A recent patch was merged into 2.6.8-rc3 [story] providing an x86-optimized assembly-code implementation of AES. The original version of this code was written by Dr. Brian Gladman in 2001, about which Linux creator Linus Torvalds noted, "I refused the code originally because I didn't feel that Gladman's license was a proper subset of the GPL. I only accepted it after dual-licensing under the GPL had been ok'd by Dr Brian Gladman himself." Following the announcement that this code had been merged, Jari Ruusu complained that this changed his license without permission. What Jari's actual standing is with the license was called into question, though he did provide patches in late 2001 and early 2002 and continues to maintain loop-aes. The end result was the removal of the current optimized patch, with the intention of rewriting it. Linus noted, "we'll see just how quickly somebody steps up to the plate. I spent some time taking the original Gladman source into gas format, and have a really ugly (untested) direct conversion if somebody wants to work on it."

AES is the Advanced Encryption Standard, a replacement for DES, the Data Encryption Standard. The Rijndael algorithm is a block cipher and was developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, selected by the US National Institute of Standards and Technology (NIST) to become AES in October of 2000. Rijndael has its own fan page and is based on an earlier block cipher known as Square, designed by the same authors. A good overview of how Rijndael works, complete with diagrams, can be found here.

From: Jari Ruusu [email blocked]
To: Linus Torvalds [email blocked], James Morris [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 04 Aug 2004 18:04:46 +0300

Linus Torvalds wrote:
> Summary of changes from v2.6.8-rc2 to v2.6.8-rc3
[snip]
> James Morris:
>   o [CRYPTO]: Add i586 optimized AES

My work on aes-i586.S is only licensed under original three clause BSD
license. You do not have my permission to change the license.

Either use original license or drop this code.

-- 
Jari Ruusu  1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9  DB 1D EB E3 24 0E A9 DD



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 4 Aug 2004 09:23:12 -0700 (PDT)




On Wed, 4 Aug 2004, Jari Ruusu wrote:
>
> Linus Torvalds wrote:
> > Summary of changes from v2.6.8-rc2 to v2.6.8-rc3
> [snip]
> > James Morris:
> >   o [CRYPTO]: Add i586 optimized AES
> 
> My work on aes-i586.S is only licensed under original three clause BSD
> license. You do not have my permission to change the license.
> 
> Either use original license or drop this code.

We'll drop it immediately. It should be easy enough to get somebody saner 
than you to re-convert from the original AES code which is dual-GPL'd.

		Linus



From: James Morris [email blocked]
Subject: [PATCH] Drop asm i586 AES code.
Date: 	Thu, 5 Aug 2004 11:04:28 -0400 (EDT)

This patch reverts the i586 AES module.  A new one should be ready soon.

Signed-off-by: James Morris [email blocked]

[patch]



From: James Morris [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 4 Aug 2004 12:00:26 -0400 (EDT)

On Wed, 4 Aug 2004, Jari Ruusu wrote:

> Linus Torvalds wrote:
> > Summary of changes from v2.6.8-rc2 to v2.6.8-rc3
> [snip]
> > James Morris:
> >   o [CRYPTO]: Add i586 optimized AES
> 
> My work on aes-i586.S is only licensed under original three clause BSD
> license. You do not have my permission to change the license.
> 
> Either use original license or drop this code.

Can you assert licensing restrictions which override the original author's
(Brian Gladman)?  I don't know the answer, just asking.


- James
-- 
James Morris
[email blocked]



From: J.Bruce Fields [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 4 Aug 2004 12:10:46 -0400

On Wed, Aug 04, 2004 at 12:00:26PM -0400, James Morris wrote:
> On Wed, 4 Aug 2004, Jari Ruusu wrote:
> 
> > Linus Torvalds wrote:
> > > Summary of changes from v2.6.8-rc2 to v2.6.8-rc3
> > [snip]
> > > James Morris:
> > >   o [CRYPTO]: Add i586 optimized AES
> > 
> > My work on aes-i586.S is only licensed under original three clause BSD
> > license. You do not have my permission to change the license.
> > 
> > Either use original license or drop this code.
> 
> Can you assert licensing restrictions which override the original author's
> (Brian Gladman)?  I don't know the answer, just asking.

Well, the license is an "or", so you're free to create derived works
under either or both licenses as you prefer.

But I don't even see why it's an issue; every source I've ever seen
seems to agree that the two are compatible, so you're always free to
relicense under 3-clause BSD under BSD or GPL anyway.  So, unless I'm
missing something, the "or GPL" probably doesn't do anything more than
make explicit something that was allowed already.

--Bruce Fields



From: Arjan van de Ven [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 04 Aug 2004 18:27:30 +0200


> relicense under 3-clause BSD under BSD or GPL anyway.  So, unless I'm
> missing something, the "or GPL" probably doesn't do anything more than
> make explicit something that was allowed already.

not entirely; in a dual license scheme one has the freedom to ignore one
of the two licenses and also to place derived work only under the one
chosen. That and it's outright rude to take someone else's code and
relicense it.



From: Patrick McFarland [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 4 Aug 2004 14:19:32 -0400

On Wed, 04 Aug 2004 18:27:30 +0200, Arjan van de Ven [email blocked] wrote:
> not entirely; in a dual license scheme one has the freedom to ignore one
> of the two licenses and also to place derived work only under the one
> chosen. That and it's outright rude to take someone else's code and
> relicense it.

So will 2.6.8-rc4 be released with no optimized aes, or with a saner
optimized aes?

-- 
Patrick "Diablo-D3" McFarland || [email blocked]
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd 
all be running around in darkened rooms, munching magic pills and listening to
repetitive electronic music." -- Kristian Wilson, Nintendo, Inc, 1989



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3
Date: 	Wed, 4 Aug 2004 11:45:12 -0700 (PDT)



On Wed, 4 Aug 2004, Patrick McFarland wrote:
> 
> So will 2.6.8-rc4 be released with no optimized aes, or with a saner
> optimized aes?

We'll see just how quickly somebody steps up to the plate. I spent some
time taking the original Gladman source into gas format, and have a really
ugly (untested) direct conversion if somebody wants to work on it.

Side note: Jari Ruusu has himself been distributing the code he now 
objects to as part of his own linux kernel loop-aes patches. From the 
loop-aes README:

	Copyright 2001,2002,2003,2004 by Jari Ruusu.
	Redistribution of this file is permitted under the GNU Public License.

But the original x86 assembler code that is part of that loop-aes patch
was copyright Dr Brian Gladman, and was NOT originally under the GPL, so
it was Jari Ruusu who originally did something very suspect from a
copyright angle. Now he claims he never wanted to GPL it, but the fact is,
he's been distributing kernel patches with the code for a long time, and
claiming it is GPL'd.

So then David and James wanted to include it into the kernel as part of
the standard encryption layer, and I said no, since I felt the copyright
wasn't clear. So James asked Dr Gladman for permission to dual-license
under the GPL, and got it. So I was happy.

Now Jari Ruusu comes along and starts complaining about things. 

Jari: mitä helvetin järkeä tuossa on? Selitä.

		Linus


From: Fruhwirth Clemens [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Wed, 04 Aug 2004 20:37:43 +0200

On Wed, 2004-08-04 at 18:00, James Morris wrote:
> On Wed, 4 Aug 2004, Jari Ruusu wrote:
> 
> > Linus Torvalds wrote:
> > > Summary of changes from v2.6.8-rc2 to v2.6.8-rc3
> > [snip]
> > > James Morris:
> > >   o [CRYPTO]: Add i586 optimized AES
> > 
> > My work on aes-i586.S is only licensed under original three clause BSD
> > license. You do not have my permission to change the license.
> > 
> > Either use original license or drop this code.
> 
> Can you assert licensing restrictions which override the original author's
> (Brian Gladman)?  I don't know the answer, just asking.

Short: override no; add yes.

Long:
The BSD license starts with[1]:
''Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:''

The conditions followed by that sentence are compatible with the GPL
(legally), but the GPL does not include a verbatim copy of those
conditions, therefor these conditions must not be stripped. Thus, the
''instead of'' clause, added below the BSD conditions, is invalid for
sure.

However, I could add additional conditions to the list. If you reread
[1] carefully you will come to the conclusion that adding restrictions
does not affect the 3-clauses and therefor is legal to do (imagine this
as a series of logical ANDs). That's exactly the reason the FSF calls
BSD permissive and that's the reason Microsoft has used the BSD TCP/IP
stack.

As a matter of principle I do not add additional restrictions as respect
for the original author's efforts. But James, David or Linus might do
that, and by accident choose these additional restrictions to be like
those of the GPL. I would understand such action as I'd would like to
see that every kernel code is protected by the GPL.

The impotent difference is, the code is not GPL only. It's Dual BSD/GPL.
('/' does not mean OR). As the BSD license is effectively a legal subset
of the GPL, the GPL is the dominant and defining license here. At the
end that's all we want.

I advise to replace the ALTERNATIVELY paragraph of aes-i586.S by:
''Additionally all provisions of the GNU General Public License (GPL)
must be met''. 

-- 
Fruhwirth Clemens [email blocked]  http://clemens.endorphin.org



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Wed, 4 Aug 2004 11:51:17 -0700 (PDT)



On Wed, 4 Aug 2004, Fruhwirth Clemens wrote:
> 
> As a matter of principle I do not add additional restrictions as respect
> for the original author's efforts. But James, David or Linus might do
> that, and by accident choose these additional restrictions to be like
> those of the GPL. I would understand such action as I'd would like to
> see that every kernel code is protected by the GPL.

That's not actually what we did. I refused the code originally because I
didn't feel that Gladman's license was a proper subset of the GPL. I only
accepted it after dual-licensing under the GPL had been ok'd by Dr Brian
Gladman himself.

Note that the kernel is perfectly fine with dual-licensing: there's a
number of drivers in the kernel that can be distributed either under BSD
or GPL licenses. I hate adding restrictions too, so when we have a mix of
licenses, I much prefer allowing _both_ for that piece of code. That's why 
the current aes-i586-asm.S file has

//  ALTERNATIVELY, provided that this notice is retained in full, this product
//  may be distributed under the terms of the GNU General Public License (GPL),
//  in which case the provisions of the GPL apply INSTEAD OF those given above.

Of course, the kernel itself always uses the GPL version, but dual
licensing is how we can allow certain drivers to be maintained across
Linux and the BSD's (or other projects, for that matter). No need to 
duplicate work that way.

		Linus



From: Fruhwirth Clemens [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Wed, 04 Aug 2004 21:26:52 +0200

On Wed, 2004-08-04 at 20:51, Linus Torvalds wrote:
> On Wed, 4 Aug 2004, Fruhwirth Clemens wrote:
> > 
> > As a matter of principle I do not add additional restrictions as respect
> > for the original author's efforts. But James, David or Linus might do
> > that, and by accident choose these additional restrictions to be like
> > those of the GPL. I would understand such action as I'd would like to
> > see that every kernel code is protected by the GPL.
> 
> That's not actually what we did. I refused the code originally because I
> didn't feel that Gladman's license was a proper subset of the GPL. 

I don't view the FSF as sort of last instance, but just for the
protocol: The exact wording of this license is labeled 'GPL-compatible'
by the FSF. Imho, this makes it a subset.

> I only accepted it after dual-licensing under the GPL had been ok'd by Dr Brian
> Gladman himself.

Additional coding, no problem, but additional social work, I'd prefer
not to be involved with. As there is no legal requirement, such efforts

would just make a good appearance. But, hey, if someone volunteers to
sort out these problems, my modifications to aes-i586.S can be
relicensed under the GPL anytime, no problem.

-- 
Fruhwirth Clemens [email blocked]  http://clemens.endorphin.org



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Wed, 4 Aug 2004 12:56:20 -0700 (PDT)



On Wed, 4 Aug 2004, Fruhwirth Clemens wrote:
> 
> I don't view the FSF as sort of last instance, but just for the
> protocol: The exact wording of this license is labeled 'GPL-compatible'
> by the FSF. Imho, this makes it a subset.

Ahh. Fair enough. I didn't have any lawyer look at it, I just don't like 
assuming.

> Additional coding, no problem, but additional social work, I'd prefer
> not to be involved with. As there is no legal requirement, such efforts
> would just make a good appearance.

I'd much rather do the social work, not so much necessarily for legal 
reasons, but for my own menal well-being. It's just _so_ much nicer to 
work with a code-base where none of the authors might complain about being 
included.

So even if the original license is GPL-compatible, just the fact that Jari 
doesn't want his work re-licensed means that I don't want his work in the 
kernel - whether it's a legal issue or not. 

Now, I obviously believe that Jari has acted like an ass, since he has
used the very same code under the GPL before, but hey, that's his problem. 

Jari - please stop distributing your loop-aes patches. If you consider the 
license to be non-GPL-compatible, then you have no business distributing 
the thing as kernel patches. Alternatively, just say it's GPL'd. You can't 
have it both ways.

		Linus



From: Jari Ruusu [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Thu, 05 Aug 2004 15:33:03 +0300

Linus Torvalds wrote:
> Now, I obviously believe that Jari has acted like an ass, since he has
> used the very same code under the GPL before, but hey, that's his problem.

Linus, are you saying that anyone who refuses to re-license their work under
license of your choice, is an ass? Or just the ones who catch you
re-licencing their work without permission?

> Jari - please stop distributing your loop-aes patches. If you consider the
> license to be non-GPL-compatible, then you have no business distributing
> the thing as kernel patches. Alternatively, just say it's GPL'd. You can't
> have it both ways.

I say that loop-AES is GPL-compatible.

Most of the files in loop-AES are licensed under GPL. Some files have less
restrictive license, but are still licensed under GPL-compatible license.
I am not aware of any files in loop-AES that are GPL-incompatible.

-- 
Jari Ruusu  1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9  DB 1D EB E3 24 0E A9 DD



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Thu, 5 Aug 2004 09:50:22 -0700 (PDT)



On Thu, 5 Aug 2004, Jari Ruusu wrote:
> 
> Most of the files in loop-AES are licensed under GPL. Some files have less
> restrictive license, but are still licensed under GPL-compatible license.
> I am not aware of any files in loop-AES that are GPL-incompatible.

You're saying that you consider Gladman's original AES license to be
GPL-compatible (ie a subset of it)? That's fine - apparently the FSF
agrees.

However, that is incompatible with you then complaining when it gets 
released under the GPL. If the original license was a proper subset of the 
GPL, then it can _always_ be re-released under the GPL, and you don't have 
anything to complain about.

So which is it? Either it's GPL-compatible or it isn't. If it is
GPL-compatible, why are you making noises? And if it is not, why are you
claiming that you can distribute loop-AES as a GPL'd project?

You seem to be very very confused, Jari. There really _are_ only these two 
cases:

 - the AES code is GPL-compatible

   This fundamentally means that it has no more restrictions than the GPL, 
   and that in turn means that it can always be re-licensed as GPL'd code. 
   Which James Morris did (well, it was dual-licensed, but the only 
   license that matters for the _kernel_ is the GPL).

   In this case, you can't say "you can't do that". I'm sorry, but James 
   _can_ do that, and it is _you_ who can't do that. 

 - the AES code is _not_ GPL compatible.

   This fundamentally means that you can't relicense it under the GPL, but 
   it _also_ means that you can't link it with GPL code, since the GPL
   _requires_ that the code be under the GPL. In this case, loop-AES was 
   always wrogn and lying about beign GPL'd, and you should stop
   distributing it immediately.

You can't have it both ways. And there aren't any third alternatives.

Explain yourself.

		Linus



From: Jari Ruusu [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date: 	Fri, 06 Aug 2004 12:47:31 +0300

Linus Torvalds wrote:
> You're saying that you consider Gladman's original AES license to be
> GPL-compatible (ie a subset of it)? That's fine - apparently the FSF
> agrees.

Yes, it is GPL-compatible.

> However, that is incompatible with you then complaining when it gets
> released under the GPL. If the original license was a proper subset of the
> GPL, then it can _always_ be re-released under the GPL, and you don't have
> anything to complain about.

Linus, you are mixing two completely different rights here; re-distribution
right and re-licensing right. Original license grants you GPL-compatible
re-distribution rights, which means that the code can be distributed and
linked with GPL code just fine. To relicense the code under more restrictive
license you need permission from all authors of the code. You clearly do not
have such permission from all authors. Therefore, you can not re-license the
code.

-- 
Jari Ruusu  1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9  DB 1D EB E3 24 0E A9 DD



From: Linus Torvalds [email blocked]
Subject: Re: Linux 2.6.8-rc3 - BSD licensing
Date:   Fri, 6 Aug 2004 09:39:00 -0700 (PDT)

On Fri, 6 Aug 2004, Jari Ruusu wrote:
>
> Linus, you are mixing two completely different rights here;
> re-distribution right and re-licensing right.

Ehh.. You're wrong.

Copyright law has nothing to do with "licensing". In fact, if you actually
read copyright law, you will find that the _only_ thing that it's about is
the right to distribute a work and the right to make derived works.

(Side note: there are also certain "right of attribution" etc, but that's
still not about re-licensing and those are about the author, not the owner
of the copyright).

In other words, being the "owner" of a work has nothing to do with the
right to "relicence".

Being able to license somebody else to distribute the work does NOT
require ownership. It only requires a _license_ to do so. You can keep
owning your copyright, and let somebody else distribute the copy for you
by liccensing him to do that.

And a license like the BSD license that allows very broad rights to
_everybody_ means that pretty much everybody can not only distribute it,
but since the BSD license doesn't even limit how they re-distribute it,
you can distribute it with some additional requirements of your own.

Why do you think Microsoft etc can take BSD code and then slap their EULA
on it? Right. They were given the right to distribute.

> Original license grants
> you GPL-compatible re-distribution rights, which means that the code can
> be distributed and linked with GPL code just fine.

You clearly do not know what you're talking about.

You haven't even read the GPL, have you?

The GPL doesn't say "you can link this with a GPL-compatible license". It
says:

    b) You must cause any work that you distribute or publish, that in
    whole or in part contains or is derived from the Program or any
    part thereof, to be licensed as a whole at no charge to all third
    parties under the terms of this License.

Notice? It says "this License". Not "this license or some more permissive
license".

The ONLY license you can use to create a GPL derivative is the GPL itself.

And the way "GPL-compatible" licenses work is _exactly_ because these
licenses are "weaker" than the GPL, and as such can always be _relicensed_
as the GPL.

THAT IS WHAT GPL-COMPATIBLE MEANS!

So when you claim that the code isn't GPL-compatible, and at the same time
claim that we can't re-license it under the GPL, you are very very
confused indeed. Either it is GPL-compatible, or it is not. And if it is
GPL-compatible, that ABSOLUTELY means that it can be relicensed under the
GPL.

Comprende?

Anyway, the point is moot.  We've removed the code you touched, and I'm
about to apply the new version that is based on Gladman's code (I did the
conversion myself, and James Morris did the final stuff and the
integration with the rest of the code).

And we did that not for legal reasons, but because quite frankly, I don't
want to have _anything_ to do with somebody as confused as you are.

                        Linus

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