Don't store obfuscated passwords in a script. There will always be a Perl-genius somewhere who can figure it out. Better is to store a cryptographic one-way hash of the password. That makes the password itself inaccessible, no matter what (theoretically), while allowing for simple authentication. The idea is that when the user enters the password, it is hashed using the same algorithm that created the cryptographic hash you've got in your script. This is an irreversible process, but when the algorithm is applied to the password entered by the user, it will match the hashed value you've stored in the script, and you will thus be able to authenticate. However, it's impossible to take that hashed value and use it to figure out the original password.

The other good thing about this approach is that it is unnecessary to obfuscate the code that crypts the password to check against the encrypted hashed value stored in the script, because though the algorithm is known, no way of reversing is known. Most good encryption mechanisms operate this way; they produce irreversible results; results that are impossible to reverse-engineer into the original clear text, even though the encryption algorithm is known.

Update: As with most things in Perl, this has already been done, and tested exhaustively. I recommend the Digest::MD5 module. It will allow you to store a 128bit checksum (an MD5 hash) of the password, against which you can check passwords entered by the user, after passing their entry through the same MD5 algorithm. Bingo!

Update2: I wanted to comment on 'obfu' also. Don't view obfu as a means of writing code that cannot be deciphered. It is only a game, a toy, and at best, a means of exploring the dusty corners of Perl syntax. It's not a way to hide code. It's just for fun.


Dave

In reply to Re: How to hide a password in a script? by davido
in thread How to hide a password in a script? by dataking

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