Should enterprise attestation support be flagged explicitly?

[nsatragno]

At the June F2F, the topic of how painful it can be to require enterprise attestation came up. Right now browsers throw a type error if not supported, but that would turn into a request with no attestation after updating browsers to ignore unknown enum values. This is undesirable: RPs might want to know in advance whether enterprise attestation can succeed or not.

[ve7jtb]

Is this a flag in WebAuthn that can be checked to see if the browser is going to throw a type error?

That would be helpful for RP.

You can't say if an enterprise attestation is available only if the browser supports the enum for enterprise attestation.

[timcappalli]

2023-08-30 meeting: address this as a client capability in #1923