Re: Patch to support GELI passphrase passthrough

[Kris Moore <kris@pcbsd.org>]

On 10/22/2014 13:50, Kris Moore wrote:
> On 10/22/2014 13:47, Andrei Borzenkov wrote:
>> В Wed, 22 Oct 2014 13:12:32 -0400
>> Kris Moore <kris@pcbsd.org> пишет:
>>
>>> Hey, just a small patch to submit today. If you rather I send this to
>>> the bug tracker then I can do that also.
>>>
>>> This patch allows exporting the FreeBSD GELI passphrase to the kernel
>>> environment, which we will be doing in PC-BSD to avoid prompting for the
>>> passphrase a second time at bootup.
>>>
>>>    if (!grub_password_get (passphrase, MAX_PASSPHRASE))
>>>      return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
>>>  
>>> +  /* Set the GELI passphrase to GRUB env, for passing to FreeBSD kernel */
>>> +  grub_env_set ("gelipassphrase", passphrase);
>>> +
>> If I read BSD loader correctly, this should be kFreeBSD.gelipassphrase.
>> Is geli freebsd-specific?
>>
>>>    /* Calculate the PBKDF2 of the user supplied passphrase.  */
>>>    if (grub_le_to_cpu32 (header.niter) != 0)
>>>      {
>> It sounds more logical to export it after it has been verified?
>>
>> I tried to find out about this "gelipassphrase" kernel variable but did
>> not find anything. Is it already used anywhere?
>>
>>> Let me know if you have any suggestions or need any changes. I'm
>>> currently hacking on support for EFI framebuffer settings to be passed
>>> to FreeBSD kernel as well, will send patches once I get things working
>>> there.
>>>
>> _______________________________________________
>> Grub-devel mailing list
>> Grub-devel@gnu.org
>> https://lists.gnu.org/mailman/listinfo/grub-devel
> Well, this patch just makes the variable available to grub.cfg file,
> then we do some stuff there like this:
>
> set kFreeBSD.kern.geom.eli.passphrase=<passphrase>
>
> The patch for support in FreeBSD should be in HEAD soon, but here it is
> if you want to take a look:
>
> https://github.com/pcbsd/freebsd/commit/79f4efcf6a7d4268781adc227d76ed9f7f0b685d
>

Any further thoughts on this patch? The FreeBSD integration hit HEAD a
few days back.

https://github.com/freebsd/freebsd/commit/bdb0ac02b9fd8f331fa70c8a4c29495b7ee43293

The reason I don't export the variable directly is so that when GRUB is
used to boot older versions of FreeBSD we don't set that variable, where
it isn't cleared from kernel memory. I would rather users enable it in
their grub.cfg manually, just so they know what it is doing.




-- 
Kris Moore
PC-BSD Software
iXsystems