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diff --git a/doc/src/sgml/html/auth-ldap.html b/doc/src/sgml/html/auth-ldap.html new file mode 100644 index 0000000..274241f --- /dev/null +++ b/doc/src/sgml/html/auth-ldap.html @@ -0,0 +1,190 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!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="Content-Type" content="text/html; charset=UTF-8" /><title>21.10. LDAP Authentication</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="auth-peer.html" title="21.9. Peer Authentication" /><link rel="next" href="auth-radius.html" title="21.11. RADIUS Authentication" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">21.10. LDAP Authentication</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="auth-peer.html" title="21.9. Peer Authentication">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="client-authentication.html" title="Chapter 21. Client Authentication">Up</a></td><th width="60%" align="center">Chapter 21. Client Authentication</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.2 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="auth-radius.html" title="21.11. RADIUS Authentication">Next</a></td></tr></table><hr /></div><div class="sect1" id="AUTH-LDAP"><div class="titlepage"><div><div><h2 class="title" style="clear: both">21.10. LDAP Authentication <a href="#AUTH-LDAP" class="id_link">#</a></h2></div></div></div><a id="id-1.6.8.17.2" class="indexterm"></a><p> + This authentication method operates similarly to + <code class="literal">password</code> except that it uses LDAP + as the password verification method. LDAP is used only to validate + the user name/password pairs. Therefore the user must already + exist in the database before LDAP can be used for + authentication. + </p><p> + LDAP authentication can operate in two modes. In the first mode, + which we will call the simple bind mode, + the server will bind to the distinguished name constructed as + <em class="replaceable"><code>prefix</code></em> <em class="replaceable"><code>username</code></em> <em class="replaceable"><code>suffix</code></em>. + Typically, the <em class="replaceable"><code>prefix</code></em> parameter is used to specify + <code class="literal">cn=</code>, or <em class="replaceable"><code>DOMAIN</code></em><code class="literal">\</code> in an Active + Directory environment. <em class="replaceable"><code>suffix</code></em> is used to specify the + remaining part of the DN in a non-Active Directory environment. + </p><p> + In the second mode, which we will call the search+bind mode, + the server first binds to the LDAP directory with + a fixed user name and password, specified with <em class="replaceable"><code>ldapbinddn</code></em> + and <em class="replaceable"><code>ldapbindpasswd</code></em>, and performs a search for the user trying + to log in to the database. If no user and password is configured, an + anonymous bind will be attempted to the directory. The search will be + performed over the subtree at <em class="replaceable"><code>ldapbasedn</code></em>, and will try to + do an exact match of the attribute specified in + <em class="replaceable"><code>ldapsearchattribute</code></em>. + Once the user has been found in + this search, the server disconnects and re-binds to the directory as + this user, using the password specified by the client, to verify that the + login is correct. This mode is the same as that used by LDAP authentication + schemes in other software, such as Apache <code class="literal">mod_authnz_ldap</code> and <code class="literal">pam_ldap</code>. + This method allows for significantly more flexibility + in where the user objects are located in the directory, but will cause + two separate connections to the LDAP server to be made. + </p><p> + The following configuration options are used in both modes: + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">ldapserver</code></span></dt><dd><p> + Names or IP addresses of LDAP servers to connect to. Multiple + servers may be specified, separated by spaces. + </p></dd><dt><span class="term"><code class="literal">ldapport</code></span></dt><dd><p> + Port number on LDAP server to connect to. If no port is specified, + the LDAP library's default port setting will be used. + </p></dd><dt><span class="term"><code class="literal">ldapscheme</code></span></dt><dd><p> + Set to <code class="literal">ldaps</code> to use LDAPS. This is a non-standard + way of using LDAP over SSL, supported by some LDAP server + implementations. See also the <code class="literal">ldaptls</code> option for + an alternative. + </p></dd><dt><span class="term"><code class="literal">ldaptls</code></span></dt><dd><p> + Set to 1 to make the connection between PostgreSQL and the LDAP server + use TLS encryption. This uses the <code class="literal">StartTLS</code> + operation per <a class="ulink" href="https://tools.ietf.org/html/rfc4513" target="_top">RFC 4513</a>. + See also the <code class="literal">ldapscheme</code> option for an alternative. + </p></dd></dl></div><p> + </p><p> + Note that using <code class="literal">ldapscheme</code> or + <code class="literal">ldaptls</code> only encrypts the traffic between the + PostgreSQL server and the LDAP server. The connection between the + PostgreSQL server and the PostgreSQL client will still be unencrypted + unless SSL is used there as well. + </p><p> + The following options are used in simple bind mode only: + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">ldapprefix</code></span></dt><dd><p> + String to prepend to the user name when forming the DN to bind as, + when doing simple bind authentication. + </p></dd><dt><span class="term"><code class="literal">ldapsuffix</code></span></dt><dd><p> + String to append to the user name when forming the DN to bind as, + when doing simple bind authentication. + </p></dd></dl></div><p> + </p><p> + The following options are used in search+bind mode only: + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">ldapbasedn</code></span></dt><dd><p> + Root DN to begin the search for the user in, when doing search+bind + authentication. + </p></dd><dt><span class="term"><code class="literal">ldapbinddn</code></span></dt><dd><p> + DN of user to bind to the directory with to perform the search when + doing search+bind authentication. + </p></dd><dt><span class="term"><code class="literal">ldapbindpasswd</code></span></dt><dd><p> + Password for user to bind to the directory with to perform the search + when doing search+bind authentication. + </p></dd><dt><span class="term"><code class="literal">ldapsearchattribute</code></span></dt><dd><p> + Attribute to match against the user name in the search when doing + search+bind authentication. If no attribute is specified, the + <code class="literal">uid</code> attribute will be used. + </p></dd><dt><span class="term"><code class="literal">ldapsearchfilter</code></span></dt><dd><p> + The search filter to use when doing search+bind authentication. + Occurrences of <code class="literal">$username</code> will be replaced with the + user name. This allows for more flexible search filters than + <code class="literal">ldapsearchattribute</code>. + </p></dd><dt><span class="term"><code class="literal">ldapurl</code></span></dt><dd><p> + An <a class="ulink" href="https://tools.ietf.org/html/rfc4516" target="_top">RFC 4516</a> + LDAP URL. This is an alternative way to write some of the + other LDAP options in a more compact and standard form. The format is +</p><pre class="synopsis"> +ldap[s]://<em class="replaceable"><code>host</code></em>[:<em class="replaceable"><code>port</code></em>]/<em class="replaceable"><code>basedn</code></em>[?[<em class="replaceable"><code>attribute</code></em>][?[<em class="replaceable"><code>scope</code></em>][?[<em class="replaceable"><code>filter</code></em>]]]] +</pre><p> + <em class="replaceable"><code>scope</code></em> must be one + of <code class="literal">base</code>, <code class="literal">one</code>, <code class="literal">sub</code>, + typically the last. (The default is <code class="literal">base</code>, which + is normally not useful in this application.) <em class="replaceable"><code>attribute</code></em> can + nominate a single attribute, in which case it is used as a value for + <code class="literal">ldapsearchattribute</code>. If + <em class="replaceable"><code>attribute</code></em> is empty then + <em class="replaceable"><code>filter</code></em> can be used as a value for + <code class="literal">ldapsearchfilter</code>. + </p><p> + The URL scheme <code class="literal">ldaps</code> chooses the LDAPS method for + making LDAP connections over SSL, equivalent to using + <code class="literal">ldapscheme=ldaps</code>. To use encrypted LDAP + connections using the <code class="literal">StartTLS</code> operation, use the + normal URL scheme <code class="literal">ldap</code> and specify the + <code class="literal">ldaptls</code> option in addition to + <code class="literal">ldapurl</code>. + </p><p> + For non-anonymous binds, <code class="literal">ldapbinddn</code> + and <code class="literal">ldapbindpasswd</code> must be specified as separate + options. + </p><p> + LDAP URLs are currently only supported with + <span class="productname">OpenLDAP</span>, not on Windows. + </p></dd></dl></div><p> + </p><p> + It is an error to mix configuration options for simple bind with options + for search+bind. + </p><p> + When using search+bind mode, the search can be performed using a single + attribute specified with <code class="literal">ldapsearchattribute</code>, or using + a custom search filter specified with + <code class="literal">ldapsearchfilter</code>. + Specifying <code class="literal">ldapsearchattribute=foo</code> is equivalent to + specifying <code class="literal">ldapsearchfilter="(foo=$username)"</code>. If neither + option is specified the default is + <code class="literal">ldapsearchattribute=uid</code>. + </p><p> + If <span class="productname">PostgreSQL</span> was compiled with + <span class="productname">OpenLDAP</span> as the LDAP client library, the + <code class="literal">ldapserver</code> setting may be omitted. In that case, a + list of host names and ports is looked up via + <a class="ulink" href="https://tools.ietf.org/html/rfc2782" target="_top">RFC 2782</a> DNS SRV records. + The name <code class="literal">_ldap._tcp.DOMAIN</code> is looked up, where + <code class="literal">DOMAIN</code> is extracted from <code class="literal">ldapbasedn</code>. + </p><p> + Here is an example for a simple-bind LDAP configuration: +</p><pre class="programlisting"> +host ... ldap ldapserver=ldap.example.net ldapprefix="cn=" ldapsuffix=", dc=example, dc=net" +</pre><p> + When a connection to the database server as database + user <code class="literal">someuser</code> is requested, PostgreSQL will attempt to + bind to the LDAP server using the DN <code class="literal">cn=someuser, dc=example, + dc=net</code> and the password provided by the client. If that connection + succeeds, the database access is granted. + </p><p> + Here is an example for a search+bind configuration: +</p><pre class="programlisting"> +host ... ldap ldapserver=ldap.example.net ldapbasedn="dc=example, dc=net" ldapsearchattribute=uid +</pre><p> + When a connection to the database server as database + user <code class="literal">someuser</code> is requested, PostgreSQL will attempt to + bind anonymously (since <code class="literal">ldapbinddn</code> was not specified) to + the LDAP server, perform a search for <code class="literal">(uid=someuser)</code> + under the specified base DN. If an entry is found, it will then attempt to + bind using that found information and the password supplied by the client. + If that second connection succeeds, the database access is granted. + </p><p> + Here is the same search+bind configuration written as a URL: +</p><pre class="programlisting"> +host ... ldap ldapurl="ldap://ldap.example.net/dc=example,dc=net?uid?sub" +</pre><p> + Some other software that supports authentication against LDAP uses the + same URL format, so it will be easier to share the configuration. + </p><p> + Here is an example for a search+bind configuration that uses + <code class="literal">ldapsearchfilter</code> instead of + <code class="literal">ldapsearchattribute</code> to allow authentication by + user ID or email address: +</p><pre class="programlisting"> +host ... ldap ldapserver=ldap.example.net ldapbasedn="dc=example, dc=net" ldapsearchfilter="(|(uid=$username)(mail=$username))" +</pre><p> + </p><p> + Here is an example for a search+bind configuration that uses DNS SRV + discovery to find the host name(s) and port(s) for the LDAP service for the + domain name <code class="literal">example.net</code>: +</p><pre class="programlisting"> +host ... ldap ldapbasedn="dc=example,dc=net" +</pre><p> + </p><div class="tip"><h3 class="title">Tip</h3><p> + Since LDAP often uses commas and spaces to separate the different + parts of a DN, it is often necessary to use double-quoted parameter + values when configuring LDAP options, as shown in the examples. + </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="auth-peer.html" title="21.9. Peer Authentication">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="client-authentication.html" title="Chapter 21. Client Authentication">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="auth-radius.html" title="21.11. RADIUS Authentication">Next</a></td></tr><tr><td width="40%" align="left" valign="top">21.9. Peer Authentication </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.2 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 21.11. RADIUS Authentication</td></tr></table></div></body></html>
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