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<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing,<a name="line.12"></a>
<span class="sourceLineNo">013</span> * software distributed under the License is distributed on an<a name="line.13"></a>
<span class="sourceLineNo">014</span> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY<a name="line.14"></a>
<span class="sourceLineNo">015</span> * KIND, either express or implied. See the License for the<a name="line.15"></a>
<span class="sourceLineNo">016</span> * specific language governing permissions and limitations<a name="line.16"></a>
<span class="sourceLineNo">017</span> * under the License.<a name="line.17"></a>
<span class="sourceLineNo">018</span> */<a name="line.18"></a>
<span class="sourceLineNo">019</span>/*<a name="line.19"></a>
<span class="sourceLineNo">020</span> * The apr_md5_encode() routine in the APR project's apr_md5.c file uses much<a name="line.20"></a>
<span class="sourceLineNo">021</span> * code obtained from the FreeBSD 3.0 MD5 crypt() function, which is licenced<a name="line.21"></a>
<span class="sourceLineNo">022</span> * as follows:<a name="line.22"></a>
<span class="sourceLineNo">023</span> * ----------------------------------------------------------------------------<a name="line.23"></a>
<span class="sourceLineNo">024</span> * "THE BEER-WARE LICENSE" (Revision 42):<a name="line.24"></a>
<span class="sourceLineNo">025</span> * &lt;phk@login.dknet.dk&gt; wrote this file. As long as you retain this notice you<a name="line.25"></a>
<span class="sourceLineNo">026</span> * can do whatever you want with this stuff. If we meet some day, and you think<a name="line.26"></a>
<span class="sourceLineNo">027</span> * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp<a name="line.27"></a>
<span class="sourceLineNo">028</span> * ----------------------------------------------------------------------------<a name="line.28"></a>
<span class="sourceLineNo">029</span> */<a name="line.29"></a>
<span class="sourceLineNo">030</span>package org.apache.shiro.codec;<a name="line.30"></a>
<span class="sourceLineNo">031</span><a name="line.31"></a>
<span class="sourceLineNo">032</span>import java.io.IOException;<a name="line.32"></a>
<span class="sourceLineNo">033</span><a name="line.33"></a>
<span class="sourceLineNo">034</span>/**<a name="line.34"></a>
<span class="sourceLineNo">035</span> * Codec for &lt;a href="http://en.wikipedia.org/wiki/Crypt_(Unix)"&gt;Unix Crypt&lt;/a&gt;-style encoding. While similar to<a name="line.35"></a>
<span class="sourceLineNo">036</span> * Base64, it is not compatible with Base64.<a name="line.36"></a>
<span class="sourceLineNo">037</span> * &lt;p/&gt;<a name="line.37"></a>
<span class="sourceLineNo">038</span> * This implementation is based on encoding algorithms found in the Apache Portable Runtime library's<a name="line.38"></a>
<span class="sourceLineNo">039</span> * &lt;a href="http://svn.apache.org/viewvc/apr/apr/trunk/crypto/apr_md5.c?revision=HEAD&amp;view=markup"&gt;apr_md5.c&lt;/a&gt;<a name="line.39"></a>
<span class="sourceLineNo">040</span> * implementation for its {@code crypt}-style support. The APR team in turn received inspiration for its encoding<a name="line.40"></a>
<span class="sourceLineNo">041</span> * implementation based on FreeBSD 3.0's {@code /usr/src/lib/libcrypt/crypt.c} implementation. The<a name="line.41"></a>
<span class="sourceLineNo">042</span> * accompanying license headers have been retained at the top of this source file.<a name="line.42"></a>
<span class="sourceLineNo">043</span> * &lt;p/&gt;<a name="line.43"></a>
<span class="sourceLineNo">044</span> * This file and all that it contains is ASL 2.0 compatible.<a name="line.44"></a>
<span class="sourceLineNo">045</span> *<a name="line.45"></a>
<span class="sourceLineNo">046</span> * @since 1.2<a name="line.46"></a>
<span class="sourceLineNo">047</span> */<a name="line.47"></a>
<span class="sourceLineNo">048</span>public class H64 {<a name="line.48"></a>
<span class="sourceLineNo">049</span><a name="line.49"></a>
<span class="sourceLineNo">050</span> private static final char[] itoa64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span> private static short toShort(byte b) {<a name="line.52"></a>
<span class="sourceLineNo">053</span> return (short) (b &amp; 0xff);<a name="line.53"></a>
<span class="sourceLineNo">054</span> }<a name="line.54"></a>
<span class="sourceLineNo">055</span><a name="line.55"></a>
<span class="sourceLineNo">056</span> private static int toInt(byte[] bytes, int offset, int numBytes) {<a name="line.56"></a>
<span class="sourceLineNo">057</span> if (numBytes &lt; 1 || numBytes &gt; 4) {<a name="line.57"></a>
<span class="sourceLineNo">058</span> throw new IllegalArgumentException("numBytes must be between 1 and 4.");<a name="line.58"></a>
<span class="sourceLineNo">059</span> }<a name="line.59"></a>
<span class="sourceLineNo">060</span> int val = toShort(bytes[offset]); //1st byte<a name="line.60"></a>
<span class="sourceLineNo">061</span> for (int i = 1; i &lt; numBytes; i++) { //any remaining bytes:<a name="line.61"></a>
<span class="sourceLineNo">062</span> short s = toShort(bytes[offset + i]);<a name="line.62"></a>
<span class="sourceLineNo">063</span> switch (i) {<a name="line.63"></a>
<span class="sourceLineNo">064</span> case 1: val |= s &lt;&lt; 8; break;<a name="line.64"></a>
<span class="sourceLineNo">065</span> case 2: val |= s &lt;&lt; 16; break;<a name="line.65"></a>
<span class="sourceLineNo">066</span> case 3: val |= s &lt;&lt; 24; break;<a name="line.66"></a>
<span class="sourceLineNo">067</span> }<a name="line.67"></a>
<span class="sourceLineNo">068</span> }<a name="line.68"></a>
<span class="sourceLineNo">069</span> return val;<a name="line.69"></a>
<span class="sourceLineNo">070</span> }<a name="line.70"></a>
<span class="sourceLineNo">071</span><a name="line.71"></a>
<span class="sourceLineNo">072</span> /**<a name="line.72"></a>
<span class="sourceLineNo">073</span> * Appends the specified character into the buffer, rethrowing any encountered<a name="line.73"></a>
<span class="sourceLineNo">074</span> * {@link IOException} as an {@link IllegalStateException} (since this method is used for internal<a name="line.74"></a>
<span class="sourceLineNo">075</span> * implementation needs and we only ever use StringBuilders, we should never encounter an IOException).<a name="line.75"></a>
<span class="sourceLineNo">076</span> *<a name="line.76"></a>
<span class="sourceLineNo">077</span> * @param buf the buffer to append to<a name="line.77"></a>
<span class="sourceLineNo">078</span> * @param c the character to append.<a name="line.78"></a>
<span class="sourceLineNo">079</span> */<a name="line.79"></a>
<span class="sourceLineNo">080</span> private static void append(Appendable buf, char c) {<a name="line.80"></a>
<span class="sourceLineNo">081</span> try {<a name="line.81"></a>
<span class="sourceLineNo">082</span> buf.append(c);<a name="line.82"></a>
<span class="sourceLineNo">083</span> } catch (IOException e) {<a name="line.83"></a>
<span class="sourceLineNo">084</span> throw new IllegalStateException("Unable to append character to internal buffer.", e);<a name="line.84"></a>
<span class="sourceLineNo">085</span> }<a name="line.85"></a>
<span class="sourceLineNo">086</span> }<a name="line.86"></a>
<span class="sourceLineNo">087</span><a name="line.87"></a>
<span class="sourceLineNo">088</span> /**<a name="line.88"></a>
<span class="sourceLineNo">089</span> * Encodes the specified integer to {@code numChars} H64-compatible characters and appends them into {@code buf}.<a name="line.89"></a>
<span class="sourceLineNo">090</span> *<a name="line.90"></a>
<span class="sourceLineNo">091</span> * @param value the integer to encode to H64-compatible characters<a name="line.91"></a>
<span class="sourceLineNo">092</span> * @param buf the output buffer<a name="line.92"></a>
<span class="sourceLineNo">093</span> * @param numChars the number of characters the value should be converted to. 3, 2 or 1.<a name="line.93"></a>
<span class="sourceLineNo">094</span> */<a name="line.94"></a>
<span class="sourceLineNo">095</span> private static void encodeAndAppend(int value, Appendable buf, int numChars) {<a name="line.95"></a>
<span class="sourceLineNo">096</span> for (int i = 0; i &lt; numChars; i++) {<a name="line.96"></a>
<span class="sourceLineNo">097</span> append(buf, itoa64[value &amp; 0x3f]);<a name="line.97"></a>
<span class="sourceLineNo">098</span> value &gt;&gt;= 6;<a name="line.98"></a>
<span class="sourceLineNo">099</span> }<a name="line.99"></a>
<span class="sourceLineNo">100</span> }<a name="line.100"></a>
<span class="sourceLineNo">101</span><a name="line.101"></a>
<span class="sourceLineNo">102</span> /**<a name="line.102"></a>
<span class="sourceLineNo">103</span> * Encodes the specified bytes to an {@code H64}-encoded String.<a name="line.103"></a>
<span class="sourceLineNo">104</span> *<a name="line.104"></a>
<span class="sourceLineNo">105</span> * @param bytes<a name="line.105"></a>
<span class="sourceLineNo">106</span> * @return<a name="line.106"></a>
<span class="sourceLineNo">107</span> */<a name="line.107"></a>
<span class="sourceLineNo">108</span> public static String encodeToString(byte[] bytes) {<a name="line.108"></a>
<span class="sourceLineNo">109</span> if (bytes == null || bytes.length == 0) return null;<a name="line.109"></a>
<span class="sourceLineNo">110</span><a name="line.110"></a>
<span class="sourceLineNo">111</span> StringBuilder buf = new StringBuilder();<a name="line.111"></a>
<span class="sourceLineNo">112</span><a name="line.112"></a>
<span class="sourceLineNo">113</span> int length = bytes.length;<a name="line.113"></a>
<span class="sourceLineNo">114</span> int remainder = length % 3;<a name="line.114"></a>
<span class="sourceLineNo">115</span> int i = 0; //starting byte<a name="line.115"></a>
<span class="sourceLineNo">116</span> int last3ByteIndex = length - remainder; //last byte whose index is a multiple of 3<a name="line.116"></a>
<span class="sourceLineNo">117</span><a name="line.117"></a>
<span class="sourceLineNo">118</span> for(; i &lt; last3ByteIndex; i += 3) {<a name="line.118"></a>
<span class="sourceLineNo">119</span> int twentyFourBit = toInt(bytes, i, 3);<a name="line.119"></a>
<span class="sourceLineNo">120</span> encodeAndAppend(twentyFourBit, buf, 4);<a name="line.120"></a>
<span class="sourceLineNo">121</span> }<a name="line.121"></a>
<span class="sourceLineNo">122</span> if (remainder &gt; 0) {<a name="line.122"></a>
<span class="sourceLineNo">123</span> //one or two bytes that we still need to encode:<a name="line.123"></a>
<span class="sourceLineNo">124</span> int a = toInt(bytes, i, remainder);<a name="line.124"></a>
<span class="sourceLineNo">125</span> encodeAndAppend(a, buf, remainder + 1);<a name="line.125"></a>
<span class="sourceLineNo">126</span> }<a name="line.126"></a>
<span class="sourceLineNo">127</span> return buf.toString();<a name="line.127"></a>
<span class="sourceLineNo">128</span> }<a name="line.128"></a>
<span class="sourceLineNo">129</span>}<a name="line.129"></a>
</pre>
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