md5.h

/* $Id: md5.h,v 1.3 2006-01-02 18:16:26 quentin Exp $ */

/*
  * Implementation of the md5 algorithm described in RFC1321
  * Copyright (C) 2005 Quentin Carbonneaux <crazyjoke@free.fr>
  * 
 * This file is part of md5sum.
  *
  * md5sum is a free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Softawre Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * md5sum 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 hav received a copy of the GNU General Public License
  * along with md5sum; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */

#ifndef MD5_H
#define MD5_H

#include <assert.h>
#include <stdlib.h>

/* WARNING :
  * This implementation is using 32 bits long values for sizes
  */
typedef unsigned int md5_size;

/* MD5 context */
struct md5_ctx {
  struct {
    unsigned int A, B, C, D; /* registers */
  } regs;
  unsigned char *buf;
  md5_size size;
  md5_size bits;
};

/* Size of the MD5 buffer */
#define MD5_BUFFER 1024
#define MD5_DIGEST_LENGTH 16

/* Basic md5 functions */
#define F(x,y,z) ((x & y) | (~x & z))
#define G(x,y,z) ((x & z) | (~z & y))
#define H(x,y,z) (x ^ y ^ z)
#define I(x,y,z) (y ^ (x | ~z))

/* Rotate left 32 bits values (words) */
#define ROTATE_LEFT(w,s) ((w << s) | ((w & 0xFFFFFFFF) >> (32 - s)))

#define FF(a,b,c,d,x,s,t) (a = b + ROTATE_LEFT((a + F(b,c,d) + x + t), s))
#define GG(a,b,c,d,x,s,t) (a = b + ROTATE_LEFT((a + G(b,c,d) + x + t), s))
#define HH(a,b,c,d,x,s,t) (a = b + ROTATE_LEFT((a + H(b,c,d) + x + t), s))
#define II(a,b,c,d,x,s,t) (a = b + ROTATE_LEFT((a + I(b,c,d) + x + t), s))

unsigned char *md5(unsigned char *, md5_size, unsigned char *);
void md5_init(struct md5_ctx *);
void md5_update(struct md5_ctx *context);
void md5_final(unsigned char *digest, struct md5_ctx *context);

#endif /* MD5_H */