Java Security

Hi,

I am having problem with password encryption/decryption. I can successfully encrypt but when I do the decryption I am getting few exceptions like IllegalBlockSizeException, BadPaddingException. Below is the code which I have written and the exception I am getting when I am decrypting the encrypted password.


import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.util.*;
import java.io.*;

public class PwdEncryption
{

Cipher ecipher;
Cipher dcipher;
SecretKey key = null;
KeyGenerator desKeyGen;

protected static String KEYGEN_STR = "";


public PwdEncryption()
{
try
{
KeyGenerator keyGen = KeyGenerator.getInstance("DES");
SecretKey desSecretKey = keyGen.generateKey();
byte[] bytes = desSecretKey.getEncoded();
DataInputStream dis = null;
try
{
FileInputStream fis = new FileInputStream("C:/DESKey.txt");
BufferedInputStream bis = new BufferedInputStream(fis);
dis = new DataInputStream(bis);
int count = 0;
String result = null;
StringBuffer buf = new StringBuffer();

while((result = dis.readLine()) != null)
{
buf.append(result);
count++;
}
KEYGEN_STR = buf.toString();
}
catch(FileNotFoundException ex)
{ }
finally
{
if(dis != null)
{
try
{
dis.close();
}
catch (IOException ioe)
{ }
}
}
}
catch(Exception ex)
{
ex.printStackTrace();
}
}

private Key getKey()
{
try
{
byte[] bytes = getbytes(KEYGEN_STR);
DESKeySpec pass = new DESKeySpec(bytes);

SecretKeyFactory sKeyFactory = SecretKeyFactory.getInstance("DES");
SecretKey sKey = sKeyFactory.generateSecret(pass);

return sKey;
}
catch(Exception ex)
{
ex.printStackTrace();
}
return null;
}

private byte[] getbytes(String str)
{
ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream();

StringTokenizer sTokenizer = new StringTokenizer(str, "-", false);
while(sTokenizer.hasMoreTokens())
{
try
{
byteOutputStream.write(sTokenizer.nextToken().getBytes());
}
catch(IOException ex)
{
}
}

byteOutputStream.toByteArray());
return byteOutputStream.toByteArray();
}


public String encrypt(String sourceStr)
{
try
{
// Get secret key
Key key = getKey();

ecipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
ecipher.init(Cipher.ENCRYPT_MODE, key);

byte[] enc = ecipher.doFinal((new String(sourceStr)).getBytes("UTF-8"));

// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);

}
catch(Exception ex)
{
ex.printStackTrace();
}
return null;
}


public String decrypt(String sourceStr)
{
try
{
// Get secret key
Key key = getKey();

dcipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
dcipher.init(Cipher.DECRYPT_MODE, key);

// Decode base64 to get bytes
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(sourceStr);

//Decrypt data in a single step

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

// Decode using utf-8
return new String(utf8, "UTF-8");
}
catch(Exception ex)
{
ex.printStackTrace();
}
return null;
}
}

javax.crypto.IllegalBlockSizeException: Input length (with padding) not multiple of 8 bytes
at com.sun.crypto.provider.SunJCE_h.a(DashoA6275)
at com.sun.crypto.provider.SunJCE_h.b(DashoA6275)
at com.sun.crypto.provider.SunJCE_h.b(DashoA6275)
at com.sun.crypto.provider.DESCipher.engineDoFinal(DashoA6275)
at javax.crypto.Cipher.doFinal(DashoA6275)


Can anyone please help me with the code so that it would work. It is very urgent.


Thanks