/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm *//* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. Allrights reserved.License to copy and use this software is granted provided that itis identified as the "RSA Data Security, Inc. MD5 Message-DigestAlgorithm" in all material mentioning or referencing this softwareor this function.License is also granted to make and use derivative works providedthat such works are identified as "derived from the RSA DataSecurity, Inc. MD5 Message-Digest Algorithm" in all materialmentioning or referencing the derived work.RSA Data Security, Inc. makes no representations concerning eitherthe merchantability of this software or the suitability of thissoftware 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 thisdocumentation and/or software. */#include <string.h>#include "md5.h"/* Constants for MD5_transform 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 _MD5_transform(unsigned long [4], unsigned char [64]);static void _encode(unsigned char *, unsigned long *, unsigned int);static void _decode(unsigned long *, 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 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 __cdecl _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. */void __cdecl _MD5_update(_MD5_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((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. */void __cdecl _MD5_final(unsigned char digest[16], _MD5_CTX *context){    unsigned char bits[8];    unsigned int index, padLen;    /* 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);    _MD5_update(context, PADDING, padLen);    /* Append length (before padding) */    _MD5_update(context, bits, 8);    /* Store state in digest */    _encode(digest, context->state, 16);    /* Zero sensitive information */    memset((unsigned char *)context, 0, sizeof(*context));}/* MD5 basic transformation. Transforms state based on block */static void _MD5_transform(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((unsigned char *)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 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 long). Assumes len is a multiple of 4 */static void _decode(unsigned long *output, unsigned char *input, unsigned int 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);    }}/* For testing the C version... */void c_md5_test(unsigned char digest[16], unsigned char *data, unsigned int dataLen){    _MD5_CTX ctx;    _MD5_init(&ctx);    _MD5_update(&ctx, data, dataLen);    _MD5_final(digest, &ctx);}