int ECDSA_sign(int type, const unsigned char *dgst, int dgst_len, unsigned char *sig,
unsigned int *siglen, ECDSA *ecdsa);
int ECDSA_verify(int type, const unsigned char *dgst, int dgst_len, const unsigned char *sig,
int ECDSA_sign(int type, const unsigned char *dgst, int dgst_len, unsigned char *sig,
unsigned int *siglen, ECDSA *ecdsa);
int ECDSA_verify(int type, const unsigned char *dgst, int dgst_len, const unsigned char *sig,