watcha-synapse/docs/password_auth_providers.md

Password auth provider modules

Password auth providers offer a way for server administrators to integrate their Synapse installation with an existing authentication system.

A password auth provider is a Python class which is dynamically loaded into Synapse, and provides a number of methods by which it can integrate with the authentication system.

This document serves as a reference for those looking to implement their own password auth providers.

Required methods

Password auth provider classes must provide the following methods:

class SomeProvider.parse_config(config)

This method is passed the config object for this module from the homeserver configuration file.

It should perform any appropriate sanity checks on the provided configuration, and return an object which is then passed into __init__.

class SomeProvider(config, account_handler)

The constructor is passed the config object returned by parse_config, and a synapse.module_api.ModuleApi object which allows the password provider to check if accounts exist and/or create new ones.

Optional methods

Password auth provider classes may optionally provide the following methods.

class SomeProvider.get_db_schema_files()

This method, if implemented, should return an Iterable of (name, stream) pairs of database schema files. Each file is applied in turn at initialisation, and a record is then made in the database so that it is not re-applied on the next start.

someprovider.get_supported_login_types()

This method, if implemented, should return a dict mapping from a login type identifier (such as m.login.password) to an iterable giving the fields which must be provided by the user in the submission to the /login api. These fields are passed in the login_dict dictionary to check_auth.

For example, if a password auth provider wants to implement a custom login type of com.example.custom_login, where the client is expected to pass the fields secret1 and secret2, the provider should implement this method and return the following dict:

{"com.example.custom_login": ("secret1", "secret2")}

someprovider.check_auth(username, login_type, login_dict)

This method is the one that does the real work. If implemented, it will be called for each login attempt where the login type matches one of the keys returned by get_supported_login_types.

It is passed the (possibly UNqualified) user provided by the client, the login type, and a dictionary of login secrets passed by the client.

The method should return a Twisted Deferred object, which resolves to the canonical @localpart:domain user id if authentication is successful, and None if not.

Alternatively, the Deferred can resolve to a (str, func) tuple, in which case the second field is a callback which will be called with the result from the /login call (including access_token, device_id, etc.)

someprovider.check_3pid_auth(medium, address, password)

This method, if implemented, is called when a user attempts to register or log in with a third party identifier, such as email. It is passed the medium (ex. "email"), an address (ex. "jdoe@example.com") and the user's password.

The method should return a Twisted Deferred object, which resolves to a str containing the user's (canonical) User ID if authentication was successful, and None if not.

As with check_auth, the Deferred may alternatively resolve to a (user_id, callback) tuple.

someprovider.check_password(user_id, password)

This method provides a simpler interface than get_supported_login_types and check_auth for password auth providers that just want to provide a mechanism for validating m.login.password logins.

Iif implemented, it will be called to check logins with an m.login.password login type. It is passed a qualified @localpart:domain user id, and the password provided by the user.

The method should return a Twisted Deferred object, which resolves to True if authentication is successful, and False if not.

someprovider.on_logged_out(user_id, device_id, access_token)

This method, if implemented, is called when a user logs out. It is passed the qualified user ID, the ID of the deactivated device (if any: access tokens are occasionally created without an associated device ID), and the (now deactivated) access token.

It may return a Twisted Deferred object; the logout request will wait for the deferred to complete but the result is ignored.