Code:
#include <stdio.h>
#include <string.h>
#include "md5.h"
int main(int argc, char ** argv){
char msg_block[BLOCK_LEN], digest[DIGEST_LEN], * end;
uint8 read_len = 0, curr_len = 0, msg_len = 0;
uint4 h[4], k[64], r[64];
end = (char *)(argv[1] + strlen(argv[1]) - 1);
msg_len = strlen(argv[1]);
/*
while((read_len = get_block( msg_block, argv[1], end )) <= msg_len){
do_hash( msg_block, h, k, r );
curr_len += read_len;
}
*/
do{
read_len = get_block( msg_block, argv[1], end );
do_hash( msg_block, h, k, r);
curr_len += read_len;
}while( curr_len < msg_len );
msg_block[read_len++] = 0x80;
if( read_len > (BLOCK_LEN - 64) ){
while( read_len < BLOCK_LEN ){
msg_block[read_len++] = 0x0;
curr_len += read_len;
}
do_hash( msg_block, h, k, r );
read_len = 0;
}
while( read_len < BLOCK_LEN - 64 )
msg_block[read_len++] = 0x0;
curr_len += read_len;
do_hash( msg_block, h, k, r );
memcpy( msg_block + (BLOCK_LEN - 64), &curr_len, 64 );
do_hash( msg_block, h, k, r );
// for(int i = 0; i <= 15; i++)
//((uint4 *)digest)[i] = h[i];
printf("Digest: %X%X%X%X\n", h[0], h[1], h[2], h[3]);
return 0;
}
void do_hash(char * msg_block, uint4 * h, uint4 * k, uint4 * r){
uint4 word[16],
a = h[0],
b = h[1],
c = h[2],
d = h[3],
f,
g,
temp;
char * msg_ptr = msg_block;
// Break the block into 16 32bit words
for(int i = 0; i <= 15; i++)
word[i] = ((uint4 *)msg_block)[i];
for(int i = 0; i <= 63; i++){
if( 0 <= i && i <= 15 ){
f = (b & c) | ((~b) & d);
g = i;
}
else if( 16 <= i && i <= 31){
f = (d & b) | ((~d) & c);
g = (5 * i) % 16;
}
else if( 32 <= i && i <= 47 ){
f = b ^ c ^ d;
g = (3 * i + 5) % 16;
}
else if( 47 <= i && i <= 63 ){
f = c ^ (b | (~d));
g = (7 * i) %16;
}
temp = d;
d = c;
c = b;
b = b + leftrotate((a + f + k[i] + word[g]), r[i]);
a = temp;
}
h[0] += a;
h[1] += b;
h[2] += c;
h[3] += d;
}
/*
Gets a 512 block of characters from the buffer specified by input
end denotes the final memory address of input
*/
uint4 get_block(char * msg_block, char * input, char * end){
uint4 read_len;
memset(msg_block, 0x0, BLOCK_LEN);
for(read_len = 0; (read_len <= BLOCK_LEN) && (input <= end); read_len++)
msg_block[read_len] = *input++;
return read_len;
}
uint4 leftrotate(uint4 x, uint4 c){
return (x << c) | (x >> (32 - c));
}
void md5_init( uint4 * k, uint4 * r, uint4 * h){
h[0] = 0x67452301;
h[1] = 0xefcdab89;
h[2] = 0x98badcfe;
h[3] = 0x10325476;
uint4 temp_r[] = { 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};
uint4 temp_k[] = { 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};
for(int i = 0; i <= 63; i++)
r[i] = temp_r[i], k[i] = temp_k[i];
}