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<?php |
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|
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namespace Getwid; |
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|
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final class StringEncryption { |
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|
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private $cipher = 'aes-256-ctr'; |
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private $salt; |
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private $passphrase; |
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|
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public function __construct() { |
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$this->salt = $this->get_salt(); |
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$this->passphrase = $this->get_passphrase(); |
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} |
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|
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public function encrypt( $string_to_encrypt ) { |
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|
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if ( ! $this->can_encrypt() ) { |
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return $string_to_encrypt; |
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} |
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|
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$ivlen = openssl_cipher_iv_length( $this->cipher ); |
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$iv = openssl_random_pseudo_bytes( $ivlen ); |
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|
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$encrypted_string = openssl_encrypt( |
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$string_to_encrypt . $this->salt, |
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$this->cipher, |
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$this->passphrase, |
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0, |
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$iv |
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); |
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|
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return base64_encode( $iv . $encrypted_string ); |
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} |
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|
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public function decrypt( $string_to_decrypt ) { |
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|
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if ( ! $this->can_encrypt() ) { |
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return $string_to_decrypt; |
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} |
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|
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$encrypted_string = base64_decode( $string_to_decrypt, true ); |
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|
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$ivlen = openssl_cipher_iv_length( $this->cipher ); |
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$iv = substr( $encrypted_string, 0, $ivlen ); |
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|
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$encrypted_string = substr( $encrypted_string, $ivlen ); |
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|
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$decrypted_string = openssl_decrypt( |
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$encrypted_string, |
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$this->cipher, |
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$this->passphrase, |
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0, |
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$iv |
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); |
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|
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if ( ! $decrypted_string || substr( $decrypted_string, - strlen( $this->salt ) ) !== $this->salt ) { |
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return $string_to_decrypt; |
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} |
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|
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return substr( $decrypted_string, 0, - strlen( $this->salt ) ); |
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} |
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|
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private function can_encrypt() { |
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|
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if ( ! function_exists( 'openssl_encrypt' ) ) { |
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return false; |
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} |
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|
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if ( ! in_array( $this->cipher, openssl_get_cipher_methods() ) ) { |
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return false; |
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} |
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|
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return true; |
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} |
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|
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private function get_passphrase() { |
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|
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if ( function_exists('wp_salt') && wp_salt() ) { |
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return wp_salt(); |
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} |
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|
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return 'getwid_non_secret_passphrase'; |
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} |
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|
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private function get_salt() { |
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return 'getwid_non_secret_salt'; |
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} |
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|
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} |
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|
