable_signature_parse_compact( secp256k1_context_static,
      25       60717 :                                                                          &recoverable_sig, (uchar const *) sig,
      26       60717 :                                                                          recovery_id ) ) ) {
      27           6 :     return NULL;
      28           6 :   }
      29             : 
      30       60711 :   if( FD_UNLIKELY( !secp256k1_ecdsa_recover( secp256k1_context_static, &internal_public_key,
      31       60711 :                                              &recoverable_sig, msg_hash ) ) ) {
      32       30042 :     return NULL;
      33       30042 :   }
      34             : 
      35       30669 :   if( FD_UNLIKELY( !secp256k1_ec_pubkey_serialize( secp256k1_context_static, serialized_public_key, &public_key_len,
      36       30669 :                                                     &internal_public_key, SECP256K1_EC_UNCOMPRESSED ) ) ) {
      37             :     /* COV: the output of secp256k1_ecdsa_recover should always serialize */
      38           0 :     return NULL;
      39           0 :   }
      40             : 
      41             :   /* Skip 1st byte: libsecp256k1 prepends 0x04 to the public key
      42             :      https://github.com/bitcoin-core/secp256k1/blob/v0.5.0/src/eckey_impl.h#L49 */
      43       30669 :   return fd_memcpy(public_key, &serialized_public_key[1], 64);
      44       30669 : }