Ok, I have this header for MD5 related functions that I'm using for password authentication in something im writing (feel free to scroll through it for now):
and this quick script to compare two hashes and return true if they match:Code:#ifndef _MD5_H_
#define _MD5_H_
#endif
typedef unsigned long uint32;
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]);
char *MD5str(char *string);
typedef struct MD5Context MD5_CTX;
#ifndef HIGHFIRST
#define byteReverse(buf, len)
#else
void byteReverse (unsigned char *buf, unsigned longs);
#ifndef ASM_MD5
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
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;
}
void MD5Update (struct MD5Context *ctx, unsigned char const *buf, unsigned len)
{
uint32 t;
t = ctx->bits[0];
if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
ctx->bits[1]++;
ctx->bits[1] += len >> 29;
t = (t >> 3) & 0x3f;
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;
}
while (len >= 64)
{
memcpy (ctx->in, buf, 64);
byteReverse (ctx->in, 16);
MD5Transform (ctx->buf, (uint32 *) ctx->in);
buf += 64;
len -= 64;
}
memcpy (ctx->in, buf, len);
}
void MD5Final (unsigned char digest[16], struct MD5Context *ctx)
{
unsigned count;
unsigned char *p;
count = (ctx->bits[0] >> 3) & 0x3F;
p = ctx->in + count;
*p++ = 0x80;
count = 64 - 1 - count;
if (count < 8)
{
memset (p, 0, count);
byteReverse (ctx->in, 16);
MD5Transform (ctx->buf, (uint32 *) ctx->in);
memset (ctx->in, 0, 56);
}
else
{
memset (p, 0, count - 8);
}
byteReverse (ctx->in, 14);
((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));
}
#ifndef ASM_MD5
#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))
#define MD5STEP(f, w, x, y, z, data, s) \
( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
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;
}
char *MD5str(char *string)
{
struct MD5Context mdc;
static unsigned char d[16];
static char h[36];
MD5Init(&mdc);
MD5Update(&mdc, string, strlen(string));
MD5Final(d, &mdc);
sprintf(h, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
return h;
}
#endif
Now, first of all, when calling MD5str() by itself to generate a hash, depending on the plaintext string you're encrypting, sometimes there is a gap in the hash, for example:Code:#include <stdio.h>
#include "md5.h"
int main(void)
{
char hash[35] = "34819d7beeabb926a5c854bc85b3e44";
if(hash == (MD5str("mypassword"))){
printf("match\n");
}else{
printf("no match\n");
}
return 0;
}
Plaintext: mypassword
Outputted hash: 34819d7beeabb926 a5c854bc85b3e44
Correct hash: 34819d7beeabb9260a5c854bc85b3e44
Plaintext: test123
Outputted hash: cc 3e747a6afbbcbf8be7668acfebee5
Correct hash: cc03e747a6afbbcbf8be7668acfebee5
It seems as if only 0's are being excluded when looking at these examples, however this is not always the case.. it works fine on some strings, generating a complete and correct hash, while it messes up others with a gap as previously demonstrated..
This is the beginning of the problem though, when using the above code to compare two hashes, I can't for the live of me get it to work properly. It either spits out "match" for _everything_ I throw at it, or "no match" for _everything_, which obviously isn't what I'm going for, heh. I've tweaked the script atleast a couple dozen times now, and tried everything I can think of to get it working properly, only to end up with the same end result...
My only assumption would be that it's a problem with an MD5 related function other than MD5str() (either MD5Init(), MD5Update(), MD5Final(), or MD5Transform()).. but at this point I'm stuck =(.. and can't get this working properly.. I just need it to compare two (password, in my case) hashes effectively and well, do something, based on the result.. buuut obviously that's not how it's working out :mad: .. any help would be *GREATLY* appreciated, thanks in advance! :rolleyes:
