Update sm2_lib.c

This commit is contained in:
Zhi Guan
2022-10-20 17:52:26 +08:00
parent c5b14a700b
commit d8b4348736

View File

@@ -146,6 +146,23 @@ int sm2_do_verify(const SM2_KEY *key, const uint8_t dgst[32], const SM2_SIGNATUR
return 1;
}
// verify the xR of R = s * G + (s + r) * P
// so (-r, -s) is also a valid SM2 signature
int sm2_signature_conjugate(const SM2_SIGNATURE *sig, SM2_SIGNATURE *new_sig)
{
SM2_Fn r;
SM2_Fn s;
sm2_bn_from_bytes(r, sig->r);
sm2_bn_from_bytes(s, sig->s);
sm2_fn_neg(r, r);
sm2_fn_neg(s, s);
sm2_bn_to_bytes(r, new_sig->r);
sm2_bn_to_bytes(s, new_sig->s);
return 1;
}
int sm2_signature_to_der(const SM2_SIGNATURE *sig, uint8_t **out, size_t *outlen)
{
size_t len = 0;