Configure saslauthd

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    saslauthd is a daemon process that handles plaintext authentication requests on behalf of the SASL library.

    LDAP and Legacy saslauthd Authentication

    Couchbase Server provides Native LDAP support. This allows external users to be authenticated by LDAP, and provides support for LDAP groups. For details on using this recommended procedure, see Configure LDAP.

    The saslauthd process can still be used to support authentication on LDAP or other servers if required. In LDAP authentication, the saslauthd process handles authentication requests on behalf of Couchbase Server while the LDAP protocol is used to connect to the LDAP server. The saslauthd agent, which must be installed and configured on each Couchbase Server node.

    Note that either Native LDAP Support or saslauthd must be selected for the cluster. The two cannot be used simultaneously.

    Note also that both Native LDAP Support and saslauthd require clients to use the PLAIN authentication mechanism, ideally with TLS.

    For an overview of authentication options on Couchbase Server, see Authentication.

    Migrating from saslauthd to Native LDAP

    If you have been using saslauthd with previous versions of Couchbase Server, you are strongly recommended to migrate to Native LDAP. See Authentication Domains for a full account of the benefits.

    To migrate, proceed as follows:

    1. Configure Native LDAP. This is described in detail, in Configure LDAP.

      Note that the procedure provides two principal options, which are Enable LDAP user authentication and Enable LDAP group authorization & sync. During your configuration procedure:

      • You must select Enable LDAP user authentication, and then configure associated details.

      • If LDAP group authorization is required, you can select Enable LDAP group authorization & sync, and then configure associated details. Alternatively, you can leave this option disabled for now: it does not need to have been enabled, for migration to succeed. Instead, it can be enabled and configured later, after migration has been completed.

    2. Disable saslauthd authentication, as follows:

      couchbase-cli setting-saslauthd -c 10.143.192.101:9001 -u Administrator -p password --enabled 0
    3. Perform appropriate tests, to ensure that authentication with Native LDAP is working correctly.

      • If you encounter any problems, you can re-enable saslauthd, and continue to rely on it while you troubleshoot your environment.

      • If there are no problems, stop the saslauthd daemon. All authentication for external users is now handled by Native LDAP.

    This completes the migration process.

    Supported Packages

    If you have chosen to support external authentication by means of saslauthd, install your Unix operating system with the saslauthd package that is supported for LDAP integration.

    Make sure that you have the prerequisites for the LDAP software you are installing, such as OpenLDAP libraries. On RPM-based distros, installation packages are a part of cyrus-sasl rpm, so make sure that it is installed.

    CentOS 6

    saslauthd 2.1.23 or higher

    CentOS 7

    saslauthd 2.1.26 or higher

    Ubuntu

    saslauthd 2.1.25 or higher

    SUSE

    saslauthd 2.1.23 or higher

    Preparation

    Make sure your LDAP setup is working, by running a test ldapsearch as follows:

    ldapsearch -LLL -H ldap://ldapserver:389 -D cn=someuser,ou=users,dc=mydomain,dc=com -w Passw0rd -x -bou=users,dc=mydomain,dc=com cn=someuser

    Install saslauthd

    Install the saslauthd package on your operating system. On Ubuntu, install saslauthd with the following command:

    sudo apt-get install sasl2-bin

    Determine mux File Location

    To communicate with the LDAP server, Couchbase Server makes use of the mux file provided by the saslauthd package. The location of the mux file varies, according to distribution. Couchbase Server checks for the file at two locations, which are /var/run/sasl2/mux and /var/run/saslauthd/mux.

    • Debian/Ubuntu: By default, the file is located at /var/run/sasl2/mux.

    • RHEL/CentOS 6: By default, the file is located at at /var/run/saslauthd/mux.

    • RHEL/CentOS 7: By default, the file is located at /run/saslauthd/mux; but a symlink from /var/run to /run/ allows Couchbase Server to access the file at /var/run/saslauthd/mux.

    If, on your system, the location of the mux file is neither /var/run/sasl2/mux nor /var/run/saslauthd/mux, set the CBAUTH_SOCKPATH environment variable to the mux file’s actual location. Couchbase Server will attempt to access the mux file there.

    Getting Started with saslauthd and LDAP

    1. Ensure that the Couchbase Cluster is running. Then, enable external authentication on the cluster, using the Couchbase CLI setting-saslauthd command: specifying server IP-address and port number, username and password:

      couchbase-cli setting-saslauthd -c 10.143.192.101 \
      --username Administrator \
      --password password \
      --enabled 1

      Note that --enabled 1 enables external authentication, and --enabled 0 disables. See setting-saslauthd for further information. When successfully executed, the command provides the following notification: SUCCESS: saslauthd settings modified.

    2. Configure the MECHANISMS option for ldap.

      Red Hat Enterprise Linux, CentOS, and Amazon Linux AMI edit /etc/sysconfig/saslauthd (/etc/default/saslauthd on Debian/Ubuntu) to set the mechanism MECH to ldap:

      MECH=ldap

      Ubuntu and Debian edit /etc/default/saslauthd, setting MECHANISMS option to ldap:

      MECHANISMS=ldap

      On Debian and Ubuntu, you should also add Couchbase to the sasl group:

      sudo adduser couchbase sasl
    3. The default configuration file used to obtain the LDAP configuration parameters is located at /usr/local/etc/saslauthd.conf. Open this in your editor of choice.

    4. Set up ldap_servers

      Specify URIs of the LDAP servers used for authentication, such as ldap:///10.1.1.11/, ldap://10.1.1.12/. Multiple LDAP servers can be specified in the list, which is then tested to find out whether one of the servers is offline. If you install OpenLDAP on the local host machine, you can specify the value ldap://localhost:389.

      If using LDAP over SSL, you can specify the value ldaps://localhost:636.

      ldap_servers: ldaps://10.1.1.25 ldaps://10.1.1.15
    5. Set up ldap_search_base

      Specify the distinguished name to which the search is relative. The search includes the base or objects below.

      It also includes Domain Components (dc) such as in dc=company and dc=com.

      The administrative users created in LDAP with the attribute uid are placed under the user’s organizational unit ou under the two domain components (example and com).

      ldap_search_base: ou=Users,dc=company,dc=com
    6. Set up ldap_filter

      Specify the search filter. The values for these configuration options correspond to the values specific to the test. For example, to filter on email specify ldap_filter: (mail=%n).

      ldap_filter: (uid=%u)

      Configure LDAP options /etc/saslauthd.conf:

      ldap_servers: ldaps://ad.example.net
      ldap_search_base: ou=Users,dc=example,dc=com
      ldap_filter: (uid=%u)
    7. Running automatically

      For sasld to run automatically on start up, you’ll need to change the START value to YES.

      START = yes
    8. Optionally, set up TLS.

      If you wish to use saslauthd with TLS, add the following to your saslauthd.conf file:

      ldap_start_tls: yes
      ldap_tls_cacert_dir: <your-cert-directory>
      ldap_tls_cacert_file: <your-crt-file>

      Note that once you have added these lines, your inclusion of ldap_start_tls: yes means that you may not now use ldaps:<ldap_server> in your LDAP server configurations: therefore, if necessary, remove it.

      Note also that you can use TCPtrace, to verify that TLS is enabled between saslauthd and LDAP.

    9. Test yoursaslauthdset-up.

      If the connection is properly working, the user couchbase must have access to /var/run/saslauthd/mux (or the appropriate alternate directory for SUSE), in order to communicate to saslauthd.

      1. Start the saslauthd service (or set it to start automatically with chkconfig).

        service saslauthd restart
        Stopping saslauthd:                             [  OK  ]
        Starting saslauthd:                             [  OK  ]
        
        chkconfig  saslauthd on
        chkconfig --list saslauthd
        saslauthd   	0:off   1:off   2:on	3:on	4:on	5:on	6:off
      2. Test saslauthd by using the testsaslauth script to test LDAP authentication:

        sudo -u couchbase /usr/sbin/testsaslauthd -u <username> \
        -p mypassword -f /var/run/saslauthd/mux
        0: OK "Success."
    10. Restart the Couchbase service, to allow authentication through the changed configuration.

      $ sudo service couchbase-server restart

    Example

    Putting the above steps into typical configuration files:

    cat /etc/saslauthd.conf
    # ldap_servers: ldap:<URI>:<PORT> or ldaps:<URI>:<PORT> for TLS protected connection
    ldap_servers: ldap://my.company.com:389
    # The administrative users created in LDAP with the attribute uid are placed under the user's
    # organizational unit ou under the two domain components (example and com).
    ldap_search_base: OU=InteractiveUsers,DC=my,DC=company,DC=com
    # Specifies the search filter. The values for these configuration options correspond to the
    # values specific to the test
    ldap_filter: uid=%u
    # Optional: specify a user to perform ldap queries
    ldap_bind_dn: CN=user_ldap,OU=Users,DC=my,DC=company,DC=com
    # Optional: specify ldap user’s password
    ldap_password: -sEcReTp#AssWoRd!
    cat /etc/sysconfig/saslauthd
    # Just keep the default
    SOCKETDIR=/var/run/saslauthd
    # Make sure MECH is set to ldap (pam is default)
    MECH=ldap
    # Include the config file described above
    FLAGS="-O /etc/saslauthd.conf"

    Configuring saslauthd with Windows Active Directory

    A common requirement is to delegate some or all authentication to another LDAP server. Here is a sample saslauthd configuration that uses Microsoft Active Directory (AD) as the LDAP server:

    Here is a sample saslauthd configuration with Microsoft Active Directory (AD):

    ldap_servers: ldap://dc1.example.com:<port>
    ldap_search_base: cn=Users,DC=ad,DC=example,DC=com
    ldap_filter: sAMAccountName=%u
    ldap_bind_dn: cn=saslauthd,cn=Users,DC=ad,DC=example,DC=com
    ldap_password: secret

    Troubleshooting LDAP Settings

    After you set up the LDAP server, saslauthd, and LDAP administrators, likely causes of problems include:

    • Firewall ports are not open for LDAP.

    • The Proxy did not start or has started with an inappropriate protocol or hostname.

    • The configuration of saslauthd is incorrect (look at /etc/sysconfig/saslauthd or /etc/saslauthd.conf)

    • The LDAP filters are not correct.

    • You can also encounter error messages from the system. These errors belong either to issues caused by saslauthd or the LDAP server.