Web/API/AuthenticatorAssertionResponse/signature

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

The signature read-only property of the AuthenticatorAssertionResponse interface is an ArrayBuffer object which is the signature of the authenticator for both AuthenticatorAssertionResponse.authenticatorData and a SHA-256 hash of the client data (AuthenticatorAssertionResponse.clientDataJSON).

This signature will be sent to the server for control, as part of the response. It provides the proof that an authenticator does possess the private key which was used for the credential's generation.

Note: An AuthenticatorAssertionResponse instance is available on PublicKeyCredential.response after calling navigator.credentials.get().

Note: This property may only be used in top-level contexts and will not be available in an <iframe> for example.

Syntax

signature = authenticatorAssertionResponse.signature

Value

An ArrayBuffer object which the signature of the authenticator (using its private key) for both AuthenticatorAssertionResponse.authenticatorData and a SHA-256 hash given by the client for its data (the challenge, the origin, etc. and available from AuthenticatorAssertionResponse.clientDataJSON).

Examples

var options = {
  challenge: new Uint8Array(26), // will be another value, provided by the relying party server
  timeout: 60000
};

navigator.credentials.get({  publickey: options })
  .then(function (assertionPKCred) {
    var signature = assertionPKCred.response.signature;

    // Send response and client extensions to the server so that it can
    // go on with the authentication
    
}).catch(function (err) {
   console.error(err);
});

Specifications

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

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`signature`	Chrome Full support 67 Full support 67 Full support 65 Notes' Disabled' Notes' Only supports USB U2F tokens. Disabled' From version 65: this feature is behind the `Web Authentication API` preference (needs to be set to `Enabled`). To change preferences in Chrome, visit chrome://flags.	Edge Full support 18	Firefox Full support 60 Notes' Full support 60 Notes' Notes' Only supports USB U2F tokens.	IE No support No	Opera No support No	Safari Full support 13	WebView Android Full support 70	Chrome Android Full support 70	Firefox Android Full support 60 Notes' Full support 60 Notes' Notes' Only supports USB U2F tokens.	Opera Android No support No	Safari iOS Full support 13.3	Samsung Internet Android No support No

Legend

Full support: Full support
No support: No support
See implementation notes.': See implementation notes.
User must explicitly enable this feature.': User must explicitly enable this feature.

AuthenticatorAssertionResponse.signature by Mozilla Contributors is licensed under CC-BY-SA 2.5.