Multiple MSI signatures with different algorithms and a MsiDigitalSignatureEx entry about osslsigncode

[mtrojnar]

Could you elaborate on the reason you consider this a useful feature?

[ebourg]

That's useful for the same reasons users want to sign multiple times other file formats I guess. It also impacts the signature verification, if osslsigncode computes MsiDigitalSignatureEx when verifying the signature, it may see a signature as invalid while Windows consider it valid. In order to replicate the Windows verification process, the existing MsiDigitalSignatureEx entry should be taken as is and not recomputed when verifying.

[mtrojnar]

@olszomal Can you take a look? How hard would it be to implement?

[mtrojnar]

Bug-for-bug compatibility with Microsoft is not a goal of this project. Depending on missing checks in the current implementation of Windows may backfire when Microsoft decides to fix them.

The check was added in 180a775. @mkrautz: Do you think it's a good idea to remove it?