PublicKeyCredentialRequestOptions.challenge

The challenge property of the PublicKeyCredentialRequestOptions dictionary is a BufferSource used as a cryptographic challenge. This is randomly generated then sent from the relying party's server. This value (among other client data) will be signed by the authenticator's private key and produce AuthenticatorAssertionResponse.signature which should be sent back to the server as part of the response.

Syntax

challenge = publicKeyCredentialRequestOptions.challenge

Value

A BufferSource which is at least 16 bytes long. Contains a cryptographic challenge emitted from the relying party's server which must be signed by the authenticator's private key and sent back (within the response) to the relying party's server for verification.

Examples

var options = {
  challenge: new Uint8Array([/* bytes sent from the server */])
};

navigator.credentials.get({ "publicKey": options })
    .then(function (credentialInfoAssertion) {
    // send assertion response back to the server
    // to proceed with the control of the credential
}).catch(function (err) {
     console.error(err);
});

Specifications

Browser compatibility

See also

• AuthenticatorAssertionResponse.signature which is produced using the challenge and the private key of the authenticator when fetching a credential.
• PublicKeyCredentialCreationOptions.challenge, the analogous option property used when creating a credential.
• AuthenticatorAttestationResponse.attestationObject which contains the signature of the challenge within its attStmt property when creating a credential.