Red Hat Bugzilla – Bug 464089
Anaconda uses only AES, no options for any other cipher
Last modified: 2010-06-28 06:45:03 EDT
Description of problem:
Anaconda prompts for encryption of a partition and passphrase, but not for a cipher. It can only use AES, not blowfish, twofish, etc.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Boot an install CD/DVD/etc.
2. Check the box to encrypt the system (alternatively in the custom layout, check to encrypt a specific partition).
3. Enter a passphrase.
Anaconda chooses AES as the cipher, thus allowing an adversary to know what cipher to attack.
A drop-down menu with a list of possible ciphers.
Having multiple ciphers available requires a hacker to guess what cipher is used, thus requiring exponentially more work to crack the system.
Seconding this request.
Another reason for allowing other ciphers is for performance reasons. Twofish scores slightly better than AES on benchmark tests which makes it attractive for whole-system encryption.
We have intentionally created a simple user interface for the creation of encrypted block devices. It is possible that we will expand it at some point in the future, but this is not high on the list of priorities at this time.
You can certainly create the encrypted devices however you want using parted, lvm, mdadm, and cryptsetup in a kickstart %pre script.
*** Bug 473285 has been marked as a duplicate of this bug. ***
It would be very nice if anaconda supports aes-xts-plain with 256bit key for example, using kickstart is not always possible...
cryptsetup allows that already.
This bug appears to have been reported against 'rawhide' during the Fedora 11 development cycle.
Changing version to '11'.
More information and reason for this action is here:
This is a "me too"
I installed F12 with the whole disk encryption option and was merrily using it. However I noticed a post on the dm-crypt list regarding benchmarking the performance of the different keysize and cipher options and tested my system. End result was that the anaconda-enforced option was the *3rd best* in performance!!!
I don't know if there are hardware-specific reasons for this (Dell D430 laptop - Intel CPU), but there was around a 30% I/O difference: aes-cbc-essiv:sha256 with 128bit key was much faster than the options anaconda chose...
The weird thing is that I think that aes-cbc-essiv:sha256 is the default for cryptsetup? So anaconda is using other options because someone at Redhat thought they were better? Then why choose a slower one?
(In reply to comment #6)
> This is a "me too"
> I installed F12 with the whole disk encryption option and was merrily using it.
> However I noticed a post on the dm-crypt list regarding benchmarking the
> performance of the different keysize and cipher options and tested my system.
> End result was that the anaconda-enforced option was the *3rd best* in
> I don't know if there are hardware-specific reasons for this (Dell D430 laptop
> - Intel CPU), but there was around a 30% I/O difference: aes-cbc-essiv:sha256
> with 128bit key was much faster than the options anaconda chose...
> The weird thing is that I think that aes-cbc-essiv:sha256 is the default for
> cryptsetup? So anaconda is using other options because someone at Redhat
> thought they were better? Then why choose a slower one?
Because the encryption is stronger. I/O performance is a secondary concern. Cryptsetup's defaults to a very old algorithm, largely for backwards compatibility reasons.
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