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<?php |
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/* |
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* This file is part of the PHPASN1 library. |
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* |
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* Copyright © Friedrich Große <[email protected]> |
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* |
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* For the full copyright and license information, please view the LICENSE |
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* file that was distributed with this source code. |
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*/ |
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|
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namespace WP_DEFENDER_VENDOR\FG\ASN1\Universal; |
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|
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use Exception; |
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use WP_DEFENDER_VENDOR\FG\ASN1\Exception\ParserException; |
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use WP_DEFENDER_VENDOR\FG\ASN1\Parsable; |
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use WP_DEFENDER_VENDOR\FG\ASN1\Identifier; |
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|
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class BitString extends OctetString implements Parsable |
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{ |
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private $nrOfUnusedBits; |
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|
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/** |
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* Creates a new ASN.1 BitString object. |
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* |
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* @param string|int $value Either the hexadecimal value as a string (spaces are allowed - leading 0x is optional) or a numeric value |
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* @param int $nrOfUnusedBits the number of unused bits in the last octet [optional]. |
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* |
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* @throws Exception if the second parameter is no positive numeric value |
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*/ |
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public function __construct($value, $nrOfUnusedBits = 0) |
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{ |
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parent::__construct($value); |
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|
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if (!is_numeric($nrOfUnusedBits) || $nrOfUnusedBits < 0) { |
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throw new Exception('BitString: second parameter needs to be a positive number (or zero)!'); |
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} |
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|
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$this->nrOfUnusedBits = $nrOfUnusedBits; |
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} |
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|
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public function getType() |
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{ |
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return Identifier::BITSTRING; |
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} |
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|
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protected function calculateContentLength() |
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{ |
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// add one to the length for the first octet which encodes the number of unused bits in the last octet |
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return parent::calculateContentLength() + 1; |
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} |
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|
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protected function getEncodedValue() |
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{ |
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// the first octet determines the number of unused bits |
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$nrOfUnusedBitsOctet = chr($this->nrOfUnusedBits); |
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$actualContent = parent::getEncodedValue(); |
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|
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return $nrOfUnusedBitsOctet.$actualContent; |
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} |
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|
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public function getNumberOfUnusedBits() |
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{ |
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return $this->nrOfUnusedBits; |
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} |
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|
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public static function fromBinary(&$binaryData, &$offsetIndex = 0) |
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{ |
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self::parseIdentifier($binaryData[$offsetIndex], Identifier::BITSTRING, $offsetIndex++); |
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$contentLength = self::parseContentLength($binaryData, $offsetIndex, 2); |
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|
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$nrOfUnusedBits = ord($binaryData[$offsetIndex]); |
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$value = substr($binaryData, $offsetIndex + 1, $contentLength - 1); |
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|
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if ($nrOfUnusedBits > 7 || // no less than 1 used, otherwise non-minimal |
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($contentLength - 1) == 1 && $nrOfUnusedBits > 0 || // content length only 1, no |
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(ord($value[strlen($value)-1])&((1<<$nrOfUnusedBits)-1)) != 0 // unused bits set |
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) { |
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throw new ParserException("Can not parse bit string with invalid padding", $offsetIndex); |
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} |
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|
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$offsetIndex += $contentLength; |
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|
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$parsedObject = new self(bin2hex($value), $nrOfUnusedBits); |
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$parsedObject->setContentLength($contentLength); |
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|
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return $parsedObject; |
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} |
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} |
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|
