com.ibm.security.auth.module
Class LdapLoginModule
- java.lang.Object
com.ibm.security.auth.module.LdapLoginModule
- public class LdapLoginModule
- extends java.lang.Object
- implements LoginModule
LoginModule
performs LDAP-based authentication.
A username and password is verified against the corresponding user
credentials stored in an LDAP directory.
This module requires the supplied CallbackHandler
to support a
NameCallback
and a PasswordCallback
.
If authentication is successful then a new LdapPrincipal
is created
using the user's distinguished name and a new UserIDPrincipal
is
created using the user's username and both are associated
with the current Subject
.
This module operates in one of three modes: search-first, authentication-first or authentication-only. A mode is selected by specifying a particular set of options.
In search-first mode, the LDAP directory is searched to determine the
user's distinguished name and then authentication is attempted.
An (anonymous) search is performed using the supplied username in
conjunction with a specified search filter.
If successful then authentication is attempted using the user's
distinguished name and the supplied password.
To enable this mode, set the userFilter
option and omit the
authIdentity
option.
Use search-first mode when the user's distinguished name is not
known in advance.
In authentication-first mode, authentication is attempted using the
supplied username and password and then the LDAP directory is searched.
If authentication is successful then a search is performed using the
supplied username in conjunction with a specified search filter.
To enable this mode, set the authIdentity
and the
userFilter
options.
Use authentication-first mode when accessing an LDAP directory
that has been configured to disallow anonymous searches.
In authentication-only mode, authentication is attempted using the
supplied username and password. The LDAP directory is not searched because
the user's distinguished name is already known.
To enable this mode, set the authIdentity
option to a valid
distinguished name and omit the userFilter
option.
Use authentication-only mode when the user's distinguished name is
known in advance.
The following option is mandatory and must be specified in this
module's login Configuration
:
-
-
userProvider=ldap_urls
- This option identifies the LDAP directory that stores user entries.
ldap_urls is a list of space-separated LDAP URLs
(RFC 2255)
that identifies the LDAP server to use and the position in
its directory tree where user entries are located.
When several LDAP URLs are specified then each is attempted,
in turn, until the first successful connection is established.
Spaces in the distinguished name component of the URL must be escaped
using the standard mechanism of percent character ('
%
') followed by two hexadecimal digits (seeURI
). Query components must also be omitted from the URL.Automatic discovery of the LDAP server via DNS (RFC 2782) is supported (once DNS has been configured to support such a service). It is enabled by omitting the hostname and port number components from the LDAP URL.
-
This module also recognizes the following optional Configuration
options:
-
-
userFilter=ldap_filter
- This option specifies the search filter to use to locate a user's
entry in the LDAP directory. It is used to determine a user's
distinguished name.
ldap_filter
is an LDAP filter string (RFC 2254). If it contains the special token "{USERNAME}
" then that token will be replaced with the supplied username value before the filter is used to search the directory. -
authIdentity=auth_id
- This option specifies the identity to use when authenticating a user
to the LDAP directory.
auth_id
may be an LDAP distinguished name string (RFC 2253) or some other string name. It must contain the special token "{USERNAME}
" which will be replaced with the supplied username value before the name is used for authentication. Note that if this option does not contain a distinguished name then theuserFilter
option must also be specified. -
authzIdentity=authz_id
- This option specifies an authorization identity for the user.
authz_id
is any string name. If it comprises a single special token with curly braces then that token is treated as a attribute name and will be replaced with a single value of that attribute from the user's LDAP entry. If the attribute cannot be found then the option is ignored. When this option is supplied and the user has been successfully authenticated then an additionalUserIDPrincipal
is created using the authorization identity and it is assocated with the currentSubject
. -
useSSL
- if
false
, this module does not establish an SSL connection to the LDAP server before attempting authentication. SSL is used to protect the privacy of the user's password because it is transmitted in the clear over LDAP. By default, this module uses SSL. -
useFirstPass
- if
true
, this module retrieves the username and password from the module's shared state, using "javax.security.auth.login.name" and "javax.security.auth.login.password" as the respective keys. The retrieved values are used for authentication. If authentication fails, no attempt for a retry is made, and the failure is reported back to the calling application. -
tryFirstPass
- if
true
, this module retrieves the username and password from the module's shared state, using "javax.security.auth.login.name" and "javax.security.auth.login.password" as the respective keys. The retrieved values are used for authentication. If authentication fails, the module uses theCallbackHandler
to retrieve a new username and password, and another attempt to authenticate is made. If the authentication fails, the failure is reported back to the calling application. -
storePass
- if
true
, this module stores the username and password obtained from theCallbackHandler
in the module's shared state, using "javax.security.auth.login.name" and "javax.security.auth.login.password" as the respective keys. This is not performed if existing values already exist for the username and password in the shared state, or if authentication fails. -
clearPass
- if
true
, this module clears the username and password stored in the module's shared state after both phases of authentication (login and commit) have completed. -
debug
- if
true
, debug messages are displayed on the standard output stream.
-
Arbitrary
JNDI properties
may also be specified in the Configuration
.
They are added to the environment and passed to the LDAP provider.
Note that the following four JNDI properties are set by this module directly
and are ignored if also present in the configuration:
-
java.naming.provider.url
-
java.naming.security.principal
-
java.naming.security.credentials
-
java.naming.security.protocol
Three sample Configuration
s are shown below.
The first one activates search-first mode. It identifies the LDAP server
and specifies that users' entries be located by their uid
and
objectClass
attributes. It also specifies that an identity
based on the user's employeeNumber
attribute should be created.
The second one activates authentication-first mode. It requests that the
LDAP server be located dynamically, that authentication be performed using
the supplied username directly but without the protection of SSL and that
users' entries be located by one of three naming attributes and their
objectClass
attribute.
The third one activates authentication-only mode. It identifies alternative
LDAP servers, it specifies the distinguished name to use for
authentication and a fixed identity to use for authorization. No directory
search is performed.
ExampleApplication { com.ibm.security.auth.module.LdapLoginModule REQUIRED userProvider="ldap://ldap-svr/ou=people,dc=example,dc=com" userFilter="(&(uid={USERNAME})(objectClass=inetOrgPerson))" authzIdentity="{EMPLOYEENUMBER}" debug=true; }; ExampleApplication { com.ibm.security.auth.module.LdapLoginModule REQUIRED userProvider="ldap:///cn=users,dc=example,dc=com" authIdentity="{USERNAME}" userFilter="(&(|(samAccountName={USERNAME})(userPrincipalName={USERNAME})(cn={USERNAME}))(objectClass=user))" useSSL=false debug=true; }; ExampleApplication { com.ibm.security.auth.module.LdapLoginModule REQUIRED userProvider="ldap://ldap-svr1 ldap://ldap-svr2" authIdentity="cn={USERNAME},ou=people,dc=example,dc=com" authzIdentity="staff" debug=true; };
- Note:
- When a
SecurityManager
is active then an application that creates aLoginContext
and uses aLoginModule
must be granted certain permissions.If the application creates a login context using an installed
Configuration
then the application must be granted theAuthPermission
to create login contexts. For example, the following security policy allows an application in the user's current directory to instantiate any login context:grant codebase "file:${user.dir}/" { permission javax.security.auth.AuthPermission "createLoginContext.*"; };
Alternatively, if the application creates a login context using a caller-specifiedConfiguration
then the application must be granted the permissions required by theLoginModule
. This module requires the following two permissions:- The
SocketPermission
to connect to an LDAP server. - The
AuthPermission
to modify the set ofPrincipal
s associated with aSubject
.
For example, the following security policy grants an application in the user's current directory all the permissions required by this module:
grant codebase "file:${user.dir}/" { permission java.net.SocketPermission "*:389", "connect"; permission java.net.SocketPermission "*:636", "connect"; permission javax.security.auth.AuthPermission "modifyPrincipals"; };
- The
Constructor Summary
Constructor and Description |
---|
LdapLoginModule()
|
Method Summary
Modifier and Type | Method and Description |
---|---|
|
abort()
Abort user authentication.
|
|
commit()
Complete user authentication.
|
|
initialize(Subject subject,CallbackHandler callbackHandler,java.util.Map<java.lang.String,?> sharedState,java.util.Map<java.lang.String,?> options)
Initialize this
LoginModule .
|
|
login()
Begin user authentication.
|
|
logout()
Logout a user.
|
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail
LdapLoginModule
- public LdapLoginModule()
Method Detail
initialize
- public void initialize(Subject subject,
- CallbackHandler callbackHandler,
- java.util.Map<java.lang.String,?> sharedState,
- java.util.Map<java.lang.String,?> options)
initialize
in interface LoginModule
subject
- the Subject
to be authenticated. callbackHandler
- a CallbackHandler
to acquire the
username and password. sharedState
- shared LoginModule
state. options
- options specified in the login
Configuration
for this particular
LoginModule
. login
- public boolean login()
- throws LoginException
Acquire the user's credentials and verify them against the specified LDAP directory.
login
in interface LoginModule
LoginModule
should not be ignored. FailedLoginException
- if the authentication fails. LoginException
- if this LoginModule
is unable to perform the authentication. commit
- public boolean commit()
- throws LoginException
This method is called if the LoginContext's overall authentication succeeded (the relevant REQUIRED, REQUISITE, SUFFICIENT and OPTIONAL LoginModules succeeded).
If this LoginModule's own authentication attempt
succeeded (checked by retrieving the private state saved by the
login
method), then this method associates an
LdapPrincipal
and one or more UserIDPrincipal
s
with the Subject
located in the
LoginModule
. If this LoginModule's own
authentication attempted failed, then this method removes
any state that was originally saved.
commit
in interface LoginModule
LoginException
- if the commit fails abort
- public boolean abort()
- throws LoginException
This method is called if the overall authentication failed. (the relevant REQUIRED, REQUISITE, SUFFICIENT and OPTIONAL LoginModules did not succeed).
If this LoginModule's own authentication attempt
succeeded (checked by retrieving the private state saved by the
login
and commit
methods),
then this method cleans up any state that was originally saved.
abort
in interface LoginModule
LoginException
- if the abort fails. logout
- public boolean logout()
- throws LoginException
This method removes the Principals
that were added by the commit
method.
logout
in interface LoginModule
LoginModule
should not be ignored. LoginException
- if the logout fails.
LoginModule
.