MD5 Algorithm

This is a discussion on MD5 Algorithm within the C Programming forums, part of the General Programming Boards category; Whats the deal with every single MD5 algorithm I find? I've tried them all (the ones that you have to ...

  1. #1
    Rebooted Inquirer's Avatar
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    Apr 2002
    Posts
    281

    MD5 Algorithm

    Whats the deal with every single MD5 algorithm I find? I've tried them all (the ones that you have to call like 3 methods just to get the md5 hash), or at least all of the ones I can find, and none of them work. I jsut get long strings of 0's with the occasional letter interspersed randomly (different even between subsequent identical calls). What I need is a one-function MD5 algorithm, that doesn't require external libraries, because I cannot install them on my computer. I have openSSL, but haven't even figured out how to link those libraries into my prog, so that would be helpful too if you know how to do it with that. Thanks!!
    Compilers:
    GCC on Red Hat 8.1 (Primary)
    GCC on Mac OS X 10.2.4 (Secondary)

    Others:
    MinGW on XP

  2. #2
    Registered User kryptkat's Avatar
    Join Date
    Dec 2002
    Posts
    638

    md5

    i posted md5 on hdc a while back compiles under borland.

  3. #3
    Registered User
    Join Date
    Dec 2003
    Posts
    5
    Code:
    main.c:
    #include <stdio.h>
    #include <stdlib.h>
    #include "md5.h"
    
    void hexhash(char *str, char *hash);
    
    int main(int argc, char *argv[])
    {
    	char hash[33];
    	hexhash("hello", hash);
    	printf("%s", hash);
    	getchar();
    }
    
    void hexhash(char *str, char *hash)
    {
    	struct MD5Context mdc;
    	unsigned char dg[16];
    	MD5Init(&mdc);
    	MD5Update(&mdc, str, strlen(str));
    	MD5Final(dg, &mdc);
    	
    	sprintf(hash, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x", 
    		dg[0], dg[1], dg[2],
     		dg[3], dg[4], dg[5], dg[6], dg[7], dg[8], dg[9], dg[10], dg[11],	
     		dg[12], dg[13], dg[14], dg[15]);
    }
    Code:
    md5.c
    #ifdef FREEBSD
    # include <machine/endian.h>
    #elif defined(LINUX)
    # include <endian.h>
    #elif defined(SOLARIS)
    # include <sys/isa_defs.h>
    #endif
    #if __BYTE_ORDER == __BIG_ENDIAN
    #define HIGHFIRST 1
    #endif
    
    /*
     * This code implements the MD5 message-digest algorithm.
     * The algorithm is due to Ron Rivest.  This code was
     * written by Colin Plumb in 1993, no copyright is claimed.
     * This code is in the public domain; do with it what you wish.
     *
     * Equivalent code is available from RSA Data Security, Inc.
     * This code has been tested against that, and is equivalent,
     * except that you don't need to include two pages of legalese
     * with every copy.
     *
     * To compute the message digest of a chunk of bytes, declare an
     * MD5Context structure, pass it to MD5Init, call MD5Update as
     * needed on buffers full of bytes, and then call MD5Final, which
     * will fill a supplied 16-byte array with the digest.
     */
    #include <string.h>             /* for memcpy() */
    #include "md5.h"
    
    #ifndef HIGHFIRST
    #define byteReverse(buf, len)   /* Nothing */
    #else
    void byteReverse (unsigned char *buf, unsigned longs);
    
    #ifndef ASM_MD5
    /*
     * Note: this code is harmless on little-endian machines.
     */
    void byteReverse (unsigned char *buf, unsigned longs)
    {
        uint32 t;
        do
        {
            t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
                ((unsigned) buf[1] << 8 | buf[0]);
            *(uint32 *) buf = t;
            buf += 4;
        }
        while (--longs);
    }
    #endif
    #endif
    
    /*
     * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
     * initialization constants.
     */
    void MD5Init (struct MD5Context *ctx)
    {
        ctx->buf[0] = 0x67452301;
        ctx->buf[1] = 0xefcdab89;
        ctx->buf[2] = 0x98badcfe;
        ctx->buf[3] = 0x10325476;
    
        ctx->bits[0] = 0;
        ctx->bits[1] = 0;
    }
    
    /*
     * Update context to reflect the concatenation of another buffer full
     * of bytes.
     */
    void MD5Update (struct MD5Context *ctx, unsigned char const *buf,
                    unsigned len)
    {
        uint32 t;
    
        /* Update bitcount */
    
        t = ctx->bits[0];
        if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
            ctx->bits[1]++;         /* Carry from low to high */
        ctx->bits[1] += len >> 29;
    
        t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
    
        /* Handle any leading odd-sized chunks */
    
        if (t)
        {
            unsigned char *p = (unsigned char *) ctx->in + t;
    
            t = 64 - t;
            if (len < t)
            {
                memcpy (p, buf, len);
                return;
            }
            memcpy (p, buf, t);
            byteReverse (ctx->in, 16);
            MD5Transform (ctx->buf, (uint32 *) ctx->in);
            buf += t;
            len -= t;
        }
        /* Process data in 64-byte chunks */
    
        while (len >= 64)
        {
            memcpy (ctx->in, buf, 64);
            byteReverse (ctx->in, 16);
            MD5Transform (ctx->buf, (uint32 *) ctx->in);
            buf += 64;
            len -= 64;
        }
    
        /* Handle any remaining bytes of data. */
    
        memcpy (ctx->in, buf, len);
    }
    
    /*
     * Final wrapup - pad to 64-byte boundary with the bit pattern 
     * 1 0* (64-bit count of bits processed, MSB-first)
     */
    void MD5Final (unsigned char digest[16], struct MD5Context *ctx)
    {
        unsigned count;
        unsigned char *p;
    
        /* Compute number of bytes mod 64 */
        count = (ctx->bits[0] >> 3) & 0x3F;
    
        /* Set the first char of padding to 0x80.  This is safe since there is
           always at least one byte free */
        p = ctx->in + count;
        *p++ = 0x80;
    
        /* Bytes of padding needed to make 64 bytes */
        count = 64 - 1 - count;
    
        /* Pad out to 56 mod 64 */
        if (count < 8)
        {
            /* Two lots of padding:  Pad the first block to 64 bytes */
            memset (p, 0, count);
            byteReverse (ctx->in, 16);
            MD5Transform (ctx->buf, (uint32 *) ctx->in);
    
            /* Now fill the next block with 56 bytes */
            memset (ctx->in, 0, 56);
        }
        else
        {
            /* Pad block to 56 bytes */
            memset (p, 0, count - 8);
        }
        byteReverse (ctx->in, 14);
    
        /* Append length in bits and transform */
        ((uint32 *) ctx->in)[14] = ctx->bits[0];
        ((uint32 *) ctx->in)[15] = ctx->bits[1];
    
        MD5Transform (ctx->buf, (uint32 *) ctx->in);
        byteReverse ((unsigned char *) ctx->buf, 4);
        memcpy (digest, ctx->buf, 16);
        memset (ctx, 0, sizeof (ctx));      /* In case it's sensitive */
    }
    
    #ifndef ASM_MD5
    
    /* The four core functions - F1 is optimized somewhat */
    
    /* #define F1(x, y, z) (x & y | ~x & z) */
    #define F1(x, y, z) (z ^ (x & (y ^ z)))
    #define F2(x, y, z) F1(z, x, y)
    #define F3(x, y, z) (x ^ y ^ z)
    #define F4(x, y, z) (y ^ (x | ~z))
    
    /* This is the central step in the MD5 algorithm. */
    #define MD5STEP(f, w, x, y, z, data, s) \
    	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
    
    /*
     * The core of the MD5 algorithm, this alters an existing MD5 hash to
     * reflect the addition of 16 longwords of new data.  MD5Update blocks
     * the data and converts bytes into longwords for this routine.
     */
    void MD5Transform (uint32 buf[4], uint32 const in[16])
    {
        register uint32 a, b, c, d;
    
        a = buf[0];
        b = buf[1];
        c = buf[2];
        d = buf[3];
    
        MD5STEP (F1, a, b, c, d, in[0] + 0xd76aa478, 7);
        MD5STEP (F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
        MD5STEP (F1, c, d, a, b, in[2] + 0x242070db, 17);
        MD5STEP (F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
        MD5STEP (F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
        MD5STEP (F1, d, a, b, c, in[5] + 0x4787c62a, 12);
        MD5STEP (F1, c, d, a, b, in[6] + 0xa8304613, 17);
        MD5STEP (F1, b, c, d, a, in[7] + 0xfd469501, 22);
        MD5STEP (F1, a, b, c, d, in[8] + 0x698098d8, 7);
        MD5STEP (F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
        MD5STEP (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
        MD5STEP (F1, b, c, d, a, in[11] + 0x895cd7be, 22);
        MD5STEP (F1, a, b, c, d, in[12] + 0x6b901122, 7);
        MD5STEP (F1, d, a, b, c, in[13] + 0xfd987193, 12);
        MD5STEP (F1, c, d, a, b, in[14] + 0xa679438e, 17);
        MD5STEP (F1, b, c, d, a, in[15] + 0x49b40821, 22);
    
        MD5STEP (F2, a, b, c, d, in[1] + 0xf61e2562, 5);
        MD5STEP (F2, d, a, b, c, in[6] + 0xc040b340, 9);
        MD5STEP (F2, c, d, a, b, in[11] + 0x265e5a51, 14);
        MD5STEP (F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
        MD5STEP (F2, a, b, c, d, in[5] + 0xd62f105d, 5);
        MD5STEP (F2, d, a, b, c, in[10] + 0x02441453, 9);
        MD5STEP (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
        MD5STEP (F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
        MD5STEP (F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
        MD5STEP (F2, d, a, b, c, in[14] + 0xc33707d6, 9);
        MD5STEP (F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
        MD5STEP (F2, b, c, d, a, in[8] + 0x455a14ed, 20);
        MD5STEP (F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
        MD5STEP (F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
        MD5STEP (F2, c, d, a, b, in[7] + 0x676f02d9, 14);
        MD5STEP (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
    
        MD5STEP (F3, a, b, c, d, in[5] + 0xfffa3942, 4);
        MD5STEP (F3, d, a, b, c, in[8] + 0x8771f681, 11);
        MD5STEP (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
        MD5STEP (F3, b, c, d, a, in[14] + 0xfde5380c, 23);
        MD5STEP (F3, a, b, c, d, in[1] + 0xa4beea44, 4);
        MD5STEP (F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
        MD5STEP (F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
        MD5STEP (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
        MD5STEP (F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
        MD5STEP (F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
        MD5STEP (F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
        MD5STEP (F3, b, c, d, a, in[6] + 0x04881d05, 23);
        MD5STEP (F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
        MD5STEP (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
        MD5STEP (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
        MD5STEP (F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
    
        MD5STEP (F4, a, b, c, d, in[0] + 0xf4292244, 6);
        MD5STEP (F4, d, a, b, c, in[7] + 0x432aff97, 10);
        MD5STEP (F4, c, d, a, b, in[14] + 0xab9423a7, 15);
        MD5STEP (F4, b, c, d, a, in[5] + 0xfc93a039, 21);
        MD5STEP (F4, a, b, c, d, in[12] + 0x655b59c3, 6);
        MD5STEP (F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
        MD5STEP (F4, c, d, a, b, in[10] + 0xffeff47d, 15);
        MD5STEP (F4, b, c, d, a, in[1] + 0x85845dd1, 21);
        MD5STEP (F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
        MD5STEP (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
        MD5STEP (F4, c, d, a, b, in[6] + 0xa3014314, 15);
        MD5STEP (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
        MD5STEP (F4, a, b, c, d, in[4] + 0xf7537e82, 6);
        MD5STEP (F4, d, a, b, c, in[11] + 0xbd3af235, 10);
        MD5STEP (F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
        MD5STEP (F4, b, c, d, a, in[9] + 0xeb86d391, 21);
    
        buf[0] += a;
        buf[1] += b;
        buf[2] += c;
        buf[3] += d;
    }
    
    #endif
    Code:
    md5.h
    #ifndef MD5_H
    #define MD5_H
    
    #ifdef __alpha
    typedef unsigned int uint32;
    #else
    typedef unsigned long uint32;
    #endif
    
    struct MD5Context
    {
        uint32 buf[4];
        uint32 bits[2];
        unsigned char in[64];
    };
    
    void MD5Init (struct MD5Context *context);
    void MD5Update (struct MD5Context *context, unsigned char const *buf,
                    unsigned len);
    void MD5Final (unsigned char digest[16], struct MD5Context *context);
    void MD5Transform (uint32 buf[4], uint32 const in[16]);
    
    /*
     * This is needed to make RSAREF happy on some MS-DOS compilers.
     */
    typedef struct MD5Context MD5_CTX;
    
    #endif /* !MD5_H */

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