com.hurence.logisland.util.string.Anonymizer.java Source code

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Here is the source code for com.hurence.logisland.util.string.Anonymizer.java

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/**
 * Copyright (C) 2016 Hurence (support@hurence.com)
 *
 * 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 com.hurence.logisland.util.string;

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import org.apache.commons.codec.binary.Hex;

/**
 *
 * @author tom
 */
public class Anonymizer {

    public static final String PBKDF2_ALGORITHM = "PBKDF2WithHmacSHA1";

    // The following constants may be changed without breaking existing hashes.
    public static final int SALT_BYTE_SIZE = 4;
    public static final int HASH_BYTE_SIZE = 8;
    public static final int PBKDF2_ITERATIONS = 3;

    public static final int ITERATION_INDEX = 0;
    public static final int SALT_INDEX = 1;
    public static final int PBKDF2_INDEX = 2;

    private final SecureRandom random;
    private final byte[] salt;
    private final long timeSalt;

    public Anonymizer() {
        random = new SecureRandom();
        salt = new byte[SALT_BYTE_SIZE];

        timeSalt = random.nextInt(1000000000) + 1000000000;
        random.nextBytes(salt);
    }

    public String anonymize(String str) throws NoSuchAlgorithmException, InvalidKeySpecException {

        // Hash the password
        PBEKeySpec spec = new PBEKeySpec(str.toCharArray(), salt, PBKDF2_ITERATIONS, HASH_BYTE_SIZE * 8);
        SecretKeyFactory skf = SecretKeyFactory.getInstance(PBKDF2_ALGORITHM);
        byte[] hash = skf.generateSecret(spec).getEncoded();

        return Hex.encodeHexString(hash);
    }

    /**
     * hash the input string but keep extension
     *
     * "http://www.google.com/support/enterprise/static/gsa/docs/admin/70/gsa_doc_set/integrating_apps/images/google_logo.png";
     * would become something like fe29e95f11e85425.png
     *
     * @param str
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    public String anonymizeKeepExtension(String str) throws NoSuchAlgorithmException, InvalidKeySpecException {

        String extension = "";
        String pathToHash = "";

        if (str != null && str.contains(".")) {
            int dotId = str.lastIndexOf(".");
            extension = str.substring(dotId);
            pathToHash = str.substring(0, dotId - 1);
        }

        return anonymize(pathToHash) + extension;
    }

    public Date anonymize(Date d) {
        long newTimestamp = d.getTime() - timeSalt;

        if (newTimestamp > 0) {
            return new Date(d.getTime() - timeSalt);
        } else {
            return d;
        }
    }

    public static void main(String[] args) {
        try {

            Anonymizer anon = new Anonymizer();

            String ip1 = "123.90.3.23";
            String ip2 = "123.90.3.24";
            System.out.println(anon.anonymize(ip1));

            System.out.println(anon.anonymize(ip1));
            System.out.println(anon.anonymize(ip2));

            String url = "http://www.google.com/support/enterprise/static/gsa/docs/admin/70/gsa_doc_set/integrating_apps/images/google_logo.png";

            System.out.println(anon.anonymizeKeepExtension(url));

        } catch (NoSuchAlgorithmException | InvalidKeySpecException ex) {
            Logger.getLogger(Anonymizer.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}