MD5 decrypt

[Crew-Portal]

Everyone in the PHP world knows its impossible to decrypt MD5 and SHA1 But A site has done it! But how? Can anyone help me understand how they did this?

 

http://md5encryption.com/?mod=decrypt

[rajivgonsalves]

Well it just takes the input key say "test" get the md5 for that "098f6bcd4621d373cade4e832627b4f6" then stores it in the database say

 

keyword | md5

test      | 098f6bcd4621d373cade4e832627b4f6

 

then when you search the md5 098f6bcd4621d373cade4e832627b4f6 it will search the database and give you the result (atleast thats my understanding)

[Crew-Portal]

Every Word in the world is in that database! Holy **** Thats a lots or records! Guess theres no-one else responding to my question so you must be right. Thanx

[Crew-Portal]

Hahahaha! I figured it out!

<?php
function md5_encrypt($plain_text, $password, $iv_len = 16)
{
    $plain_text .= "\x13";
    $n = strlen($plain_text);
    if ($n % 16) $plain_text .= str_repeat("\0", 16 - ($n % 16));
    $i = 0;
    $enc_text = get_rnd_iv($iv_len);
    $iv = substr($password ^ $enc_text, 0, 512);
    while ($i < $n) {
        $block = substr($plain_text, $i, 16) ^ pack('H*', md5($iv));
        $enc_text .= $block;
        $iv = substr($block . $iv, 0, 512) ^ $password;
        $i += 16;
    }
    return base64_encode($enc_text);
}

function md5_decrypt($enc_text, $password, $iv_len = 16)
{
    $enc_text = base64_decode($enc_text);
    $n = strlen($enc_text);
    $i = $iv_len;
    $plain_text = '';
    $iv = substr($password ^ substr($enc_text, 0, $iv_len), 0, 512);
    while ($i < $n) {
        $block = substr($enc_text, $i, 16);
        $plain_text .= $block ^ pack('H*', md5($iv));
        $iv = substr($block . $iv, 0, 512) ^ $password;
        $i += 16;
    }
    return preg_replace('/\\x13\\x00*$/', '', $plain_text);
}
?>

[rajivgonsalves]

well actually its mentioned on the site "Or enter a MD5 hash or SHA1 hash and we will look into our database and try to decrypt MD5 or decrypt SHA1"

[Crew-Portal]

Ohh... That makes sense. I think my way would be faster than searching a whole database though. That is if the code above even works?

[Crew-Portal]

Oh well. Whatever. Off to bed Goodnight everyone thanx for the help especially you Rajivgonsalves, Cya all tommorrow. If anyone finds another way to decrypt MD5 Hash please post it! Cya night bye!