[tor-bugs] #34368 [Applications/Tor Browser]: Improve authenticode-signing script to better check for a signature

[Tor Bug Tracker & Wiki]

#34368: Improve authenticode-signing script to better check for a signature
------------------------------------------+----------------------
     Reporter:  gk                        |      Owner:  tbb-team
         Type:  enhancement               |     Status:  new
     Priority:  Medium                    |  Milestone:
    Component:  Applications/Tor Browser  |    Version:
     Severity:  Normal                    |   Keywords:  tbb-sign
Actual Points:                            |  Parent ID:
       Points:                            |   Reviewer:
      Sponsor:                            |
------------------------------------------+----------------------
 Our current `authenticode-signing.sh` script checks two things at the
 moment:

 1) Whether a .exe is still unsigned
 2) Whether removing a signature (using `osslsigncode remove-signature`) is
 producing the same SHA-256 sum as outlined in the SHA-256 sums file.

 If both conditions hold it concludes that the bundles are properly signed.

 There are ways for improvement here. While I think it's important to check
 that removing the signature provides the expected unsigned SHA-256 we
 could try to check the signature directly.

 `osslsigncode verify -require-leaf-hash` comes to mind. We should
 investigate, though, how that behaves in case of truncated/broken
 signatures or no signatures at all.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/34368>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online