Emre Akay
10 years ago
6 changed files with 435 additions and 87 deletions
@ -0,0 +1,208 @@
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<?php |
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/** |
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* PHP Class for handling Google Authenticator 2-factor authentication |
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* |
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* @author Michael Kliewe |
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* @copyright 2012 Michael Kliewe |
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* @license http://www.opensource.org/licenses/bsd-license.php BSD License |
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* @link http://www.phpgangsta.de/ |
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*/ |
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class PHPGangsta_GoogleAuthenticator |
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{ |
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protected $_codeLength = 6; |
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/** |
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* Create new secret. |
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* 16 characters, randomly chosen from the allowed base32 characters. |
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* |
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* @param int $secretLength |
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* @return string |
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*/ |
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public function createSecret($secretLength = 16) |
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{ |
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$validChars = $this->_getBase32LookupTable(); |
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unset($validChars[32]); |
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$secret = ''; |
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for ($i = 0; $i < $secretLength; $i++) { |
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$secret .= $validChars[array_rand($validChars)]; |
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} |
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return $secret; |
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} |
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/** |
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* Calculate the code, with given secret and point in time |
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* |
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* @param string $secret |
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* @param int|null $timeSlice |
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* @return string |
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*/ |
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public function getCode($secret, $timeSlice = null) |
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{ |
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if ($timeSlice === null) { |
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$timeSlice = floor(time() / 30); |
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} |
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$secretkey = $this->_base32Decode($secret); |
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// Pack time into binary string |
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$time = chr(0).chr(0).chr(0).chr(0).pack('N*', $timeSlice); |
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// Hash it with users secret key |
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$hm = hash_hmac('SHA1', $time, $secretkey, true); |
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// Use last nipple of result as index/offset |
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$offset = ord(substr($hm, -1)) & 0x0F; |
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// grab 4 bytes of the result |
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$hashpart = substr($hm, $offset, 4); |
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// Unpak binary value |
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$value = unpack('N', $hashpart); |
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$value = $value[1]; |
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// Only 32 bits |
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$value = $value & 0x7FFFFFFF; |
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$modulo = pow(10, $this->_codeLength); |
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return str_pad($value % $modulo, $this->_codeLength, '0', STR_PAD_LEFT); |
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} |
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/** |
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* Get QR-Code URL for image, from google charts |
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* |
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* @param string $name |
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* @param string $secret |
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* @param string $title |
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* @return string |
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*/ |
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public function getQRCodeGoogleUrl($name, $secret, $title = null) { |
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$urlencoded = urlencode('otpauth://totp/'.$name.'?secret='.$secret.''); |
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if(isset($title)) { |
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$urlencoded .= urlencode('&issuer='.urlencode($title)); |
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} |
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return 'https://chart.googleapis.com/chart?chs=200x200&chld=M|0&cht=qr&chl='.$urlencoded.''; |
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} |
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/** |
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* Check if the code is correct. This will accept codes starting from $discrepancy*30sec ago to $discrepancy*30sec from now |
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* |
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* @param string $secret |
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* @param string $code |
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* @param int $discrepancy This is the allowed time drift in 30 second units (8 means 4 minutes before or after) |
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* @param int|null $currentTimeSlice time slice if we want use other that time() |
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* @return bool |
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*/ |
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public function verifyCode($secret, $code, $discrepancy = 1, $currentTimeSlice = null) |
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{ |
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if ($currentTimeSlice === null) { |
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$currentTimeSlice = floor(time() / 30); |
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} |
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for ($i = -$discrepancy; $i <= $discrepancy; $i++) { |
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$calculatedCode = $this->getCode($secret, $currentTimeSlice + $i); |
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if ($calculatedCode == $code ) { |
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return true; |
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} |
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} |
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return false; |
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} |
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/** |
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* Set the code length, should be >=6 |
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* |
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* @param int $length |
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* @return PHPGangsta_GoogleAuthenticator |
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*/ |
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public function setCodeLength($length) |
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{ |
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$this->_codeLength = $length; |
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return $this; |
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} |
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/** |
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* Helper class to decode base32 |
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* |
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* @param $secret |
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* @return bool|string |
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*/ |
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protected function _base32Decode($secret) |
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{ |
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if (empty($secret)) return ''; |
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$base32chars = $this->_getBase32LookupTable(); |
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$base32charsFlipped = array_flip($base32chars); |
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$paddingCharCount = substr_count($secret, $base32chars[32]); |
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$allowedValues = array(6, 4, 3, 1, 0); |
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if (!in_array($paddingCharCount, $allowedValues)) return false; |
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for ($i = 0; $i < 4; $i++){ |
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if ($paddingCharCount == $allowedValues[$i] && |
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substr($secret, -($allowedValues[$i])) != str_repeat($base32chars[32], $allowedValues[$i])) return false; |
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} |
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$secret = str_replace('=','', $secret); |
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$secret = str_split($secret); |
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$binaryString = ""; |
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for ($i = 0; $i < count($secret); $i = $i+8) { |
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$x = ""; |
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if (!in_array($secret[$i], $base32chars)) return false; |
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for ($j = 0; $j < 8; $j++) { |
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$x .= str_pad(base_convert(@$base32charsFlipped[@$secret[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT); |
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} |
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$eightBits = str_split($x, 8); |
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for ($z = 0; $z < count($eightBits); $z++) { |
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$binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:""; |
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} |
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} |
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return $binaryString; |
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} |
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/** |
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* Helper class to encode base32 |
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* |
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* @param string $secret |
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* @param bool $padding |
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* @return string |
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*/ |
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protected function _base32Encode($secret, $padding = true) |
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{ |
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if (empty($secret)) return ''; |
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$base32chars = $this->_getBase32LookupTable(); |
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$secret = str_split($secret); |
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$binaryString = ""; |
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for ($i = 0; $i < count($secret); $i++) { |
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$binaryString .= str_pad(base_convert(ord($secret[$i]), 10, 2), 8, '0', STR_PAD_LEFT); |
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} |
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$fiveBitBinaryArray = str_split($binaryString, 5); |
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$base32 = ""; |
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$i = 0; |
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while ($i < count($fiveBitBinaryArray)) { |
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$base32 .= $base32chars[base_convert(str_pad($fiveBitBinaryArray[$i], 5, '0'), 2, 10)]; |
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$i++; |
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} |
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if ($padding && ($x = strlen($binaryString) % 40) != 0) { |
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if ($x == 8) $base32 .= str_repeat($base32chars[32], 6); |
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elseif ($x == 16) $base32 .= str_repeat($base32chars[32], 4); |
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elseif ($x == 24) $base32 .= str_repeat($base32chars[32], 3); |
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elseif ($x == 32) $base32 .= $base32chars[32]; |
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} |
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return $base32; |
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} |
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/** |
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* Get array with all 32 characters for decoding from/encoding to base32 |
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* |
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* @return array |
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*/ |
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protected function _getBase32LookupTable() |
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{ |
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return array( |
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', // 7 |
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'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15 |
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'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23 |
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'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31 |
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'=' // padding char |
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); |
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} |
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} |
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