add methods to decrypt return data from router

[GitHub/Stricted/speedport-hybrid-php-api.git] / CryptLib / Cipher / Block / AbstractCipher.php

diff --git a/CryptLib/Cipher/Block/AbstractCipher.php b/CryptLib/Cipher/Block/AbstractCipher.php
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+++ b/CryptLib/Cipher/Block/AbstractCipher.php
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+<?php
+/**
+ * An abstract class for simplifing creation of ciphers
+ *
+ * PHP version 5.3
+ *
+ * @category   PHPCryptLib
+ * @package    Cipher
+ * @subpackage Block
+ * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
+ * @copyright  2011 The Authors
+ * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @version    Build @@version@@
+ */
+
+namespace CryptLib\Cipher\Block;
+
+/**
+ * An abstract class for simplifing creation of ciphers
+ *
+ * @category   PHPCryptLib
+ * @package    Cipher
+ * @subpackage Block
+ */
+abstract class AbstractCipher implements \CryptLib\Cipher\Block\Cipher {
+
+    /**
+     * @var int The block size for the cipher
+     */
+    protected $blockSize = 0;
+
+    /**
+     * @var string The cipher name for the current instance
+     */
+    protected $cipher = '';
+
+    /**
+     * @var boolean Is the cipher ready to encrypt/decrypt
+     */
+    protected $initialized = false;
+
+    /**
+     * @var string The key to use for encryption/decryption
+     */
+    protected $key = '';
+
+    /**
+     * @var int The size of the key to use
+     */
+    protected $keySize = 0;
+
+    /**
+     * Decrypt a block of data
+     * 
+     * @param string $data The ciphertext to decrypt
+     * 
+     * @return string The decrypted data
+     */
+    abstract protected function decryptBlockData($data);
+
+    /**
+     * Encrypt a block of data
+     * 
+     * @param string $data The plaintext to encrypt
+     * 
+     * @return string The encrypted cipher text
+     */
+    abstract protected function encryptBlockData($data);
+
+    /**
+     * Construct the instance for the supplied cipher name
+     *
+     * @param string $cipher The cipher to implement
+     *
+     * @return void
+     * @throws InvalidArgumentException if the cipher is not supported
+     */
+    public function __construct($cipher) {
+        $ciphers = static::getSupportedCiphers();
+        if (in_array($cipher, $ciphers)) {
+            $this->cipher = $cipher;
+        } else {
+            throw new \InvalidArgumentException('Unsupported Cipher Supplied');
+        }
+    }
+
+    /**
+     * Decrypt a block of data using the supplied string key.
+     *
+     * Note that the supplied data should be the same size as the block size of
+     * the cipher being used.
+     *
+     * @param string $data The data to decrypt
+     *
+     * @return string The result decrypted data
+     * @throws InvalidArgumentException If the data size is not the block size
+     * @throws RuntimeException If the cipher is not initialized
+     */
+    public function decryptBlock($data) {
+        $this->enforceInitializedCipher();
+        $this->enforceProperBlockSize($data);
+        return $this->decryptBlockData($data);
+    }
+
+    /**
+     * Encrypt a block of data using the supplied string key.
+     *
+     * Note that the supplied data should be the same size as the block size of
+     * the cipher being used.
+     *
+     * @param string $data The data to encrypt
+     *
+     * @return string The result encrypted data
+     * @throws InvalidArgumentException If the data size is not the block size
+     * @throws RuntimeException If the cipher is not initialized
+     */
+    public function encryptBlock($data) {
+        $this->enforceInitializedCipher();
+        $this->enforceProperBlockSize($data);
+        return $this->encryptBlockData($data);
+    }
+
+    /**
+     * Get the block size for the current initialized cipher
+     *
+     * @param string $key The key the data will be encrypted with
+     *
+     * @return int The block size for the current cipher
+     */
+    public function getBlockSize() {
+        return $this->blockSize;
+    }
+
+    /**
+     * Get the string name of the current cipher instance
+     *
+     * @return string The current instantiated cipher
+     */
+    public function getCipher() {
+        return $this->cipher;
+    }
+
+    /**
+     * Get the key size for the current initialized cipher
+     * 
+     * @return int The key size for the current cipher
+     */
+    public function getKeySize() {
+        return $this->keySize;
+    }
+
+    /**
+     * Set the key to use for the cipher
+     *
+     * @param string $key The key to use
+     * 
+     * @throws InvalidArgumentException If the key is not the correct size
+     * @return void
+     */
+    public function setKey($key) {
+        if (strlen($key) != $this->getKeySize()) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    'The supplied key block is not the correct size [%d:%d]',
+                    strlen($key),
+                    $this->getKeySize()
+                )
+            );
+        }
+        $this->key         = $key;
+        $this->initialized = $this->initialize();
+    }
+
+    /**
+     * Check to see if the cipher is initialized
+     * 
+     * @return void
+     * @throws RuntimeException If the cipher is not initialized
+     */
+    protected function enforceInitializedCipher() {
+        if (!$this->initialized) {
+            throw new \RuntimeException(
+                'The cipher has not been properly initialized'
+            );
+        }
+    }
+
+    /**
+     * Check to see if the data is of the correct block size
+     *
+     * @param string $data The data block to check
+     * 
+     * @return void
+     * @throws InvalidArgumentException if the data is not the correct size
+     */
+    protected function enforceProperBlockSize($data) {
+        if (strlen($data) != $this->getBlockSize()) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    'The supplied data block is not the correct size [%d:%d]',
+                    strlen($data),
+                    $this->getBlockSize()
+                )
+            );
+        }
+    }
+
+    /**
+     * Initialize the function after the key is set
+     *
+     * @return boolean The status of the initialization
+     */
+    protected function initialize() {
+        return true;
+    }
+
+}
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