LDAP

LDAP Cached Credentials

If you configure an instance to use LDAP cached credentials, it stores (caches) a copy of the credentials that it most recently used to authenticate each user. If an instance supports cached credentials and it cannot connect to the LDAP server, then it uses the cached LDAP credentials to authenticate users. This can be caused by an issue with the LDAP server itself or with the connection to the server.

To secure cached credentials, InterSystems IRIS stores all LDAP passwords in the security database as a one-way hash. If the instance cannot use the LDAP server to validate the user, it then attempts to confirm that:

• The hash of the entered password matches the hash of the stored password

• The cached expiration date from the last LDAP login has not been reached

If both conditions are true, the instance authenticates the user and login proceeds; otherwise, login fails.

LDAP Configuration Fields

An LDAP configuration includes the following fields:

• Login Domain Name — Required. The name of the LDAP configuration. This is typically in the form of example.com or example.org.

  If you enter a value that does not include a period, the system appends .com to it, so that example becomes example.com. If you enter a value in uppercase, the system puts in lowercase, so that EXAMPLE.COM becomes example.com. The system performs both transformations, if appropriate.

  The system uses the transformed value of the Name field to populate the LDAP Base DN to use for searches field.

• Description — Any text to describe the configuration.

• Copy from — Available only when creating a configuration. Whether or not InterSystems IRIS copies attributes from an existing LDAP configuration to specify initial values for this one.

• LDAP Enabled — Whether or not InterSystems IRIS can use the configuration to connect to an LDAP server.

• LDAP server is a Windows Active Directory server — Windows only. Whether or not the LDAP server is a Windows Active Directory server.

• LDAP hostnames — Required. The name(s) of the host(s) on which the LDAP server is running. The complexity of each hostname can range from an unqualified hostname to fully-qualified hostname with a port number; the required form of the hostname(s) depends on the particular configuration.

  If the LDAP server is configured to use a particular port, you can specify it by appending “:portname” to the hostname; typical usage is not to specify a port and to let the LDAP functions use the default port. You can specify the domain example.com as your hostname if you have multiple replicated domain servers on your network like:

  ldapserver.example.com
  ldapserver1.example.com
  ldapserver2.example.com
  ldapserver3.example.com
  

  LDAP performs a DNS query for the addresses of all the matching LDAP servers and then automatically selects one to connect to.

  Important:

  Including a port number in the value of LDAP hostnames affects the TLS behavior when establishing a connection:

  • If the value specified contains a port number other than 636, such as ldapserver.example.com:389 and the Use TLS/SSL encryption for LDAP sessions check box is selected, then the instance attempts to establish a plaintext connection to the LDAP server and then issue a StartTLS command to encrypt the connection.

  • If the value specified for LDAP hostnames contains the port number 636, such as ldapserver.example.com:636, then the instance attempts to establish a TLS connection with the LDAP server directly—whether or not the Use TLS/SSL encryption for LDAP sessions check box is selected. Note, however, that connecting directly to port 636 from UNIX® client instances is not supported.

  For background, see the class reference for the %SYS.LDAP.Init()Opens in a new tab method.

• LDAP search information — varies based on the client (the platform running InterSystems IRIS) and the type of LDAP server it connects to:

  • LDAP username to use for searches — For Windows clients connecting to Active Directory servers. Required if available. The user name provided to the LDAP server to establish an initial connection and which is used to perform LDAP searches and lookups. This user is also known as the search user.

    The search user must have permission to read the entire LDAP database. It is important to ensure that the search user has uninterrupted access to the LDAP database. For example, the user’s LDAP account should be set so that:

    • The user cannot change the account’s password

    • The password never expires

    • The account never expires

    For more information on searching the LDAP database, see How LDAP Looks Up the Target User in Its Database.

  • LDAP search user DN — For all non-Windows clients and for Windows clients connecting to non-Active Directory servers. Required if available. The Distinguished Name (DN) of the user provided to the LDAP server to establish an initial connection and which is used to perform LDAP searches and lookups. This user is also known as the search user.

    The search user must have permission to read the entire LDAP database. It is also important to ensure that the search user has uninterrupted access to the LDAP database. For example, the user’s LDAP account should be set so that:

    • The user cannot change the account’s password

    • The password never expires

    • The account never expires

    For example, if the search user is “ldapsearchuser”, the LDAP DN (distinguished name) might be as follows:

    uid=ldapsearchuser,ou=People,dc=example,dc=com 
    

    For more information on searching the LDAP database, see How LDAP Looks Up the Target User in Its Database.

• LDAP username password — Available only when creating or modifying a configuration. The password associated with the account used for the initial connection.

• LDAP Base DN to use for searches — Required. The point in the directory tree from which searches begin. This typically consists of domain components, such as DC=example,DC=com.

• LDAP Base DN for Groups to use for searches — Required. The point in the directory tree from which searches for nested groups begin. This typically consists of organizational units and domain components, such as OU=IRIS,OU=Groups,DC=test,DC=com. By default, this is set to the same value as LDAP Base DN to use for searches.

• LDAP Unique search attribute — Required. A unique identifying element of each record, which therefore makes it appropriate for searches. For more information on searching the LDAP database, see How LDAP Looks Up the Target User in Its Database.

• Use TLS/SSL encryption for LDAP sessions — Whether or not the InterSystems IRIS instance and the LDAP server encrypt their communications using TLS (disabled by default).

  Important:

  InterSystems recommends that you enable TLS encryption for LDAP.

  For connections to Active Directory servers, note the following:

  • When enabled for an LDAP connection from an instance on Windows to an Active Directory server, the connection uses port 636 (which is a TLS-encrypted port).

  • When enabled for an LDAP connection from an instance on UNIX® to an Active Directory server, InterSystems IRIS first establishes the connection on port 389 (the unencrypted LDAP port); encryption is then turned on by a StartTLS call.

  InterSystems also recommends setting the LDAP server signing requirements parameter to Require signature on the Active Directory Server. This prevents any LDAP bind command on the server on port 389 to be executed unless the channel is encrypted with StartTLS. For more information, see Domain Controller: LDAP Server Signing RequirementsOpens in a new tab article on the Microsoft web site.

• File with Certificate Authority certificate(s) to authenticate the LDAP server — UNIX® only. The location of the file containing any TLS certificates (in PEM format) being used to authenticate the server.

  On Windows, to specify the location of a file containing any TLS certificates (in PEM format) being used to authenticate the server certificate to establish a secure LDAP connection, use Microsoft Certificate ServicesOpens in a new tab. Certificates must be installed in the Certificates (Local Computer)\Trusted Root Certification Authorities certificate store.

• Allow ISC_LDAP_CONFIGURATION environment variable — If you are using OS-based LDAP and multiple domains, specifies whether or not to use the ISC_LDAP_CONFIGURATION environment variable. If the environment variable is defined, then OS-based LDAP uses it to determine which LDAP configuration to use for authentication.

• Use LDAP Groups for Roles/Routine/Namespace — Whether or not the user’s roles, routine, and namespace come from the user’s group memberships (true by default); if not, then they come from the attribute fields of the user’s LDAP record. If you select this field, the system enables and disables other fields (see each subsequent field for details).

  Note:

  InterSystems recommends the use of LDAP groups for authorization, rather than LDAP attributes (including InterSystems registered LDAP properties). If you have existing code or are otherwise required to use registered properties, see Configure Authorization with LDAP Attributes for details.

• Search Nested Groups for Roles/Routine/Namespace — Only active if LDAP server is a Windows Active Directory server and Use LDAP Groups for Roles/Routine/Namespace are selected. Whether or not search returns all of a user’s nested groups. See Nested Groups for more information on nested groups.

• Organization ID prefix for group names — Only active if Use LDAP Groups for Roles/Routine/Namespace is selected. See LDAP Group Name Configuration for more information.

• Allow Universal group Authorization — Only active if Use LDAP Groups for Roles/Routine/Namespace is selected. Whether or not searches use the attributes on the LDAP server that are relevant for all InterSystems IRIS instances. See Create Universal LDAP Authorization Groups for more information.

• Authorization Group ID — Only active if Use LDAP Groups for Roles/Routine/Namespace is selected. The multiple-instance group to which this instance belongs. See Create LDAP Authorization Groups for Multiple Instances (Multiple-Instance Groups) for more information.

• Authorization Instance ID — Only active if Use LDAP Groups for Roles/Routine/Namespace is selected. The single-instance group to which this instance belongs. See Create LDAP Authorization Groups for a Single Instance (Single-Instance Groups) for more information.

• User attribute to retrieve default namespace (not active if LDAP groups are selected) — The attribute whose value is the source for the Startup namespace property for a user. This property of an InterSystems IRIS user is described in User Account Properties; this LDAP property is described in Configure Authorization with LDAP Attributes.

• User attribute to retrieve default routine (not active if LDAP groups are selected) — The attribute whose value is the source for the Tag^Routine property for a user. This property of an InterSystems IRIS user is described in User Account Properties; this LDAP property is described in Configure Authorization with LDAP Attributes.

• User attribute to retrieve roles (not active if LDAP groups are selected) — The attribute whose value determines the roles to which a user is assigned. When creating this attribute, it must be specified as an LDAP multivalued attribute. For information about an InterSystems IRIS user’s roles, see the Roles tab of a user’s Edit User page; this LDAP property is described in Configure Authorization with LDAP Attributes.

• User attribute to retrieve comment attribute — The attribute whose value is the source for the Comment property for a user. This property is described in User Account Properties. Once a user has logged in, you can retrieve the value of this property using the Security.Users.Get() method.

• User attribute to retrieve full name from — The attribute whose value is the source for the Full name property for a user. This property is described in User Account Properties. Once a user has logged in, you can retrieve the value of this property using the Security.Users.Get() method.

• User attribute to retrieve mail address — The attribute whose value is the source for the Email address property for a user. This property is described in User Account Properties. Once a user has logged in, you can retrieve the value of this property using the Security.Users.Get() method.

• User attribute to retrieve mobile phone — The attribute whose value is the source for the Mobile Phone Number property for a user. This property is described in User Account Properties. Once a user has logged in, you can retrieve the value of this property using the Security.Users.Get() method.

• User attribute to retrieve mobile provider from — The attribute whose value is the source for the Mobile Phone Service Provider property for a user. This property is described in User Account Properties. Once a user has logged in, you can retrieve the value of this property using the Security.Users.Get() method.

• LDAP attributes to retrieve for each user — Any attributes whose values are the source for any application-specific variables. Application code can then use the Get method of the Security.UsersOpens in a new tab class to return this information.

The values of the fields of an LDAP configuration are stored in an instance of the Security.LDAPConfigsOpens in a new tab class.

Note on LDAP/Kerberos Configuration Fields

If Kerberos authentication is enabled for an instance, then the page for creating an LDAP configuration is Edit LDAP/Kerberos configurations page. It has the same fields as the Edit LDAP configurations page, as described in LDAP Configuration Fields.

The Security LDAP Configurations Page

The Portal’s Security LDAP Configurations page (System Operation > LDAP Configurations) displays a list of the instance’s LDAP configurations. Click the name of a configuration to view its properties. If Kerberos authentication is enabled for the instance, this is called the Security LDAP/Kerberos configurations page (System Operation > LDAP/Kerberos configurations).

LDAP Groups and InterSystems IRIS

LDAP groups allow you to assign privileges to users using an LDAP server:

• The schema on the LDAP server specifies the names of groups. Typically, the LDAP administrator defines these names; InterSystems IRIS uses one of three predefined name structures described below.

• Each group has a distinguished name (DN) that uniquely identifies it.

• Each group specifies access to an InterSystems IRIS role, routine, or namespace

InterSystems IRIS supports LDAP groups that provide authorization for:

• A single instance

• Multiple instances

• All instances

To set up groups for InterSystems IRIS:

1. Determine if you are going to use groups for a single instance, for multiple instances, or for all instances.

2. Create one or more groups with names that follow the appropriate naming convention. Each group specifies a user’s role, default namespace, or default routine; since a user can have multiple roles, it is valid to belong to multiple groups that specify roles.

   Note:

   Note that when defining these groups on your LDAP server, they should be created as security groups, and not distribution groups.

3. Configure your LDAP users to specify which ones belong to which groups. This requires that, for each user’s LDAP account, you assign the user to multiple groups to specify one or more roles, a default namespace, and a default routine. This determines which roles each user has after logging in, the user’s default namespace, and the user’s default routine.

4. Configure the local InterSystems IRIS instance so that there are definitions for all the roles that are specified on the LDAP server.

LDAP Authorization Group Models

InterSystems IRIS supports for three kinds of group authorization using LDAP.

• Create LDAP authorization groups for a single instance (single-instance groups)

• Create LDAP authorization groups for multiple instances (multiple-instance groups), including mirroring

• Create universal LDAP authorization groups

intersystems-Instance-Node1_Test-Role-Administrator
intersystems-Instance-Node1_Test-Role-LocalApplication 
intersystems-Instance-Node1_Test-Role-%All 
intersystems-Instance-Node1_Test-Routine-LocalApplication 
intersystems-Instance-Node1_Test-Routine-%SS
intersystems-Instance-Node1_Test-Routine-%pmode
intersystems-Instance-Node1_Test-Namespace-%SYS
intersystems-Instance-Node1_Test-Namespace-USER

intersystems-Group-SALESAPP-Role-%All
intersystems-Group-SALESAPP-Role-LocalApplication 
intersystems-Group-SALESAPP-Routine-LocalApplication
intersystems-Group-SALESAPP-Routine-%pmode
intersystems-Group-SALESAPP-Namespace-USER
intersystems-Group-SALESAPP-Namespace-%SYS
intersystems-Group-SALESDB-Role-Administrator
intersystems-Group-SALESDB-Routine-INTEGRIT
intersystems-Group-SALESDB-Namespace-%SYS

intersystems-Role-%All
intersystems-Role-Administrator
intersystems-Role-LocalApplication
intersystems-Routine-%SS
intersystems-Routine-LocalApplication
intersystems-Namespace-USER
intersystems-Namespace-%SYS

LDAP Group Definition Structure

Group definitions typically include:

• The group name

• A declaration of the group’s organizational unit: OU=Groups

• A declaration of the domain component (DC) such as DC=example,DC=com

• Any other required information

For example, some possible group definitions might be:

CN=intersystems-Role-Administrator,OU=Groups,DC=intersystems,DC=com
CN=intersystems-Group-MyGroup-Namespace-USER,OU=Groups,DC=intersystems,DC=com
CN=intersystems-Instance-MyNode:MyInstance-Routine-INTEGRIT,OU=Groups,DC=intersystems,DC=com 

LDAP Group Name Configuration

InterSystems IRIS allows you to further configure LDAP group names. The following sections describe the default configuration, the configurable properties, and the procedure to change them.

Mix Different Kinds of Groups

You can use universal groups in conjunction with single-instance or multiple-instance roles.

For example, suppose you:

• Have an application on multiple instances

• Are using universal groups

• Have a user named UserOne who can run the application on all instances, but cannot use it as an administrator on any machine

You would like for UserOne to:

• Continue to be able to run the application on all instance

• Additionally, to be able to administer the application on a particular instance, called APPTEST, on a particular machine, called Test

To do this:

1. Set the authorization instance ID on the APPTEST instance on the Test machine to Test:APPTEST

2. Create the following group on the LDAP server:

   intersystems-Instance-Test_APPTEST-Role-Administrator

3. Assign this group to UserOne on the LDAP server

4. Create the Administrator role on the APPTEST instance on the Test machine and grant it administrative access

You can also mix authorization groups in other ways. For example, if UserTwo has %All permission on all the instances authenticating to the LDAP server, you can give UserTwo exclusive administrative permission on an instance called SECRET on a machine called Server10. To do this, disable Allow universal groups access and then go through the process of assigning an intersystems-Instance-Server10_SECRET-Role-Administrator to that user.

Nested Groups

On an Active Directory LDAP server, LDAP groups include support for what are known as nested groups. A nested group is a group that is a member of a parent group, which means that all the users who are members of the nested group are implicitly members of the parent group. For example, suppose that there are two LDAP groups defined, known as ABC and DEF. You can make ABC a nested group within DEF; this means that, if a user is a member of ABC, then they are also a member of DEF without explicitly assigning the user to that group.

When searching for a user’s nested groups, InterSystem IRIS returns only groups that are defined as Security Groups on the LDAP server. If you are using nested groups, ensure that any group used as a role for an InterSystems IRIS system is created as a Security Group.

How LDAP Groups Regulate Access to InterSystems IRIS

Through their LDAP groups, users receive roles along with a default namespace and a default routine. If the user’s granted roles lack sufficient privilege for any required point of access for an instance, the user then is denied access to that instance; for example, if a user lacks sufficient privilege to use their default routine, that user is denied access.

The following rules also apply:

• If a user is assigned to a group for a role, but that role is not defined on the instance where the user is logging in, then the user does not have that role on that instance.

• If a user is assigned to a group for a default routine, but that routine is not defined on the instance where the user are logging in, then the user cannot connect to the instance.

• If a user is assigned to a group for a default namespace, but that namespace is not defined on the instance where the user are logging in, then the user cannot connect to the instance.

Operating System LDAP Authentication

InterSystems IRIS allows you to configure your system to support operating system–based authentication, and then to perform authorization via LDAP. This is known as Operating System LDAP authorization or OS/LDAP. It allows a user to authenticate to InterSystems IRIS using credentials from the operating system login and then to have their authorization information retrieved from an LDAP server. Operating system LDAP authorization is available in the Console on Windows and in the Terminal and on UNIX®, Linux, and macOS.

To configure OS/LDAP:

1. Enable OS-based authentication with LDAP authorization for an InterSystems IRIS instance.

2. As with standard LDAP authentication, set up a role that is required in order to be able to log in to the instance.

3. Enable OS/LDAP for the %Service_Console and %Service_Terminal services.

4. Configure authorization. This occurs in the same manner as that which accompanies LDAP authentication, as described in Configure LDAP Authorization for InterSystems IRIS.

5. If you are using multiple domains, optionally configure OS/LDAP for simplified prompting.

Enable OS/LDAP for an InterSystems IRIS Instance

To use OS/LDAP, first enable it for the instance:

1. From the Management Portal home page, go to the Authentication/Web Session Options page (System Administration > Security > System Security > Authentication/Web Session Options).

2. On the Authentication/Web Session Options page, select Allow Operating Systems LDAP authentication.

3. Click Save to apply the changes.

Enable OS/LDAP for the %Service_Console and %Service_Terminal Services

To enable OS/LDAP for the instance’s relevant services or applications:

1. With LDAP authentication enabled for the instance, an Operating System LDAP Authorization check box appears on the Edit Service page for %Service_Console and %Service_Terminal, which are the services that support OS/LDAP.

2. Enable LDAP authentication for those services, as appropriate.

OS/LDAP with a Single Domain and Multiple Domains

OS/LDAP supports the use of a single domain or multiple domains.

When InterSystems IRIS is configured to support only a single domain:

1. The system prompts the user for a username and password for the first login.

2. For subsequent logins, there is no prompt because the operating system has already authenticated the user.

When InterSystems IRIS is configured to support multiple domains:

1. The system prompts the user for a username and password for the first login.

2. For subsequent logins, the operating system prompts for a username and password by default. You can configure InterSystems IRIS to prevent this prompting; see the next section.

Configure OS/LDAP with Multiple Domains for Simplified Prompting

If you are using OS/LDAP and multiple domains, you can configure the instance for simplified prompting. By default, users are prompted for a username and password at every login. You can configure InterSystems IRIS so that there is only a username/password prompt when a user first logs in, and that subsequent connections are authenticated without prompting.

To configure InterSystems IRIS for this behavior:

1. For each user, create the environment variable ISC_LDAP_CONFIGURATION with a value of the domain in which the user is authenticating.

2. For each domain in which users are authenticating:

   1. Ensure that there is an LDAP configuration or create one.

   2. For that LDAP configuration, select the Allow ISC_LDAP_CONFIGURATION environment variable check box, which enables use of the environment variable.

How LDAP Performs Authentication and Authorization

When a user attempts to authenticate to an instance of InterSystems IRIS that uses LDAP authentication, the process is:

1. The user is prompted for a user name and password. This user, who is trying to authenticate, is known as the target user.

2. InterSystems IRIS establishes a connection to the LDAP server using the values specified for the LDAP username to use for searches and LDAP username password. This user, who has privileges to search the LDAP database so that InterSystems IRIS can retrieve information, is known as the search user.

3. Once the connection is established, the next step is to look up the target user in the LDAP database using the LDAP Unique search attribute.

4. If the target user is found in the LDAP database, it retrieves the attributes associated with the user, such as the user’s roles, namespace, and routine.

5. InterSystems IRIS then attempts to authenticate the user to the LDAP database, using the user name and password provided in step 1.

6. If authentication succeeds, authorization occurs on the LDAP server (either via group assignment or attributes). The user can then interact with InterSystems IRIS based on the privileges associated with their roles and any publicly available resources. The user’s properties are displayed read-only in the Management Portal and are not editable from within InterSystems IRIS.

How LDAP Looks Up the Target User in Its Database

Once InterSystems IRIS has established a connection to the LDAP server as the search user, it next retrieves information about the target user. To do this, InterSystems IRIS checks the username provided at login against values in the LDAP database for the LDAP Unique search attribute. The name of this attribute is often “sAMAccountName” for an Active Directory LDAP server and “uid” for an OpenLDAP server.

Once InterSystems IRIS has located the user, it retrieves attribute information. It retrieves information about every named attribute in the InterSystems IRIS LDAP configuration fields (described in Create or Modify an LDAP Configuration), and it retrieves all values associated with each attribute. Note that InterSystems IRIS retrieves all values associated with all attributes specified for the user in the InterSystems IRIS LDAP configuration fields; it is not possible to configure it to retrieve only a subset of these.

How an Instance Checks and Removes Local Accounts Based on LDAP Account Conditions

InterSystems IRIS removes a user account on the local instance when the account meets any of the following conditions:

• The LDAP account no longer exists

• The LDAP account is disabled

• On Active Directory only, the LDAP account has the flag set to require a password change

• On Active Directory only, the LDAP account is expired

InterSystems IRIS checks for these conditions and removes accounts under the following circumstances:

• When a user attempts to log in to an InterSystems IRIS instance, the instance checks the user’s LDAP account. If any of the specified conditions are true for the LDAP account, InterSystems IRIS removes the local user account.

• As a result of the SecurityScan task. InterSystems IRIS comes with this task; run it to determine if any of these conditions are true for the LDAP account associated with any local user account. If so, InterSystems IRIS removes the local user account.