LDAP User Access

The is an authentication mechanism which authenticates users against an LDAP server and stores the role in the server. It does not create an administrative account on module initialization on the LDAP server, however it uses an internal administrative account 'i2ce_admin' with password as defined below.

This user access mechanism is implemented by the I2CE_UserAccess_LDAP class.

Configuration

To use the default user authentication, you need to enable the module and set an initialization string.

Enabling the Module

To enable, just make sure you have: <source lang='xml'>

<requirement name='UserAccess_LDAP'>
  <atLeast version='4.0'/>
  <lessThan version='4.1'/>
</requirement>

</source>

Initialization String

The initialization string is sent to I2CE::initialize() in the index.php as the fourth argument, $user_access_init. This string must be prefixed with the 'LDAP://. What follows take any of the following formats:

• null: The is the default value and means that we use the default DN (distinguished name) for querying and authenticating users
• a JSON encoded string: The data to is a JSON enocode string of optional configuration value for the user access. The JSON encoded data has the following keys:
  • host: Defaults to 'localhost' The hostname where the openLDAP server lives
  • port: The port openLDAP is listening on. Defaults to 389
  • ldap_user: The user to attempt to bind the ldap connection to. Defaults to 'admin'. If empty we do an anonymous connection
  • ldap_pass: The password to attempt to bind the ldap connection with. If this value is not set, it is the same password used for the database connection.
  • ldap_user_dn: The dn to bind the ldap_user against. If not set, then the value of dn below is used
  • dn: The DN used to query against. Defaults to 'dc=localhost'
  • people: The oranzataional unit under which users live. Defaults to 'ou=People'.
  • person_comp: The qualifier to query people against. Defaults to 'cn'
  • person_objectClass: defaults to 'inetOrgPerson'
  • password_field: the field the user's password is stored. Defaults to 'userPassword'
  • encrypt: how the password is stored on the openLDAP server. Default is SHA. Possible values are:
    • 'bind' authentication is through a bind to the ldap server
    • 'plaintext'
    • 'SHA'
    • 'SSHA'
    • 'MD5'
  • salt: the salt to use for encryption (if needed). Defaults to none.
  • p_details: associative array of the user details that are querriable against People.Defaults as follows:
    • firstname:givenName
    • lastname:sn
    • email:mail
    • commonname:cn
    • locale:Preferred Local
  • p_detail_names: associative array of the display names of user details that are querriable against People.Defaults as follows:
    • firstname:Firstname
    • lastname:Surname
    • commonname:Common Name
    • email:E-mail
    • locale:preferredLanguage
  • can_change_pass: defaults to true
  • can_create_user: defaults to true
  • can_edit_user: defaults to true
  • admin_user: The LDAP internal (not stored on LDAP) username for an administrative account. If not set, it uses 'i2ce_admin'
  • admin_pass: It is the password for an administrative account with username 'administrator'. This account is not authenticated against LDAP. If this value is not set, it is the same password used for the database connection.
  • admin_details: associative array of the details for the admin user. Defaults to be as follows:
    • firstname: System
    • lastname: Administrator
    • email: root@localhost
    • locale: en_US
    • commonname: Admin
  • apps: The oragnaization unit for apps. Defaults to 'Application'
  • app: The application name used to check for user roles in. If not set, it will use the site module's name
  • roles: The qualifier to query user roles against. Defaults to 'Roles'.
  • ids: The qualifier to query user roles against. Defaults to 'Ids'.

For example:

LDAP://

would be a minimal initialization string needed to authenticate against. For the examples below, you would use:

 LDAP://{"dn": "dc=moh,dc=example,dc=org"}

LDAP Directory Structure

Example Entries

A user could be represented as:

   dn: uid=litlfred, ou=People, dc=moh,dc=example,dc=gov
   sn: Leitner
   givenName: Carl
   cn: Carl Leitner
   userPassword: {SSHA}DkMTwBl+a/3DQTxCYEApdUtNXGgdUac3
   email: cleitner@intrahealth.org

User roles be unique on the pair (username, software-component) and there may be software component specific information to share,

   dn: uid=litlfred, cn=ihris-manage, ou=Application, dc=moh,dc=example,dc=gov
   role: hr_staff
   appid: 25
   #preferred locale is specific to ihris-manage based on the available locales
   locale: he_IL
   locale: en_US
   
   dn: uid=litlfred, cn=ihris-qualify, ou=Application, dc=moh,dc=example,dc=gov
   role: admin
   appid: 25
   #preferred locale is specific to ihris-qualify based on the available locales
   locale: en_US
 
   dn: uid=litlfred, cn=dhis2, ou=Application, dc=moh,dc=example,dc=gov
   role: guest
   appid: 42

Passwords

We will use SHA and salted SSHA. For a php implementation see this and this

openLDAP Server Configuration

This describes how to set up openLDAP for use with openMRS, DHIS and iHIS on an ubuntu machine. First, see this tutorial.

Install slapd

Here are the steps I followed:

sudo apt-get install slapd ldap-utils

sudo dpkg-reconfigure slapd

• choose to Omit OpenLDAP server configuration?: No
• DNS Domain Name: moh.example.gov
• Organization Name: moh.example.gov
• Choose HDB as the storage format
• Do you want the database to be removed...: no
• set the admin password to XXXXX. This should be set in the initialization string above
• allow LDAPv2: no

Now, let us make openLDAP only listen on localhhost

sudo gedit /etc/default/slapd

and specify:

SLAPD_SERVICES="ldap://127.0.0.1:389/"

then restart

sudo /etc/init.d/slapd restart

Once Initialized

In our scenario above initializing the UserAccess_LDAP module we will have: <source lang='text'> dn: dc=localhost objectClass: top objectClass: dcObject objectClass: organization o: localhost dc: localhost

dn: cn=admin,dc=localhost objectClass: simpleSecurityObject objectClass: organizationalRole cn: admin description: LDAP administrator

dn: ou=People,dc=localhost objectClass: organizationalUnit ou: People

dn: ou=Application,dc=localhost objectClass: organizationalUnit ou: Application

dn: ou=ihris-manage-site-demo,ou=Application,dc=localhost objectClass: organizationalUnit ou: ihris-manage-site-demo

dn: ou=Roles, ou=ihris-manage-site-demo, ou=Application,dc=localhost objectClass: organizationalUnit ou: Roles

dn: ou=Ids, ou=ihris-manage-site-demo, ou=Application,dc=localhost objectClass: organizationalUnit ou: Ids </source>

Here is a sample user with their role and id.

<source lang='text'> dn: uid=administrator,ou=People,dc=localhost givenName: Site sn: Administrator cn: Site Admin mail: administrator@example.com preferredLanguage: en_US objectClass: inetOrgPerson uid: administrator

dn: ou=administrator,ou=Roles, ou=ihris-manage-site-demo,ou=Application,dc=localhost ou: administrator objectClass: applicationProcess cn: admin

dn: ou=administrator,ou=Ids, ou=ihris-manage-site-demo,ou=Application,dc=localhost ou: administrator objectClass: applicationProcess cn: 1

</source>