/* Declarations of functions and data types used for SHA1 sum
   library functions.
   Copyright (C) 2000-2023 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, see <http://www.gnu.org/licenses/>. */

#ifndef _MAILUTILS_SHA1_H
# define _MAILUTILS_SHA1_H 1

# include <stdio.h>
# include <stdint.h>

# define sha1_ctx mu_sha1_ctx
# define sha1_init_ctx mu_sha1_init_ctx
# define sha1_process_block mu_sha1_process_block  
# define sha1_process_bytes mu_sha1_process_bytes  
# define sha1_finish_ctx mu_sha1_finish_ctx     
# define sha1_read_ctx mu_sha1_read_ctx       
# define sha1_stream mu_sha1_stream         
# define sha1_buffer mu_sha1_buffer          

/* Structure to save state of computation between the single steps.  */
struct sha1_ctx
{
  uint32_t A;
  uint32_t B;
  uint32_t C;
  uint32_t D;
  uint32_t E;

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


/* Initialize structure containing state of computation. */
extern void sha1_init_ctx (struct sha1_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 sha1_process_block (const void *buffer, size_t len,
				struct sha1_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 sha1_process_bytes (const void *buffer, size_t len,
				struct sha1_ctx *ctx);

/* Process the remaining bytes in the buffer and put result from CTX
   in first 20 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 *sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf);


/* Put result from CTX in first 20 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 *sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf);


/* Compute SHA1 message digest for bytes read from STREAM.  The
   resulting message digest number will be written into the 20 bytes
   beginning at RESBLOCK.  */
extern int sha1_stream (FILE *stream, void *resblock);

/* Compute SHA1 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 *sha1_buffer (const char *buffer, size_t len, void *resblock);

#endif
