Re: DM-Verity Tool

[Milan Broz <gmazyland@gmail.com>]

On 05/23/2013 08:41 AM, pavankumar.p@globaledgesoft.com wrote:
> 1. What are the difference between configuring a verity target using
> dmsetup & veritysetup. Can these be used interchangeably?

dmsetup is just low level tool, you need to know all table parameters
while veritysetup will prepare table for you using high level commands
and on-disk metadata (if present).

> 2. I tried passing the root hash value generated by veritysetup as a
> parameter to dmsetup but this doesn't work. On doing dmsetup status, the
> output is showing as the target corrupted (C). I examined dmesg & found
> the following error

Be sure you are using proper parameters, metadata version etc.

Try activate device with veritysetup, then run "dmsetup table" and
check what is different in your dmsetup line.

> 3. After creating a verity target using "veritysetup" how to test the
> target for corrupted case (As soon as creating the status is Verified (V))

By corrupting the image? :) See tests/verity-compat-test in cryptsetup
tree, it is basic regression test which is simulating both data and hash
corruption (it just dd random data to know offset and expects failure.)

Milan