Comment 20 for bug 1696154

------- Comment From <email address hidden> 2017-09-27 16:47 EDT-------
(In reply to comment #30)
> Attached is the ESL db update for Canonical's POWER SecureBoot signing key.
> It is signed with Canonical's KEK key, which will be provided to IBM out of
> band to ensure integrity of the delivery channel.

Thanks Andy and Vorlon for the attached files. The kernel appended signature verified successfully.

We didn't test the Canonical-POWER-SB-20170926.esl.signed file yet.


1) The certificate provided contains a 4096-bit key and it was signed using sha512WithRSAEncryption. We had no problem to use it to verify the kernel appended signature - the kernel crypto API supports 4096-bit RSA keys. However, we don't have much space in our keystore and that's why we prefer to use 2048-bit RSA keys, same as UEFI SecureBoot. Could the Canonical-POWER-SB-20170926.esl.signed file be regenerated to contain a certificate that contains a 2048-bit RSA key instead? The certificate would be signed using sha256WithRSAEncryption.

2) We will need to put in the KEK a certificate that can be used to verify the signed ESL db updates provided by Canonical. How does Canonical have provided that for UEFI SecureBoot? certificate, ESL (not signed, since PK is not provided by Canonical)?
Currently, we are working on the code that will validate/process the authenticated variable updates. We will probably start testing it by the end of this year.