halflife-thewastes-sdk/dedicated/md5.cpp

///////////////////////////
// md5.cpp  :  MD5 hashing functions
//
#include <stdio.h>
#include <memory.h>
#include <string.h>
#include "md5.h"

// MD5 Hash
typedef struct
{
	unsigned int	buf[ 4 ];
    unsigned int	bits[ 2 ];
    unsigned char	in[ 64 ];
} MD5Context_t;

/* 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 )

/*
=================
MD5Transform

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( unsigned int buf[4], unsigned int const in[16] )
{
    register unsigned int 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;
}

/*
==================
MD5Init

Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious initialization constants.
==================
*/
void MD5Init(MD5Context_t *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;
}

/*
===================
MD5Update

Update context to reflect the concatenation of another buffer full of bytes.
===================
*/
void MD5Update( MD5Context_t *ctx, unsigned char const *buf, unsigned int len )
{
    unsigned int t;

    /* Update bitcount */

    t = ctx->bits[0];
    if ((ctx->bits[0] = t + ((unsigned int) 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, (unsigned int *) 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, (unsigned int *) ctx->in);
        buf += 64;
        len -= 64;
    }

    /* Handle any remaining bytes of data. */
    memcpy(ctx->in, buf, len);
}

/*
===============
MD5Final

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], MD5Context_t *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, (unsigned int *) 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 */
    ((unsigned int *) ctx->in)[14] = ctx->bits[0];
    ((unsigned int *) ctx->in)[15] = ctx->bits[1];

    MD5Transform(ctx->buf, (unsigned int *) ctx->in);
    //byteReverse((unsigned char *) ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
}

/*
===================
MD5_Hash_File

 ==================
*/
int MD5_Hash_File(unsigned char digest[16], char *pszFileName )
{
	FILE			*fp;
	unsigned char	chunk[1024];
	int				bytesread;
	MD5Context_t	ctx;
	int				size;

	memset( &ctx, 0, sizeof(MD5Context_t) );

	MD5Init( &ctx );

	fp = fopen( pszFileName, "rb" );
	if ( !fp )
		return 0;

	fseek ( fp, 0, SEEK_END );
	size = ftell ( fp );
	fseek ( fp, 0, SEEK_SET );

	if ( size <= 0 )
	{
		fclose ( fp );
		return 0;
	}

	// Now read in 1K chunks
	while ( size > 0 )
	{
		if ( size > 1024 )
		{
			bytesread = fread(chunk, 1, 1024, fp);
		}
		else
		{
			bytesread = fread(chunk, 1, size, fp);
		}

		// If any data was received, CRC it.
		if ( bytesread > 0 )
		{
			size -= bytesread;
			MD5Update(&ctx, chunk, bytesread);
		}

		// We we are end of file, break loop and return
		if ( feof( fp ) )
		{
			break;
		}
		
		// If there was a disk error, indicate failure.
		if ( ferror(fp) )
		{
			fclose(fp);
			return 0;
		}
	}	

	if ( fp )
	{
		fclose(fp);
	}

	MD5Final( digest, &ctx );

	return 1;
}