/*
   This header file is hereby released to the public domain.
   ~aaaaaa123456789, 2014-10-25
*/
#ifndef SHA256

#define SHA256

#ifdef __cplusplus
  extern "C" {
#endif

enum sha256_opcodes {
  // inputs
  SHA256_IN_BLOCK = 0,
  SHA256_IN_BUFFER = 1,
  SHA256_IN_FILE = 2,
  SHA256_IN_FILENAME = 3,
  // outputs
  SHA256_OUT_WORDS = 0, // 32 bits
  SHA256_OUT_BYTES = 4,
  SHA256_OUT_LONGS = 8, // 64 bits
  SHA256_OUT_STRING = 12,
  // flags
  SHA256_LENGTH_BITS = 16, // length is in bits
  SHA256_REVERSE_WORDS = 32, // reverse word order
  SHA256_UPPERCASE_HEX = 64, // hex digits A-F are uppercase in string outputs
  SHA256_REVERSE_ENDIAN = 64, // when not returning 32-bit words
};

enum sha256_errors {
  SHA256_INVALID_OPCODE = 1,
  SHA256_FILE_NOT_FOUND = 2,
  SHA256_INVALID_ARGUMENT = 3,
  SHA256_IO_ERROR = 4,
  SHA256_PREMATURE_EOF = 5,
};

int sha256(int op, void * in, void * out, long long skip, long long length);

#ifdef __cplusplus
  }
#endif

#endif