webpki::Error::RequiredEkuNotFoundContext takes KeyUsage instead of KeyPurposeId, which enforces user to use deprecated webpki::Error::RequiredEkuNotFound

[sgrams]

webpki::Error::RequiredEkuNotFoundContext takes KeyUsage instead of KeyPurposeId, which enforces user to use deprecated webpki::Error::RequiredEkuNotFound when defining own implementation of ExtendedKeyUsageValidator

[djc]

Right, so KeyUsage is what we use internally to represent what we check against, and this would be prone to not have the same flexibility as external implementations. But I think you can just create a KeyUsage::required() to go in RequiredEkuNotFoundContext::required? I'm not sure it makes sense to do something more complex for this use case.

As for RequiredEkuNotFoundContext::present, this PR might help:

• Expose KeyPurposeId::to_decoded_oid() #385

Please test it and confirm that this allows you to implement the trait as desired.