When installing from something involving an ISO image, d-i will load the wrong loop module and later on setting up loop-aes will fail.

After generating enough randomness, you will receive the message “An error has occured while configuring encrypted volumes”, and the syslog shows

partman-crypto: ioctl: LOOP_SET_STATUS: Invalid argument, requested cipher or key length (256 bits) not supported by kernel.

To fix this problem, first proceed to the partitioner and select encryption with loop-aes. That will make d-i unpack the necessary files to lib/modules/*/updates

Now switch to a console and modprobe -v -r loop (this is a rmmod replacement.)

You will probably need to umount the cd image first: umount /cdrom (Now try again: modprobe -v -r loop) Then cd to lib/modules/*/updates and insmod ./loop-aes.ko (this will load the right loop module for use with loop-AES!) You might want to remount your cdrom: mount /hd-media/*.iso /cdrom -o loop (Alternatively, you can Esc out a few times in d-i and select the autodetection from the main menu again.)

Now you should succeed in setting up loop-aes.

(This problem should be fixed in one of the next debian-installer versions.)