allow saving/loading of kerberos tickets

example-apache-kerberos.php

@@ -1,5 +1,7 @@
 <?php
 
+use Icewind\SMB\KerberosTicket;
+
 require('vendor/autoload.php');
 
 if (php_sapi_name() == "cli") {
@@ -10,7 +12,8 @@ if (php_sapi_name() == "cli") {
 $host = 'krb.domain.test';
 $share = 'netlogon';
 
-$auth = new \Icewind\SMB\KerberosApacheAuth();
+$auth = new \Icewind\SMB\KerberosAuth();
+$auth->setTicket(KerberosTicket::fromEnv());
 $serverFactory = new \Icewind\SMB\ServerFactory();
 
 $server = $serverFactory->createServer($host, $auth);

psalm.xml

@@ -6,6 +6,9 @@
     xmlns="https://getpsalm.org/schema/config"
     xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
 >
+    <stubs>
+        <file name="tests/krb.phpstub" preloadClasses="true"/>
+    </stubs>
     <projectFiles>
         <directory name="src" />
         <ignoreFiles>

src/Exception/InvalidTicket.php

@@ -0,0 +1,28 @@
+<?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\Exception;
+
+class InvalidTicket extends Exception {
+
+}

src/KerberosApacheAuth.php

@@ -23,24 +23,24 @@ namespace Icewind\SMB;
 
 use Icewind\SMB\Exception\DependencyException;
 use Icewind\SMB\Exception\Exception;
+use Icewind\SMB\Exception\InvalidTicket;
 
 /**
  * Use existing kerberos ticket to authenticate and reuse the apache ticket cache (mod_auth_kerb)
+ *
+ * @deprecated Use `KerberosAuth` with `$auth->setTicket(KerberosTicket::fromEnv())` instead
  */
 class KerberosApacheAuth extends KerberosAuth implements IAuth {
-	/** @var string */
-	private $ticketPath = "";
-
-	/** @var bool */
-	private $init = false;
-
-	/** @var string|false */
-	private $ticketName;
-
-	public function __construct() {
-		$this->ticketName = getenv("KRB5CCNAME");
+	public function getTicket(): KerberosTicket {
+		if ($this->ticket === null) {
+			$ticket = KerberosTicket::fromEnv();
+			if ($ticket === null) {
+				throw new InvalidTicket("No ticket found in environment");
+			}
+			$this->ticket = $ticket;
+		}
+		return $this->ticket;
 	}
-
 
 	/**
 	 * Copy the ticket to a temporary location and use that ticket for authentication
@@ -48,89 +48,15 @@ class KerberosApacheAuth extends KerberosAuth implements IAuth {
 	 * @return void
 	 */
 	public function copyTicket(): void {
-		if (!$this->checkTicket()) {
-			return;
-		}
-		$krb5 = new \KRB5CCache();
-		$krb5->open($this->ticketName);
-		$tmpFilename = tempnam("/tmp", "krb5cc_php_");
-		$tmpCacheFile = "FILE:" . $tmpFilename;
-		$krb5->save($tmpCacheFile);
-		$this->ticketPath = $tmpFilename;
-		$this->ticketName = $tmpCacheFile;
-	}
-
-	/**
-	 * Pass the ticket to smbclient by memory instead of path
-	 *
-	 * @return void
-	 */
-	public function passTicketFromMemory(): void {
-		if (!$this->checkTicket()) {
-			return;
-		}
-		$krb5 = new \KRB5CCache();
-		$krb5->open($this->ticketName);
-		$this->ticketName = (string)$krb5->getName();
+		$this->ticket = KerberosTicket::load($this->getTicket()->save());
 	}
 
 	/**
 	 * Check if a valid kerberos ticket is present
 	 *
 	 * @return bool
-	 * @psalm-assert-if-true string $this->ticketName
 	 */
 	public function checkTicket(): bool {
-		//read apache kerberos ticket cache
-		if (!$this->ticketName) {
-			return false;
-		}
-
-		$krb5 = new \KRB5CCache();
-		$krb5->open($this->ticketName);
-		/** @psalm-suppress MixedArgument */
-		return count($krb5->getEntries()) > 0;
-	}
-
-	private function init(): void {
-		if ($this->init) {
-			return;
-		}
-		$this->init = true;
-		// inspired by https://git.typo3.org/TYPO3CMS/Extensions/fal_cifs.git
-
-		if (!extension_loaded("krb5")) {
-			// https://pecl.php.net/package/krb5
-			throw new DependencyException('Ensure php-krb5 is installed.');
-		}
-
-		//read apache kerberos ticket cache
-		if (!$this->checkTicket()) {
-			throw new Exception('No kerberos ticket cache environment variable (KRB5CCNAME) found.');
-		}
-
-		// note that even if the ticketname is the value we got from `getenv("KRB5CCNAME")` we still need to set the env variable ourselves
-		// this is because `getenv` also reads the variables passed from the SAPI (apache-php) and we need to set the variable in the OS's env
-		putenv("KRB5CCNAME=" . $this->ticketName);
-	}
-
-	public function getExtraCommandLineArguments(): string {
-		$this->init();
-		return parent::getExtraCommandLineArguments();
-	}
-
-	public function setExtraSmbClientOptions($smbClientState): void {
-		$this->init();
-		try {
-			parent::setExtraSmbClientOptions($smbClientState);
-		} catch (Exception $e) {
-			// suppress
-		}
-	}
-
-	public function __destruct() {
-		if (!empty($this->ticketPath) && file_exists($this->ticketPath) && is_file($this->ticketPath)) {
-			unlink($this->ticketPath);
-		}
+		return $this->getTicket()->isValid();
 	}
 }

src/KerberosAuth.php

@@ -27,6 +27,17 @@ use Icewind\SMB\Exception\Exception;
  * Use existing kerberos ticket to authenticate
  */
 class KerberosAuth implements IAuth {
+	/** @var ?KerberosTicket */
+	protected $ticket = null;
+
+	public function getTicket(): ?KerberosTicket {
+		return $this->ticket;
+	}
+
+	public function setTicket(KerberosTicket $ticket): void {
+		$this->ticket = $ticket;
+	}
+
 	public function getUsername(): ?string {
 		return 'dummy';
 	}
@@ -39,11 +50,25 @@ class KerberosAuth implements IAuth {
 		return null;
 	}
 
+	private function setEnv():void {
+		$ticket = $this->getTicket();
+		if ($ticket) {
+			$ticket->validate();
+
+			// note that even if the ticket name is the value we got from `getenv("KRB5CCNAME")` we still need to set the env variable ourselves
+			// this is because `getenv` also reads the variables passed from the SAPI (apache-php) and we need to set the variable in the OS's env
+			putenv("KRB5CCNAME=" . $ticket->getCacheName());
+		}
+	}
+
 	public function getExtraCommandLineArguments(): string {
+		$this->setEnv();
 		return '-k';
 	}
 
 	public function setExtraSmbClientOptions($smbClientState): void {
+		$this->setEnv();
+
 		$success = (bool)smbclient_option_set($smbClientState, SMBCLIENT_OPT_USE_KERBEROS, true);
 		$success = $success && smbclient_option_set($smbClientState, SMBCLIENT_OPT_FALLBACK_AFTER_KERBEROS, false);
 

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;
+	}
+}

tests/krb.phpstub

@@ -0,0 +1,12 @@
+<?php
+
+class KRB5CCache {
+    public function getEntries(): array { return [];}
+    public function getName(): string {return "";}
+    public function initKeytab(string $principal, string $keytab, array $flags = []): void {}
+    public function initPassword(string $principal, string $password, array $flags = []): void {}
+    public function isValid(): bool {return false;}
+    public function open(string $source): void {}
+    public function save(string $destination): void {}
+    public function setConfig(string $destination): void {}
+}