[arch-projects] [PATCH] UUID support for kernel cmdline argument cryptdevice

[Dave Reisner]

On Sun, Jun 12, 2011 at 07:08:17PM +0200, Andrwe Lord Weber wrote:
> Hi,
> 
> I just encoutered the problem that my system couldn't boot because the devices changed and the encrypt hook couldn't decrypt my system.
> Because UUIDs are more reliable in such cases I added a new syntax to the hook.
> if you set cryptdevice=UUID=<UUID>:root UUID will be used to get the real device using "blkid -U".
> 
> Signed-off-by: Andrwe Lord Weber <archlinux at andrwe.org>
> ---
>  cryptsetup/trunk/PKGBUILD     |    2 +-
>  cryptsetup/trunk/encrypt_hook |    5 +++++
>  2 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/cryptsetup/trunk/PKGBUILD b/cryptsetup/trunk/PKGBUILD
> index 0af6df5..fd6c387 100644
> --- a/cryptsetup/trunk/PKGBUILD
> +++ b/cryptsetup/trunk/PKGBUILD
> @@ -15,7 +15,7 @@ source=(http://cryptsetup.googlecode.com/files/${pkgname}-${pkgver}.tar.bz2
>          encrypt_hook
>  	encrypt_install)
>  sha256sums=('7ceb18a0c91fa1546077b41b93463dd2ec9d7f83e6fd93757fb84cc608206a6a'
> -            '64601eae6fbf3e3afceccec5877557aa208a82497c33cc94ad0a686b4022b5dc'
> +            'fcd107764ef6de8e3dfb8864c15e7e4cf2ef394b57bb70f8c6978123d0c9f8b6'
>              '07918fc349b3a7c4a73e8ad1cc3d97a2a79ebc7655090ab9ebb00b1e092c85aa')
>  
>  build() {
> diff --git a/cryptsetup/trunk/encrypt_hook b/cryptsetup/trunk/encrypt_hook
> index e84bc6e..270edd2 100644
> --- a/cryptsetup/trunk/encrypt_hook
> +++ b/cryptsetup/trunk/encrypt_hook
> @@ -39,6 +39,11 @@ run_hook ()
>          if [ -n "${cryptdevice}" ]; then
>              DEPRECATED_CRYPT=0
>              cryptdev="$(echo "${cryptdevice}" | cut -d: -f1)"
> +	    # Check if given device is introduced by UUID=
> +            if [[ "$(echo "${cryptdev}" | cut -d= -f1)" = "UUID" ]]; then

if [ "${cryptdev:0:5}" = 'UUID=' ]; then

Even though Busybox allows [[ ]], we don't use them because they're
functionally equivalent to [ ]. Since busybox ash is closer to POSIX
than Bash, we opt for the more POSIX-like syntax.

> +	        # get device of given UUID and set it as cryptdev
> +                cryptdev="$(blkid -U $(echo "${cryptdev}" | cut -d= -f2))"

cryptdev=$(blkid -t "$cryptdev" -o device)

Quotes are unnecessary in assigning a command substituion.

> +            fi
>              cryptname="$(echo "${cryptdevice}" | cut -d: -f2)"
>          else
>              DEPRECATED_CRYPT=1
> -- 

Since this hook is actually part of cryptsetup, it might be better
served as a bug report on flyspray.

regards,
dave