Re: mlock(1)

[Nigel Cunningham <ncunningham@linuxmail.org>]

Hi.

On Tue, 2004-09-28 at 08:43, Andrea Arcangeli wrote:
> On Tue, Sep 28, 2004 at 08:22:41AM +1000, Nigel Cunningham wrote:
> > > I figured out how to make the swap encryption completely transparent to
> > > userspace, and even to swap suspend, so I think it's much better than
> > > having userspace asking the user for a password, or userspace choosing a
> > > random password.
> > 
> But why did you quote the above? for cryptoswap it cannot work, for
> cryptoswap there's no reason to ever ask the user to anything and it
> must read and write all the time anyways, it's not like suspend
> write-only and resume read-only, a problem where public/private
> encryption can fit.

I think I was a bit confused. Sorry.

> > > yes, but the bootloader passes the paramters via /proc/cmdline, and it's
> > > not nice to show the password in cleartext there.
> > 
> > If this password is only needed when resuming, that's not an issue
> > because the command line given when resuming will be lost when the
> > original kernel data is copied back.
> 
> my point is that you would not be allowed to give anyone ssh access to
> your machine (assuming you trust local security). If he gets ssh access,
> then he could as well stole the laptop and read the encrypted data.

Don't follow, sorry. Perhaps I'm being thick!

> But if calling set_fs(KERNEL_DS); sys_read(0) sounds troublesome, you
> could also erase the password from the cmdline, and you would still
> pass the passphrase via bootloader. I'd recommend not to make it visible
> to userspace.
> 
> > There's already compression support. It's simpler to reverse, of course,
> > but it doesn't help?
> 
> that should be trivial to reverse, no?

Yes, it would be.

Regards,

Nigel
-- 
Nigel Cunningham
Pastoral Worker
Christian Reformed Church of Tuggeranong
PO Box 1004, Tuggeranong, ACT 2901

Many today claim to be tolerant. True tolerance, however, can cope with others
being intolerant.