com.nexmo.client.auth.MD5Util Maven / Gradle / Ivy

/*
 * Copyright (c) 2011-2017 Nexmo Inc
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.nexmo.client.auth;


import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Contains utility methods that use MD5 hashing. The class uses STANDARD JVM MD5 algorithm.
 *
 * @author Paul Cook
 */
public class MD5Util {

    /**
     * Calculates MD5 hash for string. assume string is UTF-8 encoded
     * @param input string which is going to be encoded into MD5 format
     * @return  MD5 representation of the input string
     * @throws NoSuchAlgorithmException if the MD5 algorithm is not available.
     */
    public static String calculateMd5(String input) throws NoSuchAlgorithmException {
        try {
            return calculateMd5(input, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            return null; // -- impossible --
        }
    }

    /**
     * Calculates MD5 hash for string.
     * @param input string which is going to be encoded into MD5 format
     * @param encoding character encoding of the string which is going to be encoded into MD5 format
     * @return  MD5 representation of the input string
     * @throws NoSuchAlgorithmException if the MD5 algorithm is not available.
     * @throws UnsupportedEncodingException if the specified encoding is unavailable.
     */
    public static String calculateMd5(String input, String encoding) throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(input.getBytes(encoding));
        byte digest[] = md.digest();

        final StringBuilder hexString = new StringBuilder();
        for (byte element : digest) {
            int z = 0xFF & element;
            if (z < 16)
                hexString.append("0");
            hexString.append(Integer.toHexString(z));
        }

        return hexString.toString();
    }

}