br.edu.ufcg.lsd.commune.network.signature.Util.java Source code

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Here is the source code for br.edu.ufcg.lsd.commune.network.signature.Util.java

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/*
 * Copyright (C) 2008 Universidade Federal de Campina Grande
 *  
 * This file is part of Commune. 
 *
 * Commune 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 3 of the License, or (at your option) 
 * any later version. 
 * 
 * This program 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. 
 * 
 * You should have received a copy of the GNU Lesser General Public License 
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package br.edu.ufcg.lsd.commune.network.signature;

import java.io.UnsupportedEncodingException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.EncodedKeySpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import org.apache.commons.codec.binary.Base64;

import br.edu.ufcg.lsd.commune.CommuneRuntimeException;

public class Util {

    private static Base64 base64 = new Base64();

    public static KeyPair generateKeyPair() {
        KeyPairGenerator keyGen;
        try {
            keyGen = KeyPairGenerator.getInstance(SignatureConstants.KEY_GEN_ALGORITHM);
        } catch (NoSuchAlgorithmException e) {
            //We're assuming that we are always using a valid algorithm
            throw new CommuneRuntimeException(e);
        }
        keyGen.initialize(SignatureConstants.KEYSIZE);
        return keyGen.genKeyPair();
    }

    public static PublicKey decodePublicKey(String pubKeyStr) throws InvalidKeySpecException {
        byte[] binaryArray = decodeStringOnBase64(pubKeyStr);
        KeyFactory keyFactory;
        try {
            keyFactory = KeyFactory.getInstance(SignatureConstants.KEY_GEN_ALGORITHM);
        } catch (NoSuchAlgorithmException e) {
            //We're assuming that we are always instantiating a valid algorithm
            throw new CommuneRuntimeException(e);
        }
        EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(binaryArray);
        return keyFactory.generatePublic(publicKeySpec);
    }

    public static PrivateKey decodePrivateKey(String privKeyStr) throws InvalidKeySpecException {
        byte[] binaryArray = decodeStringOnBase64(privKeyStr);
        KeyFactory keyFactory;
        try {
            keyFactory = KeyFactory.getInstance(SignatureConstants.KEY_GEN_ALGORITHM);
        } catch (NoSuchAlgorithmException e) {
            //We're assuming that we are always instantiating a valid algorithm
            throw new CommuneRuntimeException(e);
        }
        EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(binaryArray);
        return keyFactory.generatePrivate(privateKeySpec);
    }

    public static byte[] decodeStringOnBase64(String str) {
        byte[] encodedBase64 = str.getBytes();
        return decodeArrayOnBase64(encodedBase64);
    }

    public static byte[] decodeArrayOnBase64(byte[] encodedBase64) {
        return base64.decode(encodedBase64);
    }

    public static String encodeArrayToBase64String(byte[] binaryArray) {
        try {
            return new String(encodeArrayToBase64(binaryArray), "utf-8");
        } catch (UnsupportedEncodingException e) {
            throw new CommuneRuntimeException(e);
        }
    }

    public static byte[] encodeArrayToBase64(byte[] binaryArray) {
        return base64.encode(binaryArray);
    }

    public static String encodeArrayToHexadecimalString(byte[] binaryArray) {
        final int radix = 16;
        String result = "";
        for (byte b : binaryArray) {
            int unsignedByte = b + 128;
            result += Integer.toString(unsignedByte, radix);
        }
        return result;
    }

    public static void main(String[] args) {
        KeyPair keyPair = generateKeyPair();
        System.out.println(encodeArrayToBase64String(keyPair.getPrivate().getEncoded()));
        System.out.println(encodeArrayToBase64String(keyPair.getPublic().getEncoded()));
    }
}