The problem is on the PHP site, the host does not support the MCrypt extension. I was wondering if anyone had ever implemented DES or Triple DES using PHP alone, and if it was available anywhere.
Thanks
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This is exactly what I'm trying to do, but I'm not too bothered with heavy encryption, given that the "plaintext" is a hash. 3DES would be good enough.Change password with Rijndael using old password as key
And if you read my tutorial, I specifically say that thats what CHAP is for - you exchange a secret.budgefeeney wrote:If I transmit the new password using just MD5, an eavedropper will know the MD5 hash of the new password.
And you've failed to do a chap sequence.budgefeeney wrote: Using this they
1) connect to the login page - this gives them the salt
2) They modify the source. The original source hashes the user entered password, combines it with the salt, and hashes the result
The modified source will combine the password hash they found via eavesdropping, combine it with the salt, and hash the result.
3) they load up this modified page and hit submit
4) they login
You chose a poor salt for your hash. If the salt is time-based, and short-lived, the attacker can't replay - which I mentioned in my tutorial.budgefeeney wrote: It is for this reason that when I'm saving a NEW password, it is NOT sufficient to hash it, as an attacker can login if they have the hashed password.
He wants that as an ideal, to replace SSL. He ALSO notes that the CHAP system I described (using just md5, with time-based salts) is being used by Yahoo in areas where SSL isnt used.budgefeeney wrote: If you look at the page you referred me to (http://pajhome.org.uk/crypt/md5/chaplogin.html), the author is aware of this problem too, thus his dream system makes mention of the following:
This is exactly what I'm trying to do, but I'm not too bothered with heavy encryption, given that the "plaintext" is a hash. 3DES would be good enough.Change password with Rijndael using old password as key
I don't care about the login, that's already got a CHAP mechanism, it's fine. The problem is when you change your password. When this happens you have to send a new password to the server from your webpage, and it has to be in a form whereby the server can subsequently use it to authenticate you.When someone logs in, a salt value, based around time, IP address and some other values is embedded in the webpage. The user supplied password is hashed on the client side using JavaScript, and this is then combined with the salt value and the result is hashed. This hash (it's MD5 BTW) is then transmitted.
Not at all - I did miss that from the description you gave.budgefeeney wrote: I'm sorry to be so ratty, but this caught me by surprise, and it's been an annoyance, and the fact that a lot of people have missed the point and suggested hash based login mechanisms when I want a cipher based password update mechanism is doing my nut in!