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<?php |
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/** |
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* (c) Dennis Meckel |
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* |
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* For the full copyright and license information, |
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* please view the LICENSE file that was distributed with this source code. |
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*/ |
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namespace Rayne\VirtualPath; |
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/** |
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* A `VirtualPath` object represents a normalised path. |
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* It detects, removes and flags malicious directory traversals. |
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* |
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* *Example*: The path `hello/../world/../../test` gets normalized to `/test` |
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* but also gets the "jail-breaking attempt" flag set. |
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* |
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* @see JailedPath |
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*/ |
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class VirtualPath |
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{ |
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/** |
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* @var bool |
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*/ |
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private $hasJailbreakAttempt = false; |
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/** |
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* @var string[] |
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*/ |
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private $segments = []; |
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/** |
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* @var string |
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*/ |
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private $trustedPath; |
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/** |
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* @var string |
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*/ |
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private $untrustedPath; |
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/** |
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* @param string|mixed $untrustedPath Gets string casted if possible. Otherwise gets flagged as untrusted and replaced by an empty string. |
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*/ |
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public function __construct($untrustedPath) |
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{ |
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$this->setUntrustedPath($untrustedPath); |
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$this->createPathSegments(); |
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$this->trustedPath = '/' . implode('/', $this->segments); |
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} |
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/** |
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* @return string Normalised and trusted path relative to the virtual jail. |
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* @see VirtualPath::getTrustedPath() |
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*/ |
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public function __toString() |
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{ |
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return $this->getTrustedPath(); |
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} |
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/** |
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* Converts the untrusted input to string. |
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* If converting to string isn't possible |
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* the jailbreak attempt flag will be set |
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* and an empty string will be defined as untrusted value. |
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* |
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* @param mixed $untrustedPath |
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*/ |
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private function setUntrustedPath($untrustedPath) |
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{ |
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if (is_scalar($untrustedPath) || is_object($untrustedPath) && method_exists($untrustedPath, '__toString')) { |
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$this->untrustedPath = (string) $untrustedPath; |
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} else { |
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$this->untrustedPath = ''; |
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// Invalid input is interpreted as malicious input. |
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$this->hasJailbreakAttempt = true; |
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} |
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} |
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/** |
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* |
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*/ |
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private function createPathSegments() |
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{ |
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foreach (explode('/', str_replace('\\', '/', $this->untrustedPath)) as $segment) { |
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if ($segment === '.' || $segment === '') { |
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continue; |
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} |
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if ($segment === '..') { |
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if (null === array_pop($this->segments)) { |
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$this->hasJailbreakAttempt = true; |
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} |
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continue; |
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} |
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$this->segments[] = $segment; |
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} |
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} |
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/** |
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* @return string[] |
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*/ |
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public function getSegments() |
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{ |
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return $this->segments; |
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} |
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/** |
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* @return string Normalised and trusted path relative to the virtual jail. |
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*/ |
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public function getTrustedPath() |
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{ |
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return $this->trustedPath; |
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} |
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/** |
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* @return string Untrusted and perhaps malicious path. |
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*/ |
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147 |
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public function getUntrustedPath() |
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{ |
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return $this->untrustedPath; |
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} |
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/** |
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* @return bool Whether the original path input is trustworthy. |
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*/ |
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public function isTrusted() |
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{ |
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return !$this->hasJailbreakAttempt; |
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} |
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/** |
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* @return VirtualPath Parent of the trusted path. By definition trusted. |
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*/ |
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public function buildParent() |
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{ |
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return new self(dirname($this->getTrustedPath())); |
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} |
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} |
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Rayne /
virtual-path
