Secure contextThis feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The clientDataJSON
property of the AuthenticatorResponse
interface stores a [[../../../../Learn/JavaScript/Objects/JSON|JSON]] string in an ArrayBuffer
, representing the client data that was passed to CredentialsContainer.create()
or CredentialsContainer.get()
. This property is only accessed on one of the child objects of AuthenticatorResponse
, specifically AuthenticatorAttestationResponse
or AuthenticatorAssertionResponse
.
Syntax
var arrayBuffer = AuthenticatorAttestationResponse.clientDataJSON; var arrayBuffer = AuthenticatorAssertionResponse.clientDataJSON;
Value
An ArrayBuffer
.
Properties
After the clientDataJSON
object is converted from an ArrayBuffer
to a JavaScript object, it will have the following properties:
type
- A string which is either
"webauthn.get"
when an existing credential is retrieved or"webauthn.create"
when a new credential is created. challenge
- The base64url encoded version of the cryptographic challenge sent from the relying party's server. The original value is passed via
PublicKeyCredentialRequestOptions.challenge
orPublicKeyCredentialCreationOptions.challenge
. origin
- The fully qualified origin of the requester which has been given by the client/browser to the authenticator. We should expect the relying party's id to be a suffix of this value.
tokenBindingId
OptionalAn object describing the state of the token binding protocol for the communication with the relying party. It has two properties:
status
: A string which is either"supported"
which indicates the client support token binding but did not negotiate with the relying party or"present"
when token binding was used alreadyid
: ADOMString
which is the base64url encoding of the token binding ID which was used for the communication.
Should this property be absent, it would indicate that the client does not support token binding.
Examples
function arrayBufferToStr(buf) {
return String.fromCharCode.apply(null, new Uint8Array(buf));
}
// pk is a PublicKeyCredential that is the result of a create() or get() Promise
var clientDataStr = arrayBufferToStr(pk.clientDataJSON);
var clientDataObj = JSON.parse(clientDataStr);
console.log(clientDataObj.type); // "webauthn.create" or "webauthn.get"
console.log(clientDataObj.challenge); // base64 encoded String containing the original challenge
console.log(clientDataObj.origin); // the window.origin
Specifications
Specification | Status | Comment |
Web Authentication: An API for accessing Public Key Credentials Level 1The definition of 'clientDataJSON' in that specification. | Recommendation | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
clientDataJSON
|
Chrome Full support 67 Full support 67 Full support 65 Notes' Only supports USB U2F tokens.
Disabled' From version 65: this feature is behind the |
Edge
Full support 18 |
Firefox Full support 60 Full support 60 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 Full support 60 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.
AuthenticatorResponse.clientDataJSON by Mozilla Contributors is licensed under CC-BY-SA 2.5.