On Fri, 31 May 2013, pavankumar.p@xxxxxxxxxxxxxxxxxx wrote: > ---------------------------- Original Message ---------------------------- > Subject: Re: DM-Verity Tool > From: pavankumar.p@xxxxxxxxxxxxxxxxxx > Date: Mon, May 27, 2013 9:22 pm > To: "Milan Broz" <gmazyland@xxxxxxxxx> > mpatocka@xxxxxxxxxx > "device-mapper development" <dm-devel@xxxxxxxxxx> > "Marian Csontos" <mcsontos@xxxxxxxxxx> > -------------------------------------------------------------------------- > > Hello Mikulas, > > > 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.) > > In tests/verity-compat-test, in the following line > "check_root_hash 512 > 9de18652fe74edfb9b805aaed72ae2aa48f94333f1ba5c452ac33b1c39325174 $SALT 1 > sha256 8388608" > > How's the last parameter (hash_offset) calculated? it's hard coded > here(8388608). > > Regards, > Pavan If you use two separate devices for data and hash, hash offset is zero (hash starts at the beginning of the second device). If you use one block device for both data and hash, hash offset points to the end of the data (and beginning of hash) - if you want to use it this way, you have to set hash offset manually. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
