webRequest.onAuthRequired
Fired when the server sends a 401
or 407
status code and a WWW-Authenticate
header using the Basic
scheme (that is, when the server is asking the client to provide authentication credentials, such as a username and password).
The listener can respond in one of four different ways:
- Take no action
-
The listener can do nothing, just observing the request. If this happens, it will have no effect on the handling of the request, and the browser will probably just ask the user to log in.
- Cancel the request
-
The listener can cancel the request. If they do this, then authentication will fail, and the user will not be asked to log in. Extensions can cancel requests as follows:
- in addListener, pass
"blocking"
in theextraInfoSpec
parameter - in the listener itself, return an object with a
cancel
property set totrue
- in addListener, pass
- Provide credentials synchronously
-
If credentials are available synchronously, the extension can supply them synchronously. If the extension does this, then the browser will attempt to log in with the given credentials. The listener can provide credentials synchronously as follows:
- in addListener, pass
"blocking"
in theextraInfoSpec
parameter - in the listener, return an object with an
authCredentials
property set to the credentials to supply
- in addListener, pass
- Provide credentials asynchronously
-
The extension might need to fetch credentials asynchronously. For example, the extension might need to fetch credentials from storage, or ask the user. In this case, the listener can supply credentials asynchronously as follows:
- in addListener, pass
"blocking"
in theextraInfoSpec
parameter - in the listener, return a
Promise
that is resolved with an object containing anauthCredentials
property, set to the credentials to supply
- in addListener, pass
See Examples.
If you use "blocking"
you must have the "webRequestBlocking" API permission in your manifest.json
.
If your extension provides bad credentials, then the listener will be called again. For this reason, take care not to enter an infinite loop by repeatedly providing bad credentials.
Proxy authorization
In general, Firefox does not fire webRequest
events for system requests, such as browser or extension upgrades, or search engine queries. To enable proxy authorization to work smoothly for system requests, from version 57 Firefox implements an exception to this.
If an extension has the "webRequest"
, "webRequestBlocking"
, "proxy"
, and "<all_urls>"
permissions, then it will be able to use onAuthRequired
to supply credentials for proxy authorization (but not for normal web authorization). The listener will not be able to cancel system requests or make any other modifications to any system requests.
Syntax
js
browser.webRequest.onAuthRequired.addListener(
listener, // function
filter, // object
extraInfoSpec // optional array of strings
)
browser.webRequest.onAuthRequired.removeListener(listener)
browser.webRequest.onAuthRequired.hasListener(listener)
Events have three functions:
addListener(listener, filter, extraInfoSpec)
-
Adds a listener to this event.
removeListener(listener)
-
Stop listening to this event. The
listener
argument is the listener to remove. hasListener(listener)
-
Check whether
listener
is registered for this event. Returnstrue
if it is listening,false
otherwise.
addListener syntax
Parameters
listener
-
The function called when this event occurs. The function is passed these arguments:
details
-
object
. Details about the request. See the details section for more information.
Returns:
webRequest.BlockingResponse
or aPromise
.- To handle the request synchronously, include
"blocking"
in theextraInfoSpec
parameter and return aBlockingResponse
object, with itscancel
or itsauthCredentials
properties set. - To handle the request asynchronously, include
"blocking"
in theextraInfoSpec
parameter and return aPromise
that is resolved with aBlockingResponse
object, with itscancel
or itsauthCredentials
properties set.
filter
-
webRequest.RequestFilter
. A filter that restricts the events that is sent to this listener. extraInfoSpec
Optional-
array
ofstring
. Extra options for the event. You can pass any of the following values:"blocking"
: make the request block, so you can cancel the request or supply authentication credentials"responseHeaders"
: includeresponseHeaders
in thedetails
object passed to the listener
Additional objects
details
challenger
-
object
. The server requesting authentication. This is an object with the following properties:host
-
string
. The server's hostname. port
-
integer
. The server's port number.
-
string
. If the request is from a tab open in a contextual identity, the cookie store ID of the contextual identity. frameId
-
integer
. This is0
if the request happens in the main frame; a positive value is the ID of a subframe in which the request happens. If the document of a (sub-)frame is loaded (type
ismain_frame
orsub_frame
),frameId
indicates the ID of this frame, not the ID of the outer frame. Frame IDs are unique within a tab. incognito
-
boolean
. Whether the request is from a private browsing window. isProxy
-
boolean
.true
forProxy-Authenticate
,false
forWWW-Authenticate
.Note:
webRequest.onAuthRequired
is only called for HTTP and HTTPS/SSL proxy servers requiring authentication, and not for SOCKS proxy servers requiring authentication. method
-
string
. Standard HTTP method (For example,"GET"
or"POST"
). parentFrameId
-
integer
. ID of the frame that contains the frame which sent the request. Set to-1
if no parent frame exists. proxyInfo
-
object
. This property is present only if the request is being proxied. It contains the following properties:host
-
string
. The hostname of the proxy server. port
-
integer
. The port number of the proxy server. type
-
string
. The type of proxy server. One of:"http"
: HTTP proxy (or SSL CONNECT for HTTPS)"https"
: HTTP proxying over TLS connection to proxy"socks"
: SOCKS v5 proxy"socks4"
: SOCKS v4 proxy"direct"
: no proxy"unknown"
: unknown proxy
username
-
string
. Username for the proxy service. proxyDNS
-
boolean
. True if the proxy will perform domain name resolution based on the hostname supplied, meaning that the client should not do its own DNS lookup. failoverTimeout
-
integer
. Failover timeout in seconds. If the connection fails to connect the proxy server after this number of seconds, the next proxy server in the array returned from FindProxyForURL() will be used.
realm
Optional-
string
. The authentication realm provided by the server, if there is one. requestId
-
string
. The ID of the request. Request IDs are unique within a browser session, so you can use them to relate different events associated with the same request. responseHeaders
Optional-
webRequest.HttpHeaders
. The HTTP response headers that were received along with this response. scheme
-
string
. The authentication scheme:"basic"
or"digest
". statusCode
-
integer
. Standard HTTP status code returned by the server. statusLine
-
string
. HTTP status line of the response or the'HTTP/0.9 200 OK'
string for HTTP/0.9 responses (i.e., responses that lack a status line) or an empty string if there are no headers. tabId
-
integer
. ID of the tab in which the request takes place. Set to-1
if the request isn't related to a tab. thirdParty
-
boolean
. Indicates whether the request and its content window hierarchy are third party. timeStamp
-
number
. The time when this event fired, in milliseconds since the epoch. type
-
webRequest.ResourceType
. The type of resource being requested: for example,"image"
,"script"
,"stylesheet"
. url
-
string
. Target of the request. urlClassification
-
object
. The type of tracking associated with the request, if with the request has been classified by Firefox Tracking Protection. This is an object with the following properties:firstParty
-
array
ofstrings
. Classification flags for the request's first party. thirdParty
-
array
ofstrings
. Classification flags for the request or its window hierarchy's third parties.
The classification flags include:
fingerprinting
andfingerprinting_content
: indicates the request is involved in fingerprinting.fingerprinting_content
indicates the request is loaded from an origin that has been found to fingerprint but is not considered to participate in tracking, such as a payment provider.cryptomining
andcryptomining_content
: similar to the fingerprinting category but for cryptomining resources.tracking
,tracking_ad
,tracking_analytics
,tracking_social
, andtracking_content
: indicates the request is involved in tracking.tracking
is any generic tracking request, thead
,analytics
,social
, andcontent
suffixes identify the type of tracker.any_basic_tracking
: a meta flag that combines any tracking and fingerprinting flags, excludingtracking_content
andfingerprinting_content
.any_strict_tracking
: a meta flag that combines any tracking and fingerprinting flags, includingtracking_content
andfingerprinting_content
.any_social_tracking
: a meta flag that combines any social tracking flags.
Browser compatibility
BCD tables only load in the browser
Examples
This code just observes authentication requests for the target URL:
js
const target = "https://intranet.company.com/";
function observe(requestDetails) {
console.log(`observing: ${requestDetails.requestId}`);
}
browser.webRequest.onAuthRequired.addListener(
observe,
{urls: [target]}
);
This code cancels authentication requests for the target URL:
js
const target = "https://intranet.company.com/";
function cancel(requestDetails) {
console.log(`canceling: ${requestDetails.requestId}`);
return {cancel: true};
}
browser.webRequest.onAuthRequired.addListener(
cancel,
{urls: [target]},
["blocking"]
);
This code supplies credentials synchronously. It has to keep track of outstanding requests, to ensure that it doesn't repeatedly try to submit bad credentials:
js
const target = "https://intranet.company.com/";
const myCredentials = {
username: "me@company.com",
password: "zDR$ERHGDFy"
}
const pendingRequests = [];
// A request has completed.
// We can stop worrying about it.
function completed(requestDetails) {
console.log(`completed: ${requestDetails.requestId}`);
let index = pendingRequests.indexOf(requestDetails.requestId);
if (index > -1) {
pendingRequests.splice(index, 1);
}
}
function provideCredentialsSync(requestDetails) {
// If we have seen this request before, then
// assume our credentials were bad, and give up.
if (pendingRequests.includes(requestDetails.requestId)) {
console.log(`bad credentials for: ${requestDetails.requestId}`);
return {cancel:true};
}
pendingRequests.push(requestDetails.requestId);
console.log(`providing credentials for: ${requestDetails.requestId}`);
return {authCredentials: myCredentials};
}
browser.webRequest.onAuthRequired.addListener(
provideCredentialsSync,
{urls: [target]},
["blocking"]
);
browser.webRequest.onCompleted.addListener(
completed,
{urls: [target]}
);
browser.webRequest.onErrorOccurred.addListener(
completed,
{urls: [target]}
);
This code supplies credentials asynchronously, fetching them from storage. It also has to keep track of outstanding requests, to ensure that it doesn't repeatedly try to submit bad credentials:
js
const target = "https://httpbin.org/basic-auth/*";
const pendingRequests = [];
/*
* A request has completed. We can stop worrying about it.
*/
function completed(requestDetails) {
console.log(`completed: ${requestDetails.requestId}`);
let index = pendingRequests.indexOf(requestDetails.requestId);
if (index > -1) {
pendingRequests.splice(index, 1);
}
}
function provideCredentialsAsync(requestDetails) {
// If we have seen this request before,
// then assume our credentials were bad,
// and give up.
if (pendingRequests.includes(requestDetails.requestId)) {
console.log(`bad credentials for: ${requestDetails.requestId}`);
return {cancel: true};
} else {
pendingRequests.push(requestDetails.requestId);
console.log(`providing credentials for: ${requestDetails.requestId}`);
// we can return a promise that will be resolved
// with the stored credentials
return browser.storage.local.get(null);
}
}
browser.webRequest.onAuthRequired.addListener(
provideCredentialsAsync,
{urls: [target]},
["blocking"]
);
browser.webRequest.onCompleted.addListener(
completed,
{urls: [target]}
);
browser.webRequest.onErrorOccurred.addListener(
completed,
{urls: [target]}
);
Example extensions
Note: This API is based on Chromium's chrome.webRequest
API. This documentation is derived from web_request.json
in the Chromium code.