[dm-devel] [PATCH 2/2] dm crypt: support using trusted keys

[Ahmad Fatoum]

On 22.01.21 20:04, Ahmad Fatoum wrote:
> On 22.01.21 19:18, Jarkko Sakkinen wrote:
>> On Fri, Jan 22, 2021 at 08:05:51PM +0200, Jarkko Sakkinen wrote:
>>> On Fri, Jan 22, 2021 at 09:43:21AM +0100, Ahmad Fatoum wrote:
>>>> Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
>>>> dm-crypt to allow use of "encrypted" keys along with "user" and "logon".
>>>>
>>>> Along the same lines, teach dm-crypt to support "trusted" keys as well.

Gentle ping.
Is there anything further you require from me regarding these two patches?

>>>>
>>>> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>>>> ---
>>>
>>> Is it possible to test run this with tmpfs? Would be a good test
>>> target for Sumit's ARM-TEE trusted keys patches.
> 
> I tested these on top of Sumit's patches with TPM and a CAAM blobifier
> backend, I am preparing. The system I am developing these patches against
> doesn't have a TEE.  Steps to test these changes:
> 
> #!/bin/sh
> 
> DEV=/dev/loop0
> ALGO=aes-cbc-essiv:sha256
> KEYNAME=kmk
> BLOCKS=20
> 
> fallocate -l $((BLOCKS*512)) /tmp/loop0.img
> losetup -P $DEV /tmp/loop0.img
> mount -o remount,rw /
> KEY="$(keyctl add trusted $KEYNAME 'new 32' @s)"
> keyctl pipe $KEY >$HOME/kmk.blob
> 
> TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
> echo $TABLE | dmsetup create mydev
> echo $TABLE | dmsetup load mydev
> dd if=/dev/zero of=/dev/mapper/mydev
> echo "It works!" 1<> /dev/mapper/mydev
> cryptsetup close mydev
> 
> reboot
> 
> DEV=/dev/loop0
> ALGO=aes-cbc-essiv:sha256
> KEYNAME=kmk
> BLOCKS=20
> 
> losetup -P $DEV $HOME/loop0.img
> keyctl add trusted $KEYNAME "load $(cat $HOME/kmk.blob)" @s
> TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
> echo $TABLE | dmsetup create mydev
> echo $TABLE | dmsetup load mydev
> 
> # should print that It works!
> hexdump -C /dev/mapper/mydev
> 
>>> https://lore.kernel.org/linux-integrity/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/
>>
>> Also, I would hold merging *this* patch up until we are able to
>> test TEE trusted keys with TEE trusted keys.
> 
> Which blocks which? I tested this with TPM-Trusted keys, so it's usable
> as is. For convenient usage, it would be nice to have cryptsetup
> support for trusted and encrypted keys. I intended to look at this next week.
> 
> Cheers,
> Ahmad
> 
>>
>> /Jarkko
>>
> 

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