diff options
Diffstat (limited to 'libs/Authenticator/TwoFactorAuthenticator.php')
| -rw-r--r-- | libs/Authenticator/TwoFactorAuthenticator.php | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/libs/Authenticator/TwoFactorAuthenticator.php b/libs/Authenticator/TwoFactorAuthenticator.php new file mode 100644 index 0000000000..fc0b962856 --- /dev/null +++ b/libs/Authenticator/TwoFactorAuthenticator.php @@ -0,0 +1,195 @@ +<?php +/** + * PHP Class for handling Google Authenticator 2-factor authentication + * + * @author Michael Kliewe + * @copyright 2012 Michael Kliewe + * @license http://www.opensource.org/licenses/bsd-license.php BSD License + * @link http://www.phpgangsta.de/ + * + * small adjustments by @sgiehl / matomo.org + * - renamed class + * - removed method getQRCodeGoogleUrl + */ + +class TwoFactorAuthenticator +{ + protected $_codeLength = 6; + + /** + * Create new secret. + * 16 characters, randomly chosen from the allowed base32 characters. + * + * @param int $secretLength + * @return string + */ + public function createSecret($secretLength = 16) + { + $validChars = $this->_getBase32LookupTable(); + unset($validChars[32]); + + $secret = ''; + for ($i = 0; $i < $secretLength; $i++) { + $secret .= $validChars[array_rand($validChars)]; + } + return $secret; + } + + /** + * Calculate the code, with given secret and point in time + * + * @param string $secret + * @param int|null $timeSlice + * @return string + */ + public function getCode($secret, $timeSlice = null) + { + if ($timeSlice === null) { + $timeSlice = floor(time() / 30); + } + + $secretkey = $this->_base32Decode($secret); + + // Pack time into binary string + $time = chr(0).chr(0).chr(0).chr(0).pack('N*', $timeSlice); + // Hash it with users secret key + $hm = hash_hmac('SHA1', $time, $secretkey, true); + // Use last nipple of result as index/offset + $offset = ord(substr($hm, -1)) & 0x0F; + // grab 4 bytes of the result + $hashpart = substr($hm, $offset, 4); + + // Unpak binary value + $value = unpack('N', $hashpart); + $value = $value[1]; + // Only 32 bits + $value = $value & 0x7FFFFFFF; + + $modulo = pow(10, $this->_codeLength); + return str_pad($value % $modulo, $this->_codeLength, '0', STR_PAD_LEFT); + } + + /** + * Check if the code is correct. This will accept codes starting from $discrepancy*30sec ago to $discrepancy*30sec from now + * + * @param string $secret + * @param string $code + * @param int $discrepancy This is the allowed time drift in 30 second units (8 means 4 minutes before or after) + * @param int|null $currentTimeSlice time slice if we want use other that time() + * @return bool + */ + public function verifyCode($secret, $code, $discrepancy = 1, $currentTimeSlice = null) + { + if ($currentTimeSlice === null) { + $currentTimeSlice = floor(time() / 30); + } + + for ($i = -$discrepancy; $i <= $discrepancy; $i++) { + $calculatedCode = $this->getCode($secret, $currentTimeSlice + $i); + if ($calculatedCode == $code ) { + return true; + } + } + + return false; + } + + /** + * Set the code length, should be >=6 + * + * @param int $length + * @return self + */ + public function setCodeLength($length) + { + $this->_codeLength = $length; + return $this; + } + + /** + * Helper class to decode base32 + * + * @param $secret + * @return bool|string + */ + protected function _base32Decode($secret) + { + if (empty($secret)) return ''; + + $base32chars = $this->_getBase32LookupTable(); + $base32charsFlipped = array_flip($base32chars); + + $paddingCharCount = substr_count($secret, $base32chars[32]); + $allowedValues = array(6, 4, 3, 1, 0); + if (!in_array($paddingCharCount, $allowedValues)) return false; + for ($i = 0; $i < 4; $i++){ + if ($paddingCharCount == $allowedValues[$i] && + substr($secret, -($allowedValues[$i])) != str_repeat($base32chars[32], $allowedValues[$i])) return false; + } + $secret = str_replace('=','', $secret); + $secret = str_split($secret); + $binaryString = ""; + for ($i = 0; $i < count($secret); $i = $i+8) { + $x = ""; + if (!in_array($secret[$i], $base32chars)) return false; + for ($j = 0; $j < 8; $j++) { + $x .= str_pad(base_convert(@$base32charsFlipped[@$secret[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT); + } + $eightBits = str_split($x, 8); + for ($z = 0; $z < count($eightBits); $z++) { + $binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:""; + } + } + return $binaryString; + } + + /** + * Helper class to encode base32 + * + * @param string $secret + * @param bool $padding + * @return string + */ + protected function _base32Encode($secret, $padding = true) + { + if (empty($secret)) return ''; + + $base32chars = $this->_getBase32LookupTable(); + + $secret = str_split($secret); + $binaryString = ""; + for ($i = 0; $i < count($secret); $i++) { + $binaryString .= str_pad(base_convert(ord($secret[$i]), 10, 2), 8, '0', STR_PAD_LEFT); + } + $fiveBitBinaryArray = str_split($binaryString, 5); + $base32 = ""; + $i = 0; + while ($i < count($fiveBitBinaryArray)) { + $base32 .= $base32chars[base_convert(str_pad($fiveBitBinaryArray[$i], 5, '0'), 2, 10)]; + $i++; + } + if ($padding && ($x = strlen($binaryString) % 40) != 0) { + if ($x == 8) $base32 .= str_repeat($base32chars[32], 6); + elseif ($x == 16) $base32 .= str_repeat($base32chars[32], 4); + elseif ($x == 24) $base32 .= str_repeat($base32chars[32], 3); + elseif ($x == 32) $base32 .= $base32chars[32]; + } + return $base32; + } + + /** + * Get array with all 32 characters for decoding from/encoding to base32 + * + * @return array + */ + protected function _getBase32LookupTable() + { + return array( + 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', // 7 + 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15 + 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23 + 'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31 + '=' // padding char + ); + } +}
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