Subversion Repositories bacoAlunos

package jomm.utils;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;

/**
 * @author Jorge Machado
 * @date 20/Mai/2008
 * @see jomm.utils
 */
public class DesUtils
{
    static 1.5.0/docs/api/javax/crypto/Cipher.html">Cipher ecipher;
    static 1.5.0/docs/api/javax/crypto/Cipher.html">Cipher dcipher;

    static 1.5.0/docs/api/javax/crypto/SecretKey.html">SecretKey key;


    public static byte[] addParity(byte[] in) {
        byte[] result = new byte[8];

        // Keeps track of the bit position in the result
        int resultIx = 1;

        // Used to keep track of the number of 1 bits in each 7-bit chunk
        int bitCount = 0;

        // Process each of the 56 bits
        for (int i=0; i<56; i++) {
            // Get the bit at bit position i
            boolean bit = (in[6-i/8]&(1<<(i%8))) > 0;

            // If set, set the corresponding bit in the result
            if (bit) {
                result[7-resultIx/8] |= (1<<(resultIx%8))&0xFF;
                bitCount++;
            }

            // Set the parity bit after every 7 bits
            if ((i+1) % 7 == 0) {
                if (bitCount % 2 == 0) {
                    // Set low-order bit (parity bit) if bit count is even
                    result[7-resultIx/8] |= 1;
                }
                resultIx++;
                bitCount = 0;
            }
            resultIx++;
        }
        return result;
    }

    // Get the 56-bit value


    private static DesUtils desUtils;

    private DesUtils()
    {
        try {
            byte[] raw = new byte[]{0x01, 0x72, 0x43, 0x3E, 0x1C, 0x7A, 0x55};
            byte[] keyBytes = addParity(raw);
            key = new 1.5.0/docs/api/javax/crypto/spec/SecretKeySpec.html">SecretKeySpec(keyBytes, "DES");
            ecipher = 1.5.0/docs/api/javax/crypto/Cipher.html">Cipher.getInstance("DES");
            dcipher = 1.5.0/docs/api/javax/crypto/Cipher.html">Cipher.getInstance("DES");
            ecipher.init(1.5.0/docs/api/javax/crypto/Cipher.html">Cipher.ENCRYPT_MODE, key);
            dcipher.init(1.5.0/docs/api/javax/crypto/Cipher.html">Cipher.DECRYPT_MODE, key);

        } catch (javax.crypto.1.5.0/docs/api/javax/crypto/NoSuchPaddingException.html">NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (java.security.1.5.0/docs/api/java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (java.security.5+0%2Fdocs%2Fapi+InvalidKeyException">InvalidKeyException e) {
            e.printStackTrace();
        }
    }

    public static DesUtils getInstance()
    {
        if(desUtils == null)
            desUtils = new DesUtils();
        return desUtils;
    }

    public 1.5.0/docs/api/java/lang/String.html">String encrypt(1.5.0/docs/api/java/lang/String.html">String str) {
        try {
            // Encode the string into bytes using utf-8
            byte[] utf8 = str.getBytes("UTF8");

            // Encrypt
            byte[] enc = ecipher.doFinal(utf8);

            // Encode bytes to base64 to get a string
            return new sun.misc.BASE64Encoder().encode(enc);
        } catch (javax.crypto.1.5.0/docs/api/javax/crypto/BadPaddingException.html">BadPaddingException e) {
        } catch (1.5.0/docs/api/javax/crypto/IllegalBlockSizeException.html">IllegalBlockSizeException e) {
        } catch (1.5.0/docs/api/java/io/UnsupportedEncodingException.html">UnsupportedEncodingException e) {
        } catch (java.io.1.5.0/docs/api/java/io/IOException.html">IOException e) {
        }
        return null;
    }

    public 1.5.0/docs/api/java/lang/String.html">String decrypt(1.5.0/docs/api/java/lang/String.html">String str) {
        try {
            // Decode base64 to get bytes
            byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);

            // Decrypt
            byte[] utf8 = dcipher.doFinal(dec);

            // Decode using utf-8
            return new 1.5.0/docs/api/java/lang/String.html">String(utf8, "UTF8");
        } catch (javax.crypto.1.5.0/docs/api/javax/crypto/BadPaddingException.html">BadPaddingException e) {
        } catch (1.5.0/docs/api/javax/crypto/IllegalBlockSizeException.html">IllegalBlockSizeException e) {
        } catch (1.5.0/docs/api/java/io/UnsupportedEncodingException.html">UnsupportedEncodingException e) {
        } catch (java.io.1.5.0/docs/api/java/io/IOException.html">IOException e) {
        }
        return null;
    }

    public static void main(1.5.0/docs/api/java/lang/String.html">String[] args)
    {
        1.5.0/docs/api/java/lang/String.html">String code = DesUtils.getInstance().encrypt("jorge machado");
        1.5.0/docs/api/java/lang/System.html">System.out.println(code);
        1.5.0/docs/api/java/lang/System.html">System.out.println(DesUtils.getInstance().decrypt(code));
    }
}