On 03/22/2011 07:47 PM, Rudolf Deilmann wrote: > On Mon, 21 Mar 2011 19:21:50 +0100 > Milan Broz <mbroz@xxxxxxxxxx> wrote: >> I added offset support, seems loopAES always uses offset==skip >> (IOW initial vector is always related to absolute sector size on the >> device). > > No, loopAES supports both options. It depends on user input: > > -- > -o offset > The data start is moved offset bytes into the specified file or > device. Normally offset is included in IV (initialization > vector) computations. If offset is prefixed with @ character, then > offset is not included in IV computations. @ prefix functionality > may not be supported on some older kernels and/or loop drivers. I wonder how I missed that. Ok, the we just allow --skip and if it is not explicitly defined, it will behave as now. So @offset => --skip 0 --offset $offset/512, right? I added test for default offset (and verification with losetup passes), so it is just that @ prefix mode missing now. > Both options seems to be supported by dmcrypt/dmsetup. In the first case > IV offset is always identic to the sector offset, in the second case IV > offset is always zero. yes, everything is supported, this is just userspace handling. > (IV offset: 6th value at dmsetup table, sector offset: 8th value. I > hope, I haven't muddle something ) FYI the documentation is in kernel itself http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/device-mapper/dm-crypt.txt;hb=HEAD Thanks, Milan _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
