PublicKeyCredentialRequestOptions.challenge

Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

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.

Note: When the credential is created with a navigator.credentials.create() call, the signature of the challenge is contained within AuthenticatorAttestationResponse.attestationObject.

Note: A challenge will be at least 16 bytes long.

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

Specification Status Comment
Web Authentication: An API for accessing Public Key Credentials Level 1
The definition of 'challenge' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
challenge
Experimental
Chrome Full support 67Edge ? Firefox Full support 60IE ? Opera Full support YesSafari ? WebView Android ? Chrome Android ? Edge Mobile ? Firefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also

Document Tags and Contributors

Contributors to this page: mdnwebdocs-bot, SphinxKnight
Last updated by: mdnwebdocs-bot,