Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
/*
* Simple MD5 implementation
*
* Compile with: gcc -o md5 -O3 -lm md5.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
// leftrotate function definition
#define LEFTROTATE(x, c) (((x) << (c)) | ((x) >> (32 - (c))))
// These vars will contain the hash
uint32_t h0, h1, h2, h3;
void md5(uint8_t *initial_msg, size_t initial_len) {
// Message (to prepare)
uint8_t *msg = NULL;
// Note: All variables are unsigned 32 bit and wrap modulo 2^32 when calculating
// r specifies the per-round shift amounts
uint32_t 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};
// Use binary integer part of the sines of integers (in radians) as constants// Initialize variables:
uint32_t 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};
h0 = 0x67452301;
h1 = 0xefcdab89;
h2 = 0x98badcfe;
h3 = 0x10325476;
// Pre-processing: adding a single 1 bit
//append "1" bit to message
/* Notice: the input bytes are considered as bits strings,
where the first bit is the most significant bit of the byte.[37] */
// Pre-processing: padding with zeros
//append "0" bit until message length in bit ≡ 448 (mod 512)
//append length mod (2 pow 64) to message
int new_len;
for(new_len = initial_len*8 + 1; new_len%512!=448; new_len++);
new_len /= 8;
msg = calloc(new_len + 64, 1); // also appends "0" bits
// (we alloc also 64 extra bytes...)
memcpy(msg, initial_msg, initial_len);
msg[initial_len] = 128; // write the "1" bit
uint32_t bits_len = 8*initial_len; // note, we append the len
memcpy(msg + new_len, &bits_len, 4); // in bits at the end of the buffer
// Process the message in successive 512-bit chunks:
//for each 512-bit chunk of message:
int offset;
for(offset=0; offset<new_len; offset += (512/8)) {
// break chunk into sixteen 32-bit words w[j], 0 ≤ j ≤ 15
uint32_t *w = (uint32_t *) (msg + offset);
#ifdef DEBUG
printf("offset: %d %x\n", offset, offset);
int j;
for(j =0; j < 64; j++) printf("%x ", ((uint8_t *) w)[j]);
puts("");
#endif
// Initialize hash value for this chunk:
uint32_t a = h0;
uint32_t b = h1;
uint32_t c = h2;
uint32_t d = h3;
// Main loop:
uint32_t i;
for(i = 0; i<64; i++) {
#ifdef ROUNDS
uint8_t *p;
printf("%i: ", i);
p=(uint8_t *)&a;
printf("%2.2x%2.2x%2.2x%2.2x ", p[0], p[1], p[2], p[3], a);
p=(uint8_t *)&b;
printf("%2.2x%2.2x%2.2x%2.2x ", p[0], p[1], p[2], p[3], b);
p=(uint8_t *)&c;
printf("%2.2x%2.2x%2.2x%2.2x ", p[0], p[1], p[2], p[3], c);
p=(uint8_t *)&d;
printf("%2.2x%2.2x%2.2x%2.2x", p[0], p[1], p[2], p[3], d);
puts("");
#endif
uint32_t f, g;
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;
}
#ifdef ROUNDS
printf("f=%x g=%d w[g]=%x\n", f, g, w[g]);
#endif
uint32_t temp = d;
d = c;
c = b;
printf("rotateLeft(%x + %x + %x + %x, %d)\n", a, f, k[i], w[g], r[i]);
b = b + LEFTROTATE((a + f + k[i] + w[g]), r[i]);
a = temp;
}
// Add this chunk's hash to result so far:
h0 += a;
h1 += b;
h2 += c;
h3 += d;
}
// cleanup
free(msg);
}
int main(int argc, char **argv) {
if (argc < 2) {
printf("usage: %s 'string'\n", argv[0]);
return 1;
}
char *msg = argv[1];
size_t len = strlen(msg);
// benchmark
// int i;
// for (i = 0; i < 1000000; i++) {
md5(msg, len);
// }
//var char digest[16] := h0 append h1 append h2 append h3 //(Output is in little-endian)
uint8_t *p;
// display result
p=(uint8_t *)&h0;
printf("%2.2x%2.2x%2.2x%2.2x", p[0], p[1], p[2], p[3], h0);
p=(uint8_t *)&h1;
printf("%2.2x%2.2x%2.2x%2.2x", p[0], p[1], p[2], p[3], h1);
p=(uint8_t *)&h2;
printf("%2.2x%2.2x%2.2x%2.2x", p[0], p[1], p[2], p[3], h2);
p=(uint8_t *)&h3;
printf("%2.2x%2.2x%2.2x%2.2x", p[0], p[1], p[2], p[3], h3);
puts("");
return 0;
}
@PrateekJoshi

This comment has been minimized.

Copy link

commented Oct 30, 2017

Can you please explain the line

msg[initial_len] = 128; // write the "1" bit
@schmidtw

This comment has been minimized.

Copy link

commented Nov 1, 2017

What do you license this code as? (MIT/Apache/GPL/Public Domain/other)

@simeonpilgrim

This comment has been minimized.

Copy link

commented Dec 25, 2017

Can you please explain the line

msg[initial_len] = 128; // write the "1" bit

@PrarteekJoshi the original md5 code has a "padding fill" block, used when the last of the input block does not fill the current block, which starts with 0x80 (128) and is the rest zeros, so this code has just refactored that out

original code: https://people.csail.mit.edu/rivest/Md5.c

@BrendanSimon

This comment has been minimized.

Copy link

commented Feb 4, 2018

So is this code licensed under? yes, no ???

@OragonDre

This comment has been minimized.

Copy link

commented Mar 22, 2018

The preprocessing of your code seems to be wrong.

If you Encrypt this message "The quick brown fox jumps over the lazy dog" and check your printed preprocessed message, from your code, you get this

54 68 65 20 71 75 69 63 6b 20 62 72 6f 77 6e 20 66 6f 78 20 6a 75 6d 70 73 20 6f 76 65 72 20 74 68 65 20 6c 61 7a 79 20 64 6f 67 80 0 0 0 0 0 0 0 0 0 0 0 0 58 1 0 0 0 0 0 0

You notice that the length (0x158) in bits of the original text messages (43 Bytes long = 344 = 0x158) is not stored correctly at the last 64 bits. Your preprocessed message had to be like this.

54 68 65 20 71 75 69 63 6b 20 62 72 6f 77 6e 20 66 6f 78 20 6a 75 6d 70 73 20 6f 76 65 72 20 74 68 65 20 6c 61 7a 79 20 64 6f 67 80 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 58

Or is there something i am missing in the algo?.

@tedwu726

This comment has been minimized.

Copy link

commented May 17, 2018

Why does the result is different from md5sum command? The md5sum command is at git or other application.

@vcsrocks

This comment has been minimized.

Copy link

commented Jul 2, 2018

You notice that the length (0x158) in bits of the original text messages (43 Bytes long = 344 = 0x158) is not stored correctly at the last 64 bits. Your preprocessed message had to be like this.

@OragonDre the message length should be little-endian

@nura767

This comment has been minimized.

Copy link

commented Jul 19, 2018

how to put the message on the line ?
i mean where to put the msg there ? thanks

@BilalPasta

This comment has been minimized.

Copy link

commented Aug 9, 2018

it is with collision program?

@fouzan786

This comment has been minimized.

Copy link

commented Sep 21, 2018

Hi can you resolve my mistakes in php, i am writing like this,but i not shifting the bits

> (32 - ($c))))'); $h0; $h1; $h2; $h3; $msg = NULL; $r=array(0=>7,1=>12,2=>17,3=>22,4=>7,5=>12,6=>17,7=>22,8=>7,9=>12,10=>17,11=>22,12=>7,13=>12,14=>17,15=>22,16=>5,17=>9,18=>14,19=>20,20=>5,21=>9,22=>14,23=>20,24=>5,25=>9,26=>14,27=>20,28=>5,29=>9,30=>14,31=>20,32=>4,33=>11,34=>16,35=>23,36=>4,37=>11,38=>16,39=>23,40=>4,41=>11,42=>16,43=>23,44=>4,45=>11,46=>16,47=>23,48=>6,49=>10,50=>15,51=>21,52=>6,53=>10,54=>15,55=>21,56=>6,57=>10,58=>15,59=>21,60=>6,61=>10,62=>15,63=>21); $k=array(0=>0xd76aa478,1=>0xe8c7b756,2=>0x242070db,3=>0xc1bdceee,4=>0xf57c0faf,5=>0x4787c62a,6=>0xa8304613,7=>0xfd469501,8=>0x698098d8,9=>0x8b44f7af,10=>0xffff5bb1,11=>0x895cd7be,12=>0x6b901122,13=>0xfd987193,14=>0xa679438e,15=>0x49b40821,16=>0xf61e2562,17=>0xc040b340,18=>0x265e5a51,19=>0xe9b6c7aa,20=>0xd62f105d,21=>0x02441453,22=>0xd8a1e681,23=>0xe7d3fbc8,24=>0x21e1cde6,25=>0xc33707d6,26=>0xf4d50d87,27=>0x455a14ed,28=>0xa9e3e905,29=>0xfcefa3f8,30=>0x676f02d9,31=>0x8d2a4c8a,32=>0xfffa3942,33=>0x8771f681,34=>0x6d9d6122,35=>0xfde5380c,36=>0xa4beea44,37=>0x4bdecfa9,38=>0xf6bb4b60,39=>0xbebfbc70,40=>0x289b7ec6,41=>0xeaa127fa,42=>0xd4ef3085,43=>0x04881d05,44=>0xd9d4d039,45=>0xe6db99e5,46=>0x1fa27cf8,47=>0xc4ac5665,48=>0xf4292244,49=>0x432aff97,50=>0xab9423a7,51=>0xfc93a039,52=>0x655b59c3,53=>0x8f0ccc92,54=>0xffeff47d,55=>0x85845dd1,56=>0x6fa87e4f,57=>0xfe2ce6e0,58=>0xa3014314,59=>0x4e0811a1,60=>0xf7537e82,61=>0xbd3af235,62=>0x2ad7d2bb,63=>0xeb86d391); /* for($i=0;$i<=63;$i++) { echo $k[$i]=floor(232*abs(sin($i+1)))."
"; } */ /*for($j=0;$j<=63;$j++) { echo $k[$j]."
"; }*/ $h0 = 0x67452301; //A $h1 = 0xefcdab89; //B $h2 = 0x98badcfe; //C $h3 = 0x10325476; //D $new_len; for($new_len = $initial_len*8 + 1; $new_len%512!=448; $new_len++); $new_len /= 8; // $msg = calloc($new_len + 64, 1); $msg= memory_get_usage($new_len + 64); // memcpy($msg, $initial_msg, $initial_len); memory_get_peak_usage($msg); memory_get_peak_usage($initial_msg); memory_get_peak_usage($initial_len); //$msg[$initial_len] = 128; $msg=array($initial_len); $msg= 128; $bits_len = 8*$initial_len; // memcpy($msg + $new_len, $bits_len, 4); memory_get_peak_usage($msg + $new_len); memory_get_peak_usage($bits_len); memory_get_peak_usage(4); $offset; for($offset=0; $offset<$new_len; $offset += (512/8)) { $w = ($msg + $offset); #ifdef DEBUG printf("$offset: %d %x\n",$offset,$offset); $j; for($j =0; $j < 64; $j++) printf("%x ", $w[$j]); // puts(""); echo ""; #endif $a = $h0; $b = $h1; $c = $h2; $d = $h3; $i; for($i = 0; $i<64; $i++) { #ifdef ROUNDS $p; printf("%$i: ", $i); $p=& $a; printf("%2.2$x%2.2$x%2.2$x%2.2$x ", $p[0], $p[1], $p[2], $p[3], $a); $p=& $b; printf("%2.2$x%2.2$x%2.2$x%2.2$x ", $p[0], $p[1], $p[2], $p[3], $b); $p=& $c; printf("%2.2$x%2.2$x%2.2$x%2.2$x ", $p[0], $p[1], $p[2], $p[3], $c); $p=& $d; printf("%2.2$x%2.2$x%2.2$x%2.2$x", $p[0], $p[1], $p[2], $p[3], $d); //puts(""); echo ""; #endif $f; $g; if ($i < 16) { $f = ($b & $c) | ((~$b) & $d); $g = $i; } elseif($i < 32) { $f = ($d & $b) | ((~$d) & $c); $g = (5*$i + 1) % 16; } elseif($i < 48) { $f = $b^$c^$d; $g = (3*$i + 5) % 16; } else { $f = $c^($b|(~$d)); $g = (7*$i) % 16; } #ifdef ROUNDS printf("$f=%$x $g=%$d $w[$g]=%$x \n", $f, $g, $w[$g]); #endif  $temp = $d; $d = $c; $c = $b; //printf("rotateLeft(%x + %x + %x + %x, %d)\n", $a, $f, $k[$i], $w[$g], $r[$i]); printf("%x + %x + %x + %x, %d\n", $a, $f, $k[$i], $w[$g], $r[$i]); //$b = $b + LEFTROTATE(($a + $f + $k[$i] + $w[$g]), $r[$i]); $b = $b + LEFTROTATE.($a + $f + $k[$i] + $w[$g]); $a = $temp; } $h0 += $a; $h1 += $b; $h2 += $c; $h3 += $d; } unset($msg); } function main($argc,$argv) { global $x,$w; if ($argc < 2) { printf("usage: %s 'string'\n", $argv[0]); return 1; } $msg=$argv[1]; $len = strlen($msg); md55($msg,$len); $p; $p=&$h0; printf("%2.2$x%2.2$x%2.2$x%2.2$x", $p[0], $p[1], $p[2], $p[3], $h0); $p=&$h1; printf("%2.2$x%2.2$x%2.2$x%2.2$x", $p[0], $p[1], $p[2], $p[3], $h1); $p=&$h2; printf("%2.2$x%2.2$x%2.2$x%2.2$x", $p[0], $p[1], $p[2], $p[3], $h2); $p=&$h3; printf("%2.2$x%2.2$x%2.2$x%2.2$x", $p[0], $p[1], $p[2], $p[3], $h3); //puts(""); echo ""; return 0; } echo md55('',1); ?>
@emandret

This comment has been minimized.

Copy link

commented Jan 14, 2019

This crap is not working. Don't waste your time.

@ackasjimmy

This comment has been minimized.

Copy link

commented Apr 1, 2019

it work!

@foothsu

This comment has been minimized.

Copy link

commented Jun 4, 2019

uint32_t bits_len = 8*initial_len; // note, we append the len
memcpy(msg + new_len, &bits_len, 4); // in bits at the end of the buffer````

These two lines are different from MD5.
The document says

A 64-bit representation of b (the length of the message before the
padding bits were added) is appended to the result of the previous
step. In the unlikely event that b is greater than 2^64, then only
the low-order 64 bits of b are used.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.