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How Authentication works with MoinMoin

MoinMoin historically has supported only username/password authentication and cookie-based sessions: you log in via the login form, moin sets a cookie and from then on this cookie is used for authenticating you - until you log off and the cookie gets deleted (or until the cookie expires).

In many environments this is often not optimal as access restrictions should be based on other user databases like LDAP (Active Directory). Hence, modular authentication was developed for MoinMoin. You use the auth configuration value to set up a list of authenticators that are processed in exactly that order.

When an external user database is used you do not want to recreate all users in moin. For this case the configuration option user_autocreate was added. If you set it to True a new user profile will be created automatically when a new user has passed authentication (and the authenticator supports auto creation).

Presently the following authenticators are supported:

1. Other pseudo-authenticators

These are not strictly authenticators, as they don't authenticate users, but use auth information for other purposes:

2. Shipped plugins

2.1. MoinAuth (default)

This is the default auth list moin uses (so if you just want that, you don't need to configure it). 

   1     from MoinMoin.auth import MoinAuth
   2     auth = [MoinAuth()]

2.2. HTTP authentication

To activate http authentication you have to add following lines to wikiconfig.py: 

   1     from MoinMoin.auth.http import HTTPAuth
   2     auth = [HTTPAuth()]

For HTTP basic auth used with a web server like Apache, the web server handles authentication before moin gets called. You either enter a valid username and password or your access will be denied by the web server.

Moin's HTTP authenticator will just check if user authentication happened and allow access if it has and a valid user is found for the given username.

Unfortunately, it is a bit more complicated:

2.3. SSL client certification authentication

To activate authentication via SSL client certificates you have to add following lines to wikiconfig.py: 

   1     from MoinMoin.auth.sslclientcert import SSLClientCertAuth
   2     auth = [SSLClientCertAuth()]

SSL client certification authentication must be used with a web server like Apache that handles the SSL bits and just presents a few environment variables to Moin.

The SSLClientCertAuth authenticator has a few parameters that you pass to the constructor (example below):

Parameter

Default

Meaning

authorities

None

a list of authorities that are accepted, or None to accept all

email_key

True

indicates whether the email in the certificate should be used to find the Moin user

name_key

True

indiciates whether the name in the certificate should be used to find the Moin user

use_email

False

if set to True, the account email cannot be changed and is forced to the one given in the certificate

use_name

False

if set to True, the account name cannot be changed and is forced to the one given in the certificate

For example, to accept only certificates that Apache has verified and that are signed by a certain authority, use: 

   1     from MoinMoin.auth.sslclientcert import SSLClientCertAuth
   2     auth = [SSLClientCertAuth(authorities=['my.authority.tld'])]

or similar.

2.4. PHP session

To activate Single-Sign-On integration with PHP applications, use this module. It reads PHP session files and therefore directly integrates with existing PHP authentication systems.

To use this module, use the following lines of code in your configuration: 

   1     from MoinMoin.auth.php_session import PHPSessionAuth
   2     auth = [PHPSessionAuth()]

PHPSessionAuth has the following parameters: 

   1     PHPSessionAuth(apps=['egw'], s_path="/tmp", s_prefix="sess_")

The only supported PHP application is eGroupware 1.2 currently. But it should be fairly easy to add a few lines of code that extract the necessary information from the PHP session, if you do that, please open a feature request with a patch.

2.5. OpenID (with BotBouncer)

The OpenID authentication plugin allows users to sign in using their OpenID and connect that OpenID to a new or existing Moin account. To allow users to sign in with OpenID, add the plugin to the auth list, or to require OpenID with http://botbouncer.com/ verification use: 

   1     from MoinMoin.auth.openidrp import OpenIDAuth
   2     from MoinMoin.auth.botbouncer import BotBouncer
   3     auth = [OpenIDAuth(), BotBouncer("your-botbouncer-API-key")]

OpenID authentication requires anonymous sessions, set anonymous_session_lifetime to anything bigger than zero. See HelpOnConfiguration for more details on the value. For OpenID, very little time should be sufficient.

2.5.1. Advanced OpenID RP configuration

The OpenID RP code can also be configured for two use cases:

  1. You can force a specific provider to be used, there are two ways to achieve this:

    • Simply configure the OpenIDAuth authenticator like this: 

      auth = OpenIDAuth(forced_service='http://myopenid.com/')

    • Create an OpenIDServiceEndpoint object and use that for the forced_service parameter: 

      fs = OpenIDServiceEndpoint()
fs.type_uris = OPENID_2_0_TYPE
fs.server_url = 'http://localhost:8000/openidserver'
fs.claimed_id = 'http://specs.openid.net/auth/2.0/identifier_select'

auth = OpenIDAuth(forced_service=fs)
    In the latter case, no discovery needs to be done.

  2. You can specify functions to be called in various steps of the OpenID authentication process to, for example, implement Attribute Exchange. For now, this is not documented here, you'll have to look at the file MoinMoin/auth/openidrp.py.

2.6. LDAP based user authentication

The LDAP authenticator of MoinMoin enables single-sign-on (SSO) - assuming you already have a LDAP directory with your users, passwords, email adresses. On Linux this could be some OpenLDAP server, on a Windows server (usually the domain controller) this is called "Active Directory" (short: AD).

It works like this:

2.6.1. LDAP auth installation / configuration

You need to install python-ldap module (and everything it depends on, see its documentation).

You need an LDAP or AD server. :)

See wiki/config/more_samples/ldap_wikiconfig_snippet.py in your moin dist archive for a snippet you can use in your wiki config.

(!) Please also read the README file in that directory.

2.6.2. LDAP auth Problems?

MoinMoin support does not know your LDAP server setup, so please follow these steps before asking for help:

/!\ Only ask MoinMoin support if you successfully used ldapsearch (or some similar tool) and you double checked your wiki config and it does still not work with moin.

2.7. XMLRPC auth

   1 import xmlrpclib
   2 
   3 name = "TestUser"
   4 password = "secret"
   5 wikiurl = "http://localhost:8080/"
   6 
   7 homewiki = xmlrpclib.ServerProxy(wikiurl + "?action=xmlrpc2", allow_none=True)
   8 auth_token = homewiki.getAuthToken(name, password)
   9 
  10 mc = xmlrpclib.MultiCall(homewiki)
  11 mc.applyAuthToken(auth_token)
  12 # you can add more xmlrpc method calls to the multicall here,
  13 # they will run authenticated as user <name>.
  14 result = mc()

3. Combining multiple authenticators

For combining e.g. SSL client certificate and username/password authentication, your wikiconfig.py might contain: 

   1     from MoinMoin.auth import MoinAuth
   2     from MoinMoin.auth.sslclientcert import SSLClientCertAuth
   3     auth = [SSLClientCertAuth(), MoinAuth()]

In that case, any client certificates that the user provides will be used to log him on, but if they do not provide one they still have the option of logging on with their username/password.

4. Writing your own authenticator

See the commented config file fragment contrib/auth_externalcookie/ and MoinMoin/auth/*.py in your moin distribution archive for examples of how to do authentication. Also, the docstring in MoinMoin/auth/__init__.py contains an explanation of what can be done and how it is achieved.

Authenticators can

2018-04-20 12:04