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| <FONT color="green">001</FONT> /*<a name="line.1"></a> |
| <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a> |
| <FONT color="green">003</FONT> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a> |
| <FONT color="green">004</FONT> * distributed with this work for additional information<a name="line.4"></a> |
| <FONT color="green">005</FONT> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a> |
| <FONT color="green">006</FONT> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a> |
| <FONT color="green">007</FONT> * "License"); you may not use this file except in compliance<a name="line.7"></a> |
| <FONT color="green">008</FONT> * with the License. You may obtain a copy of the License at<a name="line.8"></a> |
| <FONT color="green">009</FONT> *<a name="line.9"></a> |
| <FONT color="green">010</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a> |
| <FONT color="green">011</FONT> *<a name="line.11"></a> |
| <FONT color="green">012</FONT> * Unless required by applicable law or agreed to in writing,<a name="line.12"></a> |
| <FONT color="green">013</FONT> * software distributed under the License is distributed on an<a name="line.13"></a> |
| <FONT color="green">014</FONT> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY<a name="line.14"></a> |
| <FONT color="green">015</FONT> * KIND, either express or implied. See the License for the<a name="line.15"></a> |
| <FONT color="green">016</FONT> * specific language governing permissions and limitations<a name="line.16"></a> |
| <FONT color="green">017</FONT> * under the License.<a name="line.17"></a> |
| <FONT color="green">018</FONT> */<a name="line.18"></a> |
| <FONT color="green">019</FONT> package org.apache.shiro.crypto;<a name="line.19"></a> |
| <FONT color="green">020</FONT> <a name="line.20"></a> |
| <FONT color="green">021</FONT> import org.apache.shiro.util.ByteSource;<a name="line.21"></a> |
| <FONT color="green">022</FONT> <a name="line.22"></a> |
| <FONT color="green">023</FONT> /**<a name="line.23"></a> |
| <FONT color="green">024</FONT> * A component that can generate random number/byte values as needed. Useful in cryptography or security scenarios<a name="line.24"></a> |
| <FONT color="green">025</FONT> * where random byte arrays are needed, such as for password salts, nonces, initialization vectors and other seeds.<a name="line.25"></a> |
| <FONT color="green">026</FONT> * <p/><a name="line.26"></a> |
| <FONT color="green">027</FONT> * This is essentially the same as a {@link java.security.SecureRandom SecureRandom}, and indeed implementations<a name="line.27"></a> |
| <FONT color="green">028</FONT> * of this interface will probably all use {@link java.security.SecureRandom SecureRandom} instances, but this<a name="line.28"></a> |
| <FONT color="green">029</FONT> * interface provides a few additional benefits to end-users:<a name="line.29"></a> |
| <FONT color="green">030</FONT> * <ul><a name="line.30"></a> |
| <FONT color="green">031</FONT> * <li>It is an interface rather than the JDK's {@code SecureRandom} concrete implementation. Implementation details<a name="line.31"></a> |
| <FONT color="green">032</FONT> * can be customized as necessary based on the application's needs</li><a name="line.32"></a> |
| <FONT color="green">033</FONT> * <li>Default per-instance behavior can be customized on implementations, typically via JavaBeans mutators.</li><a name="line.33"></a> |
| <FONT color="green">034</FONT> * <li>Perhaps most important for Shiro end-users, tt can more easily be used as a source of cryptographic seed data,<a name="line.34"></a> |
| <FONT color="green">035</FONT> * and the data returned is already in a more convenient {@link ByteSource ByteSource} format in case that data needs<a name="line.35"></a> |
| <FONT color="green">036</FONT> * to be {@link org.apache.shiro.util.ByteSource#toHex() hex} or<a name="line.36"></a> |
| <FONT color="green">037</FONT> * {@link org.apache.shiro.util.ByteSource#toBase64() base64}-encoded.</li><a name="line.37"></a> |
| <FONT color="green">038</FONT> * </ul><a name="line.38"></a> |
| <FONT color="green">039</FONT> * For example, consider the following example generating password salts for new user accounts:<a name="line.39"></a> |
| <FONT color="green">040</FONT> * <pre><a name="line.40"></a> |
| <FONT color="green">041</FONT> * RandomNumberGenerator saltGenerator = new {@link org.apache.shiro.crypto.SecureRandomNumberGenerator SecureRandomNumberGenerator}();<a name="line.41"></a> |
| <FONT color="green">042</FONT> * User user = new User();<a name="line.42"></a> |
| <FONT color="green">043</FONT> * user.setPasswordSalt(saltGenerator.nextBytes().toBase64());<a name="line.43"></a> |
| <FONT color="green">044</FONT> * userDAO.save(user);<a name="line.44"></a> |
| <FONT color="green">045</FONT> * </pre><a name="line.45"></a> |
| <FONT color="green">046</FONT> *<a name="line.46"></a> |
| <FONT color="green">047</FONT> * @since 1.1<a name="line.47"></a> |
| <FONT color="green">048</FONT> */<a name="line.48"></a> |
| <FONT color="green">049</FONT> public interface RandomNumberGenerator {<a name="line.49"></a> |
| <FONT color="green">050</FONT> <a name="line.50"></a> |
| <FONT color="green">051</FONT> /**<a name="line.51"></a> |
| <FONT color="green">052</FONT> * Generates a byte array of fixed length filled with random data, often useful for generating salts,<a name="line.52"></a> |
| <FONT color="green">053</FONT> * initialization vectors or other seed data. The length is specified as a configuration<a name="line.53"></a> |
| <FONT color="green">054</FONT> * value on the underlying implementation.<a name="line.54"></a> |
| <FONT color="green">055</FONT> * <p/><a name="line.55"></a> |
| <FONT color="green">056</FONT> * If you'd like per-invocation control the number of bytes generated, use the<a name="line.56"></a> |
| <FONT color="green">057</FONT> * {@link #nextBytes(int) nextBytes(int)} method instead.<a name="line.57"></a> |
| <FONT color="green">058</FONT> *<a name="line.58"></a> |
| <FONT color="green">059</FONT> * @return a byte array of fixed length filled with random data.<a name="line.59"></a> |
| <FONT color="green">060</FONT> * @see #nextBytes(int)<a name="line.60"></a> |
| <FONT color="green">061</FONT> */<a name="line.61"></a> |
| <FONT color="green">062</FONT> ByteSource nextBytes();<a name="line.62"></a> |
| <FONT color="green">063</FONT> <a name="line.63"></a> |
| <FONT color="green">064</FONT> /**<a name="line.64"></a> |
| <FONT color="green">065</FONT> * Generates a byte array of the specified length filled with random data.<a name="line.65"></a> |
| <FONT color="green">066</FONT> *<a name="line.66"></a> |
| <FONT color="green">067</FONT> * @param numBytes the number of bytes to be populated with random data.<a name="line.67"></a> |
| <FONT color="green">068</FONT> * @return a byte array of the specified length filled with random data.<a name="line.68"></a> |
| <FONT color="green">069</FONT> * @see #nextBytes()<a name="line.69"></a> |
| <FONT color="green">070</FONT> */<a name="line.70"></a> |
| <FONT color="green">071</FONT> ByteSource nextBytes(int numBytes);<a name="line.71"></a> |
| <FONT color="green">072</FONT> }<a name="line.72"></a> |
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