Main.java Source code

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Here is the source code for Main.java

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//package com.java2s;
/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 *
 */

import java.security.MessageDigest;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

public class Main {
    public static byte[] generateCramMD5HexClientResponse(String userName, String userPassword,
            byte[] challengeBytes) throws Exception {
        String macAlgorithm = "HmacMD5";
        byte[] digestedPasswordBytes = MessageDigest.getInstance("MD5").digest(userPassword.getBytes("UTF-8"));
        byte[] hexEncodedDigestedPasswordBytes = toHex(digestedPasswordBytes).getBytes("UTF-8");
        Mac mac = Mac.getInstance(macAlgorithm);
        mac.init(new SecretKeySpec(hexEncodedDigestedPasswordBytes, macAlgorithm));
        final byte[] messageAuthenticationCode = mac.doFinal(challengeBytes);
        String responseAsString = userName + " " + toHex(messageAuthenticationCode);
        return responseAsString.getBytes();
    }

    public static String toHex(byte[] data) {
        StringBuffer hash = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
            String hex = Integer.toHexString(0xFF & data[i]);
            if (hex.length() == 1) {
                hash.append('0');
            }
            hash.append(hex);
        }
        return hash.toString();
    }
}