Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2007-01-02 Thread Olaf Manczak
james hughes wrote: This is intended as a defense in depth measure and also a sufficiently good measure for the customers that don't need full compliance with NIST like requirements that need degausing or physical destruction. Govt, finance, healthcare all require the NIST overwrite... Jim,

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-21 Thread Darren J Moffat
Darren Reed wrote: Darren, A point I don't yet believe that has been addressed in this discussion is: what is the threat model? There are several and this is about providing functionality so that customers can choose what they want to use when it is appropriate. Using format(1M) for whole "

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-21 Thread Darren J Moffat
Torrey McMahon wrote: Darren Reed wrote: Darren, A point I don't yet believe that has been addressed in this discussion is: what is the threat model? Are we targetting NIST requirements for some customers or just general use by everyday folks? Even higher level: What problem are you/we tryin

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-21 Thread Darren J Moffat
james hughes wrote: On Dec 20, 2006, at 1:37 PM, Bill Sommerfeld wrote: On Wed, 2006-12-20 at 03:21 -0800, james hughes wrote: This would be mostly a "vanity erase" not really a serious "security erase" since it will not over write the remnants of remapped sectors. Yup. As usual, your mila

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Torrey McMahon
Darren Reed wrote: Darren, A point I don't yet believe that has been addressed in this discussion is: what is the threat model? Are we targetting NIST requirements for some customers or just general use by everyday folks? Even higher level: What problem are you/we trying to solve? _

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Darren Reed
Darren, A point I don't yet believe that has been addressed in this discussion is: what is the threat model? Are we targetting NIST requirements for some customers or just general use by everyday folks? Darrn ___ zfs-discuss mailing list zfs-discuss@

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread james hughes
On Dec 20, 2006, at 5:46 AM, Darren J Moffat wrote: james hughes wrote: Not to add a cold blanket to this... This would be mostly a "vanity erase" not really a serious "security erase" since it will not over write the remnants of remapped sectors. Indeed and as you said there is other so

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread james hughes
On Dec 20, 2006, at 1:37 PM, Bill Sommerfeld wrote: On Wed, 2006-12-20 at 03:21 -0800, james hughes wrote: This would be mostly a "vanity erase" not really a serious "security erase" since it will not over write the remnants of remapped sectors. Yup. As usual, your milage will vary dependin

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Jan Parcel
true, it is the drive manufacturers who are in a position to address this. >Date: Wed, 20 Dec 2006 15:32:48 -0800 (PST) >From: Gary Winiger <[EMAIL PROTECTED]> >Subject: Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto >To: [EMAIL

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Gary Winiger
> On Wed, 2006-12-20 at 03:21 -0800, james hughes wrote: > > This would be mostly a "vanity erase" not really a serious "security > > erase" since it will not over write the remnants of remapped sectors. > > Yup. As usual, your milage will vary depending on your threat model. > > My gut fe

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Bill Sommerfeld
On Wed, 2006-12-20 at 03:21 -0800, james hughes wrote: > This would be mostly a "vanity erase" not really a serious "security > erase" since it will not over write the remnants of remapped sectors. Yup. As usual, your milage will vary depending on your threat model. My gut feel is that the

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Torrey McMahon
Jonathan Edwards wrote: On Dec 20, 2006, at 04:41, Darren J Moffat wrote: Bill Sommerfeld wrote: There also may be a reason to do this when confidentiality isn't required: as a sparse provisioning hack.. If you were to build a zfs pool out of compressed zvols backed by another pool, then it w

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Jonathan Edwards
On Dec 20, 2006, at 04:41, Darren J Moffat wrote: Bill Sommerfeld wrote: There also may be a reason to do this when confidentiality isn't required: as a sparse provisioning hack.. If you were to build a zfs pool out of compressed zvols backed by another pool, then it would be very convenient i

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Darren J Moffat
james hughes wrote: Not to add a cold blanket to this... This would be mostly a "vanity erase" not really a serious "security erase" since it will not over write the remnants of remapped sectors. Indeed and as you said there is other software to deal with this for those types of customers t

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread james hughes
Not to add a cold blanket to this... This would be mostly a "vanity erase" not really a serious "security erase" since it will not over write the remnants of remapped sectors. Serious security erase software will unmap sectors and erase both locations using special microcode features. While

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Darren J Moffat
Matthew Ahrens wrote: Darren J Moffat wrote: I believe that ZFS should provide a method of bleaching a disk or part of it that works without crypto having ever been involved. I see two use cases here: 1. This filesystem contains sensitive information. When it is freed, make sure it's really

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-20 Thread Darren J Moffat
Bill Sommerfeld wrote: There also may be a reason to do this when confidentiality isn't required: as a sparse provisioning hack.. If you were to build a zfs pool out of compressed zvols backed by another pool, then it would be very convenient if you could run in a mode where freed blocks were ov

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Matthew Ahrens
Bill Sommerfeld wrote: On Tue, 2006-12-19 at 16:19 -0800, Matthew Ahrens wrote: Darren J Moffat wrote: I believe that ZFS should provide a method of bleaching a disk or part of it that works without crypto having ever been involved. I see two use cases here: I agree with your two, but I thin

Re: [security-discuss] Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Bill Sommerfeld
On Tue, 2006-12-19 at 16:19 -0800, Matthew Ahrens wrote: > Darren J Moffat wrote: > > I believe that ZFS should provide a method of bleaching a disk or part > > of it that works without crypto having ever been involved. > > I see two use cases here: I agree with your two, but I think I see a thi

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Matthew Ahrens
Darren J Moffat wrote: I believe that ZFS should provide a method of bleaching a disk or part of it that works without crypto having ever been involved. I see two use cases here: 1. This filesystem contains sensitive information. When it is freed, make sure it's really gone. I believe that

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Bill Sommerfeld
On Mon, 2006-12-18 at 16:05 +, Darren J Moffat wrote: > 6) When modifying any file you want to bleach the old blocks in a way > very simlar to case 1 above. I think this is the crux of the problem. If you fail to solve it, you can't meaningfully say that all blocks which once contained parts

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Darren J Moffat
Frank Hofmann wrote: would not be a call to posix_fallocate() or ftruncate(), instead an unlink(2) or a zfs destory or zpool destroy. Also on hotsparing in a disk - if the old disk can still be written to in some way we should do our best to bleach it. Since VOP_*() requires a filesystem (wi

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Frank Hofmann
On Tue, 19 Dec 2006, Darren J Moffat wrote: Frank Hofmann wrote: On the technical side, I don't think a new VOP will be needed. This could easily be done in VOP_SPACE together with a new per-fs property - bleach new block when it's allocated (aka VOP_SPACE directly, or in a backend also calle

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Darren J Moffat
Frank Hofmann wrote: On the technical side, I don't think a new VOP will be needed. This could easily be done in VOP_SPACE together with a new per-fs property - bleach new block when it's allocated (aka VOP_SPACE directly, or in a backend also called e.g. on allocating writes / filling holes),

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Frank Hofmann
On Tue, 19 Dec 2006, Jonathan Edwards wrote: On Dec 18, 2006, at 11:54, Darren J Moffat wrote: [EMAIL PROTECTED] wrote: Rather than bleaching which doesn't always remove all stains, why can't we use a word like "erasing" (which is hitherto unused for filesystem use in Solaris, AFAIK) and t

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Jonathan Edwards
On Dec 18, 2006, at 11:54, Darren J Moffat wrote: [EMAIL PROTECTED] wrote: Rather than bleaching which doesn't always remove all stains, why can't we use a word like "erasing" (which is hitherto unused for filesystem use in Solaris, AFAIK) and this method doesn't remove all stains from t

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Jonathan Edwards
On Dec 19, 2006, at 08:59, Darren J Moffat wrote: Darren Reed wrote: If/when ZFS supports this then it would be nice to also be able to have Solaris bleach swap on ZFS when it shuts down or reboots. Although it may be that this option needs to be put into how we manage swap space and not speci

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-19 Thread Darren J Moffat
Darren Reed wrote: If/when ZFS supports this then it would be nice to also be able to have Solaris bleach swap on ZFS when it shuts down or reboots. Although it may be that this option needs to be put into how we manage swap space and not specifically zomething for ZFS. Doing this to swap space

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-18 Thread Darren Reed
Darren J Moffat wrote: .. I think we need 5 distinct places to set the policy: 1) On file delete This would be a per dataset policy. The bleaching would happen in a new transaction group created by the one that did the normal deletion, and would run only if theoriginal one c

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-18 Thread Darren J Moffat
[EMAIL PROTECTED] wrote: Rather than bleaching which doesn't always remove all stains, why can't we use a word like "erasing" (which is hitherto unused for filesystem use in Solaris, AFAIK) and this method doesn't remove all stains from the disk anyway it just reduces them so they can't be eas

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-18 Thread Casper . Dik
>Darren J Moffat wrote: >> I think we need 5 distinct places to set the policy: >> >> 1) On file delete >> This would be a per dataset policy. >> The bleaching would happen in a new transaction group >> created by the one that did the normal deletion, and would >> run only if the

Re: [zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-18 Thread Darren J Moffat
Darren J Moffat wrote: I think we need 5 distinct places to set the policy: 1) On file delete This would be a per dataset policy. The bleaching would happen in a new transaction group created by the one that did the normal deletion, and would run only if theoriginal one compl

[zfs-discuss] Thoughts on ZFS Secure Delete - without using Crypto

2006-12-18 Thread Darren J Moffat
[ This is for discussion, it doesn't mean I'm actively working on this functionality at this time or that I might do so in the future. ] When we get crypto support one way to do "secure delete" is to destroy the key. This is usually a much simpler and faster task than erasing and overwriting