PHP中的md5解密

Question

I am developing a system for Online Hotel booking system which I did not start from scratch. The information of customers(bookers) in the system are encrypted using MD5 but unlike normal md5() php function the system is quite complicated as you can see here :

$psw = md5("vhdsxnjuobef");
$t_cred_num = md5_encrypt($t_cred_num, $psw, 16);

and for Decryption it goes like :

$psw = md5("vhdsxnjuobef");
$t_credit_num = md5_decrypt($t_cred_num, $psw, 16);

this code is not Working though on my Server and there is alot of Customer's information Encrypted.

Example of hash of t_cred_num variable =>

 fdRucZHctr7vIX+U400xGHq53Qemze0YQH1sAUjvmaC1P+XaRadI9CaX0wrkDXu6

Any Ideas on how to Decrypt these hashes ? When I use md5_decrypt with the hashes nothing happens.

Answer 1

I think the md5_crypt and md5_encrypt are functions hand crafted by the previous developer. md5 isn't supposed to be decryptable. Hash's are supposed to be one way functions: http://en.wikipedia.org/wiki/Hash_function

So, you'll need to find the definition of those functions. A search for "function md5_" in the code files should find the place in the code where they are defined.

Answer 2

there's no way to decrypt an md5. there are two things you can do:

1. if you have other account or know the password of another account then copy the md5 characters of it and place it on yours.
2. search for an md5 of let's say "admin". Paste the md5 equivalent of the word "admin" on your account. You can also use other words.

After that, login to your account then change back your password