diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index a91c398..454f8e6 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -704,6 +704,19 @@ function drupal_environment_initialize() {
   // Set sane locale settings, to ensure consistent string, dates, times and
   // numbers handling.
   setlocale(LC_ALL, 'C');
+
+  // PHP's built-in phar:// stream wrapper is not sufficiently secure. Override
+  // it with a more secure one, which requires PHP 5.3.3. For lower versions,
+  // unregister the built-in one without replacing it. Sites needing phar
+  // support for lower PHP versions must implement hook_stream_wrappers() to
+  // register their desired implementation.
+  if (in_array('phar', stream_get_wrappers(), TRUE)) {
+    stream_wrapper_unregister('phar');
+    if (version_compare(PHP_VERSION, '5.3.3', '>=')) {
+      include_once DRUPAL_ROOT . '/includes/file.phar.inc';
+      file_register_phar_wrapper();
+    }
+  }
 }
 
 /**
diff --git a/includes/file.inc b/includes/file.inc
index fa7f5eb..565e1d7 100644
--- a/includes/file.inc
+++ b/includes/file.inc
@@ -1534,7 +1534,7 @@ function file_save_upload($form_field_name, $validators = array(), $destination
   // rename filename.php.foo and filename.php to filename.php.foo.txt and
   // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
   // evaluates to TRUE.
-  if (!variable_get('allow_insecure_uploads', 0) && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->filename) && (substr($file->filename, -4) != '.txt')) {
+  if (!variable_get('allow_insecure_uploads', 0) && preg_match('/\.(php|phar|pl|py|cgi|asp|js)(\.|$)/i', $file->filename) && (substr($file->filename, -4) != '.txt')) {
     $file->filemime = 'text/plain';
     $file->uri .= '.txt';
     $file->filename .= '.txt';
diff --git a/includes/file.phar.inc b/includes/file.phar.inc
new file mode 100644
index 0000000..3d7ba01
--- /dev/null
+++ b/includes/file.phar.inc
@@ -0,0 +1,41 @@
+<?php
+
+use Drupal\Core\Security\PharExtensionInterceptor;
+use TYPO3\PharStreamWrapper\Manager as PharStreamWrapperManager;
+use TYPO3\PharStreamWrapper\Behavior as PharStreamWrapperBehavior;
+use TYPO3\PharStreamWrapper\PharStreamWrapper;
+
+/**
+ * Registers a phar stream wrapper that is more secure than PHP's built-in one.
+ *
+ * @see file_get_stream_wrappers()
+ */
+function file_register_phar_wrapper() {
+  $directory = DRUPAL_ROOT . '/misc/typo3/phar-stream-wrapper/src';
+  include_once $directory . '/Assertable.php';
+  include_once $directory . '/Behavior.php';
+  include_once $directory . '/Exception.php';
+  include_once $directory . '/Helper.php';
+  include_once $directory . '/Manager.php';
+  include_once $directory . '/PharStreamWrapper.php';
+  include_once DRUPAL_ROOT . '/misc/typo3/drupal-security/PharExtensionInterceptor.php';
+
+  // Set up a stream wrapper to handle insecurities due to PHP's built-in
+  // phar stream wrapper.
+  try {
+    $behavior = new PharStreamWrapperBehavior();
+    PharStreamWrapperManager::initialize(
+      $behavior->withAssertion(new PharExtensionInterceptor())
+    );
+  }
+  catch (\LogicException $e) {
+    // Continue if the PharStreamWrapperManager is already initialized.
+    // For example, this occurs following a drupal_static_reset(), such
+    // as during tests.
+  };
+
+  // To prevent file_stream_wrapper_valid_scheme() treating "phar" as a valid
+  // scheme, this is registered with PHP only, not with  hook_stream_wrappers()
+  // or the internal storage of file_get_stream_wrappers().
+  stream_wrapper_register('phar', '\\TYPO3\\PharStreamWrapper\\PharStreamWrapper');
+}
diff --git a/misc/typo3/drupal-security/PharExtensionInterceptor.php b/misc/typo3/drupal-security/PharExtensionInterceptor.php
new file mode 100644
index 0000000..a77e9f8
--- /dev/null
+++ b/misc/typo3/drupal-security/PharExtensionInterceptor.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace Drupal\Core\Security;
+
+use TYPO3\PharStreamWrapper\Assertable;
+use TYPO3\PharStreamWrapper\Helper;
+use TYPO3\PharStreamWrapper\Exception;
+
+/**
+ * An alternate PharExtensionInterceptor to support phar-based CLI tools.
+ *
+ * @see \TYPO3\PharStreamWrapper\Interceptor\PharExtensionInterceptor
+ */
+class PharExtensionInterceptor implements Assertable {
+
+  /**
+   * Determines whether phar file is allowed to execute.
+   *
+   * The phar file is allowed to execute if:
+   * - the base file name has a ".phar" suffix.
+   * - it is the CLI tool that has invoked the interceptor.
+   *
+   * @param string $path
+   *   The path of the phar file to check.
+   *
+   * @param string $command
+   *   The command being carried out.
+   *
+   * @return bool
+   *   TRUE if the phar file is allowed to execute.
+   *
+   * @throws Exception
+   *   Thrown when the file is not allowed to execute.
+   */
+  public function assert($path, $command) {
+    if ($this->baseFileContainsPharExtension($path)) {
+      return TRUE;
+    }
+    throw new Exception(
+      sprintf(
+        'Unexpected file extension in "%s"',
+        $path
+      ),
+      1535198703
+    );
+  }
+
+  /**
+   * @param string $path
+   *   The path of the phar file to check.
+   *
+   * @return bool
+   *   TRUE if the file has a .phar extension or if the execution has been
+   *   invoked by the phar file.
+   */
+  private function baseFileContainsPharExtension($path) {
+    $baseFile = Helper::determineBaseFile($path);
+    if ($baseFile === NULL) {
+      return FALSE;
+    }
+    // If the stream wrapper is registered by invoking a phar file that does
+    // not not have .phar extension then this should be allowed. For
+    // example, some CLI tools recommend removing the extension.
+    $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
+    $caller = array_pop($backtrace);
+    if (isset($caller['file']) && $baseFile === $caller['file']) {
+      return TRUE;
+    }
+    $fileExtension = pathinfo($baseFile, PATHINFO_EXTENSION);
+    return strtolower($fileExtension) === 'phar';
+  }
+
+}
diff --git a/misc/typo3/phar-stream-wrapper/LICENSE b/misc/typo3/phar-stream-wrapper/LICENSE
new file mode 100644
index 0000000..d71267a
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 TYPO3 project - https://typo3.org/
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/misc/typo3/phar-stream-wrapper/README.md b/misc/typo3/phar-stream-wrapper/README.md
new file mode 100644
index 0000000..b632784
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/README.md
@@ -0,0 +1,155 @@
+[![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/TYPO3/phar-stream-wrapper/badges/quality-score.png?b=v2)](https://scrutinizer-ci.com/g/TYPO3/phar-stream-wrapper/?branch=v2)
+[![Travis CI Build Status](https://travis-ci.org/TYPO3/phar-stream-wrapper.svg?branch=v2)](https://travis-ci.org/TYPO3/phar-stream-wrapper)
+
+# PHP Phar Stream Wrapper
+
+## Abstract & History
+
+Based on Sam Thomas' findings concerning
+[insecure deserialization in combination with obfuscation strategies](https://blog.secarma.co.uk/labs/near-phar-dangerous-unserialization-wherever-you-are)
+allowing to hide Phar files inside valid image resources, the TYPO3 project
+decided back then to introduce a `PharStreamWrapper` to intercept invocations
+of the `phar://` stream in PHP and only allow usage for defined locations in
+the file system.
+
+Since the TYPO3 mission statement is **inspiring people to share**, we thought
+it would be helpful for others to release our `PharStreamWrapper` as standalone
+package to the PHP community.
+
+The mentioned security issue was reported to TYPO3 on 10th June 2018 by Sam Thomas
+and has been addressed concerning the specific attack vector and for this generic
+`PharStreamWrapper` in TYPO3 versions 7.6.30 LTS, 8.7.17 LTS and 9.3.1 on 12th
+July 2018.
+
+* https://typo3.org/security/advisory/typo3-core-sa-2018-002/
+* https://blog.secarma.co.uk/labs/near-phar-dangerous-unserialization-wherever-you-are
+* https://youtu.be/GePBmsNJw6Y
+
+## License
+
+In general the TYPO3 core is released under the GNU General Public License version
+2 or any later version (`GPL-2.0-or-later`). In order to avoid licensing issues and
+incompatibilities this `PharStreamWrapper` is licenced under the MIT License. In case
+you duplicate or modify source code, credits are not required but really appreciated.
+
+## Credits
+
+Thanks to [Alex Pott](https://github.com/alexpott), Drupal for creating
+back-ports of all sources in order to provide compatibility with PHP v5.3.
+
+## Installation
+
+The `PharStreamWrapper` is provided as composer package `typo3/phar-stream-wrapper`
+and has minimum requirements of PHP v5.3 ([`v2`](https://github.com/TYPO3/phar-stream-wrapper/tree/v2) branch) and PHP v7.0 ([`master`](https://github.com/TYPO3/phar-stream-wrapper) branch).
+
+### Installation for PHP v7.0
+
+```
+composer require typo3/phar-stream-wrapper ^3.0
+```
+
+### Installation for PHP v5.3
+
+```
+composer require typo3/phar-stream-wrapper ^2.0
+```
+
+## Example
+
+The following example is bundled within this package, the shown
+`PharExtensionInterceptor` denies all stream wrapper invocations files
+not having the `.phar` suffix. Interceptor logic has to be individual and
+adjusted to according requirements.
+
+```
+$behavior = new \TYPO3\PharStreamWrapper\Behavior();
+Manager::initialize(
+    $behavior->withAssertion(new PharExtensionInterceptor())
+);
+
+if (in_array('phar', stream_get_wrappers())) {
+    stream_wrapper_unregister('phar');
+    stream_wrapper_register('phar', 'TYPO3\\PharStreamWrapper\\PharStreamWrapper');
+}
+```
+
+* `PharStreamWrapper` defined as class reference will be instantiated each time
+  `phar://` streams shall be processed.
+* `Manager` as singleton pattern being called by `PharStreamWrapper` instances
+  in order to retrieve individual behavior and settings.
+* `Behavior` holds reference to interceptor(s) that shall assert correct/allowed
+  invocation of a given `$path` for a given `$command`. Interceptors implement
+  the interface `Assertable`. Interceptors can act individually on following
+  commands or handle all of them in case not defined specifically:  
+  + `COMMAND_DIR_OPENDIR`
+  + `COMMAND_MKDIR`
+  + `COMMAND_RENAME`
+  + `COMMAND_RMDIR`
+  + `COMMAND_STEAM_METADATA`
+  + `COMMAND_STREAM_OPEN`
+  + `COMMAND_UNLINK`
+  + `COMMAND_URL_STAT`
+
+## Interceptor
+
+The following interceptor is shipped with the package and ready to use in order
+to block any Phar invocation of files not having a `.phar` suffix. Besides that
+individual interceptors are possible of course.
+
+```
+class PharExtensionInterceptor implements Assertable
+{
+    /**
+     * Determines whether the base file name has a ".phar" suffix.
+     *
+     * @param string $path
+     * @param string $command
+     * @return bool
+     * @throws Exception
+     */
+    public function assert($path, $command)
+    {
+        if ($this->baseFileContainsPharExtension($path)) {
+            return true;
+        }
+        throw new Exception(
+            sprintf(
+                'Unexpected file extension in "%s"',
+                $path
+            ),
+            1535198703
+        );
+    }
+
+    /**
+     * @param string $path
+     * @return bool
+     */
+    private function baseFileContainsPharExtension($path)
+    {
+        $baseFile = Helper::determineBaseFile($path);
+        if ($baseFile === null) {
+            return false;
+        }
+        $fileExtension = pathinfo($baseFile, PATHINFO_EXTENSION);
+        return strtolower($fileExtension) === 'phar';
+    }
+}
+```
+
+## Helper
+
+* `Helper::determineBaseFile(string $path)`: Determines base file that can be
+  accessed using the regular file system. For instance the following path
+  `phar:///home/user/bundle.phar/content.txt` would be resolved to
+  `/home/user/bundle.phar`.
+* `Helper::resetOpCache()`: Resets PHP's OPcache if enabled as work-around for
+  issues in `include()` or `require()` calls and OPcache delivering wrong
+  results. More details can be found in PHP's bug tracker, for instance like
+  https://bugs.php.net/bug.php?id=66569
+
+## Security Contact
+
+In case of finding additional security issues in the TYPO3 project or in this
+`PharStreamWrapper` package in particular, please get in touch with the
+[TYPO3 Security Team](mailto:security@typo3.org).
diff --git a/misc/typo3/phar-stream-wrapper/composer.json b/misc/typo3/phar-stream-wrapper/composer.json
new file mode 100644
index 0000000..d308f8c
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/composer.json
@@ -0,0 +1,24 @@
+{
+    "name": "typo3/phar-stream-wrapper",
+    "description": "Interceptors for PHP's native phar:// stream handling",
+    "type": "library",
+    "license": "MIT",
+    "homepage": "https://typo3.org/",
+    "keywords": ["php", "phar", "stream-wrapper", "security"],
+    "require": {
+        "php": "^5.3.3|^7.0"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^4.8.36"
+    },
+    "autoload": {
+        "psr-4": {
+            "TYPO3\\PharStreamWrapper\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "TYPO3\\PharStreamWrapper\\Tests\\": "tests/"
+        }
+    }
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/Assertable.php b/misc/typo3/phar-stream-wrapper/src/Assertable.php
new file mode 100644
index 0000000..a21b1da
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Assertable.php
@@ -0,0 +1,22 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+interface Assertable
+{
+    /**
+     * @param string $path
+     * @param string $command
+     * @return bool
+     */
+    public function assert($path, $command);
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/Behavior.php b/misc/typo3/phar-stream-wrapper/src/Behavior.php
new file mode 100644
index 0000000..0b640ef
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Behavior.php
@@ -0,0 +1,124 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+class Behavior implements Assertable
+{
+    const COMMAND_DIR_OPENDIR = 'dir_opendir';
+    const COMMAND_MKDIR = 'mkdir';
+    const COMMAND_RENAME = 'rename';
+    const COMMAND_RMDIR = 'rmdir';
+    const COMMAND_STEAM_METADATA = 'stream_metadata';
+    const COMMAND_STREAM_OPEN = 'stream_open';
+    const COMMAND_UNLINK = 'unlink';
+    const COMMAND_URL_STAT = 'url_stat';
+
+    /**
+     * @var string[]
+     */
+    private $availableCommands = array(
+        self::COMMAND_DIR_OPENDIR,
+        self::COMMAND_MKDIR,
+        self::COMMAND_RENAME,
+        self::COMMAND_RMDIR,
+        self::COMMAND_STEAM_METADATA,
+        self::COMMAND_STREAM_OPEN,
+        self::COMMAND_UNLINK,
+        self::COMMAND_URL_STAT,
+    );
+
+    /**
+     * @var Assertable[]
+     */
+    private $assertions;
+
+    /**
+     * @param Assertable $assertable
+     * @return static
+     */
+    public function withAssertion(Assertable $assertable)
+    {
+        $commands = func_get_args();
+        array_shift($commands);
+        $this->assertCommands($commands);
+        $commands = $commands ?: $this->availableCommands;
+
+        $target = clone $this;
+        foreach ($commands as $command) {
+            $target->assertions[$command] = $assertable;
+        }
+        return $target;
+    }
+
+    /**
+     * @param string $path
+     * @param string $command
+     * @return bool
+     */
+    public function assert($path, $command)
+    {
+        $this->assertCommand($command);
+        $this->assertAssertionCompleteness();
+
+        return $this->assertions[$command]->assert($path, $command);
+    }
+
+    /**
+     * @param array $commands
+     */
+    private function assertCommands(array $commands)
+    {
+        $unknownCommands = array_diff($commands, $this->availableCommands);
+        if (empty($unknownCommands)) {
+            return;
+        }
+        throw new \LogicException(
+            sprintf(
+                'Unknown commands: %s',
+                implode(', ', $unknownCommands)
+            ),
+            1535189881
+        );
+    }
+
+    private function assertCommand($command)
+    {
+        if (in_array($command, $this->availableCommands, true)) {
+            return;
+        }
+        throw new \LogicException(
+            sprintf(
+                'Unknown command "%s"',
+                $command
+            ),
+            1535189882
+        );
+    }
+
+    private function assertAssertionCompleteness()
+    {
+        $undefinedAssertions = array_diff(
+            $this->availableCommands,
+            array_keys($this->assertions)
+        );
+        if (empty($undefinedAssertions)) {
+            return;
+        }
+        throw new \LogicException(
+            sprintf(
+                'Missing assertions for commands: %s',
+                implode(', ', $undefinedAssertions)
+            ),
+            1535189883
+        );
+    }
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/Exception.php b/misc/typo3/phar-stream-wrapper/src/Exception.php
new file mode 100644
index 0000000..690121a
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Exception.php
@@ -0,0 +1,16 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+class Exception extends \RuntimeException
+{
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/Helper.php b/misc/typo3/phar-stream-wrapper/src/Helper.php
new file mode 100644
index 0000000..32d0da6
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Helper.php
@@ -0,0 +1,183 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+class Helper
+{
+    /*
+     * Resets PHP's OPcache if enabled as work-around for issues in `include()`
+     * or `require()` calls and OPcache delivering wrong results.
+     *
+     * @see https://bugs.php.net/bug.php?id=66569
+     */
+    public static function resetOpCache()
+    {
+        if (function_exists('opcache_reset')
+            && function_exists('opcache_get_status')
+        ) {
+            $status = opcache_get_status();
+            if (!empty($status['opcache_enabled'])) {
+                opcache_reset();
+            }
+        }
+    }
+
+    /**
+     * Determines base file that can be accessed using the regular file system.
+     * For e.g. "phar:///home/user/bundle.phar/content.txt" that would result
+     * into "/home/user/bundle.phar".
+     *
+     * @param string $path
+     * @return string|null
+     */
+    public static function determineBaseFile($path)
+    {
+        $parts = explode('/', static::normalizePath($path));
+
+        while (count($parts)) {
+            $currentPath = implode('/', $parts);
+            if (@is_file($currentPath)) {
+                return $currentPath;
+            }
+            array_pop($parts);
+        }
+
+        return null;
+    }
+
+    /**
+     * @param string $path
+     * @return string
+     */
+    public static function removePharPrefix($path)
+    {
+        $path = trim($path);
+        if (stripos($path, 'phar://') !== 0) {
+            return $path;
+        }
+        return substr($path, 7);
+    }
+
+    /**
+     * Normalizes a path, removes phar:// prefix, fixes Windows directory
+     * separators. Result is without trailing slash.
+     *
+     * @param string $path
+     * @return string
+     */
+    public static function normalizePath($path)
+    {
+        return rtrim(
+            static::getCanonicalPath(
+                static::removePharPrefix($path)
+            ),
+            '/'
+        );
+    }
+
+    /**
+     * Fixes a path for windows-backslashes and reduces double-slashes to single slashes
+     *
+     * @param string $path File path to process
+     * @return string
+     */
+    private static function normalizeWindowsPath($path)
+    {
+        return str_replace('\\', '/', $path);
+    }
+
+    /**
+     * Resolves all dots, slashes and removes spaces after or before a path...
+     *
+     * @param string $path Input string
+     * @return string Canonical path, always without trailing slash
+     */
+    private static function getCanonicalPath($path)
+    {
+        $path = static::normalizeWindowsPath($path);
+
+        $absolutePathPrefix = '';
+        if (static::isAbsolutePath($path)) {
+            if (static::isWindows() && strpos($path, ':/') === 1) {
+                $absolutePathPrefix = substr($path, 0, 3);
+                $path = substr($path, 3);
+            } else {
+                $path = ltrim($path, '/');
+                $absolutePathPrefix = '/';
+            }
+        }
+
+        $pathParts = explode('/', $path);
+        $pathPartsLength = count($pathParts);
+        for ($partCount = 0; $partCount < $pathPartsLength; $partCount++) {
+            // double-slashes in path: remove element
+            if ($pathParts[$partCount] === '') {
+                array_splice($pathParts, $partCount, 1);
+                $partCount--;
+                $pathPartsLength--;
+            }
+            // "." in path: remove element
+            if ((isset($pathParts[$partCount]) ? $pathParts[$partCount] : '') === '.') {
+                array_splice($pathParts, $partCount, 1);
+                $partCount--;
+                $pathPartsLength--;
+            }
+            // ".." in path:
+            if ((isset($pathParts[$partCount]) ? $pathParts[$partCount] : '') === '..') {
+                if ($partCount === 0) {
+                    array_splice($pathParts, $partCount, 1);
+                    $partCount--;
+                    $pathPartsLength--;
+                } elseif ($partCount >= 1) {
+                    // Rremove this and previous element
+                    array_splice($pathParts, $partCount - 1, 2);
+                    $partCount -= 2;
+                    $pathPartsLength -= 2;
+                } elseif ($absolutePathPrefix) {
+                    // can't go higher than root dir
+                    // simply remove this part and continue
+                    array_splice($pathParts, $partCount, 1);
+                    $partCount--;
+                    $pathPartsLength--;
+                }
+            }
+        }
+
+        return $absolutePathPrefix . implode('/', $pathParts);
+    }
+
+    /**
+     * Checks if the $path is absolute or relative (detecting either '/' or
+     * 'x:/' as first part of string) and returns TRUE if so.
+     *
+     * @param string $path File path to evaluate
+     * @return bool
+     */
+    private static function isAbsolutePath($path)
+    {
+        // Path starting with a / is always absolute, on every system
+        // On Windows also a path starting with a drive letter is absolute: X:/
+        return (isset($path[0]) ? $path[0] : null) === '/'
+            || static::isWindows() && (
+                strpos($path, ':/') === 1
+                || strpos($path, ':\\') === 1
+            );
+    }
+
+    /**
+     * @return bool
+     */
+    private static function isWindows()
+    {
+        return stripos(PHP_OS, 'WIN') === 0;
+    }
+}
\ No newline at end of file
diff --git a/misc/typo3/phar-stream-wrapper/src/Interceptor/PharExtensionInterceptor.php b/misc/typo3/phar-stream-wrapper/src/Interceptor/PharExtensionInterceptor.php
new file mode 100644
index 0000000..db500af
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Interceptor/PharExtensionInterceptor.php
@@ -0,0 +1,55 @@
+<?php
+namespace TYPO3\PharStreamWrapper\Interceptor;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+use TYPO3\PharStreamWrapper\Assertable;
+use TYPO3\PharStreamWrapper\Helper;
+use TYPO3\PharStreamWrapper\Exception;
+
+class PharExtensionInterceptor implements Assertable
+{
+    /**
+     * Determines whether the base file name has a ".phar" suffix.
+     *
+     * @param string $path
+     * @param string $command
+     * @return bool
+     * @throws Exception
+     */
+    public function assert($path, $command)
+    {
+        if ($this->baseFileContainsPharExtension($path)) {
+            return true;
+        }
+        throw new Exception(
+            sprintf(
+                'Unexpected file extension in "%s"',
+                $path
+            ),
+            1535198703
+        );
+    }
+
+    /**
+     * @param string $path
+     * @return bool
+     */
+    private function baseFileContainsPharExtension($path)
+    {
+        $baseFile = Helper::determineBaseFile($path);
+        if ($baseFile === null) {
+            return false;
+        }
+        $fileExtension = pathinfo($baseFile, PATHINFO_EXTENSION);
+        return strtolower($fileExtension) === 'phar';
+    }
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/Manager.php b/misc/typo3/phar-stream-wrapper/src/Manager.php
new file mode 100644
index 0000000..1eb9735
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/Manager.php
@@ -0,0 +1,85 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+class Manager implements Assertable
+{
+    /**
+     * @var self
+     */
+    private static $instance;
+
+    /**
+     * @var Behavior
+     */
+    private $behavior;
+
+    /**
+     * @param Behavior $behaviour
+     * @return self
+     */
+    public static function initialize(Behavior $behaviour)
+    {
+        if (self::$instance === null) {
+            self::$instance = new self($behaviour);
+            return self::$instance;
+        }
+        throw new \LogicException(
+            'Manager can only be initialized once',
+            1535189871
+        );
+    }
+
+    /**
+     * @return self
+     */
+    public static function instance()
+    {
+        if (self::$instance !== null) {
+            return self::$instance;
+        }
+        throw new \LogicException(
+            'Manager needs to be initialized first',
+            1535189872
+        );
+    }
+
+    /**
+     * @return bool
+     */
+    public static function destroy()
+    {
+        if (self::$instance === null) {
+            return false;
+        }
+        self::$instance = null;
+        return true;
+    }
+
+    /**
+     * @param Behavior $behaviour
+     */
+    private function __construct(Behavior $behaviour)
+    {
+        $this->behavior = $behaviour;
+    }
+
+    /**
+     * @param string $path
+     * @param string $command
+     * @return bool
+     */
+    public function assert($path, $command)
+    {
+        return $this->behavior->assert($path, $command);
+    }
+}
diff --git a/misc/typo3/phar-stream-wrapper/src/PharStreamWrapper.php b/misc/typo3/phar-stream-wrapper/src/PharStreamWrapper.php
new file mode 100644
index 0000000..5a924e4
--- /dev/null
+++ b/misc/typo3/phar-stream-wrapper/src/PharStreamWrapper.php
@@ -0,0 +1,477 @@
+<?php
+namespace TYPO3\PharStreamWrapper;
+
+/*
+ * This file is part of the TYPO3 project.
+ *
+ * It is free software; you can redistribute it and/or modify it under the terms
+ * of the MIT License (MIT). For the full copyright and license information,
+ * please read the LICENSE file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+class PharStreamWrapper
+{
+    /**
+     * Internal stream constants that are not exposed to PHP, but used...
+     * @see https://github.com/php/php-src/blob/e17fc0d73c611ad0207cac8a4a01ded38251a7dc/main/php_streams.h
+     */
+    const STREAM_OPEN_FOR_INCLUDE = 128;
+
+    /**
+     * @var resource
+     */
+    public $context;
+
+    /**
+     * @var resource
+     */
+    protected $internalResource;
+
+    /**
+     * @return bool
+     */
+    public function dir_closedir()
+    {
+        if (!is_resource($this->internalResource)) {
+            return false;
+        }
+
+        $this->invokeInternalStreamWrapper(
+            'closedir',
+            $this->internalResource
+        );
+        return !is_resource($this->internalResource);
+    }
+
+    /**
+     * @param string $path
+     * @param int $options
+     * @return bool
+     */
+    public function dir_opendir($path, $options)
+    {
+        $this->assert($path, Behavior::COMMAND_DIR_OPENDIR);
+        $this->internalResource = $this->invokeInternalStreamWrapper(
+            'opendir',
+            $path,
+            $this->context
+        );
+        return is_resource($this->internalResource);
+    }
+
+    /**
+     * @return string|false
+     */
+    public function dir_readdir()
+    {
+        return $this->invokeInternalStreamWrapper(
+            'readdir',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @return bool
+     */
+    public function dir_rewinddir()
+    {
+        if (!is_resource($this->internalResource)) {
+            return false;
+        }
+
+        $this->invokeInternalStreamWrapper(
+            'rewinddir',
+            $this->internalResource
+        );
+        return is_resource($this->internalResource);
+    }
+
+    /**
+     * @param string $path
+     * @param int $mode
+     * @param int $options
+     * @return bool
+     */
+    public function mkdir($path, $mode, $options)
+    {
+        $this->assert($path, Behavior::COMMAND_MKDIR);
+        return $this->invokeInternalStreamWrapper(
+            'mkdir',
+            $path,
+            $mode,
+            (bool) ($options & STREAM_MKDIR_RECURSIVE),
+            $this->context
+        );
+    }
+
+    /**
+     * @param string $path_from
+     * @param string $path_to
+     * @return bool
+     */
+    public function rename($path_from, $path_to)
+    {
+        $this->assert($path_from, Behavior::COMMAND_RENAME);
+        $this->assert($path_to, Behavior::COMMAND_RENAME);
+        return $this->invokeInternalStreamWrapper(
+            'rename',
+            $path_from,
+            $path_to,
+            $this->context
+        );
+    }
+
+    /**
+     * @param string $path
+     * @param int $options
+     * @return bool
+     */
+    public function rmdir($path, $options)
+    {
+        $this->assert($path, Behavior::COMMAND_RMDIR);
+        return $this->invokeInternalStreamWrapper(
+            'rmdir',
+            $path,
+            $this->context
+        );
+    }
+
+    /**
+     * @param int $cast_as
+     */
+    public function stream_cast($cast_as)
+    {
+        throw new Exception(
+            'Method stream_select() cannot be used',
+            1530103999
+        );
+    }
+
+    public function stream_close()
+    {
+        $this->invokeInternalStreamWrapper(
+            'fclose',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @return bool
+     */
+    public function stream_eof()
+    {
+        return $this->invokeInternalStreamWrapper(
+            'feof',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @return bool
+     */
+    public function stream_flush()
+    {
+        return $this->invokeInternalStreamWrapper(
+            'fflush',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @param int $operation
+     * @return bool
+     */
+    public function stream_lock($operation)
+    {
+        return $this->invokeInternalStreamWrapper(
+            'flock',
+            $this->internalResource,
+            $operation
+        );
+    }
+
+    /**
+     * @param string $path
+     * @param int $option
+     * @param string|int $value
+     * @return bool
+     */
+    public function stream_metadata($path, $option, $value)
+    {
+        $this->assert($path, Behavior::COMMAND_STEAM_METADATA);
+        if ($option === STREAM_META_TOUCH) {
+            return call_user_func_array(
+                array($this, 'invokeInternalStreamWrapper'),
+                array_merge(array('touch', $path), (array) $value)
+            );
+        }
+        if ($option === STREAM_META_OWNER_NAME || $option === STREAM_META_OWNER) {
+            return $this->invokeInternalStreamWrapper(
+                'chown',
+                $path,
+                $value
+            );
+        }
+        if ($option === STREAM_META_GROUP_NAME || $option === STREAM_META_GROUP) {
+            return $this->invokeInternalStreamWrapper(
+                'chgrp',
+                $path,
+                $value
+            );
+        }
+        if ($option === STREAM_META_ACCESS) {
+            return $this->invokeInternalStreamWrapper(
+                'chmod',
+                $path,
+                $value
+            );
+        }
+        return false;
+    }
+
+    /**
+     * @param string $path
+     * @param string $mode
+     * @param int $options
+     * @param string|null $opened_path
+     * @return bool
+     */
+    public function stream_open(
+        $path,
+        $mode,
+        $options,
+        &$opened_path = null
+    ) {
+        $this->assert($path, Behavior::COMMAND_STREAM_OPEN);
+        $arguments = array($path, $mode, (bool) ($options & STREAM_USE_PATH));
+        // only add stream context for non include/require calls
+        if (!($options & static::STREAM_OPEN_FOR_INCLUDE)) {
+            $arguments[] = $this->context;
+        // work around https://bugs.php.net/bug.php?id=66569
+        // for including files from Phar stream with OPcache enabled
+        } else {
+            Helper::resetOpCache();
+        }
+        $this->internalResource = call_user_func_array(
+            array($this, 'invokeInternalStreamWrapper'),
+            array_merge(array('fopen'), $arguments)
+        );
+        if (!is_resource($this->internalResource)) {
+            return false;
+        }
+        if ($opened_path !== null) {
+            $metaData = stream_get_meta_data($this->internalResource);
+            $opened_path = $metaData['uri'];
+        }
+        return true;
+    }
+
+    /**
+     * @param int $count
+     * @return string
+     */
+    public function stream_read($count)
+    {
+        return $this->invokeInternalStreamWrapper(
+            'fread',
+            $this->internalResource,
+            $count
+        );
+    }
+
+    /**
+     * @param int $offset
+     * @param int $whence
+     * @return bool
+     */
+    public function stream_seek($offset, $whence = SEEK_SET)
+    {
+        return $this->invokeInternalStreamWrapper(
+            'fseek',
+            $this->internalResource,
+            $offset,
+            $whence
+        ) !== -1;
+    }
+
+    /**
+     * @param int $option
+     * @param int $arg1
+     * @param int $arg2
+     * @return bool
+     */
+    public function stream_set_option($option, $arg1, $arg2)
+    {
+        if ($option === STREAM_OPTION_BLOCKING) {
+            return $this->invokeInternalStreamWrapper(
+                'stream_set_blocking',
+                $this->internalResource,
+                $arg1
+            );
+        }
+        if ($option === STREAM_OPTION_READ_TIMEOUT) {
+            return $this->invokeInternalStreamWrapper(
+                'stream_set_timeout',
+                $this->internalResource,
+                $arg1,
+                $arg2
+            );
+        }
+        if ($option === STREAM_OPTION_WRITE_BUFFER) {
+            return $this->invokeInternalStreamWrapper(
+                'stream_set_write_buffer',
+                $this->internalResource,
+                $arg2
+            ) === 0;
+        }
+        return false;
+    }
+
+    /**
+     * @return array
+     */
+    public function stream_stat()
+    {
+        return $this->invokeInternalStreamWrapper(
+            'fstat',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @return int
+     */
+    public function stream_tell()
+    {
+        return $this->invokeInternalStreamWrapper(
+            'ftell',
+            $this->internalResource
+        );
+    }
+
+    /**
+     * @param int $new_size
+     * @return bool
+     */
+    public function stream_truncate($new_size)
+    {
+        return $this->invokeInternalStreamWrapper(
+            'ftruncate',
+            $this->internalResource,
+            $new_size
+        );
+    }
+
+    /**
+     * @param string $data
+     * @return int
+     */
+    public function stream_write($data)
+    {
+        return $this->invokeInternalStreamWrapper(
+            'fwrite',
+            $this->internalResource,
+            $data
+        );
+    }
+
+    /**
+     * @param string $path
+     * @return bool
+     */
+    public function unlink($path)
+    {
+        $this->assert($path, Behavior::COMMAND_UNLINK);
+        return $this->invokeInternalStreamWrapper(
+            'unlink',
+            $path,
+            $this->context
+        );
+    }
+
+    /**
+     * @param string $path
+     * @param int $flags
+     * @return array|false
+     */
+    public function url_stat($path, $flags)
+    {
+        $this->assert($path, Behavior::COMMAND_URL_STAT);
+        $functionName = $flags & STREAM_URL_STAT_QUIET ? '@stat' : 'stat';
+        return $this->invokeInternalStreamWrapper($functionName, $path);
+    }
+
+    /**
+     * @param string $path
+     * @param string $command
+     */
+    protected function assert($path, $command)
+    {
+        if ($this->resolveAssertable()->assert($path, $command) === true) {
+            return;
+        }
+
+        throw new Exception(
+            sprintf(
+                'Denied invocation of "%s" for command "%s"',
+                $path,
+                $command
+            ),
+            1535189880
+        );
+    }
+
+    /**
+     * @return Assertable
+     */
+    protected function resolveAssertable()
+    {
+        return Manager::instance();
+    }
+
+    /**
+     * Invokes commands on the native PHP Phar stream wrapper.
+     *
+     * @param string $functionName
+     * @param mixed ...$arguments
+     * @return mixed
+     */
+    private function invokeInternalStreamWrapper($functionName)
+    {
+        $arguments = func_get_args();
+        array_shift($arguments);
+        $silentExecution = $functionName{0} === '@';
+        $functionName = ltrim($functionName, '@');
+        $this->restoreInternalSteamWrapper();
+
+        try {
+            if ($silentExecution) {
+                $result = @call_user_func_array($functionName, $arguments);
+            } else {
+                $result = call_user_func_array($functionName, $arguments);
+            }
+        } catch (\Exception $exception) {
+            $this->registerStreamWrapper();
+            throw $exception;
+        } catch (\Throwable $throwable) {
+            $this->registerStreamWrapper();
+            throw $throwable;
+        }
+
+        $this->registerStreamWrapper();
+        return $result;
+    }
+
+    private function restoreInternalSteamWrapper()
+    {
+        stream_wrapper_restore('phar');
+    }
+
+    private function registerStreamWrapper()
+    {
+        stream_wrapper_unregister('phar');
+        stream_wrapper_register('phar', get_class($this));
+    }
+}
diff --git a/modules/simpletest/files/phar-1.phar b/modules/simpletest/files/phar-1.phar
new file mode 100644
index 0000000000000000000000000000000000000000..8d25e6d4403979bf0fb37b7d10ff721bc804130d
GIT binary patch
diff --git a/modules/simpletest/tests/file.test b/modules/simpletest/tests/file.test
index 89ecac7..55dd190 100644
--- a/modules/simpletest/tests/file.test
+++ b/modules/simpletest/tests/file.test
@@ -2766,4 +2766,64 @@ class StreamWrapperTest extends DrupalWebTestCase {
     $this->assertTrue(file_stream_wrapper_valid_scheme(file_uri_scheme('public://asdf')), 'Got a valid stream scheme from public://asdf');
     $this->assertFalse(file_stream_wrapper_valid_scheme(file_uri_scheme('foo://asdf')), 'Did not get a valid stream scheme from foo://asdf');
   }
+
+  /**
+   * Tests that phar stream wrapper is registered as expected.
+   *
+   * @see file_get_stream_wrappers()
+   */
+  public function testPharStreamWrapperRegistration() {
+    if (!class_exists('Phar', FALSE)) {
+      $this->assertFalse(in_array('phar', stream_get_wrappers(), TRUE), 'PHP is compiled without phar support. Therefore, no phar stream wrapper is registered.');
+    }
+    elseif (version_compare(PHP_VERSION, '5.3.3', '<')) {
+      $this->assertFalse(in_array('phar', stream_get_wrappers(), TRUE), 'The PHP version is <5.3.3. The built-in phar stream wrapper has been unregistered and not replaced.');
+    }
+    else {
+      $this->assertTrue(in_array('phar', stream_get_wrappers(), TRUE), 'A phar stream wrapper is registered.');
+      $this->assertFalse(file_stream_wrapper_valid_scheme('phar'), 'The phar scheme is not a valid scheme for Drupal File API usage.');
+    }
+
+    // Ensure that calling file_get_stream_wrappers() multiple times, both
+    // without and with a drupal_static_reset() in between, does not create
+    // errors due to the PharStreamWrapperManager singleton.
+    file_get_stream_wrappers();
+    file_get_stream_wrappers();
+    drupal_static_reset('file_get_stream_wrappers');
+    file_get_stream_wrappers();
+  }
+
+  /**
+   * Tests that only valid phar files can be used.
+   */
+  public function testPharFile() {
+    if (!in_array('phar', stream_get_wrappers(), TRUE)) {
+      $this->pass('There is no phar stream wrapper registered.');
+      // Nothing else in this test is relevant when there's no phar stream
+      // wrapper. testPharStreamWrapperRegistration() is sufficient for testing
+      // the conditions of when the stream wrapper should or should not be
+      // registered.
+      return;
+    }
+
+    $base = dirname(dirname(__FILE__)) . '/files';
+
+    // Ensure that file operations via the phar:// stream wrapper work for phar
+    // files with the .phar extension.
+    $this->assertFalse(file_exists("phar://$base/phar-1.phar/no-such-file.php"));
+    $this->assertTrue(file_exists("phar://$base/phar-1.phar/index.php"));
+    $file_contents = file_get_contents("phar://$base/phar-1.phar/index.php");
+    $expected_hash = 'c7e7904ea573c5ebea3ef00bb08c1f86af1a45961fbfbeb1892ff4a98fd73ad5';
+    $this->assertIdentical($expected_hash, hash('sha256', $file_contents));
+
+    // Ensure that file operations via the phar:// stream wrapper throw an
+    // exception for files without the .phar extension.
+    try {
+      file_exists("phar://$base/image-2.jpg/index.php");
+      $this->fail('Expected exception failed to be thrown when accessing an invalid phar file.');
+    }
+    catch (Exception $e) {
+      $this->assertEqual(get_class($e), 'TYPO3\PharStreamWrapper\Exception', 'Expected exception thrown when accessing an invalid phar file.');
+    }
+  }
 }
diff --git a/modules/system/system.tar.inc b/modules/system/system.tar.inc
index 86e4e3d..e160171 100644
--- a/modules/system/system.tar.inc
+++ b/modules/system/system.tar.inc
@@ -41,8 +41,8 @@
 
  /**
  * Note on Drupal 8 porting.
- * This file origin is Tar.php, release 1.4.0 (stable) with some code
- * from PEAR.php, release 1.9.5 (stable) both at http://pear.php.net.
+ * This file origin is Tar.php, release 1.4.5 (stable) with some code
+ * from PEAR.php, release 1.10.5 (stable) both at http://pear.php.net.
  * To simplify future porting from pear of this file, you should not
  * do cosmetic or other non significant changes to this file.
  * The following changes have been done:
@@ -1394,10 +1394,22 @@ class Archive_Tar
         if ($p_stored_filename == '') {
             $p_stored_filename = $p_filename;
         }
-        $v_reduce_filename = $this->_pathReduction($p_stored_filename);
 
-        if (strlen($v_reduce_filename) > 99) {
-            if (!$this->_writeLongHeader($v_reduce_filename)) {
+        $v_reduced_filename = $this->_pathReduction($p_stored_filename);
+
+        if (strlen($v_reduced_filename) > 99) {
+            if (!$this->_writeLongHeader($v_reduced_filename, false)) {
+                return false;
+            }
+        }
+
+        $v_linkname = '';
+        if (@is_link($p_filename)) {
+            $v_linkname = readlink($p_filename);
+        }
+
+        if (strlen($v_linkname) > 99) {
+            if (!$this->_writeLongHeader($v_linkname, true)) {
                 return false;
             }
         }
@@ -1406,14 +1418,10 @@ class Archive_Tar
         $v_uid = sprintf("%07s", DecOct($v_info[4]));
         $v_gid = sprintf("%07s", DecOct($v_info[5]));
         $v_perms = sprintf("%07s", DecOct($v_info['mode'] & 000777));
-
         $v_mtime = sprintf("%011s", DecOct($v_info['mtime']));
 
-        $v_linkname = '';
-
         if (@is_link($p_filename)) {
             $v_typeflag = '2';
-            $v_linkname = readlink($p_filename);
             $v_size = sprintf("%011s", DecOct(0));
         } elseif (@is_dir($p_filename)) {
             $v_typeflag = "5";
@@ -1425,7 +1433,6 @@ class Archive_Tar
         }
 
         $v_magic = 'ustar ';
-
         $v_version = ' ';
 
         if (function_exists('posix_getpwuid')) {
@@ -1440,14 +1447,12 @@ class Archive_Tar
         }
 
         $v_devmajor = '';
-
         $v_devminor = '';
-
         $v_prefix = '';
 
         $v_binary_data_first = pack(
             "a100a8a8a8a12a12",
-            $v_reduce_filename,
+            $v_reduced_filename,
             $v_perms,
             $v_uid,
             $v_gid,
@@ -1487,7 +1492,7 @@ class Archive_Tar
         $this->_writeBlock($v_binary_data_first, 148);
 
         // ----- Write the calculated checksum
-        $v_checksum = sprintf("%06s ", DecOct($v_checksum));
+        $v_checksum = sprintf("%06s\0 ", DecOct($v_checksum));
         $v_binary_data = pack("a8", $v_checksum);
         $this->_writeBlock($v_binary_data, 8);
 
@@ -1519,7 +1524,7 @@ class Archive_Tar
         $p_filename = $this->_pathReduction($p_filename);
 
         if (strlen($p_filename) > 99) {
-            if (!$this->_writeLongHeader($p_filename)) {
+            if (!$this->_writeLongHeader($p_filename, false)) {
                 return false;
             }
         }
@@ -1615,36 +1620,31 @@ class Archive_Tar
      * @param string $p_filename
      * @return bool
      */
-    public function _writeLongHeader($p_filename)
+    public function _writeLongHeader($p_filename, $is_link = false)
     {
-        $v_size = sprintf("%11s ", DecOct(strlen($p_filename)));
-
-        $v_typeflag = 'L';
-
+        $v_uid = sprintf("%07s", 0);
+        $v_gid = sprintf("%07s", 0);
+        $v_perms = sprintf("%07s", 0);
+        $v_size = sprintf("%'011s", DecOct(strlen($p_filename)));
+        $v_mtime = sprintf("%011s", 0);
+        $v_typeflag = ($is_link ? 'K' : 'L');
         $v_linkname = '';
-
-        $v_magic = '';
-
-        $v_version = '';
-
+        $v_magic = 'ustar ';
+        $v_version = ' ';
         $v_uname = '';
-
         $v_gname = '';
-
         $v_devmajor = '';
-
         $v_devminor = '';
-
         $v_prefix = '';
 
         $v_binary_data_first = pack(
             "a100a8a8a8a12a12",
             '././@LongLink',
-            0,
-            0,
-            0,
+            $v_perms,
+            $v_uid,
+            $v_gid,
             $v_size,
-            0
+            $v_mtime
         );
         $v_binary_data_last = pack(
             "a1a100a6a2a32a32a8a8a155a12",
@@ -1679,7 +1679,7 @@ class Archive_Tar
         $this->_writeBlock($v_binary_data_first, 148);
 
         // ----- Write the calculated checksum
-        $v_checksum = sprintf("%06s ", DecOct($v_checksum));
+        $v_checksum = sprintf("%06s\0 ", DecOct($v_checksum));
         $v_binary_data = pack("a8", $v_checksum);
         $this->_writeBlock($v_binary_data, 8);
 
@@ -1805,10 +1805,13 @@ class Archive_Tar
      */
     private function _maliciousFilename($file)
     {
-        if (strpos($file, '/../') !== false) {
+        if (strpos($file, 'phar://') === 0) {
             return true;
         }
-        if (strpos($file, '../') === 0) {
+        if (strpos($file, DIRECTORY_SEPARATOR . '..' . DIRECTORY_SEPARATOR) !== false) {
+            return true;
+        }
+        if (strpos($file, '..' . DIRECTORY_SEPARATOR) === 0) {
             return true;
         }
         return false;
@@ -1873,11 +1876,20 @@ class Archive_Tar
                 continue;
             }
 
-            // ----- Look for long filename
-            if ($v_header['typeflag'] == 'L') {
-                if (!$this->_readLongHeader($v_header)) {
-                    return null;
-                }
+            switch ($v_header['typeflag']) {
+                case 'L': {
+                    if (!$this->_readLongHeader($v_header)) {
+                        return null;
+                    }
+                } break;
+
+                case 'K': {
+                    $v_link_header = $v_header;
+                    if (!$this->_readLongHeader($v_link_header)) {
+                        return null;
+                    }
+                    $v_header['link'] = $v_link_header['filename'];
+                } break;
             }
 
             if ($v_header['filename'] == $p_filename) {
@@ -1978,11 +1990,20 @@ class Archive_Tar
                 continue;
             }
 
-            // ----- Look for long filename
-            if ($v_header['typeflag'] == 'L') {
-                if (!$this->_readLongHeader($v_header)) {
-                    return false;
-                }
+            switch ($v_header['typeflag']) {
+                case 'L': {
+                    if (!$this->_readLongHeader($v_header)) {
+                        return null;
+                    }
+                } break;
+
+                case 'K': {
+                    $v_link_header = $v_header;
+                    if (!$this->_readLongHeader($v_link_header)) {
+                        return null;
+                    }
+                    $v_header['link'] = $v_link_header['filename'];
+                } break;
             }
 
             // ignore extended / pax headers
