md5.cc

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/* 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 "pbd/md5.h"

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

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) + (uint32_t)(ac); \
  (a) = ROTATE_LEFT ((a), (s)); \
  (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
  (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  (a) = ROTATE_LEFT ((a), (s)); \
  (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
  (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  (a) = ROTATE_LEFT ((a), (s)); \
  (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
  (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  (a) = ROTATE_LEFT ((a), (s)); \
  (a) += (b); \
  }

MD5::MD5 ()
{
        Init ();
}

void
MD5::Init ()
{
        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;
}

void 
MD5::Update(uint8_t const *input, size_t 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] += ((uint32_t)inputLen << 3))
            < ((uint32_t)inputLen << 3))
                context.count[1]++;
        context.count[1] += ((uint32_t)inputLen >> 29);

        partLen = 64 - index;

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

                for (i = partLen; i + 63 < inputLen; i += 64) {
                        Transform (context.state, (uint8_t const *) &input[i]);
                }

                index = 0;
        }
        else
                i = 0;

        /* Buffer remaining input */
        memcpy ((void*)&context.buffer[index], (void const *)&input[i], inputLen-i);
}

// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
// Writes to digestRaw

void 
MD5::Final()
{
        uint8_t bits[8];
        size_t index, padLen;

        // Save number of bits
        Encode (bits, context.count, 8);

        // Pad out to 56 mod 64.
        index = (size_t)((context.count[0] >> 3) & 0x3f);
        padLen = (index < 56) ? (56 - index) : (120 - index);
        Update (PADDING, padLen);

        // Append length (before padding)
        Update (bits, 8);

        // Store state in digest
        Encode (digestRaw, context.state, 16);

        // Zeroize sensitive information.
        memset((void*)&context, 0, sizeof (context));

        writeToString();
}

void 
MD5::writeToString()
{
        int pos;

        for (pos = 0; pos < 16; pos++) {
                sprintf (digestChars+(pos*2), "%02x", digestRaw[pos]);
        }
}

// Digests a file and returns the result.
char* 
MD5::digestFile (char *filename)
{
        Init();
                
        FILE *file;
        int len;
        unsigned char buffer[1024];

        if ((file = fopen (filename, "rb")) == NULL) {
                printf ("%s can't be opened\n", filename);
        } else {
                while ((len = fread (buffer, 1, 1024, file))) {
                        Update (buffer, len);
                }
                Final();
                fclose (file);
        }

        return digestChars;
}

char* 
MD5::digestMemory (uint8_t const * memchunk, size_t len)
{
        Init ();
        Update (memchunk, len);
        Final ();
    
        return digestChars;
}

// Digests a string and prints the result.
char* 
MD5::digestString (char const * string)
{
        Init ();
        Update ((uint8_t const *) string, strlen (string));
        Final();

        return digestChars;
}

void 
MD5::Transform (uint32_t state[4], uint8_t const * block)
{
        uint32_t 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 (uint32_t) into output (unsigned char). Assumes len is
 * a multiple of 4.
 */
void 
MD5::Encode (uint8_t *output, uint32_t const * input, size_t len)
{
        size_t 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);
        }
}

void 
MD5::Decode (uint32_t *output, uint8_t const * input, size_t len)
{
        size_t i, j;
        
        for (i = 0, j = 0; j < len; i++, j += 4)
                output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j+1]) << 8) |
                        (((uint32_t)input[j+2]) << 16) | (((uint32_t)input[j+3]) << 24);
}