allow saving/loading of kerberos tickets

src/KerberosTicket.php

@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Icewind\SMB;
+
+use Icewind\SMB\Exception\InvalidTicket;
+use KRB5CCache;
+
+class KerberosTicket {
+	/** @var KRB5CCache */
+	private $krb5;
+	/** @var string */
+	private $cacheName;
+
+	public function __construct(KRB5CCache $krb5, string $cacheName) {
+		$this->krb5 = $krb5;
+		$this->cacheName = $cacheName;
+	}
+
+	public function getCacheName(): string {
+		return $this->cacheName;
+	}
+
+	public function getName(): string{
+		return $this->krb5->getName();
+	}
+
+	public function isValid(): bool {
+		return count($this->krb5->getEntries()) > 0;
+	}
+
+	public function validate(): void {
+		if (!$this->isValid()) {
+			throw new InvalidTicket("No kerberos ticket found.");
+		}
+	}
+
+	/**
+	 * Load the ticket from the cache specified by the KRB5CCNAME variable.
+	 *
+	 * @return KerberosTicket|null
+	 */
+	public static function fromEnv(): ?KerberosTicket {
+		$ticketName = getenv("KRB5CCNAME");
+		if (!$ticketName) {
+			return null;
+		}
+		$krb5 = new KRB5CCache();
+		$krb5->open($ticketName);
+		return new KerberosTicket($krb5, $ticketName);
+	}
+
+	public static function load(string $ticket): KerberosTicket {
+		$tmpFilename = tempnam(sys_get_temp_dir(), "krb5cc_php_");
+		file_put_contents($tmpFilename, $ticket);
+		register_shutdown_function(function () use ($tmpFilename) {
+			if (file_exists($tmpFilename)) {
+				unlink($tmpFilename);
+			}
+		});
+
+		$ticketName = "FILE:" . $tmpFilename;
+		$krb5 = new KRB5CCache();
+		$krb5->open($ticketName);
+		return new KerberosTicket($krb5, $ticketName);
+	}
+
+	public function save(): string {
+		if (substr($this->cacheName, 0, 5) === 'FILE:') {
+			$ticket = file_get_contents(substr($this->cacheName, 5));
+		} else {
+			$tmpFilename = tempnam(sys_get_temp_dir(), "krb5cc_php_");
+			$tmpCacheFile = "FILE:" . $tmpFilename;
+			$this->krb5->save($tmpCacheFile);
+			$ticket = file_get_contents($tmpFilename);
+			unlink($tmpFilename);
+		}
+		return $ticket;
+	}
+}