Need inputs on parameters for PublicKeyCredentialCreationOptions and other Extensions

[RitushreePurkait96]

As per the yubico developers document, for WebAuthn Client Registration flow The Relying Party (RP) builds an instance of the PublicKeyCredentialCreationOptions and returns it to the client. The instance contains information about the user, the RP and the type of credential desired.
Please refer to the Following example for Parsed PublicKeyCredentialCreationOptions.

"publicKey": {
   "attestation": "direct",
  "authenticatorSelection": {
    "authenticatorAttachment": "cross-platform",
   "requireResidentKey": false,
   "userVerification": "discouraged"
  },
  "challenge": "qNqrdXUrk5S7dCM1MAYH3qSVDXznb-6prQoGqiACR10=",
  "excludeCredentials": [],
  "pubKeyCredParams": [
   {
    "alg": -7,
    "type": "public-key"
   }
  ],
  "rp": {
   "id": "[demo.yubico.com](http://demo.yubico.com/)",
   "name": "Yubico Demo"
  },
   "timeout": 30000,
  "user": {
   "displayName": "Yubico demo user",
   "id": "bz9ZDfHzOBLycqISTAdWwWIZt8VO-6mT3hBNXS5jwmY="
  }
 }
}

As in the current YubiKit library most of the parameters can be found, but I couldn’t figure out how to pass the following parameters:

1. attestation
2. authenticatorAttachment
3. timeout

Few other required information :

1. Does YubiKit has something similar to FIDO2CommandCancel (FIDO2 command cancel operation), if yes how to make use of it ?
2. Does YubiKit has support for CancellationId (Cancellation ID) ?
3. Does YubiKit has support User Verification options and if yes, how to pass the possible options like : “preferred”, “required”, or “discouraged” ?.
4. How does YubiKit library allow passing the required option for Credential Protection Extensions like “userVerificationOptional” , “userVerificationOptionalWithCredentialIDList “, “userVerificationRequired” in case we want to control the behaviour ?
5. Would like to get clarified on the "hmac-secret” extensions as how to pass this as a parameter/ key-value pair.

It would be great if someone can provide some inputs on the above. Please let me know if need more clarity on any of the above queries.

[mohanio]

I too have similar question on how to pass below PublicKeyCredentialCreationOptions

• attestation
• authenticatorAttachment
• timeout

Could someone please help ?