core.SHA256Hash.java Source code

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Here is the source code for core.SHA256Hash.java

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/*
 * This Java class implements SHA-256 hash tools for NI use, has been developed
 * as part of the SAIL project. (http://sail-project.eu)
 *    
 *  Specification(s) - note, versions may change::
 *    -   http://tools.ietf.org/html/farrell-decade-ni-00
 *    -   http://tools.ietf.org/html/draft-hallambaker-decade-ni-params-00
 * 
 *    Authors:    Janne Tuonnonen <janne.tuononen@nsn.com>
 *             Petteri Pyhnen <petteri.poyhonen@nsn.com>
 * 
 *  Copyright:    Copyright 2012 Janne Tuonnonen <janne.tuononen@nsn.com> and
 *             Petteri Pyhnen <petteri.poyhonen@nsn.com>, Nokia Siemens Networks
 *   
 *  License: http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  
 *  See the License for the specific language governing permissions and
 *  limitations under the License.   
 */

package core;

import java.io.FileInputStream;
import java.security.MessageDigest;

import org.apache.commons.codec.binary.Base64;

public class SHA256Hash {

    private static final String SHA256 = "sha-256";
    private static final String SHA256_16 = "sha-256-16";

    public static String getHashAlgType(String url) throws Exception {
        if (url.contains(SHA256_16)) {
            return SHA256_16;
        }
        if (url.contains(SHA256)) {
            return SHA256;
        }
        throw new Exception("Unknown hash alg type");
    }

    public static String CalculateCheckSumBase64(String FileName, String url) throws Exception {
        MessageDigest md = MessageDigest.getInstance(SHA256);
        FileInputStream fileHandle = new FileInputStream(FileName);

        byte[] dataBytes = new byte[1024];

        int nread = 0;
        while ((nread = fileHandle.read(dataBytes)) != -1) {
            md.update(dataBytes, 0, nread);
        }
        ;
        byte[] mdbytes = md.digest();

        byte[] bytes = null;
        if (SHA256 == getHashAlgType(url)) {
            // Do base64 encoding
            bytes = Base64.encodeBase64URLSafe(mdbytes);
        } else {
            if (SHA256_16 == getHashAlgType(url))
                bytes = Base64.encodeBase64(new byte[] { mdbytes[0], mdbytes[1] }, false, true, 4);
        }

        // Store byte array as string and return it
        String value = new String(bytes);
        System.out.println("Base64 encoded " + getHashAlgType(url) + " hash: " + value);

        return value;
    }

    public static String CalculateCheckSum(String FileName, String url) throws Exception {
        MessageDigest md = MessageDigest.getInstance(getHashAlgType(url));
        FileInputStream fis = new FileInputStream(FileName);

        byte[] dataBytes = new byte[1024];

        int nread = 0;
        while ((nread = fis.read(dataBytes)) != -1) {
            md.update(dataBytes, 0, nread);
        }
        ;
        byte[] mdbytes = md.digest();

        // Store byte array as string and return it
        String value = new String(mdbytes);
        System.out.println("Encoded " + getHashAlgType(url) + " hash: " + value);

        return value;
    }

}