MD5 Generator not working.

[henryswanson]

I'm trying to write an MD5 generator (for integrity checks, not actual hashing), but it doesn't seem to be working right. And it only operates on a 512-bit chunk, for now. Hashing the empty string should get d41d8cd98f00b204e9800998ecf8427e, but instead I get a9e8a4dad18c439323fdd27947ce0fc7. The only thing I can think it would be is either an error in the k array or some business with endians. Since I've double checked k, and it seems to be correct, I'm thinking it's the latter, but I can't spot it for the life of me. What am I doing wrong? EDIT: checked k-values with the floor(abs(sin(i + 1)) * pow(2, 32)), and all are correct.

Header:

#ifndef MD5_H_
#define MD5_H_

#include <stdint.h>
#include <stdio.h>

const int md5_r[64] = {
		7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
		5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20,
		4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
		6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21
};

const uint32_t md5_k[64] = {
		0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
		0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
		0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
		0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
		0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
		0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
		0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
		0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
		0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
		0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
		0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
		0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
		0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
		0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
		0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
		0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
};

const uint32_t md5_h[4] = {0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476};

int main(int argc, char** argv);
void hashMD5(uint32_t password [], uint32_t hash[16]);
uint32_t leftrotate(uint32_t x, int c);

#endif

Source:

#include "md5.h"

int main(int argc, char** argv)
{
	uint32_t str [] = {
			0x800000, 0x000000, 0x000000, 0x000000,
			0x000000, 0x000000, 0x000000, 0x000000,
			0x000000, 0x000000, 0x000000, 0x000000,
			0x000000, 0x000000, 0x000000, 0x000000
	};

	uint32_t hash [4] = {0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476};

	hashMD5(str, hash);
}

void hashMD5(uint32_t password[], uint32_t hash[4])
{
	uint32_t a = hash[0];
	uint32_t b = hash[1];
	uint32_t c = hash[2];
	uint32_t d = hash[3];

	uint32_t f, g;

	for(int i = 0; i < 64; i++)
	{
		if(i < 16)
		{
			f = (b & c) | (~b & d);
			g = i;
		}
		else if(i < 32)
		{
			f = (d & b) | (~d & c);
			g = (5 * i + 1) % 16;
		}
		else if(i < 48)
		{
			f = b ^ c ^ d;
			g = (3 * i + 5) % 16;
		}
		else
		{
			f = c ^ (b | ~d);
			g = (7 * i) % 16;
		}
		uint32_t temp = d;
		d = c;
		c = b;
		b = b + leftrotate(a + f + md5_k[i] + password[g], md5_r[i]);
		a = temp;
	}

	hash[0] += a;
	hash[1] += b;
	hash[2] += c;
	hash[3] += d;

	printf("a: %x, b: %x, c: %x, d: %x, all: %x%x%x%x\n",
			hash[0], hash[1], hash[2], hash[3],
			hash[0], hash[1], hash[2], hash[3]);
}

uint32_t leftrotate(uint32_t x, int c)
{
	return (x << c) | (x >> (32 - c));
}