ecdsa_do_sign
return ecdsa->meth->ecdsa_do_sign(dgst, dgst_len, in_kinv, in_r, eckey);
static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
.ecdsa_do_sign = ecdsa_do_sign,
ECDSA_SIG *(*ecdsa_do_sign)(const unsigned char *dgst, int dgst_len,
ecdsa_method->ecdsa_do_sign = tls_ecdsa_do_sign;
EC_KEY_METHOD_set_sign(ec_meth, ec_sign, NULL, ecdsa_do_sign);
EC_KEY_METHOD_set_sign(ec_key_method, orig_sign, NULL, ecdsa_do_sign);