This will be a breaking change for some people.
We removed all internal password control logic. If this affects you, you have two options:
1. Use a plugin for authentication and use session based pad access (recommended).
1. Use a plugin for password setting.
The reasoning for removing this feature is to reduce the overall security footprint of Etherpad. It is unnecessary and cumbersome to keep this feature and with the thousands of available authentication methods available in the world our focus should be on supporting those and allowing more granual access based on their implementations (instead of half assed baking our own).
This currently isn't absolutely necessary because all current callers
of `userCanModify` already check for a read-only pad ID themselves.
However:
* This adds defense in depth.
* This makes it possible to simply replace the import handler's
`allowAnyoneToImport` check with a call to `userCanModify`.
There's no need to perform an authentication check in the socket.io
middleware because `PadMessageHandler.handleMessage` calls
`SecurityMananger.checkAccess` and that now performs authentication
and authorization checks.
This change also improves the user experience: Before, access denials
caused socket.io error events in the client, which `pad.js` mostly
ignores (the user doesn't see anything). Now a deny message is sent
back to the client, which causes `pad.js` to display an obvious
permission denied message.
This also fixes a minor bug: `settings.loadTest` is supposed to bypass
authentication and authorization checks, but they weren't bypassed
because `SecurityManager.checkAccess` did not check
`settings.loadTest`.
Before this change, the authorize hook was invoked twice: once before
authentication and again after (if settings.requireAuthorization is
true). Now pre-authentication authorization is instead handled by a
new preAuthorize hook, and the authorize hook is only invoked after
the user has authenticated.
Rationale: Without this change it is too easy to write an
authorization plugin that is too permissive. Specifically:
* If the plugin does not check the path for /admin then a non-admin
user might be able to access /admin pages.
* If the plugin assumes that the user has already been authenticated
by the time the authorize function is called then unauthenticated
users might be able to gain access to restricted resources.
This change also avoids calling the plugin's authorize function twice
per access, which makes it easier for plugin authors to write an
authorization plugin that is easy to understand.
This change may break existing authorization plugins: After this
change, the authorize hook will no longer be able to authorize
non-admin access to /admin pages. This is intentional. Access to admin
pages should instead be controlled via the `is_admin` user setting,
which can be set in the config file or by an authentication plugin.
Also:
* Add tests for the authenticate and authorize hooks.
* Disable the authentication failure delay when testing.
This loses some of the granularity of the default HTTP basic auth
(unknown username vs. bad password), but there is considerable value
in having logging that is consistent no matter what authentication
plugins are installed.
The export request hook wasn't testing if the pad's id was from a read-only
pad before validating with the pad manager.
This includes an extra step that makes the read-only id verification and also
avoids setting the original pad's id as the file's name.
This makes it possible for reverse proxies to transform 403 errors
into something like "upgrade to a premium account to access this
pad".
Also add some webaccess tests.
* `src/node/server.js` can now be run as a script (for normal
operation) or imported as a module (for tests).
* Move shutdown actions to `src/node/server.js` to be close to the
startup actions.
* Put startup and shutdown in functions so that tests can call them.
* Use `await` instead of callbacks.
* Block until the HTTP server is listening to avoid races during
test startup.
* Add a new `shutdown` hook.
* Use the `shutdown` hook to:
* close the HTTP server
* call `end()` on the stats collection to cancel its timers
* call `terminate()` on the Threads.Pool to stop the workers
* Exit with exit code 0 (instead of 1) on SIGTERM.
* Export the HTTP server so that tests can get the HTTP server's
port via `server.address().port` when `settings.port` is 0.
Before, a malicious user could bypass authorization restrictions
imposed by the authorize hook:
* Step 1: Fetch any resource that the malicious user is authorized to
access (e.g., static content).
* Step 2: Use the signed express_sid cookie generated in step 1 to
create a socket.io connection.
* Step 3: Perform the CLIENT_READY handshake for the desired pad.
* Step 4: Profit!
Now the authorization decision made by the authorize hook is
propagated to SecurityManager so that it can approve or reject
socket.io messages as appropriate.
This also sets up future support for per-user read-only and
modify-only (no create) authorization levels.
Authentication plugins almost always want to read and modify
`settings.users`. The settings can already be accessed in a few other
ways, but this is much more convenient.
The authorization logic determines whether the user has already
successfully authenticated by looking to see if `req.session.user`
exists. If an authentication plugin says that it successfully
authenticated the user but it did not create `req.session.user` then
authentication will re-run for every access, and authorization plugins
will be unable to determine whether the user has been authenticated.
Return a 500 internal server error to prevent these problems.
Before, anyone who could create a socket.io connection to Etherpad
could read, modify, and create pads at will without authenticating
first.
The `checkAccess` middleware in `webaccess.js` normally handles
authentication and authorization, but it does not run for `/socket.io`
requests. This means that the connection handler in `socketio.js` must
handle authentication and authorization. However, before this change:
* The handler did not require a signed `express_sid` cookie.
* After loading the express-session state, the handler did not check
to see if the user had authenticated.
Now the handler requires a signed `express_sid` cookie, and it ensures
that `socket.request.session.user` is non-null if authentication is
required. (`socket.request.session.user` is non-null if and only if
the user has authenticated.)
There are two different ways an author ID becomes associated with a
user: either bound to a token or bound to a session ID. (The token and
session ID come from the `token` and `sessionID` cookies, or, in the
case of socket.io messages, from the `token` and `sessionID` message
properties.) When `settings.requireSession` is true or the user is
accessing a group pad, the session ID should be used. Otherwise the
token should be used.
Before this change, the `/p/:pad/import` handler was always using the
token, even when `settings.requireSession` was true. This caused the
following error because a different author ID was bound to the token
versus the session ID:
> Unable to import file into ${pad}. Author ${authorID} exists but he
> never contributed to this pad
This bug was reported in issue #4006. PR #4012 worked around the
problem by binding the same author ID to the token as well as the
session ID.
This change does the following:
* Modifies the import handler to use the session ID to obtain the
author ID (when appropriate).
* Expands the documentation for the SecurityManager checkAccess
function.
* Removes the workaround from PR #4012.
* Cleans up the `bin/createUserSession.js` test script.
Not all authentication plugins require the Authorization header, so it
might not be present in subsequent attempts. (In particular, a reverse
proxy might strip it.)
* Improve the comment describing how the access check works.
* Move the `authenticate` logic to where it is used so that people
don't have to keep jumping back and forth to understand how the
access check works.
* Break up the three steps to reduce the number of indentation
levels and improve readability. This should also make it easier to
implement and review planned future changes.
