1164948 - Sign eme-adobe.dll CDM using Authenticode

Status: RESOLVED FIXED

(Core :: Audio/Video, defect, P2)

Description

[Chris Peterson [:cpeterson]]

As reported on Hacker News [1], gmpopenh264.dll and eme-adobe.dll are not signed. These DLLs are loaded from AppData, a folder with read/write permissions but not execute permissions.

Windows can be configured to *only* run signed programs, which would break the Adobe CDM. Bob says you can configure Windows to only run signed programs in the security policy mmc snap-in.

The reporter also asked for a "Publisher rule attached". What is that? Also, "The lack of a signature is at best an administrative burden and at worst an attack vector depending on how the Admin handles it ("let's just add a wildcard exeception")."


[1] https://news.ycombinator.com/item?id=9533260

Comment 1

[Bob Owen (:bobowen)]

I don't know a lot about this, but this is the Microsoft page I was looking at:
https://technet.microsoft.com/en-us/library/dd723683%28v=ws.10%29.aspx

Looks like you can add per Publisher rules, amongst other things.

Comment 2

[Henri Sivonen (:hsivonen)]

On our side, do we have anything we can do except to convince ourselves that this is a problem? Are we already convinced enough to ask Adobe to sign the DLL?

Comment 3

[Chris Peterson [:cpeterson]]

We don't have any concrete evidence that there is a problem yet. Anthony volunteered to test Windows' only-run-signed-code configuration.

cpearce already asked Adobe if they could sign their DLL like they do for Flash. They're looking into it.

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

The best evidence we have is some crash reports of the GMP process where the Firefox is a build that would check that the DLL is on disk first before starting the GMP processs and the Adobe DLL is not present in the plugin process. Implying that the Adobe DLL is on disk, but we failed to load it.

Comment 5

[Chris Peterson [:cpeterson]]

Joe says Adobe will look into signing the CDM DLL.

Comment 6

[Joe Steele]

We are working on integrating this into our build process. ETA is this Friday.

Comment 7

[Chris Pearce [:cpearce (Not reading bugmail)]]

Adobe have delivered a signed GMP.