unsigned char *SHA224(const unsigned char *d, size_t n,unsigned char *md);
int SHA256_Init(SHA256_CTX *c);
int SHA256_Update(SHA256_CTX *c, const void *data, size_t len);
unsigned char *SHA224(const unsigned char *d, size_t n,unsigned char *md);
int SHA256_Init(SHA256_CTX *c);
int SHA256_Update(SHA256_CTX *c, const void *data, size_t len);