int (*ecdsa_sign_setup)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv,
BIGNUM **r);
int (*ecdsa_do_verify)(const unsigned char *dgst, int dgst_len,
int (*ecdsa_sign_setup)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv,
BIGNUM **r);
int (*ecdsa_do_verify)(const unsigned char *dgst, int dgst_len,