Messages in this thread | | | Date | Tue, 04 Oct 2005 08:13:54 +0300 | From | Jari Ruusu <> | Subject | Re: util-linux and data encryption |
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Paulo da Silva wrote: > I had a loop filesystem encrypted with twofish > algorithm. > > Today, trying to mount the file, 'mount' claimed > I needed to enter a password of 20 chars or more! > Since I used less chars to encrypt, I was not able > to recover the information!!! > I tried CFLAGS="-DLOOP_PASSWORD_MIN_LENGTH=8" > without any success. This causes 'mount' to accept > the password, but, somehow, the decryption failled > because the fs type remained unrecognized! > > BTW, I am using gentoo and I also tried USE=old-crypt. > No way! > > I needed to install the version 2.12i to recover > my information. > > Is this related with util-linux or has something > to do with gentoo patches or something?
Seems like gentoo has merged loop-AES' util-linux patch which has always used better defaults.
Mainline util-linux compatible mount options for /etc/fstab
encryption=twofish256,phash=unhashed2
Mainline util-linux compatible losetup command options
losetup -e twofish256 -H unhashed2 ......
kerneli.org compatible mount options for /etc/fstab
encryption=twofish256,phash=rmd160
kerneli.org compatible losetup command options
losetup -e twofish256 -H rmd160 ......
mount and losetup programs don't enforce 20 character minimum passphrase length when using 'rmd160' or 'unhashed2' hash functions.
Both mainline util-linux and kerneli.org compatible setups are broken securitywise. If there still are file systems using such broken setups, now is good time to re-encrypt them using stronger crypto.
-- Jari Ruusu 1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9 DB 1D EB E3 24 0E A9 DD - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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