Java Hash Calculate getHashString(String password, String salt)

Description

get Hash String

License

Open Source License

Declaration

public static String getHashString(String password, String salt)
            throws NoSuchAlgorithmException, UnsupportedEncodingException, GeneralSecurityException

Method Source Code


//package com.java2s;
/*//from ww  w  .j a v  a  2 s . c o  m
 * Used Matthias Gartner's PKCS#5 implementation - see
 * http://rtner.de/software/PBKDF2.html
 * 
 * <p>
 * Free auxiliary functions. Copyright (c) 2007 Matthias G&auml;rtner
 * </p>
 * <p>
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * </p>
 * <p>
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * </p>
 * <p>
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * </p>
 * <p>
 * For Details, see <a
 * href="http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html"
 * >http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html</a>.
 * </p>
 */

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

public class Main {
    public static final String hex = "0123456789ABCDEF";
    public static final int iterations = 1000;

    public static String getHashString(String password, String salt)
            throws NoSuchAlgorithmException, UnsupportedEncodingException, GeneralSecurityException {
        return bin2hex(getHash(iterations, createPasswordKey(password, salt), hex2bin(salt)));
    }

    public static String getHashString(String password, byte[] salt)
            throws NoSuchAlgorithmException, UnsupportedEncodingException, GeneralSecurityException {
        return bin2hex(getHash(iterations, createPasswordKey(password, salt), salt));
    }

    /**
     * Simple binary-to-hexadecimal conversion.
     * 
     * @param b
     *            Input bytes. May be <code>null</code>.
     * @return Hexadecimal representation of b. Uppercase A-F, two characters
     *         per byte. Empty string on <code>null</code> input.
     */
    public static String bin2hex(final byte[] b) {
        if (b == null) {
            return "";
        }
        StringBuffer sb = new StringBuffer(2 * b.length);
        for (int i = 0; i < b.length; i++) {
            int v = (256 + b[i]) % 256;
            sb.append(hex.charAt((v / 16) & 15));
            sb.append(hex.charAt((v % 16) & 15));
        }
        return sb.toString();
    }

    /**
     * Takes hash value of password n times using md5 and one more time using sha  
     * */
    public static byte[] getHash(int iterationNb, String password, byte[] salt)
            throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        md5.reset();
        md5.update(salt);

        byte[] input = md5.digest(password.getBytes("UTF-8"));
        for (int i = 0; i < iterationNb; i++) {
            md5.reset();
            input = md5.digest(input);
        }

        MessageDigest sha = MessageDigest.getInstance("SHA");
        sha.reset();
        sha.update(salt);
        return sha.digest(input);
    }

    public static String createPasswordKey(String password, String salt)
            throws UnsupportedEncodingException, GeneralSecurityException {
        return createPasswordKey(password, hex2bin(salt));
    }

    public static String createPasswordKey(String password, byte[] salt)
            throws GeneralSecurityException, UnsupportedEncodingException {
        byte[] generatedPassword = getHash(iterations, password, salt);
        byte[] generatedReversedPassword = getHash(iterations, bin2hex(salt), password.getBytes());
        byte[] result = new byte[generatedPassword.length + generatedReversedPassword.length];
        int c = 0;
        for (int i = 0; i < generatedPassword.length; i++) {
            result[c++] = generatedPassword[i];
        }
        for (int j = 0; j < generatedReversedPassword.length; j++) {
            result[c++] = generatedReversedPassword[j];
        }
        return bin2hex(result);
    }

    /**
     * Convert hex string to array of bytes.
     * 
     * @param s
     *            String containing hexadecimal digits. May be <code>null</code>
     *            . On odd length leading zero will be assumed.
     * @return Array on bytes, non-<code>null</code>.
     * @throws IllegalArgumentException
     *             when string contains non-hex character
     */
    public static byte[] hex2bin(final String s) {
        String m = s;
        if (s == null) {
            // Allow empty input string.
            m = "";
        } else if (s.length() % 2 != 0) {
            // Assume leading zero for odd string length
            m = "0" + s;
        }
        byte r[] = new byte[m.length() / 2];
        for (int i = 0, n = 0; i < m.length(); n++) {
            char h = m.charAt(i++);
            char l = m.charAt(i++);
            r[n] = (byte) (hex2bin(h) * 16 + hex2bin(l));
        }
        return r;
    }

    /**
     * Convert hex digit to numerical value.
     * 
     * @param c
     *            0-9, a-f, A-F allowd.
     * @return 0-15
     * @throws IllegalArgumentException
     *             on non-hex character
     */
    public static int hex2bin(char c) {
        if (c >= '0' && c <= '9') {
            return (c - '0');
        }
        if (c >= 'A' && c <= 'F') {
            return (c - 'A' + 10);
        }
        if (c >= 'a' && c <= 'f') {
            return (c - 'a' + 10);
        }
        throw new IllegalArgumentException("Input string may only contain hex digits, but found '" + c + "'");
    }
}

Java Hash Calculate getHashString(String password, String salt)

Description

License

Declaration

Method Source Code

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