/* wvWare
 * Copyright (C) Caolan McNamara, Dom Lachowicz, and others
 *
 * 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
 * of the License, 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., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

/*
 **********************************************************************
 ** md5.c                                                            **
 ** RSA Data Security, Inc. MD5 Message Digest Algorithm             **
 ** Created: 2/17/90 RLR                                             **
 ** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version                  **
 **********************************************************************
 */

/*
 **********************************************************************
 ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. **
 **                                                                  **
 ** License to copy and use this software is granted provided that   **
 ** it is identified as the "RSA Data Security, Inc. MD5 Message     **
 ** Digest Algorithm" in all material mentioning or referencing this **
 ** software or this function.                                       **
 **                                                                  **
 ** License is also granted to make and use derivative works         **
 ** provided that such works are identified as "derived from the RSA **
 ** Data Security, Inc. MD5 Message Digest Algorithm" in all         **
 ** material mentioning or referencing the derived work.             **
 **                                                                  **
 ** RSA Data Security, Inc. makes no representations concerning      **
 ** either the merchantability of this software or the suitability   **
 ** of this software for any particular purpose.  It is provided "as **
 ** is" without express or implied warranty of any kind.             **
 **                                                                  **
 ** These notices must be retained in any copies of any part of this **
 ** documentation and/or software.                                   **
 **********************************************************************
 */

/* -- include the following line if the md5.h header file is separate -- */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "md5.h"

/* forward declaration */
static void Transform ();

static unsigned char PADDING[64] = {
    0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

/* F, G and H are basic MD5 functions: selection, majority, parity */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s, ac) \
  {(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) \
  {(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) \
  {(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) \
  {(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
  }

void
wvMD5Init (mdContext)
     wvMD5_CTX *mdContext;
{
    mdContext->i[0] = mdContext->i[1] = (UINT4) 0;

    /* Load magic initialization constants.
     */
    mdContext->buf[0] = (UINT4) 0x67452301;
    mdContext->buf[1] = (UINT4) 0xefcdab89;
    mdContext->buf[2] = (UINT4) 0x98badcfe;
    mdContext->buf[3] = (UINT4) 0x10325476;
}

void
wvMD5Update (mdContext, inBuf, inLen)
     wvMD5_CTX *mdContext;
     unsigned char *inBuf;
     unsigned int inLen;
{
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;

    /* compute number of bytes mod 64 */
    mdi = (int) ((mdContext->i[0] >> 3) & 0x3F);

    /* update number of bits */
    if ((mdContext->i[0] + ((UINT4) inLen << 3)) < mdContext->i[0])
	mdContext->i[1]++;
    mdContext->i[0] += ((UINT4) inLen << 3);
    mdContext->i[1] += ((UINT4) inLen >> 29);

    while (inLen--)
      {
	  /* add new character to buffer, increment mdi */
	  mdContext->in[mdi++] = *inBuf++;

	  /* transform if necessary */
	  if (mdi == 0x40)
	    {
		for (i = 0, ii = 0; i < 16; i++, ii += 4)
		    in[i] = (((UINT4) mdContext->in[ii + 3]) << 24) |
			(((UINT4) mdContext->in[ii + 2]) << 16) |
			(((UINT4) mdContext->in[ii + 1]) << 8) |
			((UINT4) mdContext->in[ii]);
		Transform (mdContext->buf, in);
		mdi = 0;
	    }
      }
}

void
wvMD5Final (mdContext)
     wvMD5_CTX *mdContext;
{
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;
    unsigned int padLen;

    /* save number of bits */
    in[14] = mdContext->i[0];
    in[15] = mdContext->i[1];

    /* compute number of bytes mod 64 */
    mdi = (int) ((mdContext->i[0] >> 3) & 0x3F);

    /* pad out to 56 mod 64 */
    padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
    wvMD5Update (mdContext, PADDING, padLen);

    /* append length in bits and transform */
    for (i = 0, ii = 0; i < 14; i++, ii += 4)
	in[i] = (((UINT4) mdContext->in[ii + 3]) << 24) |
	    (((UINT4) mdContext->in[ii + 2]) << 16) |
	    (((UINT4) mdContext->in[ii + 1]) << 8) |
	    ((UINT4) mdContext->in[ii]);
    Transform (mdContext->buf, in);

    /* store buffer in digest */
    for (i = 0, ii = 0; i < 4; i++, ii += 4)
      {
	  mdContext->digest[ii] = (unsigned char) (mdContext->buf[i] & 0xFF);
	  mdContext->digest[ii + 1] =
	      (unsigned char) ((mdContext->buf[i] >> 8) & 0xFF);
	  mdContext->digest[ii + 2] =
	      (unsigned char) ((mdContext->buf[i] >> 16) & 0xFF);
	  mdContext->digest[ii + 3] =
	      (unsigned char) ((mdContext->buf[i] >> 24) & 0xFF);
      }
}

/* Basic MD5 step. Transform buf based on in.
 */
static void
Transform (buf, in)
     UINT4 *buf;
     UINT4 *in;
{
    UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

    /* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
    FF (a, b, c, d, in[0], S11, 3614090360UL);	/* 1 */
    FF (d, a, b, c, in[1], S12, 3905402710UL);	/* 2 */
    FF (c, d, a, b, in[2], S13, 606105819UL);	/* 3 */
    FF (b, c, d, a, in[3], S14, 3250441966UL);	/* 4 */
    FF (a, b, c, d, in[4], S11, 4118548399UL);	/* 5 */
    FF (d, a, b, c, in[5], S12, 1200080426UL);	/* 6 */
    FF (c, d, a, b, in[6], S13, 2821735955UL);	/* 7 */
    FF (b, c, d, a, in[7], S14, 4249261313UL);	/* 8 */
    FF (a, b, c, d, in[8], S11, 1770035416UL);	/* 9 */
    FF (d, a, b, c, in[9], S12, 2336552879UL);	/* 10 */
    FF (c, d, a, b, in[10], S13, 4294925233UL);	/* 11 */
    FF (b, c, d, a, in[11], S14, 2304563134UL);	/* 12 */
    FF (a, b, c, d, in[12], S11, 1804603682UL);	/* 13 */
    FF (d, a, b, c, in[13], S12, 4254626195UL);	/* 14 */
    FF (c, d, a, b, in[14], S13, 2792965006UL);	/* 15 */
    FF (b, c, d, a, in[15], S14, 1236535329UL);	/* 16 */

    /* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
    GG (a, b, c, d, in[1], S21, 4129170786UL);	/* 17 */
    GG (d, a, b, c, in[6], S22, 3225465664UL);	/* 18 */
    GG (c, d, a, b, in[11], S23, 643717713UL);	/* 19 */
    GG (b, c, d, a, in[0], S24, 3921069994UL);	/* 20 */
    GG (a, b, c, d, in[5], S21, 3593408605UL);	/* 21 */
    GG (d, a, b, c, in[10], S22, 38016083UL);	/* 22 */
    GG (c, d, a, b, in[15], S23, 3634488961UL);	/* 23 */
    GG (b, c, d, a, in[4], S24, 3889429448UL);	/* 24 */
    GG (a, b, c, d, in[9], S21, 568446438UL);	/* 25 */
    GG (d, a, b, c, in[14], S22, 3275163606UL);	/* 26 */
    GG (c, d, a, b, in[3], S23, 4107603335UL);	/* 27 */
    GG (b, c, d, a, in[8], S24, 1163531501UL);	/* 28 */
    GG (a, b, c, d, in[13], S21, 2850285829UL);	/* 29 */
    GG (d, a, b, c, in[2], S22, 4243563512UL);	/* 30 */
    GG (c, d, a, b, in[7], S23, 1735328473UL);	/* 31 */
    GG (b, c, d, a, in[12], S24, 2368359562UL);	/* 32 */

    /* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
    HH (a, b, c, d, in[5], S31, 4294588738UL);	/* 33 */
    HH (d, a, b, c, in[8], S32, 2272392833UL);	/* 34 */
    HH (c, d, a, b, in[11], S33, 1839030562UL);	/* 35 */
    HH (b, c, d, a, in[14], S34, 4259657740UL);	/* 36 */
    HH (a, b, c, d, in[1], S31, 2763975236UL);	/* 37 */
    HH (d, a, b, c, in[4], S32, 1272893353UL);	/* 38 */
    HH (c, d, a, b, in[7], S33, 4139469664UL);	/* 39 */
    HH (b, c, d, a, in[10], S34, 3200236656UL);	/* 40 */
    HH (a, b, c, d, in[13], S31, 681279174UL);	/* 41 */
    HH (d, a, b, c, in[0], S32, 3936430074UL);	/* 42 */
    HH (c, d, a, b, in[3], S33, 3572445317UL);	/* 43 */
    HH (b, c, d, a, in[6], S34, 76029189UL);	/* 44 */
    HH (a, b, c, d, in[9], S31, 3654602809UL);	/* 45 */
    HH (d, a, b, c, in[12], S32, 3873151461UL);	/* 46 */
    HH (c, d, a, b, in[15], S33, 530742520UL);	/* 47 */
    HH (b, c, d, a, in[2], S34, 3299628645UL);	/* 48 */

    /* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
    II (a, b, c, d, in[0], S41, 4096336452UL);	/* 49 */
    II (d, a, b, c, in[7], S42, 1126891415UL);	/* 50 */
    II (c, d, a, b, in[14], S43, 2878612391UL);	/* 51 */
    II (b, c, d, a, in[5], S44, 4237533241UL);	/* 52 */
    II (a, b, c, d, in[12], S41, 1700485571UL);	/* 53 */
    II (d, a, b, c, in[3], S42, 2399980690UL);	/* 54 */
    II (c, d, a, b, in[10], S43, 4293915773UL);	/* 55 */
    II (b, c, d, a, in[1], S44, 2240044497UL);	/* 56 */
    II (a, b, c, d, in[8], S41, 1873313359UL);	/* 57 */
    II (d, a, b, c, in[15], S42, 4264355552UL);	/* 58 */
    II (c, d, a, b, in[6], S43, 2734768916UL);	/* 59 */
    II (b, c, d, a, in[13], S44, 1309151649UL);	/* 60 */
    II (a, b, c, d, in[4], S41, 4149444226UL);	/* 61 */
    II (d, a, b, c, in[11], S42, 3174756917UL);	/* 62 */
    II (c, d, a, b, in[2], S43, 718787259UL);	/* 63 */
    II (b, c, d, a, in[9], S44, 3951481745UL);	/* 64 */

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}

/*
 **********************************************************************
 ** End of md5.c                                                     **
 ******************************* (cut) ********************************
 */
