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”).

The Application Passwords section of Edit User screen, after a new application password has been created.
The Edit User screen, after a new application password has been created.

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.
A screenshot of the new Authorize Application screen in the WP-Admin. A button is displayed to approve the connection, and one to reject the connection.
A screenshot of what the authorization flow will look like to a user.

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 Windowsthose 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 alreadyhere’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

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

Proposal: REST API Authentication / Application Passwords

Problem statement: no way to authenticate third-party access to 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/.

Ever since the REST API infrastructure merged via #33982 and shipped in WordPress 4.4 in December 2015, it’s been gaining momentum and been used in more and more places—throughout WordPress’s adminadmin (and super admin), via plugins and themes, and enabled deep, robust interactions powering new functionality such as the GutenbergGutenberg The Gutenberg project is the new Editor Interface for WordPress. The editor improves the process and experience of creating new content, making writing rich content much simpler. It uses ‘blocks’ to add richness rather than shortcodes, custom HTML etc. https://wordpress.org/gutenberg/ blockBlock Block is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage using the WordPress editor. The idea combines concepts of what in the past may have achieved with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience. editor.

However, the functionality has been limited in that the only way to make authenticated requests to the 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. in coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. has been through Cookie & Nonce-based authentication—there is no good way for third-party applications to communicate with WordPress in an authenticated fashion, apart from the legacy XML-RPC API.

This has resulted in frustration for our Mobile teams especially as they’re working to integrate Gutenberg support, which relies on the REST API. After some time having to store username/password to spoof a cookie and interactive session to scrape a nonce from the wp-admin DOM, and then to use an endpoint to get it instead via [46253]. All of which is a tremendously messy and awkward usage that completely falls apart if someone uses a variant of a two-factor authentication system.

Spoofing an interactive session just to make API requests is bad form and needlessly complex.

We’d like to propose integrating Application Passwords into Core.

There have been many systems considered, including everything from multiple incarnations of OAuth, JWT, and even some solutions that are combinations of the two. Some called for a centralized app repository, some had open registration, but all were complex and none of them could build sufficient traction to come to fruition.

Broad conceptual overview of varying methods (See: WP-API/authentication#15)

A simpler alternative to Application Passwords is pure Basic Authentication and detailed in #42790. However, Application Passwords is more comprehensive, and a far superior of a choice for the reasons that follow.

Benefit: Ease of API Requests

Given a login and an application password, making an API request is as simple as

curl --user "USERNAME:APPLICATION_PASSWORD" -X POST -d "title=New Title" https://my.wordpress.site/wp-json/wp/v2/posts/POST_ID

It uses the standard HTTPHTTP HTTP is an acronym for Hyper Text Transfer Protocol. HTTP is the underlying protocol used by the World Wide Web and this protocol defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. authorization headers. Everything supports this trivially.

Benefit: Ease of Revoking Credentials

Application Passwords makes it easy to revoke any individual application password, or wholesale void all of a user’s application passwords. Application Passwords also lists the date a password was last used and the IP it was used from to help track down inactive credentials or bad actors using them from unexpected locations.

Benefit: Ease of Requesting API Credentials

While it is possible for a user to go to their user profile page and generate a new application password, for example if they are creating a command line tool for themselves, the ideal workflow looks something like this:

To request a password for your application, redirect users to:

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

The URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org is included in the REST API index to facilitate automated discovery.

{
  "name": "Trunk",
  "authentication": {
    "application-passwords": {
      "endpoints": {
        "authorization": "http://example.com/wp-admin/authorize-application.php"
      }
    }
  }
}

and use the following GET request parameters to specify:

  • 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. If omitted, the user will be required to provide an application name.
  • success_url (recommended) – The URL that you’d like the user to be sent to if they approve the connection. Two GET variables will be appended when they are passed back (user_login and password); these credentials can then be used for API calls. If the success_url variable is omitted, a password will be generated and displayed to the user, to manually enter into your 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 will be sent to their WordPress dashboard.

If the user is logged out, they’ll be redirected to the WordPress Login page. After logging in, they’ll be immediately redirected back to the Authorize Application screen.

In discussions with @timothyblynjacobs we’re unsure about whether to add a state parameter (which is just stored and passed back to the application to prevent CSRF attacks). Realistically apps could just include it on their own in the success_url or a site_url parameter (which could remind the application what site the returned credentials are for). Requiring apps to pass a state parameter could encourage best practices, but we wouldn’t be able to enforce that they validate its contents.

It’s also worth noting that the success_url and reject_url are both explicitly designed that apps can pass in custom protocols for the return URLs. That is, they could set them to be wordpress://authentication so that the user’s phone automatically redirects them back from their web browser, directly into the application with the credentials appended to the query. You may have seen this previously with other applications where you “Login with Facebook” in your browser and then Facebook sends you directly back into your app. Or with how your web browser can open Zoom directly on your laptop, pre-populating the room ID and password.

Benefit: Login Security

Unlike pure basic auth that requires entering in credentials directly into the application, Application Passwords allows for an interactive authentication flow. This means that login security features like Two Factor or reCAPTCHA can continue to protect user accounts.

One of the reasons XML-RPC is so often recommended to be disabled is that it allows brute forcing user’s passwords since those additional security protections can’t be implemented. A risk of implementing pure basic auth is that sites will be forced to disable it because it can’t be interactive.

Proposed solution: merge Application Passwords to core

While there is a standalone plugin for Application Passwords that’s developed in a GitHub repo, PR#540 to WordPress-develop is the official work we’re proposing to be merged into core. The pull request is based off of the original feature pluginFeature Plugin A plugin that was created with the intention of eventually being proposed for inclusion in WordPress Core. See Features as Plugins.’s codebase. We welcome comments on this proposal post, contributions to Application Passwords itself, and even more so review and feedback on the existing merge proposal pull request.

Props to @timothyblynjacobs for help on the content of this post, @jeffpaul for help on the structure of this post, and the many many people who have contributed to the analysis behind this proposal and to Application Passwords.

#application-passwords, #authentication, #rest-api, #two-factor

REST API Authentication

On Thursday of last week, we had an Authentication chat in #core-passwords — truth be told, the discussion spilled over into Friday and a bit on Saturday as well. I delayed posting this summary a bit to make sure there wasn’t anything else about to be said that I’d miss.

Spoiler alert: we didn’t decide anything conclusively, it was more brainstorming and voicing possibilities.

Also worth noting is that we place equal weight on the user experience of the authentication system as we do on the security when evaluating it for coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress.. That isn’t to say that we value the security any less, but rather that we also view the UXUX User experience as critical to nail down as well, and is likely easier to suss out problems earlier on in casual conversation than evaluating the eccentricities of crypto. So if some of the discussion tended more towards UX considerations than Security considerations, be aware that both are critical, we were just tending to evaluate the UX first, as it’s an easy litmus test for whether a particular method is worth pursuing, and more easily understood by more people than the intricacies of replay attacks and the sort.

There were two major areas of discourse that were addressed: Authentication Scheme, and Authentication Scope.

Authentication Scheme

The scheme would be one of several possibilities, such as OAuth 1.0a, OAuth 2, Application Passwords sent as Basic Authentication, or some other either ad-hoc or previously unconsidered system.

There are assorted concerns with various systems:

  • 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. — WordPress cannot guarantee that the site will be hosted on a HTTPS infastructure, and as such, any 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. tokens passed along with the request could potentially be sniffed in transit. However, if the site doesn’t have HTTPS available, the same thing happens on every page you view already with your authentication cookies. The major difference being that cookies become invalidated on logout or expiration, so cookie thieves have a smaller window to exploit the stolen authentication than tokens that are valid until revoked.
  • OAuth Application Registration — The user experience flow for OAuth can be particularly tricky. Imagine it: You’ve just installed an app on your phone, and you want to link it to your user account on your WordPress site. Your steps are as follows: Log in to your WordPress site, Create an AppID for the phone app, give the phone app it’s Secret tokens. Now from the Phone app, you click a button to go back to your site and approve the link to your user in the application and exchange user access tokens. That is a /lot/ of back and forth-ing. It could be simplified somewhat if there was some sort of central repository for all WordPress sites that apps could register at, and then .org sites could dynamically pull down public keys for applications that they can use to verify the secrets in the apps, but that then becomes a significant amount of overhead for the construction and maintenance of the application ‘clearing house’ and it’s been clarified that it is not something that WordPress.orgWordPress.org The community site where WordPress code is created and shared by the users. This is where you can download the source code for WordPress core, plugins and themes as well as the central location for community conversations and organization. https://wordpress.org/ (the website) is up to build or host. Long story short: this UX flow is so confusing that it really feels much more like 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 territory at its current iteration.

Probably some other points I’m missing, but those felt like the major two.

Authentication Scope

The second issue at hand is one of Authentication Scope. That is, when an application authenticates, what functionality is it permitted to do?

This is significantly different from user capabilities. We had discussed an extra field when auth’ing applications where you could ‘downgrade’ your user role for that application’s API requests (that is, if you’re an Administrator, you could only give an application Author capabilties), but that doesn’t really solve the issue — as every user role has the ability to — for example — update their password or email address. And if an application can do that, then that’s the ballgame, and they can log in to wp-adminadmin (and super admin) as you and do whatever they like.

We also talked about perhaps just disallowing certain functionality from ever being used as a part of 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/.. However, with the rise of third-party site management applications, such as Calypso, or if other programs like ManageWP or InfiniteWP or whatever the other half dozen ones are wants to truly manage your site, they’ll need access to that functionality. After all, what’s the point of aiming at eventually achieving REST API parity with the wp-admin experience if it can’t be used anywhere outside of wp-admin?

The solution we seemed to be leaning towards is a ‘two-tiered’ scope system. That is, provide a default ‘content’ tier — akin to the functionality of the legacy XML-RPC API — that can support writing and updating posts, taxonomies, comments and the like (and any custom endpoints that are explicitly opted in to the limited tier), and a second ‘full control’ tier that allows access to everything — plugins, themes, users, what have you. The second tier would be suited for full control applications like Calypso or remote management tools, whereas the first more limited tier would be more than adequate for the functionality in the legacy WordPress mobile apps, or blogging applications like Desk or Microsoft Word integration. It’s simple enough for users to understand, and technologically could be passed in via the `$args` array to `register_rest_route()` whether an endpoint should be available or not.

Still with us? Thanks for slogging through a somewhat lengthy summary, we’d love to hear your thoughts below on anything you think we missed or didn’t consider sufficiently in depth.

If anyone would like to read the full discussion, it starts here in the Slack logs: https://wordpress.slack.com/archives/core-passwords/p1455832859000040

#application-passwords, #authentication, #rest-api, #two-factor

API Authentication discussion!

I was chatting with @rmccue and we though it’d be a good decision to have an open discussion regarding potential avenues 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. Authentication on Thursday, February 18th at 22:00 UTC in the #core-passwords channel in SlackSlack Slack is a Collaborative Group Chat Platform https://slack.com/. The WordPress community has its own Slack Channel at https://make.wordpress.org/chat/..

We’ll be addressing everything from OAuth 1.0a, OAuth 2.0, Application Passwords, and what limitations should be used to scope assorted tokens.

Relevant background reading: http://georgestephanis.wordpress.com/2016/02/14/on-core-rest-api-authentication/

#api, #application-passwords, #authentication, #rest-api