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<?php |
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class SymmetricEncryption { |
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private $cipher; |
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|
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public function __construct($cipher = 'aes-256-cbc') { |
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$this->cipher = $cipher; |
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} |
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|
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private function getKeySize() { |
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if (preg_match("/([0-9]+)/i", $this->cipher, $matches)) { |
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return $matches[1] >> 3; |
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} |
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return 0; |
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} |
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|
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private function derived($password, $salt) { |
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|
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$AESKeyLength = $this->getKeySize(); |
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$AESIVLength = openssl_cipher_iv_length($this->cipher); |
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|
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$pbkdf2 = hash_pbkdf2("SHA1", $password, mb_convert_encoding($salt, 'UTF-16LE'), 1000, $AESKeyLength + $AESIVLength, TRUE); |
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|
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$key = substr($pbkdf2, 0, $AESKeyLength); |
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$iv = substr($pbkdf2, $AESKeyLength, $AESIVLength); |
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|
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$derived = new stdClass(); |
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$derived->key = $key; |
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$derived->iv = $iv; |
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return $derived; |
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} |
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|
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function encrypt($message, $password, $salt) { |
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$derived = $this->derived($password, $salt); |
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$enc = openssl_encrypt(mb_convert_encoding($message, 'UTF-16', 'UTF-8'), $this->cipher, $derived->key, 0, $derived->iv); |
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return '$$'.$enc.'$$'; |
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} |
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|
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function decrypt($message, $password, $salt) { |
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$derived = $this->derived($password, $salt); |
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$dec = openssl_decrypt($message, $this->cipher, $derived->key, 0, $derived->iv); |
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return mb_convert_encoding($dec, 'UTF-8', 'UTF-16'); |
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} |
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|
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} |
