Application Passwords: Integration Guide

WordPress 5.6 will finally see the introduction of a new system for making authenticated requests to various WordPress APIs — Application Passwords.

The existing cookie-based authentication system is not being removed, and any custom authentication solutions provided by plugins should continue to operate normally.

For any sites using the Application Passwords feature plugin, it is recommended to deactivate the pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party after upgrading to WordPress 5.6. However, sites won’t experience any errors if the plugin remains active. The current plan is to use the plugin for future prototyping.

Application Password Format

Application Passwords are 24-characters long, generated by wp_generate_password() without the use of special characters — so they consist exclusively of upper-case, lower-case, and numeric characters. For the cryptographically curious, that comes to over 142 bits of entropy.

When presented to the user for entering into an application, they are displayed chunked for ease of use, like so:

abcd EFGH 1234 ijkl MNOP 6789

Application passwords can be used with or without the spaces — if included, spaces will just be stripped out before the password is hashed and verified.

Data Store

WordPress will be storing a user’s application passwords as an array in user metaMeta Meta is a term that refers to the inside workings of a group. For us, this is the team that works on internal WordPress sites like WordCamp Central and Make WordPress., similar to how interactive login sessions (via WP_Session_Tokens) are stored already.

The WP_Application_Passwords class has all the methods for storing and retrieving records. Records include a number of attributes about them — including assigned name for the application, a timestamp for when it was created, and data on their last usage such as, date and IP address. Each application password is also assigned a uuid for reference, in case you’d like to build infrastructure for additional properties and store them in an alternate location.

Getting Credentials

Generating Manually

From the Edit User page, you can generate new, and view or revoke existing application passwords. The form and the list table are both fully extensibleExtensible This is the ability to add additional functionality to the code. Plugins extend the WordPress core software. to allow for overloading to store additional data (more on this later, in “Authentication Scoping”).

Once a given password has been used, it will keep track of where and when it has been used – the “Last Used” column is accurate to within 24 hours (so that WordPress isn’t writing to the database on every usage — only if it’s a new day). This can be incredibly useful for identifying passwords that are no longer in use, so that they can be safely revoked.

Authorization Flow

To ensure that application password functionality is available, fire off a request to the REST APIREST API The REST API is an acronym for the RESTful Application Program Interface (API) that uses HTTP requests to GET, PUT, POST and DELETE data. It is how the front end of an application (think “phone app” or “website”) can communicate with the data store (think “database” or “file system”) https://developer.wordpress.org/rest-api/. root URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org, and look at the authentication key in the response data. If this key is empty, then application passwords are not available (perhaps because the request is not over https:// or it has been intentionally disabled).

If, however, response.authentication is an object with a key of application-passwords it will offer a URL to send a user to complete the authentication flow. (You could just guess at the URL, but this gives us more of the relevant information in one go, as well as confirming that application passwords are available and enabled.)

The response.authentication['application-passwords'].endpoints.authorization url will likely look something like this:

https://example.com/wp-admin/authorize-application.php

Instead of just sending the user there to generate an application password, it would then be up to the user to reliably re-enter it into your application. So instead, some additional GET parameters are accepted along with the request:

• app_name (required) – The human readable identifier for your app. This will be the name of the generated application password, so structure it like … “WordPress Mobile App on iPhone 12” for uniqueness between multiple versions.
  Whatever name you suggest can be edited by the user if they choose before the application is created. While you can choose to not pre-populate it for the user, it is required to create a password, so they will then be forced to create their own, and could select a non-intuitive option.
• app_id (recommended) – a UUID formatted identifier. The app_id allows for identifying instances of your application, it has no special meaning in and of itself. As a developer, you can use the app_id to locate all Application Passwords created for your application.
  In the event of a data breach, your app_id could be distributed to void credentials generated with it, or if a site wants to allow only a given app_id or set of app_ids to register, this would enable that. However, it is strictly on the honor system — there is nothing to stop applications from generating new uuids with every authorization.
• success_url (recommended) – The URL that you’d like the user to be sent to if they approve the connection. Three GET variables will be appended when they are passed back (site_url, user_login, and password); these credentials can then be used for APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. calls.
  If the success_url variable is omitted, a password will be generated and displayed to the user instead, to manually enter into their application.
• reject_url (optional) – If included, the user will get sent there if they reject the connection. If omitted, the user will be sent to the success_url, with ?success=false appended to the end.
  If the success_url is omitted, the user just will be sent to their WordPress dashboard.

As the parameters are all passed in via GET variables, if the user needs to log in first, they will all be preserved through the redirect parameter, so the user can then continue with authorization.

It is also worth noting that the success_url and redirect_url parameters will generate an error if they use a http:// rather than https:// protocol — however other application protocols are acceptable! So if you have a myapp:// link that opens your Android, iOS / MacOS, or Windows — those will work!

Here is an example of a simple javascript application (under 100 lines of code) that uses this to authenticate to a WordPress site. Though not the tidiest code, it was created in under two hours one evening, but it goes through the proper flows and can make authenticated requests.

Programmatically through the REST API

If you have previously been using a different system to access the REST API and would prefer to switch over to using application passwords, it’s easy! You can generate yourself a new application password via a POST request to the new /wp/v2/users/me/application-passwords endpoint. Once you’ve got the new application password in the response data, you can delete any old credentials and just use the coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. implementation instead — but please consider using something like libsodium (which has a library bundled with WordPress already — here’s an implementation example) or Vault to store the credentials encrypted, rather than in plaintext.

Using Credentials

REST API

The credentials can be passed along to REST API requests served over https:// using Basic Auth / RFC 7617, which is nearly ubiquitous in its availability — here’s the documentation for how to use it with cURL.

For a simple command-line script example, just swap out USERNAME, PASSWORD, and HOSTNAME in this with their respective values:

curl --user "USERNAME:PASSWORD" https://HOSTNAME/wp-json/wp/v2/users?context=edit

XML-RPC API

To use a generated application password with the legacy XML-RPC API, you can just use it directly in lieu of the account’s real password.

For a simple command-line script example, again just swap out USERNAME, PASSWORD, and HOSTNAME in this with their respective values:

curl -H 'Content-Type: text/xml' -d '<methodCall><methodName>wp.getUsers</methodName><params><param><value>1</value></param><param><value>USERNAME</value></param><param><value>PASSWORD</value></param></params></methodCall>' https://HOSTNAME/xmlrpc.php

Future 🔮 APIs

The application passwords authentication scheme can also be applied to future APIs for WordPress as they become available. For example, if GraphQL or other systems are enabled in WordPress, application passwords will provide them with a solid, established authentication infrastructure to build off of out of the box.

As an example of this, with a trivial code addition identifying whether the current load is an api request, WPGraphQL will now be able to accept authenticated requests without the need of an ancillary plugin, using just the application passwords functionality that has merged into core.

Using an Application Password on wp-login.php

You can’t. 😅 The point of application passwords are that they are to be used programmatically for applications, and not by humans for interactive sessions.

Feature Availability

By default, Application Passwords is available to all users on sites served over SSLSSL Secure Sockets Layer. Provides a secure means of sending data over the internet. Used for authenticated and private actions./HTTPSHTTPS HTTPS is an acronym for Hyper Text Transfer Protocol Secure. HTTPS is the secure version of HTTP, the protocol over which data is sent between your browser and the website that you are connected to. The 'S' at the end of HTTPS stands for 'Secure'. It means all communications between your browser and the website are encrypted. This is especially helpful for protecting sensitive data like banking information.. This can be customized using the wp_is_application_passwords_available and wp_is_application_passwords_available_for_user filters.

For example, to completely disable Application Passwords add the following code snippet to your site.

add_filter( 'wp_is_application_passwords_available', '__return_false' );

Without SSL, it is possible for the Application Password to be seen by an attacker on your networknetwork (versus site, blog) or the network between your site and the authorized application. If you are ok with this risk, you can force availability with the following code snippet.

add_filter( 'wp_is_application_passwords_available', '__return_true' );

If desired, it is possible to restrict what users on your site can use the Application Passwords feature. For example, to restrict usage to administrator users, use the following code snippet.

function my_prefix_customize_app_password_availability(
	$available,
	$user
) {
	if ( ! user_can( $user, 'manage_options' ) ) {
		$available = false;
	}

	return $available;
}

add_filter(
	'wp_is_application_passwords_available_for_user',
	'my_prefix_customize_app_password_availability',
	10,
	2
);

Future Development

Authentication Scoping

In future versions, the expectation is to include the ability to scope a given application password to limit its access. The intention is to work on building this in plugin-land until it’s ready for a core proposal.

What might password scoping look like? Here’s some methods being considered:

• In a multisitemultisite Used to describe a WordPress installation with a network of multiple blogs, grouped by sites. This installation type has shared users tables, and creates separate database tables for each blog (wp_posts becomes wp_0_posts). See also network, blog, site environment, either restrict the credentials to a subset of the user’s blogs, or restrict it to only operate in a normal “blogblog (versus network, site) adminadmin (and super admin)” context, and not a “network admin” context.
• Restrict functionality to only manage content — posts, pages, comments, custom post types — and disallow infrastructure management functionality like managing plugins, themes, and users.
• Restrict the role that credentials can allow an application to operate as. For example, an Editor may restrict a set of credentials to only operate as though they had Author or Contributor permissions.

However this is done, implementing additional functionality to enforce the principle of least privilege on an application-by-application basis is a worthwhile expansion on the included functionality.

Fine-grained Capabilities

Right now, a user’s application passwords can be managed by any user who has permission to edit_user them. The ability to customize this behavior using a new set of more fine-grained capabilities is currently planned for 5.7.

Eventually Two-Factor Authentication?

Another useful bit of application passwords is that it will removes an obstacle for the inclusion of multi-factor authentication on interactive logins.

Previously, if you enabled an interactive step — whether captcha or second factor validation — on login pages, you would be in a bind with other non-interactive authentications, for example the legacy XML-RPC system. After all, if a bad actor can just brute force or use social engineering to discern the user’s password, it would be trivially usable via XML-RPC, where there is no ability to include an interactive prompt, and that functionality would need to be disabled entirely.

With that use case now being provided for via application passwords, there is additional flexibility for the normal browser-based wp-login.php system to evolve.

Further Resources

• Core Ticketticket Created for both bug reports and feature development on the bug tracker.: #42790
• Merge Proposal
• Example Client
• Feature Plugin. Further development of App Passwords will be prototyped in this repo.

For bugbug A bug is an error or unexpected result. Performance improvements, code optimization, and are considered enhancements, not defects. After feature freeze, only bugs are dealt with, with regressions (adverse changes from the previous version) being the highest priority. reports or enhancements, open a Trac ticket in the new App Passwords component with the rest-api focus.

Props @timothyblynjacobs, @m_butcher, @desrosj, @jeffmatson, for helping to write, review, and proofread.

#5-6, #application-passwords, #authentication, #core-passwords, #dev-notes, #rest-api, #two-factor