net.sf.zekr.common.util.CryptoUtils.java Source code

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Here is the source code for net.sf.zekr.common.util.CryptoUtils.java

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/*
 *               In the name of Allah
 * This file is part of The Zekr Project. Use is subject to
 * license terms.
 *
 * Author:         Mohsen Saboorian
 * Start Date:     Feb 7, 2008
 */
package net.sf.zekr.common.util;

import java.io.FileInputStream;
import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import java.security.InvalidKeyException;
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.Signature;
import java.security.SignatureException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import net.sf.zekr.common.ZekrBaseRuntimeException;

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

/**
 * @author Mohsen Saboorian
 */
public class CryptoUtils {
    public static final byte[] PUBLIC_KEY;
    static {
        try {
            PUBLIC_KEY = Base64
                    .decodeBase64(("MIIBtzCCASwGByqGSM44BAEwggEfAoGBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9EAMMeP4C2USZp"
                            + "RV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7gB00b/JmYLdrmVClpJ+f6AR7ECLCT7up1/63xhv4O1fn"
                            + "xqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv8iIDGZ3RSAHHAhUAl2BQjxUjC8yykrmCouuE"
                            + "C/BYHPUCgYEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCBgLRJ"
                            + "FnEj6EwoFhO3zwkyjMim4TwWeotUfI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImo"
                            + "g9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoDgYQAAoGAW+7HDcQiEiNnPsHa/wx5f53CltL2iTDCqSCQ"
                            + "d6AoNQe/OfBUtFUnohFh3CD0iFfCKEDbsP1Q/4tI62Y1hKFJv/S5Ju4CzBCwt5/SRDgVwJ0pP808"
                            + "OZQ38Yx6ZOqVdgaHaYt5Yo3P/shkVZvlVu9VO66dcnnS7A+NP37IbwxSJb8=").getBytes("US-ASCII"));
        } catch (UnsupportedEncodingException e) {
            throw new ZekrBaseRuntimeException(e);
        }
    }

    public static byte[] sign(String datafile, PrivateKey prvKey, String sigAlg) throws Exception {
        Signature sig = Signature.getInstance(sigAlg);
        sig.initSign(prvKey);
        FileInputStream fis = new FileInputStream(datafile);
        byte[] dataBytes = new byte[1024];
        int nread = fis.read(dataBytes);
        while (nread > 0) {
            sig.update(dataBytes, 0, nread);
            nread = fis.read(dataBytes);
        }
        return sig.sign();
    }

    public static boolean verify(byte[] text, PublicKey pubKey, byte[] sigBytes)
            throws NoSuchAlgorithmException, InvalidKeyException, SignatureException {
        Signature sig = Signature.getInstance("SHA1withDSA");
        sig.initVerify(pubKey);
        sig.update(text);
        return sig.verify(sigBytes);
    }

    public static boolean verify(byte[] text, byte[] sigBytes) throws GeneralSecurityException {
        X509EncodedKeySpec pubSpec = new X509EncodedKeySpec(PUBLIC_KEY);
        KeyFactory keyFactory = KeyFactory.getInstance("DSA");
        PublicKey pubKey = keyFactory.generatePublic(pubSpec);
        return verify(text, pubKey, sigBytes);
    }

    public static byte[] sign(byte[] text, byte[] prvKeyBytes) throws GeneralSecurityException {
        PKCS8EncodedKeySpec prvSpec = new PKCS8EncodedKeySpec(prvKeyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("DSA");
        PrivateKey prvKey = keyFactory.generatePrivate(prvSpec);
        Signature sig = Signature.getInstance("SHA1withDSA");
        sig.initSign(prvKey);
        sig.update(text);
        return sig.sign();
    }

    public static KeyPair generateKeyPair() throws NoSuchAlgorithmException {
        // Generate a 1024-bit Digital Signature Algorithm (DSA) key pair
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
        keyGen.initialize(1024);
        KeyPair keypair = keyGen.genKeyPair();
        return keypair;
    }
}