On Sun, Mar 10, 2013 at 09:19:32AM -0400, hephey@xxxxxxxxxxx wrote: > I'm having trouble calculating the amount of data I need to erase in the > header. > > The af-stripes appears to be hardcoded to 4000, according to the > specification [1]. > > First I made an encrypted loop-device, using default options: > > cryptsetup luksFormat /dev/loop0 > > I then made a header backup, using > > cryptsetup luksHeaderBackup --header-backup-file /tmp/header.img /dev/loop0 > > The size of this backup (/tmp/header.img) is exactly 1.052.672 bytes, > which fits with the number given in the FAQ (see 5.4) [2]. I'm asumming > that cryptsetup's calculation is correct. > > In the FAQ it's also stated that to wipe the header, I need to use to > formula: > > header size = (keyslots x stripes x keysize) + offset bytes In 5.4, I state just to wipe the first 10MB to be safe. Do I have the formula above anywthere as explicitely recommended for wipes? Is so, plese tell me where, so I can fix it. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@xxxxxxxxxxx GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision. -- Bertrand Russell _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
