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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.hash;<a name="line.19"></a> |
| <FONT color="green">020</FONT> <a name="line.20"></a> |
| <FONT color="green">021</FONT> /**<a name="line.21"></a> |
| <FONT color="green">022</FONT> * A {@code HashService} hashes input sources utilizing a particular hashing strategy.<a name="line.22"></a> |
| <FONT color="green">023</FONT> * <p/><a name="line.23"></a> |
| <FONT color="green">024</FONT> * A {@code HashService} sits at a higher architectural level than Shiro's simple {@link Hash} classes: it allows<a name="line.24"></a> |
| <FONT color="green">025</FONT> * for salting and iteration-related strategies to be configured and internalized in a<a name="line.25"></a> |
| <FONT color="green">026</FONT> * single component that can be re-used in multiple places in the application.<a name="line.26"></a> |
| <FONT color="green">027</FONT> * <p/><a name="line.27"></a> |
| <FONT color="green">028</FONT> * For example, for the most secure hashes, it is highly recommended to use a randomly generated salt, potentially<a name="line.28"></a> |
| <FONT color="green">029</FONT> * paired with an configuration-specific private salt, in addition to using multiple hash iterations.<a name="line.29"></a> |
| <FONT color="green">030</FONT> * <p/><a name="line.30"></a> |
| <FONT color="green">031</FONT> * While one can do this easily enough using Shiro's {@link Hash} implementations directly, this direct approach could<a name="line.31"></a> |
| <FONT color="green">032</FONT> * quickly lead to copy-and-paste behavior. For example, consider this logic which might need to repeated in an<a name="line.32"></a> |
| <FONT color="green">033</FONT> * application:<a name="line.33"></a> |
| <FONT color="green">034</FONT> * <pre><a name="line.34"></a> |
| <FONT color="green">035</FONT> * int numHashIterations = ...<a name="line.35"></a> |
| <FONT color="green">036</FONT> * ByteSource privateSalt = ...<a name="line.36"></a> |
| <FONT color="green">037</FONT> * ByteSource randomSalt = {@link org.apache.shiro.crypto.RandomNumberGenerator randomNumberGenerator}.nextBytes();<a name="line.37"></a> |
| <FONT color="green">038</FONT> * ByteSource combined = combine(privateSalt, randomSalt);<a name="line.38"></a> |
| <FONT color="green">039</FONT> * Hash hash = Sha512Hash(source, combined, numHashIterations);<a name="line.39"></a> |
| <FONT color="green">040</FONT> * save(hash);<a name="line.40"></a> |
| <FONT color="green">041</FONT> * </pre><a name="line.41"></a> |
| <FONT color="green">042</FONT> * In this example, often only the input source will change during runtime, while the hashing strategy (how salts<a name="line.42"></a> |
| <FONT color="green">043</FONT> * are generated or acquired, how many hash iterations will be performed, etc) usually remain consistent. A HashService<a name="line.43"></a> |
| <FONT color="green">044</FONT> * internalizes this logic so the above becomes simply this:<a name="line.44"></a> |
| <FONT color="green">045</FONT> * <pre><a name="line.45"></a> |
| <FONT color="green">046</FONT> * HashRequest request = new HashRequest.Builder().source(source).build();<a name="line.46"></a> |
| <FONT color="green">047</FONT> * Hash result = hashService.hash(request);<a name="line.47"></a> |
| <FONT color="green">048</FONT> * save(result);<a name="line.48"></a> |
| <FONT color="green">049</FONT> * </pre><a name="line.49"></a> |
| <FONT color="green">050</FONT> *<a name="line.50"></a> |
| <FONT color="green">051</FONT> * @since 1.2<a name="line.51"></a> |
| <FONT color="green">052</FONT> */<a name="line.52"></a> |
| <FONT color="green">053</FONT> public interface HashService {<a name="line.53"></a> |
| <FONT color="green">054</FONT> <a name="line.54"></a> |
| <FONT color="green">055</FONT> /**<a name="line.55"></a> |
| <FONT color="green">056</FONT> * Computes a hash based on the given request.<a name="line.56"></a> |
| <FONT color="green">057</FONT> *<a name="line.57"></a> |
| <FONT color="green">058</FONT> * <h3>Salt Notice</h3><a name="line.58"></a> |
| <FONT color="green">059</FONT> *<a name="line.59"></a> |
| <FONT color="green">060</FONT> * If a salt accompanies the return value<a name="line.60"></a> |
| <FONT color="green">061</FONT> * (i.e. <code>returnedHash.{@link org.apache.shiro.crypto.hash.Hash#getSalt() getSalt()} != null</code>), this<a name="line.61"></a> |
| <FONT color="green">062</FONT> * same exact salt <b><em>MUST</em></b> be presented back to the {@code HashService} if hash<a name="line.62"></a> |
| <FONT color="green">063</FONT> * comparison/verification will be performed at a later time (for example, for password hash or file checksum<a name="line.63"></a> |
| <FONT color="green">064</FONT> * comparison).<a name="line.64"></a> |
| <FONT color="green">065</FONT> * <p/><a name="line.65"></a> |
| <FONT color="green">066</FONT> * For additional security, the {@code HashService}'s internal implementation may use more complex salting<a name="line.66"></a> |
| <FONT color="green">067</FONT> * strategies than what would be achieved by computing a {@code Hash} manually.<a name="line.67"></a> |
| <FONT color="green">068</FONT> * <p/><a name="line.68"></a> |
| <FONT color="green">069</FONT> * In summary, if a {@link HashService} returns a salt in a returned Hash, it is expected that the same salt<a name="line.69"></a> |
| <FONT color="green">070</FONT> * will be provided to the same {@code HashService} instance.<a name="line.70"></a> |
| <FONT color="green">071</FONT> *<a name="line.71"></a> |
| <FONT color="green">072</FONT> * @param request the request to process<a name="line.72"></a> |
| <FONT color="green">073</FONT> * @return the hashed data<a name="line.73"></a> |
| <FONT color="green">074</FONT> * @see Hash#getSalt()<a name="line.74"></a> |
| <FONT color="green">075</FONT> */<a name="line.75"></a> |
| <FONT color="green">076</FONT> Hash computeHash(HashRequest request);<a name="line.76"></a> |
| <FONT color="green">077</FONT> }<a name="line.77"></a> |
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