On Thu, 2008-09-04 at 23:12 +0800, Ed Greshko wrote:
Patrick O'Callaghan wrote:
>
>> NAK - if a fake public key were distributed then packages signed with
>> the fake key would be matched, allowing full access to install crap in
>> your machine.
>>
>
> True.
>
Actually I don't understand the paragraph above. It seems to be saying
that packages would be signed with a public key which can't be done.
So, the person making that statement needs to clarify.
Which is the point I made earlier.
>> And packages signed with any valid redhat key would be
>> rejected.
>>
>
> Which is what I said. Thus it would be noticed immediately.
>
No, they would not be rejected as long as you still have Red Hat's
public key installed on your system. You can determine what public keys
are on your system by "rpm -qa gpg-pubkey*".
When an rpm is signed it is signed with a private key and information
about the corresponding public key is placed in the rpm file. That
information is used to retrieve the correct public key for
verification. So, as long as you've not deleted it, they will verify.
The hypothetical scenario being discussed is that you have already
replaced the former (good but now possibly suspect) public key with a
spurious new one. If that were to happen, you would be in danger of
accepting trojanned packages signed with this new fake key. My point is
that you would also *reject* packages signed with the new good key, and
this would be noticed very quickly (basically the next time you did an
update).
poc