(contrib) add Base32.php to contrib

original source https://github.com/ChristianRiesen/base32

src/opnsense/contrib/Base32.php

+<?php
+/**
+ * Copyright (c) 2013-2014 Christian Riesen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is furnished
+ * to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+*/
+
+namespace Base32;
+
+/**
+ * Base32 encoder and decoder
+ *
+ * Last update: 2012-06-20
+ *
+ * RFC 4648 compliant
+ * @link http://www.ietf.org/rfc/rfc4648.txt
+ *
+ * Some groundwork based on this class
+ * https://github.com/NTICompass/PHP-Base32
+ *
+ * @author Christian Riesen <chris.riesen@gmail.com>
+ * @link http://christianriesen.com
+ * @license MIT License see LICENSE file
+ */
+class Base32
+{
+    /**
+     * Alphabet for encoding and decoding base32
+     *
+     * @var array
+     */
+    private static $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=';
+
+    /**
+     * Creates an array from a binary string into a given chunk size
+     *
+     * @param string $binaryString String to chunk
+     * @param integer $bits Number of bits per chunk
+     * @return array
+     */
+    private static function chunk($binaryString, $bits)
+    {
+        $binaryString = chunk_split($binaryString, $bits, ' ');
+
+        if (substr($binaryString, (strlen($binaryString)) - 1)  == ' ') {
+            $binaryString = substr($binaryString, 0, strlen($binaryString)-1);
+        }
+
+        return explode(' ', $binaryString);
+    }
+
+    /**
+     * Encodes into base32
+     *
+     * @param string $string Clear text string
+     * @return string Base32 encoded string
+     */
+    public static function encode($string)
+    {
+        if (strlen($string) == 0) {
+            // Gives an empty string
+
+            return '';
+        }
+
+        // Convert string to binary
+        $binaryString = '';
+
+        foreach (str_split($string) as $s) {
+            // Return each character as an 8-bit binary string
+            $binaryString .= sprintf('%08b', ord($s));
+        }
+
+        // Break into 5-bit chunks, then break that into an array
+        $binaryArray = self::chunk($binaryString, 5);
+
+        // Pad array to be divisible by 8
+        while (count($binaryArray) % 8 !== 0) {
+            $binaryArray[] = null;
+        }
+
+        $base32String = '';
+
+        // Encode in base32
+        foreach ($binaryArray as $bin) {
+            $char = 32;
+
+            if (!is_null($bin)) {
+                // Pad the binary strings
+                $bin = str_pad($bin, 5, 0, STR_PAD_RIGHT);
+                $char = bindec($bin);
+            }
+
+            // Base32 character
+            $base32String .= self::$alphabet[$char];
+        }
+
+        return $base32String;
+    }
+
+    /**
+     * Decodes base32
+     *
+     * @param string $base32String Base32 encoded string
+     * @return string Clear text string
+     */
+    public static function decode($base32String)
+    {
+        // Only work in upper cases
+        $base32String = strtoupper($base32String);
+
+        // Remove anything that is not base32 alphabet
+        $pattern = '/[^A-Z2-7]/';
+
+        $base32String = preg_replace($pattern, '', $base32String);
+
+        if (strlen($base32String) == 0) {
+            // Gives an empty string
+            return '';
+        }
+
+        $base32Array = str_split($base32String);
+
+        $string = '';
+
+        foreach ($base32Array as $str) {
+            $char = strpos(self::$alphabet, $str);
+
+            // Ignore the padding character
+            if ($char !== 32) {
+                $string .= sprintf('%05b', $char);
+            }
+        }
+
+        while (strlen($string) %8 !== 0) {
+            $string = substr($string, 0, strlen($string)-1);
+        }
+
+        $binaryArray = self::chunk($string, 8);
+
+        $realString = '';
+
+        foreach ($binaryArray as $bin) {
+            // Pad each value to 8 bits
+            $bin = str_pad($bin, 8, 0, STR_PAD_RIGHT);
+            // Convert binary strings to ASCII
+            $realString .= chr(bindec($bin));
+        }
+
+        return $realString;
+    }
+}