/* Declarations of functions and data types used for SHA256 and SHA224 sum
   library functions.
   Copyright (C) 2005, 2006 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#ifndef SHA256_H
# define SHA256_H 1

# include <stdio.h>

#define int32_t int
#define uint32_t unsigned int

/* Structure to save state of computation between the single steps.  */
struct sha256_ctx
{
  uint32_t state[8];

  uint32_t total[2];
  uint32_t buflen;
  uint32_t buffer[32];
};


/* Initialize structure containing state of computation. */
extern void sha256_init_ctx (struct sha256_ctx *ctx);
extern void sha224_init_ctx (struct sha256_ctx *ctx);

/* Starting with the result of former calls of this function (or the
   initialization function update the context for the next LEN bytes
   starting at BUFFER.
   It is necessary that LEN is a multiple of 64!!! */
extern void sha256_process_block (const void *buffer, size_t len,
				  struct sha256_ctx *ctx);

/* Starting with the result of former calls of this function (or the
   initialization function update the context for the next LEN bytes
   starting at BUFFER.
   It is NOT required that LEN is a multiple of 64.  */
extern void sha256_process_bytes (const void *buffer, size_t len,
				  struct sha256_ctx *ctx);

/* Process the remaining bytes in the buffer and put result from CTX
   in first 32 (28) bytes following RESBUF.  The result is always in little
   endian byte order, so that a byte-wise output yields to the wanted
   ASCII representation of the message digest.

   IMPORTANT: On some systems it is required that RESBUF be correctly
   aligned for a 32 bits value.  */
extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf);
extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf);


/* Put result from CTX in first 32 (28) bytes following RESBUF.  The result is
   always in little endian byte order, so that a byte-wise output yields
   to the wanted ASCII representation of the message digest.

   IMPORTANT: On some systems it is required that RESBUF is correctly
   aligned for a 32 bits value.  */
extern void *sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf);
extern void *sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf);


/* Compute SHA256 (SHA224) message digest for bytes read from STREAM.  The
   resulting message digest number will be written into the 32 (28) bytes
   beginning at RESBLOCK.  */
extern int sha256_stream (FILE *stream, void *resblock);
extern int sha224_stream (FILE *stream, void *resblock);

/* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.  The
   result is always in little endian byte order, so that a byte-wise
   output yields to the wanted ASCII representation of the message
   digest.  */
extern void *sha256_buffer (const char *buffer, size_t len, void *resblock);
extern void *sha224_buffer (const char *buffer, size_t len, void *resblock);

#endif
