/* taken from RFC-1321/Appendix A.3 *//* * 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 <string.h>#include "md5.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 21static void MD5Transform(unsigned int[4], unsigned char[64]);static void Encode(unsigned char *, unsigned int*, unsigned int);static void Decode(unsigned int*, unsigned char *, unsigned int);static void MD5_memcpy(unsigned char *, unsigned char *, unsigned int);static void MD5_memset(char *, int, 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); \}/* * MD5 initialization. Begins an MD5 operation, writing a new context. */voidMD5Init(MD5_CTX * context) {	context->count[0] = 0;	context->count[1] = 0;	context->state[0] = 0x67452301;	context->state[1] = 0xefcdab89;	context->state[2] = 0x98badcfe;	context->state[3] = 0x10325476;}voidMD5Update(MD5_CTX * context, unsigned char *input, unsigned int inputLen) {	unsigned int i, index, partLen;	index = (unsigned int) ((context->count[0] >> 3) & 0x3F);	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;	if (inputLen >= partLen) {		MD5_memcpy(&context->buffer[index], input, partLen);		MD5Transform(context->state, context->buffer);		for (i = partLen; i + 63 < inputLen; i += 64)			MD5Transform(context->state, &input[i]);		index = 0;	} else			i = 0;	MD5_memcpy(&context->buffer[index], &input[i], inputLen - i);}voidMD5Final(unsigned char digest[16], MD5_CTX * context) {	unsigned char bits[8];	unsigned int index, padLen;	Encode(bits, context->count, 8);	index = (unsigned int) ((context->count[0] >> 3) & 0x3f);	padLen = (index < 56) ? (56 - index) : (120 - index);	MD5Update(context, PADDING, padLen);	MD5Update(context, bits, 8);	Encode(digest, context->state, 16);	MD5_memset((char *) context, 0, sizeof(*context));}static voidMD5Transform(unsigned int state[4], unsigned char block[64]) {	unsigned int 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;	MD5_memset((char *) x, 0, sizeof(x));}/* * Encodes input (unsigned int) into output (unsigned char). Assumes len is a * multiple of 4. */static voidEncode(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 voidDecode(unsigned int * output, 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);}static voidMD5_memcpy(unsigned char *output, unsigned char *input, unsigned int len) {	memcpy(output, input, len);}static voidMD5_memset(char *output, int value, unsigned int len) {	memset(output, value, len);}