feat(crl): add ILdapConnection abstraction for LDAP operations

Thin interface that wraps the ldap_* extension functions (connect,
configure, bind, read, listEntries, search, getEntries, unbind).
Enables injection of test doubles without the php-ldap extension.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/Crl/Ldap/ILdapConnection.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 LibreCode coop and contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Libresign\Service\Crl\Ldap;
+
+/**
+ * Thin abstraction over the PHP LDAP extension functions.
+ *
+ * Allows test doubles to replace real LDAP I/O without requiring a live
+ * LDAP server or the PHP ldap extension to be loaded.
+ */
+interface ILdapConnection {
+	/** @return \LDAP\Connection
+	 * @throws \RuntimeException when the connection cannot be established
+	 */
+	public function connect(string $host, int $port): mixed;
+
+	/**
+	 * Apply the recommended default options (protocol version, timeout,
+	 * referrals) to an open connection. Grouped into one method so that
+	 * callers never need to reference LDAP_OPT_* constants.
+	 */
+	public function configure(mixed $ldap): void;
+
+	/** @return bool true on success */
+	public function bind(mixed $ldap): bool;
+
+	/**
+	 * Equivalent to ldap_read (base scope — single entry).
+	 *
+	 * @return \LDAP\Result|array<array-key, \LDAP\Result>|false
+	 */
+	public function read(mixed $ldap, string $dn, string $filter, array $attributes): mixed;
+
+	/**
+	 * Equivalent to ldap_list (one-level scope).
+	 *
+	 * @return \LDAP\Result|array<array-key, \LDAP\Result>|false
+	 */
+	public function listEntries(mixed $ldap, string $dn, string $filter, array $attributes): mixed;
+
+	/**
+	 * Equivalent to ldap_search (subtree scope).
+	 *
+	 * @return \LDAP\Result|array<array-key, \LDAP\Result>|false
+	 */
+	public function search(mixed $ldap, string $dn, string $filter, array $attributes): mixed;
+
+	/** @return array<string, mixed> */
+	public function getEntries(mixed $ldap, mixed $result): array;
+
+	public function unbind(mixed $ldap): void;
+}