PublicKeyCredentialCreationOptions.attestation

attestation is an optional property of the PublicKeyCredentialCreationOptions dictionary. This is a string whose value indicates the preference regarding the attestation transport, between the authenticator, the client and the relying party.

The attestation is a mean for the relying party to verify the origin of the authenticator with an attestation certificate authority. The information contained in the attestation may thus disclose some information about the user (e.g. which device they are using).

attestation = publicKeyCredentialCreationOptions.attestation

A string which may be

• "none": the relying party is not interested in this attestation. This avoids making a check with the attestation certificate authority and asking the user consent for sharing identifying information.
• "indirect": the client may change the assertion from the authenticator (for instance, using an anonymization CA). This value is used when the relying party wishes to verify the attestation.
• "direct": the relying party wants to receive the attestation as generated by the authenticator.

The default value is "none".

var publicKey = {
  attestation: "indirect",
  challenge: new Uint8Array(26) /* this actually is given from the server */,
  rp: {
    name: "Example CORP",
    id  : "login.example.com"
  },
  user: {
    id: new Uint8Array(26), /* To be changed for each user */
    name: "jdoe@example.com",
    displayName: "John Doe",
  },
  pubKeyCredParams: [
    {
      type: "public-key",
      alg: -7
    }
  ]
};

navigator.credentials.create({ publicKey })
  .then(function (newCredentialInfo) {
    // send attestation response and client extensions
    // to the server to proceed with the registration
    // of the credential
  }).catch(function (err) {
     console.error(err);
  });

• AuthenticatorAttestationResponse.attestationObject