On Saturday 05 April 2008 05:01:23 am Stefan Schulze Frielinghaus wrote:
> My actual question is what does the standard say to passwords which are
> not exactly 256 Bit long? Often user passwords are 8 characters long
> (which means an effective key size of 64 Bit). Or someone could have a
> key file which is 300 Bit long. But AES with 256 Bit support would only
> use 256 Bit of the 300 Bit. Or it has to calculate a 256 Bit key of the
> 64 Bit material specified from the user.
You never use the password as the key. You use the password as one of the
inputs to a key derivation function. PKCS#5 appears to be the common KDF
approach.

Brad

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