gitea/services/auth/source/ldap/README.md
zeripath 5d2e11eedb
Refactor: Move login out of models (#16199)
`models` does far too much. In particular it handles all `UserSignin`.

It shouldn't be responsible for calling LDAP, SMTP or PAM for signing in.

Therefore we should move this code out of `models`.

This code has to depend on `models` - therefore it belongs in `services`.

There is a package in `services` called `auth` and clearly this functionality belongs in there.

Plan:

- [x] Change `auth.Auth` to `auth.Method` - as they represent methods of authentication.
- [x] Move `models.UserSignIn` into `auth`
- [x] Move `models.ExternalUserLogin`
- [x] Move most of the `LoginVia*` methods to `auth` or subpackages
- [x] Move Resynchronize functionality to `auth`
  - Involved some restructuring of `models/ssh_key.go` to reduce the size of this massive file and simplify its files.
- [x] Move the rest of the LDAP functionality in to the ldap subpackage
- [x] Re-factor the login sources to express an interfaces `auth.Source`?
  - I've done this through some smaller interfaces Authenticator and Synchronizable - which would allow us to extend things in future
- [x] Now LDAP is out of models - need to think about modules/auth/ldap and I think all of that functionality might just be moveable
- [x] Similarly a lot Oauth2 functionality need not be in models too and should be moved to services/auth/source/oauth2
  - [x] modules/auth/oauth2/oauth2.go uses xorm... This is naughty - probably need to move this into models.
  - [x] models/oauth2.go - mostly should be in modules/auth/oauth2 or services/auth/source/oauth2 
- [x] More simplifications of login_source.go may need to be done
- Allow wiring in of notify registration -  *this can now easily be done - but I think we should do it in another PR*  - see #16178 
- More refactors...?
  - OpenID should probably become an auth Method but I think that can be left for another PR
  - Methods should also probably be cleaned up  - again another PR I think.
  - SSPI still needs more refactors.* Rename auth.Auth auth.Method
* Restructure ssh_key.go

- move functions from models/user.go that relate to ssh_key to ssh_key
- split ssh_key.go to try create clearer function domains for allow for
future refactors here.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-07-24 11:16:34 +01:00

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Markdown

# Gitea LDAP Authentication Module
## About
This authentication module attempts to authorize and authenticate a user
against an LDAP server. It provides two methods of authentication: LDAP via
BindDN, and LDAP simple authentication.
LDAP via BindDN functions like most LDAP authentication systems. First, it
queries the LDAP server using a Bind DN and searches for the user that is
attempting to sign in. If the user is found, the module attempts to bind to the
server using the user's supplied credentials. If this succeeds, the user has
been authenticated, and his account information is retrieved and passed to the
Gogs login infrastructure.
LDAP simple authentication does not utilize a Bind DN. Instead, it binds
directly with the LDAP server using the user's supplied credentials. If the bind
succeeds and no filter rules out the user, the user is authenticated.
LDAP via BindDN is recommended for most users. By using a Bind DN, the server
can perform authorization by restricting which entries the Bind DN account can
read. Further, using a Bind DN with reduced permissions can reduce security risk
in the face of application bugs.
## Usage
To use this module, add an LDAP authentication source via the Authentications
section in the admin panel. Both the LDAP via BindDN and the simple auth LDAP
share the following fields:
* Authorization Name **(required)**
* A name to assign to the new method of authorization.
* Host **(required)**
* The address where the LDAP server can be reached.
* Example: mydomain.com
* Port **(required)**
* The port to use when connecting to the server.
* Example: 636
* Enable TLS Encryption (optional)
* Whether to use TLS when connecting to the LDAP server.
* Admin Filter (optional)
* An LDAP filter specifying if a user should be given administrator
privileges. If a user accounts passes the filter, the user will be
privileged as an administrator.
* Example: (objectClass=adminAccount)
* First name attribute (optional)
* The attribute of the user's LDAP record containing the user's first name.
This will be used to populate their account information.
* Example: givenName
* Surname attribute (optional)
* The attribute of the user's LDAP record containing the user's surname This
will be used to populate their account information.
* Example: sn
* E-mail attribute **(required)**
* The attribute of the user's LDAP record containing the user's email
address. This will be used to populate their account information.
* Example: mail
**LDAP via BindDN** adds the following fields:
* Bind DN (optional)
* The DN to bind to the LDAP server with when searching for the user. This
may be left blank to perform an anonymous search.
* Example: cn=Search,dc=mydomain,dc=com
* Bind Password (optional)
* The password for the Bind DN specified above, if any. _Note: The password
is stored in plaintext at the server. As such, ensure that your Bind DN
has as few privileges as possible._
* User Search Base **(required)**
* The LDAP base at which user accounts will be searched for.
* Example: ou=Users,dc=mydomain,dc=com
* User Filter **(required)**
* An LDAP filter declaring how to find the user record that is attempting to
authenticate. The '%s' matching parameter will be substituted with the
user's username.
* Example: (&(objectClass=posixAccount)(uid=%s))
**LDAP using simple auth** adds the following fields:
* User DN **(required)**
* A template to use as the user's DN. The `%s` matching parameter will be
substituted with the user's username.
* Example: cn=%s,ou=Users,dc=mydomain,dc=com
* Example: uid=%s,ou=Users,dc=mydomain,dc=com
* User Search Base (optional)
* The LDAP base at which user accounts will be searched for.
* Example: ou=Users,dc=mydomain,dc=com
* User Filter **(required)**
* An LDAP filter declaring when a user should be allowed to log in. The `%s`
matching parameter will be substituted with the user's username.
* Example: (&(objectClass=posixAccount)(cn=%s))
* Example: (&(objectClass=posixAccount)(uid=%s))
**Verify group membership in LDAP** uses the following fields:
* Group Search Base (optional)
* The LDAP DN used for groups.
* Example: ou=group,dc=mydomain,dc=com
* Group Name Filter (optional)
* An LDAP filter declaring how to find valid groups in the above DN.
* Example: (|(cn=gitea_users)(cn=admins))
* User Attribute in Group (optional)
* Which user LDAP attribute is listed in the group.
* Example: uid
* Group Attribute for User (optional)
* Which group LDAP attribute contains an array above user attribute names.
* Example: memberUid