add DoD short method (3-pass)

[GoogleCodeExporter]

Date: Sat, 6 Aug 2011 21:02:47 -0700
From: Terence Truong <truong.terence@gmail.com>
To: "garlick@llnl.gov" <garlick@llnl.gov>
Subject: Adding shorter DoD wipe pattern

Hi Jim,

We are using diskscrub for wiping all our hard drives. We've been
using the regular 7-pass DoD wipe pattern, and we just found out that
we can use the DoD 3-pass wipe pattern. What is the best way to do
this in the code? Here is the diff for pattern.c but am unsure that
this is correct:

88,95d87
<
< static const sequence_t dodshort_seq = {
<     "dod-short", "DoD 5220.22-M (Short Version)", 2, {
<         { NORMAL, 1, {0x00} },
<         { VERIFY, 1, {0x00} },
<     },
< };
<
239d230
<       &dodshort_seq,

Thank you in advance,

Terence Truong

Original issue reported on code.google.com by garlick....@gmail.com on 22 Aug 2011 at 3:59

[GoogleCodeExporter]

>> On Thu, Aug 11, 2011 at 05:06:45PM -0700, Jim Garlick wrote:
   >>> Hi Terence,
   >>>
   >>> Just returning from vacation - sorry for the delay.
   >>> Can you provide a citation for the 3-pass wipe pattern?
   >>>
   >>> Your patch would write two passes of zeros, then verify that the
   >>> disk contains the last pattern written. Is that what you want?
   >>>
   >>> Jim

Date: Sat, 20 Aug 2011 11:25:03 -0700
From: Terence Truong <truong.terence@gmail.com>
To: Jim Garlick <garlick@llnl.gov>
Subject: Re: Adding shorter DoD wipe pattern

   Hi Jim,

   I know you may still be on vacation, but I wanted to send this before I
   forget.

   Here is a portion of an article that I read:

                                DoD Short Method

   When the Autonuke mode starts, the enumerated devices are automatically
   sent the wipe command with the DoD Short Method. This is a triple-pass
   wipe taking sequences 1, 2, and 7 from the standard DoD 5220.22-M wipe.

   Active KillDisk has both the 3-pass and 7-pass option, and here is a link
   to the their site:
   [1]http://www.killdisk.com/commandline.htm
   It is under erasemethod 2 and 3.
   2 - US DoD 5220.22-M (3 passes, verify)
   3 - US DoD 5220.22-M ECE (7 passes,
   verify)

   Thank you again.
   Terence Truong

Original comment by garlick....@gmail.com on 22 Aug 2011 at 4:00

[GoogleCodeExporter]

Date: Mon, 22 Aug 2011 09:47:00 -0700
From: Jim Garlick <garlick@llnl.gov>
To: Terence Truong <truong.terence@gmail.com>
Subject: Re: Adding shorter DoD wipe pattern

Hi Terence-

OK, looking at 522.22-M (http://www.usaid.gov/policy/ads/500/d522022m.pdf)
sec 8-306, There is a 3-pass method (e) which is

1) a character
2) its complement
3) random

Is that the one you're looking for?  I've tentatively added that as
"dod-short".  I wonder if the killdisk documentation is referencing an
older version of 522.22-M?  I don't see a 7-pass method unless I'm missing
something.

By the way, the "dod" method in scrub is my best attempt at DoD method (d)
which is supposed to be:

1) a character
2) its complement
3) random
4) verify

but I add a another fixed pattern between pass 3 and 4 because it's easier
to verify a fixed pattern than a random pattern.

Anyway, let me know what you think.   I can always add the method you
asked for but I can't call it 522.22-M without a citation in taht document
for it.

Jim

Original comment by garlick....@gmail.com on 22 Aug 2011 at 4:47

[GoogleCodeExporter]

Turns out this is the same as the usarmy method.
I've documented this in the man page.

Original comment by garlick....@gmail.com on 29 Aug 2011 at 6:02

• Changed state: Invalid