| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  * Cryptographic protocol for multiple layered encryption. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | namespace CryptoManana\CryptographicProtocol; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  | use CryptoManana\Core\Abstractions\Containers\AbstractCryptographicProtocol as CryptographicProtocol; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | use CryptoManana\Core\Abstractions\MessageEncryption\AbstractBlockCipherAlgorithm as SymmetricBlockCipher; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  | use CryptoManana\Core\Interfaces\Containers\LayeredEncryptionInterface as LayeredDataProcessing; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  | use CryptoManana\DataStructures\EncryptionLayer as LayerConfiguration; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |  * Class LayeredEncryption - The multiple layered encryption protocol object. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |  * @package CryptoManana\CryptographicProtocol | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  | class LayeredEncryption extends CryptographicProtocol implements LayeredDataProcessing | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |      * The internal encryption cipher collection property storage. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |      * @var SymmetricBlockCipher[] | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |     protected $ciphers = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |      * Setter for the encryption layers' configuration. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |      * @param LayerConfiguration[]|array $layers Collection of layers. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |      * @return $this The cryptographic protocol object. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 | 14 |  |     public function setLayers(array $layers) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 | 14 |  |         if (count($layers) < 2) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 | 1 |  |             throw new \RuntimeException('This protocol must have at least two layers to operate.'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 | 13 |  |         foreach ($layers as $layer) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 | 13 |  |             if (!$layer instanceof LayerConfiguration) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 | 1 |  |                 throw new \RuntimeException( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 | 1 |  |                     'All supplied  configuration must be of the `EncryptionLayer` data structure.' | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 | 1 |  |                 ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 | 12 |  |             $this->addLayer($layer); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 | 11 |  |         return $this; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |      * Add a single new layer at the last of the list. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |      * @param LayerConfiguration $layer The layer configuration. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |      * @return $this The cryptographic protocol object. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 | 12 |  |     public function addLayer(LayerConfiguration $layer) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 | 12 |  |         if (class_exists($layer->cipher) && is_subclass_of($layer->cipher, SymmetricBlockCipher::class)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |             /** @var SymmetricBlockCipher $cipher */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 | 12 |  |             $cipher = new $layer->cipher(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 | 12 |  |             $cipher->setSecretKey($layer->key) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 | 12 |  |                 ->setInitializationVector($layer->iv) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 | 12 |  |                 ->setBlockOperationMode($layer->mode) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 | 12 |  |                 ->setPaddingStandard($layer->padding) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 | 12 |  |                 ->setCipherFormat($layer->format); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 | 12 |  |             $this->ciphers[] = $cipher; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 | 1 |  |             throw new \RuntimeException('All supplied ciphers must be existing and for symmetric encryption.'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 | 12 |  |         return $this; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |      * Getter for the encryption layers' configuration. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |      * @return LayerConfiguration[]|array Collection of used layers' configuration. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 | 2 |  |     public function getLayers() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 | 2 |  |         $layers = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 | 2 |  |         foreach ($this->ciphers as $cipher) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 | 2 |  |             $layers [] = new LayerConfiguration( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 | 2 |  |                 get_class($cipher), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 | 2 |  |                 $cipher->getSecretKey(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 | 2 |  |                 $cipher->getInitializationVector(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 | 2 |  |                 $cipher->getBlockOperationMode(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 | 2 |  |                 $cipher->getPaddingStandard(), | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 | 2 |  |                 $cipher->getCipherFormat() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 | 2 |  |             ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 | 2 |  |         return $layers; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |      * Container constructor. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |      * @param LayerConfiguration[]|array $configuration The layers' configuration. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 113 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |      * @throws \Exception Initialization validation. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 116 | 14 |  |     public function __construct(array $configuration = []) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 117 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 118 | 14 |  |         $this->setLayers($configuration); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 119 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 120 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 121 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 122 |  |  |      * Container destructor. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 123 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 124 | 11 |  |     public function __destruct() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 125 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 126 | 11 |  |         unset($this->ciphers); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 127 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 128 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 129 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 130 |  |  |      * Container cloning via deep copy. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 131 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 132 | 1 |  |     public function __clone() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 133 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 134 | 1 |  |         $ciphers = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 135 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 136 | 1 |  |         foreach ($this->ciphers as $cipher) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 137 | 1 |  |             $ciphers [] = clone $cipher; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 138 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 139 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 140 | 1 |  |         $this->ciphers = $ciphers; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 141 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 142 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 143 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 144 |  |  |      * Calculates a XOR of two binary strings. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 145 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 146 |  |  |      * @param string $stringOne The first binary string. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 147 |  |  |      * @param string $stringTwo The second binary string. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 148 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 149 |  |  |      * @return string The XOR output of both strings. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 150 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 151 | 4 |  |     protected function xorTwoStrings($stringOne, $stringTwo) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 152 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 153 |  |  |         /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 154 |  |  |          * {@internal The encryption standard is 8-bit wise (do not use StringBuilder) and utilizes performance. }} | 
            
                                                                                                            
                            
            
                                    
            
            
                | 155 |  |  |          */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 156 | 4 |  |         if (strlen($stringTwo) < strlen($stringOne)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 157 | 4 |  |             $stringTwo = str_pad($stringTwo, strlen($stringOne), "\x0", STR_PAD_RIGHT); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 158 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 159 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 160 | 4 |  |         $dataLength = strlen($stringOne); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 161 | 4 |  |         $keyLength = strlen($stringTwo); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 162 | 4 |  |         $xorOutput = $stringOne; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 163 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 164 | 4 |  |         for ($i = 0; $i < $dataLength; ++$i) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 165 | 4 |  |             $xorOutput[$i] = $stringOne[$i] ^ $stringTwo[$i % $keyLength]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 166 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 167 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 168 | 4 |  |         return $xorOutput; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 169 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 170 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 171 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 172 |  |  |      * Internal method for the validation of the one-time pad string. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 173 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 174 |  |  |      * @param string $oneTimePad The optional one-time pad key. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 175 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 176 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 177 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 178 | 10 |  |     protected function validateOneTimePad($oneTimePad) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 179 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 180 | 10 |  |         if (!is_string($oneTimePad)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 181 | 2 |  |             throw new \InvalidArgumentException('The one-time pad key must be a string or a binary string.'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 182 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 183 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 184 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 185 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 186 |  |  |      * Encrypts the given plain data multiple times with different algorithms as layers. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 187 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 188 |  |  |      * @param string $plainData The plain input string. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 189 |  |  |      * @param string $oneTimePad The optional one-time pad key. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 190 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 191 |  |  |      * @return string The cipher/encrypted data. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 192 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 193 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 194 |  |  |      * @note The one-time pad key must be the same length as the input date to maximize security. | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 195 |  |  |      */ | 
            
                                                                        
                            
            
                                    
            
            
                | 196 | 9 |  |     public function layeredEncryptData($plainData, $oneTimePad = '') | 
            
                                                                        
                            
            
                                    
            
            
                | 197 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 198 | 9 |  |         $this->validateOneTimePad($oneTimePad); | 
            
                                                                        
                            
            
                                    
            
            
                | 199 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 200 | 8 |  |         if (!is_string($plainData)) { | 
            
                                                                        
                            
            
                                    
            
            
                | 201 | 1 |  |             throw new \InvalidArgumentException( | 
            
                                                                        
                            
            
                                    
            
            
                | 202 | 1 |  |                 'The data for encryption must be a string or a binary string.' | 
            
                                                                        
                            
            
                                    
            
            
                | 203 | 1 |  |             ); | 
            
                                                                        
                            
            
                                    
            
            
                | 204 | 7 |  |         } elseif (!empty(trim($oneTimePad))) { | 
            
                                                                        
                            
            
                                    
            
            
                | 205 | 4 |  |             $plainData = $this->xorTwoStrings($plainData, $oneTimePad); | 
            
                                                                        
                            
            
                                    
            
            
                | 206 |  |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 207 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 208 | 7 |  |         $last = count($this->ciphers) - 1; | 
            
                                                                        
                            
            
                                    
            
            
                | 209 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 210 | 7 |  |         for ($i = 0; $i <= $last; $i++) { | 
            
                                                                        
                            
            
                                    
            
            
                | 211 | 7 |  |             $cipher = $this->ciphers[$i]; | 
            
                                                                        
                            
            
                                    
            
            
                | 212 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 213 | 7 |  |             $plainData = $cipher->encryptData($plainData); | 
            
                                                                        
                            
            
                                    
            
            
                | 214 |  |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 215 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 216 | 7 |  |         return $plainData; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 217 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 218 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 219 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 220 |  |  |      * Decrypts the given cipher data multiple times with different algorithms as layers. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 221 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 222 |  |  |      * @param string $cipherData The encrypted input string. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 223 |  |  |      * @param string $oneTimePad The optional one-time pad key. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 224 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 225 |  |  |      * @return string The decrypted/plain data. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 226 |  |  |      * @throws \Exception Validation errors. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 227 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 228 | 5 |  |     public function layeredDecryptData($cipherData, $oneTimePad = '') | 
            
                                                                                                            
                            
            
                                    
            
            
                | 229 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 230 | 5 |  |         $this->validateOneTimePad($oneTimePad); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 231 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 232 | 4 |  |         $last = count($this->ciphers) - 1; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 233 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 234 | 4 |  |         for ($i = $last; $i >= 0; $i--) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 235 | 4 |  |             $cipher = $this->ciphers[$i]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 236 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 237 | 4 |  |             $cipherData = $cipher->decryptData($cipherData); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 238 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 239 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 240 | 3 |  |         if (!empty(trim($oneTimePad))) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 241 | 3 |  |             $cipherData = $this->xorTwoStrings($cipherData, $oneTimePad); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 242 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 243 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 244 | 3 |  |         return $cipherData; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 245 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 246 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 247 |  |  |  |