pam_google is no longer in the image, so we must create /etc/login_trust_root.pem from scratch

pam_google is no longer in the image, so we must create /etc/login_trust_root.pem from scratch

pam_google used to install /etc/login_trust_root.pem, and then this script would
modify it.  We no longer install pam_google, so we need to create this file
de-novo now.

BUG=None
TEST=build_image, then mod for test.  Check that /etc/login_trust_root.pem exists, contains one cert, and has the right permissions.  For maximum goodness, run login_LoginSuccess

Change-Id: I409ffeea4b30905cf9e0506650b67556fa5ec80e

[Chris Masone, 2010-08-25 02:50:04]

On 2010/08/24 16:49:20, Chris Masone wrote:
> 

+davidjames

[davidjames, 2010-08-25 03:54:49]

I'm not familiar with pam_google. Reading your description though, the change
sounds like it's both necessary and a good idea.

LGTM, but consider checking with someone more familiar with this part of the
code before committing

[Chris Masone, 2010-08-25 04:00:03]

On 2010/08/25 03:54:49, davidjames wrote:
> I'm not familiar with pam_google. Reading your description though, the change
> sounds like it's both necessary and a good idea.
> 
> LGTM, but consider checking with someone more familiar with this part of the
> code before committing

Will, I guess you'd count as the most familar with pam_google, other than me? 
You probably did the reviews waaaaaaay back in the day.

Basically, what's happened is that pam_google used to store the root cert it'd
trust when doing SSL connections during login at /etc/login_trust_root.pem. 
When we modded the image for test, we just added another cert to this pem file,
and then had our mock google accounts server use this as its trust root.  

We recently took pam_google out of the image, so /etc/login_trust_root.pem no
longer exists, so we can't modify it any more :-)  Now we just create it
de-novo.

[Nick Sanders, 2010-08-25 04:17:32]

lgtm here as well, with the caveat that I have no idea what this code is doing.
Your explanation sounds reasonable though =)

[Will Drewry, 2010-08-25 05:00:05]

LGTM