/* ==================================================================== 
 * The Kannel Software License, Version 1.0 
 * 
 * Copyright (c) 2001-2010 Kannel Group  
 * Copyright (c) 1998-2001 WapIT Ltd.   
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 * 
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 * 
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in 
 *    the documentation and/or other materials provided with the 
 *    distribution. 
 * 
 * 3. The end-user documentation included with the redistribution, 
 *    if any, must include the following acknowledgment: 
 *       "This product includes software developed by the 
 *        Kannel Group (http://www.kannel.org/)." 
 *    Alternately, this acknowledgment may appear in the software itself, 
 *    if and wherever such third-party acknowledgments normally appear. 
 * 
 * 4. The names "Kannel" and "Kannel Group" must not be used to 
 *    endorse or promote products derived from this software without 
 *    prior written permission. For written permission, please  
 *    contact org@kannel.org. 
 * 
 * 5. Products derived from this software may not be called "Kannel", 
 *    nor may "Kannel" appear in their name, without prior written 
 *    permission of the Kannel Group. 
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED.  IN NO EVENT SHALL THE KANNEL GROUP OR ITS CONTRIBUTORS 
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,  
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT  
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR  
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,  
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE  
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,  
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 * ==================================================================== 
 * 
 * This software consists of voluntary contributions made by many 
 * individuals on behalf of the Kannel Group.  For more information on  
 * the Kannel Group, please see <http://www.kannel.org/>. 
 * 
 * Portions of this software are based upon software originally written at  
 * WapIT Ltd., Helsinki, Finland for the Kannel project.  
 */ 

/*
 * md5.c - MD5 digest algorithm
 *
 * The remaining code is the reference MD5 code (md5c.c) from rfc1321
 */

/* 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 <stdio.h>

#include "gwlib.h"
#include "md5.h"

/* Declaration of static functions */

static void md5_digest(char *md5str, unsigned char *digest);
static void md5_init(md5_ctx *);
static void md5_update(md5_ctx *, const unsigned char *, unsigned int);
static void md5_final(unsigned char[16], md5_ctx *);



static void md5_digest(char *md5str, unsigned char *digest)
{
    int i;

    for (i = 0; i < 16; i++) {
        sprintf(md5str, "%02x", digest[i]);
        md5str += 2;
    }

    *md5str = '\0';
}

/* 
 * 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 md5_transform(unsigned int[4], const unsigned char[64]);
static void md5_encode(unsigned char *, unsigned int *, unsigned int);
static void md5_decode(unsigned int *, const unsigned char *, unsigned int);

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

/* 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 int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (unsigned int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (unsigned int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (unsigned int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

static void md5_init(md5_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.
 */
static void md5_update(md5_ctx *context, const 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 int) inputLen << 3))
        < ((unsigned int) inputLen << 3))
        context->count[1]++;
    context->count[1] += ((unsigned int) inputLen >> 29);

    partLen = 64 - index;

    /* Transform as many times as possible. */
    if (inputLen >= partLen) {
        memcpy((unsigned char*) & context->buffer[index], 
               (unsigned char*) input, partLen);
        md5_transform(context->state, context->buffer);

        for (i = partLen; i + 63 < inputLen; i += 64)
            md5_transform(context->state, &input[i]);

        index = 0;
    } else
        i = 0;

    /* Buffer remaining input */
    memcpy((unsigned char*) & context->buffer[index], (unsigned char*) & input[i],
           inputLen - i);
}

/*
   MD5 finalization. Ends an MD5 message-digest operation, writing the
   the message digest and zeroizing the context.
 */
static void md5_final(unsigned char digest[16], md5_ctx *context)
{
	unsigned char bits[8];
	unsigned int index, padLen;

	/* Save number of bits */
	md5_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);
	md5_update(context, PADDING, padLen);

	/* Append length (before padding) */
	md5_update(context, bits, 8);

	/* Store state in digest */
	md5_encode(digest, context->state, 16);

	/* Zeroize sensitive information.
	 */
	memset((unsigned char*) context, 0, sizeof(*context));
}


/* 
 * MD5 basic transformation. Transforms state based on block.
 */
static void md5_transform(state, block)
unsigned int state[4];
const unsigned char block[64];
{
	unsigned int a = state[0], b = state[1], c = state[2], d = state[3], x[16];

	md5_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((unsigned char*) x, 0, sizeof(x));
}

/* 
   Encodes input (unsigned int) into output (unsigned char). Assumes len is
   a multiple of 4.
 */
static void md5_encode(output, input, len)
unsigned char *output;
unsigned int *input;
unsigned int 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 int). Assumes len is
   a multiple of 4.
 */
static void md5_decode(output, input, len)
unsigned int *output;
const unsigned char *input;
unsigned int len;
{
	unsigned int i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
		output[i] = ((unsigned int) input[j]) | (((unsigned int) input[j + 1]) << 8) |
			(((unsigned int) input[j + 2]) << 16) | (((unsigned int) input[j + 3]) << 24);
}


Octstr *md5(Octstr *data)
{
    md5_ctx context;
    unsigned char digest[16];
    Octstr *enc;

    if (data == NULL)
        return NULL;

    md5_init(&context);
    md5_update(&context, octstr_get_cstr(data), octstr_len(data));
    md5_final(digest, &context);

    enc = octstr_create_from_data(digest, 16); 

    return enc; 
}


Octstr *md5digest(Octstr *data)
{
    char md5str[33];
    Octstr *digest;

    if (data == NULL)
        return NULL;

    md5str[0] = '\0';
    digest = md5(data);
    md5_digest(md5str, octstr_get_cstr(digest));
    octstr_destroy(digest);

    digest = octstr_create(md5str);

    return digest;
}



