如何解码密码：$ password = md5（addslashes（$ _POST ['password']））;

Question

As the title, please kindly show me how to decode a password string encoded by this:

$password = md5( addslashes( $_POST['password'] ) );

For the example: f21601fea7f496cfbc23f7310e13f941

Thank you!

Answer 1

MD5 is a one-way hashing algorithm. The nature of such an algorithm is it cannot be reversed. It it could, it'd be an encryption algorithm, not hashing.

Before you go switch to an encryption algorithm, don't. Passwords should always be stored as hashes if possible (there are unusual cases, like where you're storing a password for a third-party system). This protects your users if your code/database get compromised.

For simple strings, it may be possible to lookup an MD5 hash in a "rainbow table". As an example, 098f6bcd4621d373cade4e832627b4f6 can be put into a tool like http://md5cracker.org/ to find out the password is probably test (but it could be another string that results in the same hash, known as a collision).

Note: MD5 is also insecure because of the speed for which you can generate a rainbow table. You should use PHP's built in password_hash / password_verify functions when hashing passwords, as they take advantage of the secure bcrypt hashing algorithm.