Add generic LDAP client library

app/Core/Ldap/Client.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Kanboard\Core\Ldap;
+
+/**
+ * LDAP Client
+ *
+ * @package ldap
+ * @author  Frederic Guillot
+ */
+class Client
+{
+    /**
+     * Get server connection
+     *
+     * @access public
+     * @param  string   $server  LDAP server hostname or IP
+     * @param  integer  $port    LDAP port
+     * @param  boolean  $tls     Start TLS
+     * @param  boolean  $verify  Skip SSL certificate verification
+     * @return resource
+     */
+    public function getConnection($server, $port = LDAP_PORT, $tls = LDAP_START_TLS, $verify = LDAP_SSL_VERIFY)
+    {
+        if (! function_exists('ldap_connect')) {
+            throw new ClientException('LDAP: The PHP LDAP extension is required');
+        }
+
+        if (! $verify) {
+            putenv('LDAPTLS_REQCERT=never');
+        }
+
+        $ldap = ldap_connect($server, $port);
+
+        if ($ldap === false) {
+            throw new ClientException('LDAP: Unable to connect to the LDAP server');
+        }
+
+        ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3);
+        ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0);
+        ldap_set_option($ldap, LDAP_OPT_NETWORK_TIMEOUT, 1);
+        ldap_set_option($ldap, LDAP_OPT_TIMELIMIT, 1);
+
+        if ($tls && ! @ldap_start_tls($ldap)) {
+            throw new ClientException('LDAP: Unable to start TLS');
+        }
+
+        return $ldap;
+    }
+
+    /**
+     * Anonymous authentication
+     *
+     * @access public
+     * @param  resource $ldap
+     * @return boolean
+     */
+    public function useAnonymousAuthentication($ldap)
+    {
+        if (! ldap_bind($ldap)) {
+            throw new ClientException('Unable to perform anonymous binding');
+        }
+
+        return true;
+    }
+
+    /**
+     * Authentication with username/password
+     *
+     * @access public
+     * @param  resource $ldap
+     * @param  string   $username
+     * @param  string   $password
+     * @return boolean
+     */
+    public function authenticate($ldap, $username, $password)
+    {
+        if (! ldap_bind($ldap, $username, $password)) {
+            throw new ClientException('Unable to perform anonymous binding');
+        }
+
+        return true;
+    }
+}