add methods to decrypt return data from router

[GitHub/Stricted/speedport-hybrid-php-api.git] / CryptLib / Core / BaseConverter.php

diff --git a/CryptLib/Core/BaseConverter.php b/CryptLib/Core/BaseConverter.php
new file mode 100644 (file)
index 0000000..9c086f8
--- /dev/null
+++ b/CryptLib/Core/BaseConverter.php
@@ -0,0 +1,114 @@
+<?php
+
+/**
+ * A Utility class for converting between raw binary strings and a given
+ * list of characters
+ *
+ * PHP version 5.3
+ *
+ * @category   PHPCryptLib
+ * @package    Core
+ * @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\Core;
+
+/**
+ * A Utility class for converting between raw binary strings and a given
+ * list of characters
+ *
+ * @category   PHPCryptLib
+ * @package    Core
+ * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
+ */
+class BaseConverter {
+
+    /**
+     * Convert from a raw binary string to a string of characters
+     *
+     * @param string $string     The string to convert from
+     * @param string $characters The list of characters to convert to
+     *
+     * @return string The converted string
+     */
+    public static function convertFromBinary($string, $characters) {
+        if ($string === '' || empty($characters)) {
+            return '';
+        }
+        $string   = str_split($string);
+        $callback = function($str) {
+                return ord($str);
+            };
+        $string    = array_map($callback, $string);
+        $converted = static::baseConvert($string, 256, strlen($characters));
+        $callback  = function ($num) use ($characters) {
+                return $characters[$num];
+            };
+        $ret = implode('', array_map($callback, $converted));
+        return $ret;
+    }
+
+    /**
+     * Convert to a raw binary string from a string of characters
+     *
+     * @param string $string     The string to convert from
+     * @param string $characters The list of characters to convert to
+     *
+     * @return string The converted string
+     */
+    public static function convertToBinary($string, $characters) {
+        if (empty($string) || empty($characters)) {
+            return '';
+        }
+        $string   = str_split($string);
+        $callback = function($str) use ($characters) {
+                return strpos($characters, $str);
+            };
+        $string    = array_map($callback, $string);
+        $converted = static::baseConvert($string, strlen($characters), 256);
+        $callback  = function ($num) {
+                return chr($num);
+            };
+        return implode('', array_map($callback, $converted));
+    }
+
+    /**
+     * Convert an array of input blocks to another numeric base
+     *
+     * This function was modified from an implementation found on StackOverflow.
+     * Special Thanks to @KeithRandall for supplying the implementation.
+     *
+     * @param int[] $source  The source number, as an array
+     * @param int   $srcBase The source base as an integer
+     * @param int   $dstBase The destination base as an integer
+     *
+     * @see http://codegolf.stackexchange.com/questions/1620/arb/1626#1626
+     * @return int[] An array of integers in the encoded base
+     */
+    public static function baseConvert(array $source, $srcBase, $dstBase) {
+        if ($dstBase < 2) {
+            $message = sprintf('Invalid Destination Base: %d', $dstBase);
+            throw new \InvalidArgumentException($message);
+        }
+        $result = array();
+        $count  = count($source);
+        while ($count) {
+            $itMax     = $count;
+            $remainder = $count = $i = 0;
+            while($i < $itMax) {
+                $dividend  = $source[$i++] + $remainder * $srcBase;
+                $remainder = $dividend % $dstBase;
+                $res       = ($dividend - $remainder) / $dstBase;
+                if ($count || $res) {
+                    $source[$count++] = $res;
+                }
+            }
+            $result[] = $remainder;
+        }
+        return array_reverse($result);
+    }
+
+}