Scripted Kerberos Connector

New in OpenIDM 4.5.0, the scripted Kerberos connector is an implementation of the scripted SSH connector, and is based on Java Secure Channel (JSch) and the Java implementation of the Expect library (Expect4j). The connector depends on the following files, provided with OpenIDM:

  • /path/to/openidm/lib/ssh-connector-1.4.0.0.jar

  • /path/to/openidm/lib/expect4j-<version>.jar

  • /path/to/openidm/lib/jsch-<version>.jar

The Kerberos connector enables you to manage Kerberos user principals from OpenIDM. The connector is provided in /path/to/openidm/connectors/kerberos-connector-1.4.0.0.jar and bundles a number of Groovy scripts to interact with a Kerberos admin server. Users of the Kerberos connector are not expected to edit the bundled Groovy scripts. The bundled scripts use the kadmin utility to communicate with the Kerberos server.

The Kerberos connector enables you to perform the following operations on Kerberos user principals.

  • List the existing principals

  • Display the details of a principal

  • Add a user principal

  • Change the password of a user principal and unlock the principal

  • Delete a user principal

Kerberos Connector Schema

The Kerberos connector can only be used to manage the Kerberos principal object type (which maps to the OpenICF ACCOUNT object). The following attributes are supported in the schema:

  • principal - (maps to NAME and UID)

  • PASSWORD - updatable, required when an object is created

  • LOCK_OUT - updatable only; unlock an account by setting this attribute to false

  • policy - the password policy used by the principal

  • expirationDate - the date that the user principal expires

  • passwordExpiration - the date that the password expires

  • maximumTicketLife - the maximum ticket life for the principal. At the end of the ticket lifetime, the ticket can no longer be used. However, if the renewable lifetime (maximumRenewableLife) is longer than the ticket lifetime, the ticket holder can present the ticket to the KDC and request a new ticket.

  • maximumRenewableLife - the period during which the ticket can be renewed. A renewed ticket usually has a new ticket lifetime, dating from the time that it was renewed, that is constrained by the renewable ticket lifetime.

In addition, the following read-only attributes are supported:

  • lastPasswordChange

  • lastModified

  • lastSuccessfulAuthentication

  • lastFailedAuthentication

  • failedPasswordAttempts

Configuring the Kerberos Connector

OpenIDM provides a sample connector configuration (provisioner.openicf-kerberos.json) in the /path/to/openidm/samples/kerberos/conf/ directory. You can copy the sample connector configuration to your project’s conf/ directory, and adjust it to match your Kerberos environment.

Set the authentication properties, as described in "Configuring Authentication to the SSH Server". In addition, set at least the following properties:

customConfiguration

Specify the details of the user principal and the default realm here. The sample provisioner file has the following custom configuration:

"customConfiguration" : "kadmin{
  cmd = '/usr/sbin/kadmin.local';
  user = '<KADMIN USERNAME>';
  default_realm = '<REALM, e.g. EXAMPLE.COM>'
}",

A complete custom configuration will look something like this:

"customConfiguration" : "kadmin {
       cmd = '/usr/sbin/kadmin.local';
       user = 'openidm/admin';
       default_realm = 'EXAMPLE.COM' }",
customSensitiveConfiguration

Set the password for the user principal here. The sample provisioner has the following configuration:

"customSensitiveConfiguration" : "kadmin { password = '<KADMIN PASSWORD>'}",

Change this to reflect your user principal password, for example:

"customSensitiveConfiguration" : "kadmin { password = 'Passw0rd'}"

The following section describes the configuration parameters in the sample Kerberos connector configuration. For a complete list of the configuration properties for the Kerberos connector, see "Configuration Properties":

host

The host name or IP address of the SSH server on which the kadmin command is run.

port

The port number on which the SSH server listens.

Default: 22 (the default SSH port)

user

The username of the account that is used to connect to the SSH server.

This is not the same as your Kerberos user principal. This account must be able to ssh into the server on which Kerberos is running, with the password provided in the next parameter.
password

The password of the account that is used to connect to the SSH server.

prompt

A string representing the remote SSH session prompt. This must be the exact prompt string, in the format username@target:, for example root@localhost:~$.

If the prompt includes a trailing space, you must include the space in the value of this property.

Consider customizing your Linux prompt with the PS1 and PS2 variables, to set a safe prompt. For information about customizing promtps, see this article.

sudoCommand

A string that shows the full path to the sudo command, for example /usr/bin/sudo.

echoOff

If set to true (the default), the input command echo is disabled. If set to false, every character that is sent to the server is sent back to the client in the expect() call.

terminalType

Sets the terminal type to use for the session. The list of supported types is determined by your Linux/UNIX system. For more information, see the terminfo manual page ($ man terminfo).

Default: vt102

setLocale

If set to true, indicates that the default environment locale should be changed to the value of the locale property.

Default: false

locale

Sets the locale for LC_ALL, LANG and LANGUAGE environment variables, if setLocale is set to true.

Default: en_US.utf8

connectionTimeout

Specifies the connection timeout to the remote server, in milliseconds.

Default: 5000

expectTimeout

Specifies the timeout used by the expect() calls in scripts, in milliseconds.

Default: 5000

authenticationType

Sets the authentication type, either PASSWORD or PUBKEY. For more information, see "Configuring Authentication to the SSH Server".

Default: PASSWORD

throwOperationTimeoutException

If true, the connector throws an exception when the timeout is reached for an operation. Otherwise, the operation fails silently.

Default: true

scriptRoots

The path to the Groovy scripts that will perform the OpenICF operations, relative to your OpenIDM installation directory. For the Kerberos connector, the scripts are bundled up in the connector JAR file, so this path is set to \jar:file:connectors/kerberos-connector-1.4.0.0.jar!/script/kerberos/ in the sample connector configuration.

classpath

The directory in which the compiler should look for compiled classes. The default classpath, if not is specified, is install-dir/lib.

reloadScriptOnExecution

By default, scripts are loaded and compiled when a connector instance is created and initialized. Setting reloadScriptOnExecution to true makes the connector load and compile the script every time it is called. Do not set this property to true in a production environment, because it will have a significant impact on performance.

Default: false

*ScriptFileName

The script that is used for each OpenICF operation. Do not change these script names in the bundled Kerberos connector.

OpenICF Interfaces Implemented by the Kerberos Connector

The Kerberos Connector implements the following OpenICF interfaces.

Authenticate

Provides simple authentication with two parameters, presumed to be a user name and password.

Create

Creates an object and its uid.

Delete

Deletes an object, referenced by its uid.

Resolve Username

Resolves an object by its username and returns the uid of the object.

Schema

Describes the object types, operations, and options that the connector supports.

Script on Connector

Enables an application to run a script in the context of the connector. Any script that runs on the connector has the following characteristics:

  • The script runs in the same execution environment as the connector and has access to all the classes to which the connector has access.

  • The script has access to a connector variable that is equivalent to an initialized instance of the connector. At a minimum, the script can access the connector configuration.

  • The script has access to any script-arguments passed in by the application.

Script on Resource

Runs a script on the target resource that is managed by this connector.

Search

Searches the target resource for all objects that match the specified object class and filter.

Sync

Polls the target resource for synchronization events, that is, native changes to objects on the target resource.

Test

Tests the connector configuration. Testing a configuration checks all elements of the environment that are referred to by the configuration are available. For example, the connector might make a physical connection to a host that is specified in the configuration to verify that it exists and that the credentials that are specified in the configuration are valid.

This operation might need to connect to a resource, and, as such, might take some time. Do not invoke this operation too often, such as before every provisioning operation. The test operation is not intended to check that the connector is alive (that is, that its physical connection to the resource has not timed out).

You can invoke the test operation before a connector configuration has been validated.

Update

Updates (modifies or replaces) objects on a target resource.

Kerberos Connector Configuration

The Kerberos Connector has the following configurable properties.

Configuration Properties

Property

Type

Default

Encrypted

Required

Operation Script Files Properties

Property

Type

Default

Encrypted

Required

Groovy Engine configuration Properties

Property

Type

Default

Encrypted

Required

Basic Configuration Properties Properties

Property

Type

Default

Encrypted

Required