Edit file File name : conf_ldap.html Content : <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Configuring Kerberos with OpenLDAP back-end — MIT Kerberos Documentation</title> <link rel="stylesheet" href="../_static/agogo.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <link rel="stylesheet" href="../_static/kerb.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="Application servers" href="appl_servers.html" /> <link rel="prev" title="Account lockout" href="lockout.html" /> </head><body> <div class="header-wrapper"> <div class="header"> <h1><a href="../index.html">MIT Kerberos Documentation</a></h1> <div class="rel"> <a href="../index.html" title="Full Table of Contents" accesskey="C">Contents</a> | <a href="lockout.html" title="Account lockout" accesskey="P">previous</a> | <a href="appl_servers.html" title="Application servers" accesskey="N">next</a> | <a href="../genindex.html" title="General Index" accesskey="I">index</a> | <a href="../search.html" title="Enter search criteria" accesskey="S">Search</a> | <a href="mailto:krb5-bugs@mit.edu?subject=Documentation__Configuring Kerberos with OpenLDAP back-end">feedback</a> </div> </div> </div> <div class="content-wrapper"> <div class="content"> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="configuring-kerberos-with-openldap-back-end"> <span id="conf-ldap"></span><h1>Configuring Kerberos with OpenLDAP back-end<a class="headerlink" href="#configuring-kerberos-with-openldap-back-end" title="Permalink to this headline">ΒΆ</a></h1> <blockquote> <div><ol class="arabic"> <li><p class="first">Make sure the LDAP server is using local authentication (<code class="docutils literal notranslate"><span class="pre">ldapi://</span></code>) or TLS (<code class="docutils literal notranslate"><span class="pre">ldaps</span></code>). See <a class="reference external" href="https://www.openldap.org/doc/admin24/tls.html">https://www.openldap.org/doc/admin24/tls.html</a> for instructions on configuring TLS support in OpenLDAP.</p> </li> <li><p class="first">Add the Kerberos schema file to the LDAP Server using the OpenLDAP LDIF file from the krb5 source directory (<code class="docutils literal notranslate"><span class="pre">src/plugins/kdb/ldap/libkdb_ldap/kerberos.openldap.ldif</span></code>). The following example uses local authentication:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">ldapadd</span> <span class="o">-</span><span class="n">Y</span> <span class="n">EXTERNAL</span> <span class="o">-</span><span class="n">H</span> <span class="n">ldapi</span><span class="p">:</span><span class="o">///</span> <span class="o">-</span><span class="n">f</span> <span class="o">/</span><span class="n">path</span><span class="o">/</span><span class="n">to</span><span class="o">/</span><span class="n">kerberos</span><span class="o">.</span><span class="n">openldap</span><span class="o">.</span><span class="n">ldif</span> </pre></div> </div> </li> <li><p class="first">Choose DNs for the <a class="reference internal" href="admin_commands/krb5kdc.html#krb5kdc-8"><span class="std std-ref">krb5kdc</span></a> and <a class="reference internal" href="admin_commands/kadmind.html#kadmind-8"><span class="std std-ref">kadmind</span></a> servers to bind to the LDAP server, and create them if necessary. Specify these DNs with the <strong>ldap_kdc_dn</strong> and <strong>ldap_kadmind_dn</strong> directives in <a class="reference internal" href="conf_files/kdc_conf.html#kdc-conf-5"><span class="std std-ref">kdc.conf</span></a>. The kadmind DN will also be used for administrative commands such as <a class="reference internal" href="admin_commands/kdb5_util.html#kdb5-util-8"><span class="std std-ref">kdb5_util</span></a>.</p> <p>Alternatively, you may configure krb5kdc and kadmind to use SASL authentication to access the LDAP server; see the <a class="reference internal" href="conf_files/kdc_conf.html#dbmodules"><span class="std std-ref">[dbmodules]</span></a> relations <strong>ldap_kdc_sasl_mech</strong> and similar.</p> </li> <li><p class="first">Specify a location for the LDAP service password file by setting <strong>ldap_service_password_file</strong>. Use <code class="docutils literal notranslate"><span class="pre">kdb5_ldap_util</span> <span class="pre">stashsrvpw</span></code> to stash passwords for the KDC and kadmind DNs chosen above. For example:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">kdb5_ldap_util</span> <span class="n">stashsrvpw</span> <span class="o">-</span><span class="n">f</span> <span class="o">/</span><span class="n">path</span><span class="o">/</span><span class="n">to</span><span class="o">/</span><span class="n">service</span><span class="o">.</span><span class="n">keyfile</span> <span class="n">cn</span><span class="o">=</span><span class="n">krbadmin</span><span class="p">,</span><span class="n">dc</span><span class="o">=</span><span class="n">example</span><span class="p">,</span><span class="n">dc</span><span class="o">=</span><span class="n">com</span> </pre></div> </div> <p>Skip this step if you are using SASL authentication and the mechanism does not require a password.</p> </li> <li><p class="first">Choose a DN for the global Kerberos container entry (but do not create the entry at this time). Specify this DN with the <strong>ldap_kerberos_container_dn</strong> directive in <a class="reference internal" href="conf_files/kdc_conf.html#kdc-conf-5"><span class="std std-ref">kdc.conf</span></a>. Realm container entries will be created underneath this DN. Principal entries may exist either underneath the realm container (the default) or in separate trees referenced from the realm container.</p> </li> <li><p class="first">Configure the LDAP server ACLs to enable the KDC and kadmin server DNs to read and write the Kerberos data. If <strong>disable_last_success</strong> and <strong>disable_lockout</strong> are both set to true in the <a class="reference internal" href="conf_files/kdc_conf.html#dbmodules"><span class="std std-ref">[dbmodules]</span></a> subsection for the realm, then the KDC DN only requires read access to the Kerberos data.</p> <p>Sample access control information:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">access</span> <span class="n">to</span> <span class="n">dn</span><span class="o">.</span><span class="n">base</span><span class="o">=</span><span class="s2">""</span> <span class="n">by</span> <span class="o">*</span> <span class="n">read</span> <span class="n">access</span> <span class="n">to</span> <span class="n">dn</span><span class="o">.</span><span class="n">base</span><span class="o">=</span><span class="s2">"cn=Subschema"</span> <span class="n">by</span> <span class="o">*</span> <span class="n">read</span> <span class="c1"># Provide access to the realm container.</span> <span class="n">access</span> <span class="n">to</span> <span class="n">dn</span><span class="o">.</span><span class="n">subtree</span><span class="o">=</span> <span class="s2">"cn=EXAMPLE.COM,cn=krbcontainer,dc=example,dc=com"</span> <span class="n">by</span> <span class="n">dn</span><span class="o">.</span><span class="n">exact</span><span class="o">=</span><span class="s2">"cn=kdc-service,dc=example,dc=com"</span> <span class="n">write</span> <span class="n">by</span> <span class="n">dn</span><span class="o">.</span><span class="n">exact</span><span class="o">=</span><span class="s2">"cn=adm-service,dc=example,dc=com"</span> <span class="n">write</span> <span class="n">by</span> <span class="o">*</span> <span class="n">none</span> <span class="c1"># Provide access to principals, if not underneath the realm container.</span> <span class="n">access</span> <span class="n">to</span> <span class="n">dn</span><span class="o">.</span><span class="n">subtree</span><span class="o">=</span> <span class="s2">"ou=users,dc=example,dc=com"</span> <span class="n">by</span> <span class="n">dn</span><span class="o">.</span><span class="n">exact</span><span class="o">=</span><span class="s2">"cn=kdc-service,dc=example,dc=com"</span> <span class="n">write</span> <span class="n">by</span> <span class="n">dn</span><span class="o">.</span><span class="n">exact</span><span class="o">=</span><span class="s2">"cn=adm-service,dc=example,dc=com"</span> <span class="n">write</span> <span class="n">by</span> <span class="o">*</span> <span class="n">none</span> <span class="n">access</span> <span class="n">to</span> <span class="o">*</span> <span class="n">by</span> <span class="o">*</span> <span class="n">read</span> </pre></div> </div> <p>If the locations of the container and principals or the DNs of the service objects for a realm are changed then this information should be updated.</p> </li> <li><p class="first">In <a class="reference internal" href="conf_files/kdc_conf.html#kdc-conf-5"><span class="std std-ref">kdc.conf</span></a>, make sure the following relations are set in the <a class="reference internal" href="conf_files/kdc_conf.html#dbmodules"><span class="std std-ref">[dbmodules]</span></a> subsection for the realm:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span>db_library (set to ``kldap``) ldap_kerberos_container_dn ldap_kdc_dn ldap_kadmind_dn ldap_service_password_file ldap_servers </pre></div> </div> </li> <li><p class="first">Create the realm using <a class="reference internal" href="admin_commands/kdb5_ldap_util.html#kdb5-ldap-util-8"><span class="std std-ref">kdb5_ldap_util</span></a> (see <a class="reference internal" href="database.html#ldap-create-realm"><span class="std std-ref">Creating a Kerberos realm</span></a>):</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">kdb5_ldap_util</span> <span class="n">create</span> <span class="o">-</span><span class="n">subtrees</span> <span class="n">ou</span><span class="o">=</span><span class="n">users</span><span class="p">,</span><span class="n">dc</span><span class="o">=</span><span class="n">example</span><span class="p">,</span><span class="n">dc</span><span class="o">=</span><span class="n">com</span> <span class="o">-</span><span class="n">s</span> </pre></div> </div> <p>Use the <strong>-subtrees</strong> option if the principals are to exist in a separate subtree from the realm container. Before executing the command, make sure that the subtree mentioned above <code class="docutils literal notranslate"><span class="pre">(ou=users,dc=example,dc=com)</span></code> exists. If the principals will exist underneath the realm container, omit the <strong>-subtrees</strong> option and do not worry about creating the principal subtree.</p> <p>For more information, refer to the section <a class="reference internal" href="database.html#ops-on-ldap"><span class="std std-ref">Operations on the LDAP database</span></a>.</p> <p>The realm object is created under the <strong>ldap_kerberos_container_dn</strong> specified in the configuration file. This operation will also create the Kerberos container, if not present already. This container can be used to store information related to multiple realms.</p> </li> <li><p class="first">Add an <code class="docutils literal notranslate"><span class="pre">eq</span></code> index for <code class="docutils literal notranslate"><span class="pre">krbPrincipalName</span></code> to speed up principal lookup operations. See <a class="reference external" href="https://www.openldap.org/doc/admin24/tuning.html#Indexes">https://www.openldap.org/doc/admin24/tuning.html#Indexes</a> for details.</p> </li> </ol> </div></blockquote> <p>With the LDAP back end it is possible to provide aliases for principal entries. Currently we provide no administrative utilities for creating aliases, so it must be done by direct manipulation of the LDAP entries.</p> <p>An entry with aliases contains multiple values of the <em>krbPrincipalName</em> attribute. Since LDAP attribute values are not ordered, it is necessary to specify which principal name is canonical, by using the <em>krbCanonicalName</em> attribute. Therefore, to create aliases for an entry, first set the <em>krbCanonicalName</em> attribute of the entry to the canonical principal name (which should be identical to the pre-existing <em>krbPrincipalName</em> value), and then add additional <em>krbPrincipalName</em> attributes for the aliases.</p> <p>Principal aliases are only returned by the KDC when the client requests canonicalization. Canonicalization is normally requested for service principals; for client principals, an explicit flag is often required (e.g., <code class="docutils literal notranslate"><span class="pre">kinit</span> <span class="pre">-C</span></code>) and canonicalization is only performed for initial ticket requests.</p> </div> </div> </div> </div> </div> <div class="sidebar"> <h2>On this page</h2> <ul> <li><a class="reference internal" href="#">Configuring Kerberos with OpenLDAP back-end</a></li> </ul> <br/> <h2>Table of contents</h2> <ul class="current"> <li class="toctree-l1"><a class="reference internal" href="../user/index.html">For users</a></li> <li class="toctree-l1 current"><a class="reference internal" href="index.html">For administrators</a><ul class="current"> <li class="toctree-l2"><a class="reference internal" href="install.html">Installation guide</a></li> <li class="toctree-l2"><a class="reference internal" href="conf_files/index.html">Configuration Files</a></li> <li class="toctree-l2"><a class="reference internal" href="realm_config.html">Realm configuration decisions</a></li> <li class="toctree-l2"><a class="reference internal" href="database.html">Database administration</a></li> <li class="toctree-l2"><a class="reference internal" href="dbtypes.html">Database types</a></li> <li class="toctree-l2"><a class="reference internal" href="lockout.html">Account lockout</a></li> <li class="toctree-l2 current"><a class="current reference internal" href="#">Configuring Kerberos with OpenLDAP back-end</a></li> <li class="toctree-l2"><a class="reference internal" href="appl_servers.html">Application servers</a></li> <li class="toctree-l2"><a class="reference internal" href="host_config.html">Host configuration</a></li> <li class="toctree-l2"><a class="reference internal" href="backup_host.html">Backups of secure hosts</a></li> <li class="toctree-l2"><a class="reference internal" href="pkinit.html">PKINIT configuration</a></li> <li class="toctree-l2"><a class="reference internal" href="otp.html">OTP Preauthentication</a></li> <li class="toctree-l2"><a class="reference internal" href="spake.html">SPAKE Preauthentication</a></li> <li class="toctree-l2"><a class="reference internal" href="dictionary.html">Addressing dictionary attack risks</a></li> <li class="toctree-l2"><a class="reference internal" href="princ_dns.html">Principal names and DNS</a></li> <li class="toctree-l2"><a class="reference internal" href="enctypes.html">Encryption types</a></li> <li class="toctree-l2"><a class="reference internal" href="https.html">HTTPS proxy configuration</a></li> <li class="toctree-l2"><a class="reference internal" href="auth_indicator.html">Authentication indicators</a></li> <li class="toctree-l2"><a class="reference internal" href="admin_commands/index.html">Administration programs</a></li> <li class="toctree-l2"><a class="reference internal" href="../mitK5defaults.html">MIT Kerberos defaults</a></li> <li class="toctree-l2"><a class="reference internal" href="env_variables.html">Environment variables</a></li> <li class="toctree-l2"><a class="reference internal" href="troubleshoot.html">Troubleshooting</a></li> <li class="toctree-l2"><a class="reference internal" href="advanced/index.html">Advanced topics</a></li> <li class="toctree-l2"><a class="reference internal" href="various_envs.html">Various links</a></li> </ul> </li> <li class="toctree-l1"><a class="reference internal" href="../appdev/index.html">For application developers</a></li> <li class="toctree-l1"><a class="reference internal" href="../plugindev/index.html">For plugin module developers</a></li> <li class="toctree-l1"><a class="reference internal" href="../build/index.html">Building Kerberos V5</a></li> <li class="toctree-l1"><a class="reference internal" href="../basic/index.html">Kerberos V5 concepts</a></li> <li class="toctree-l1"><a class="reference internal" href="../formats/index.html">Protocols and file formats</a></li> <li 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