Re: [webauthn] RPs cannot show "You've Already Registered This Authenticator" Message

CTAP2 authenticators must gather consent before replying with `CTAP2_ERR_CREDENTIAL_EXCLUDED`:

> When an authenticatorMakeCredential request is received, the authenticator performs the following procedure:
> 
> If the excludeList parameter is present and contains a credential ID that is present on this authenticator and bound to the specified rpId, wait for user presence, then terminate this procedure and return error code CTAP2_ERR_CREDENTIAL_EXCLUDED. User presence check is required for CTAP2 authenticators before the RP gets told that the token is already registered to behave similarly to CTAP1/U2F authenticators.

The procedure @agl suggests is what we do for U2F (CTAP1) authenticators today -- they do not have resident keys.

-- 
GitHub Notification of comment by leshi
Please view or discuss this issue at https://github.com/w3c/webauthn/issues/806#issuecomment-366360262 using your GitHub account

Received on Friday, 16 February 2018 21:14:51 UTC