I have a question about the use of the crypto api in new 2.4 kernels. My /home partition is on a cryptoloop made using a 2.4 kernel pre-crypto (2.4.20), patches from kerneli for kernel and util-linux. Now, with new kernel (2.4.23-ben1) I cannot access to this partition. I think this is because new kernel does not have the crypto-loop support but only the ciphers. Is this right?
The cryptosupport was merged in 2.4.23 and is also present in 2.6, see your .config in /usr/src/linux/, at the end it should have a CONFIG_SECURITY=y followed by CONFIG_CRYPTO=y lateron plus the different cyphers e.g. CONFIG_CRYPTO_AES=m. Then a "modprobe aes" should succeed.
Yet the API changed which confuses the losetup tool which tries to get the info from /proc/crypto/cipher/* whereas it is now just /proc/crypto.
For more info see bug #206396 <http://bugs.debian.org/206396>.
HTH
-Thomas