/* The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Mobile Application Link.
 *
 * The Initial Developer of the Original Code is AvantGo, Inc.
 * Portions created by AvantGo, Inc. are Copyright (C) 1997-1999
 * AvantGo, Inc. All Rights Reserved.
 *
 * Contributor(s):
 */

/*  Modified by Tom 1/15/99 */

/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 */

/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. 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 "md5.h"
#include <AGUtil.h>

/* Constants for MD5Transform routine.
 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static void AGMD5Transform(unsigned long a[4], unsigned char b[64]);
static void Encode(unsigned char *a, unsigned long *b, unsigned long c);
static void Decode(unsigned long *a, unsigned char *b,  unsigned long c);

/* 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) + (unsigned long)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define GG(a, b, c, d, x, s, ac) { (a) += G ((b), (c), (d)) + (x) + (unsigned long)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define HH(a, b, c, d, x, s, ac) { (a) += H ((b), (c), (d)) + (x) + (unsigned long)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define II(a, b, c, d, x, s, ac) { (a) += I ((b), (c), (d)) + (x) + (unsigned long)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

/* MD5 initialization. Begins an MD5 operation, writing a new context.
 */
void AGMD5Init (AGMD5_CTX *context)
{
    context->count[0] = context->count[1] = 0;
    /* Load magic initialization constants.
     */
    context->state[0] = 0x67452301;
    context->state[1] = 0xefcdab89;
    context->state[2] = 0x98badcfe;
    context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
   operation, processing another message block, and updating the
   context.
*/
void AGMD5Update (AGMD5_CTX *context, unsigned char *input,
                unsigned int inputLen)
{
    unsigned int i, index, partLen;
    
    /* Compute number of bytes mod 64 */
    index = (unsigned int)((context->count[0] >> 3) & 0x3F);
    
    /* Update number of bits */
    if ((context->count[0] += ((unsigned long)inputLen << 3))
        < ((unsigned long)inputLen << 3))
        context->count[1]++;
    context->count[1] += ((unsigned long)inputLen >> 29);
    
    partLen = 64 - index;
    
    /* Transform as many times as possible.
     */
    if (inputLen >= partLen) {
        memcpy((void *)&context->buffer[index], (void *)input, partLen);
        AGMD5Transform (context->state, context->buffer);
        
        for (i = partLen; i + 63 < inputLen; i += 64)
            AGMD5Transform (context->state, &input[i]);
        
        index = 0;
    }
    else
        i = 0;
    
    /* Buffer remaining input */
    memcpy((void *)&context->buffer[index], (void *)&input[i],
           inputLen-i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
   the message digest and zeroizing the context.
*/
void AGMD5Final (unsigned char digest[16], AGMD5_CTX *context)
{
    unsigned char bits[8];
    unsigned int index, padLen;
    unsigned char PADDING[64];
  
 	bzero(PADDING, 64);
 	PADDING[0] = 0x80;

    /* Save number of bits */
    Encode (bits, context->count, 8);
    
    /* Pad out to 56 mod 64.
     */
    index = (unsigned int)((context->count[0] >> 3) & 0x3f);
    padLen = (index < 56) ? (56 - index) : (120 - index);
    AGMD5Update (context, PADDING, padLen);
    
    /* Append length (before padding) */
    AGMD5Update (context, bits, 8);
    /* Store state in digest */
    Encode (digest, context->state, 16);
    
    /* Zeroize sensitive information.
     */
    memset ((void *)context, 0, sizeof (*context));
}

/* MD5 basic transformation. Transforms state based on block.
 */
static void AGMD5Transform (unsigned long state[4], unsigned char block[64])
{
    unsigned long a = state[0], b = state[1], c = state[2], d = state[3], x[16];
    
    Decode (x, block, 64);
    
    /* Round 1 */
    FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
    FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
    FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
    FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
    FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
    FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
    FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
    FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
    FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
    FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
    FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
    FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
    FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
    FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
    FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
    FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
    
    /* Round 2 */
    GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
    GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
    GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
    GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
    GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
    GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
    GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
    GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
    GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
    GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
    GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
    GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
    GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
    GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
    GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
    GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
    
    /* Round 3 */
    HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
    HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
    HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
    HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
    HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
    HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
    HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
    HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
    HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
    HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
    HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
    HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
    HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
    HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
    HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
    HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
    
    /* Round 4 */
    II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
    II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
    II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
    II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
    II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
    II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
    II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
    II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
    II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
    II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
    II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
    II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
    II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
    II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
    II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
    II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
    
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    
    /* Zeroize sensitive information.
     */
    memset ((void *)x, 0, sizeof (x));
}

/* Encodes input (unsigned long) into output (unsigned char). Assumes len is
   a multiple of 4.
*/
static void Encode (unsigned char *output, unsigned long *input, unsigned long len)
{
    unsigned int i, j;
    
    for (i = 0, j = 0; j < len; i++, j += 4) {
        output[j] = (unsigned char)(input[i] & 0xff);
        output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
        output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
        output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  }
}

/* Decodes input (unsigned char) into output (unsigned long). Assumes len is
   a multiple of 4.
*/
static void Decode (unsigned long *output, unsigned char *input, unsigned long len)
{
    unsigned int i, j;
    
    for (i = 0, j = 0; j < len; i++, j += 4)
        output[i] = ((unsigned long)input[j]) | (((unsigned long)input[j+1]) << 8) |
            (((unsigned long)input[j+2]) << 16) | (((unsigned long)input[j+3]) << 24);
}