[CentOS] Boot failed on latest CentOS 7 update

Mon Aug 3 00:51:10 UTC 2020
Gordon Messmer <gordon.messmer at gmail.com>

On 8/2/20 4:11 PM, John Pierce wrote:
> isn't it more that they simply won't work with newer boots that were signed
> by the new keys?  and the updated BIOS's won't boot older OS versions that
> weren't signed by the new keys?


I don't know if the Secure Boot PKI has a publicly documented 
contingency plan for a compromised CA, but my understanding is that 
there are multiple slots for signatures:

http://dreamhack.it/linux/2015/12/03/secure-boot-signed-modules-and-signed-elf-binaries.html

So, I would guess that clients would receive a new trust DB that did not 
contain the old root CA, and new bootloaders signed by both the old root 
CA and the new CA.  The new bootloaders would work on both new and old 
systems, having signatures from both. Old bootloaders would not work on 
new clients.