com.parworks.androidlibrary.utils.HMacShaPasswordEncoder.java Source code

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Here is the source code for com.parworks.androidlibrary.utils.HMacShaPasswordEncoder.java

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/*
 *   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.parworks.androidlibrary.utils;

import org.springframework.security.authentication.encoding.PasswordEncoder;
import org.springframework.security.crypto.codec.Base64;
import org.springframework.util.StringUtils;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

public class HMacShaPasswordEncoder implements PasswordEncoder {

    private static final int DEFAULT_ENCRYPTION_STRENGTH = 128;
    private static final String ENCODING_FOR_ENCRYPTION = "UTF-8";

    private boolean encodeHashAsBas64 = false;
    private String algorithm;

    /**
     * Initializes the ShaPasswordEncoder for SHA-1 strength
     */
    public HMacShaPasswordEncoder() {
        this(DEFAULT_ENCRYPTION_STRENGTH);
    }

    /**
     * Initialize the ShaPasswordEncoder with a given SHA stength as supported by the JVM
     * EX: <code>HmacShaPasswordEncoder encoder = new HmacShaPasswordEncoder(256);</code> initializes with SHA-256
     *
     * @param strength EX: 1, 256, 384, 512
     */
    public HMacShaPasswordEncoder(int strength) {
        this(strength, false);
    }

    public HMacShaPasswordEncoder(int strength, boolean encodeHashAsBase64) {
        this("HmacSHA" + String.valueOf(strength), encodeHashAsBase64);
    }

    public HMacShaPasswordEncoder(String algorithm, boolean encodeHashAsBase64) {
        this.algorithm = algorithm;
        setEncodeHashAsBas64(encodeHashAsBase64);
        //validity Check
        getMac();

    }

    protected final Mac getMac() throws IllegalArgumentException {
        try {
            return Mac.getInstance(algorithm);
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalArgumentException("No such algorithm [" + algorithm + "]");
        }
    }

    public String encodePassword(String rawDataToBeEncrypted, Object salt) {
        byte[] hmacData = null;
        if (rawDataToBeEncrypted != null) {
            try {
                SecretKeySpec secretKey = new SecretKeySpec(rawDataToBeEncrypted.getBytes(ENCODING_FOR_ENCRYPTION),
                        this.algorithm);
                Mac mac = getMac();
                mac.init(secretKey);
                hmacData = mac.doFinal(salt.toString().getBytes(ENCODING_FOR_ENCRYPTION));

                if (isEncodeHashAsBas64()) {
                    return new String(Base64.encode(hmacData), ENCODING_FOR_ENCRYPTION);
                } else {
                    return new String(hmacData, ENCODING_FOR_ENCRYPTION);
                }

            } catch (InvalidKeyException ike) {
                throw new RuntimeException("Invalid Key while encrypting.", ike);
            } catch (UnsupportedEncodingException e) {
                throw new RuntimeException("Unsupported Encoding while encrypting.", e);
            }
        }
        return "";

    }

    @Override
    public boolean isPasswordValid(String encPass, String rawPass, Object salt) {
        if (!StringUtils.hasText(encPass) || !StringUtils.hasText(rawPass)) {
            return false;
        }
        String pass1 = "" + encPass;
        String pass2 = encodePassword(rawPass, salt);

        boolean valid = equals(pass1, pass2);
        return valid;
    }

    public boolean isEncodeHashAsBas64() {
        return encodeHashAsBas64;
    }

    public void setEncodeHashAsBas64(boolean encodeHashAsBas64) {
        this.encodeHashAsBas64 = encodeHashAsBas64;
    }

    private static boolean equals(String expected, String actual) {
        byte[] expectedBytes = null;
        byte[] actualBytes = null;
        try {
            expectedBytes = expected.getBytes(ENCODING_FOR_ENCRYPTION);
            actualBytes = actual.getBytes(ENCODING_FOR_ENCRYPTION);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("Unsupported Encoding while encrypting.", e);
        }

        int expectedLength = expectedBytes == null ? -1 : expectedBytes.length;
        int actualLength = actualBytes == null ? -1 : actualBytes.length;
        if (expectedLength != actualLength) {
            return false;
        }

        int result = 0;
        for (int i = 0; i < expectedLength; i++) {
            result |= expectedBytes[i] ^ actualBytes[i];
        }
        return result == 0;
    }

    public static void main(String[] args) {
        HMacShaPasswordEncoder encoder = new HMacShaPasswordEncoder(256, true);
    }
}