char* SHA512_End(SHA512_CTX*, char[SHA512_DIGEST_STRING_LENGTH]);
char* SHA512_Data(const uint8_t*, size_t, char[SHA512_DIGEST_STRING_LENGTH]);
char* SHA512_End(SHA512_CTX*, char[SHA512_DIGEST_STRING_LENGTH]);
char* SHA512_Data(const uint8_t*, size_t, char[SHA512_DIGEST_STRING_LENGTH]);