/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "md5.h"

/*
**************************************************************************
** md5.c -- the source code for MD5 routines                            **
** RSA Data Security, Inc. MD5 Message-Digest Algorithm                 **
** Created: 2/17/90 RLR                                                 **
** Revised: 1/91 SRD, AJ, BSK, JT Reference C ver., 7/10 constant corr. **
**************************************************************************
*/

/*
**************************************************************************
** 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.                                       **
**************************************************************************
*/


/*
**************************************************************************
**  Message-digest routines:                                            **
**  To form the message digest for a message M                          **
**    (1) Initialize a context buffer mdContext using MD5Init           **
**    (2) Call MD5Update on mdContext and M                             **
**    (3) Call MD5Final on mdContext                                    **
**  The message digest is now in mdContext->digest[0...15]              **
**************************************************************************
*/

/* forward declaration */
static void Transform (UINT4 *buf, UINT4 *in);

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, H and I are basic MD5 functions */
#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); \
        }

/*
* The routine MD5Init initializes the message-digest context
* mdContext. All fields are set to zero.
*/
void MD5Init (MD5_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;
}

/*
* The routine MD5Update updates the message-digest context to
* account for the presence of each of the characters inBuf[0..inLen-1]
* in the message whose digest is being computed.
*/
void MD5Update (MD5_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;
                }
        }
}

/*
* The routine MD5Final terminates the message-digest computation and
* ends with the desired message digest in mdContext->digest[0...15].
*/
void MD5Final (MD5_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);
        MD5Update (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. Transforms buf based on in.
*/
static void Transform (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, 3614090360U); /* 1 */
        FF (d, a, b, c, in[ 1], S12, 3905402710U); /* 2 */
        FF (c, d, a, b, in[ 2], S13,  606105819U); /* 3 */
        FF (b, c, d, a, in[ 3], S14, 3250441966U); /* 4 */
        FF (a, b, c, d, in[ 4], S11, 4118548399U); /* 5 */
        FF (d, a, b, c, in[ 5], S12, 1200080426U); /* 6 */
        FF (c, d, a, b, in[ 6], S13, 2821735955U); /* 7 */
        FF (b, c, d, a, in[ 7], S14, 4249261313U); /* 8 */
        FF (a, b, c, d, in[ 8], S11, 1770035416U); /* 9 */
        FF (d, a, b, c, in[ 9], S12, 2336552879U); /* 10 */
        FF (c, d, a, b, in[10], S13, 4294925233U); /* 11 */
        FF (b, c, d, a, in[11], S14, 2304563134U); /* 12 */
        FF (a, b, c, d, in[12], S11, 1804603682U); /* 13 */
        FF (d, a, b, c, in[13], S12, 4254626195U); /* 14 */
        FF (c, d, a, b, in[14], S13, 2792965006U); /* 15 */
        FF (b, c, d, a, in[15], S14, 1236535329U); /* 16 */

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

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

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

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