I'm trying to encrypt my file names and folders names.
For this I'm using javax.crypto and sun.misc.BASE64Encoder packages with UTF8 Char-set for encrypting strings which will be used as file/folder names..
The problems is that encrypted string contain special characters like (/,\) and they cannot be used in file/folder names.
Please guide me how can i correct this code. I tried different character set along with sun.misc Encoders but they did not work.
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.DESedeKeySpec;
import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;
public class MyEnc
{
public static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
public static final String DES_ENCRYPTION_SCHEME = "DES";
public static final String DEFAULT_ENCRYPTION_KEY = "This is a fairly long phrase used to encrypt";
public static final String encryptionKey = "012345678901234567890123456789";
public static final String encryptionScheme = DESEDE_ENCRYPTION_SCHEME;
private KeySpec keySpec;
private SecretKeyFactory keyFactory;
private Cipher cipher;
private static final String UNICODE_FORMAT = "UTF8";
public MyEnc( )
throws EncryptionException
{
if ( encryptionKey == null )
throw new IllegalArgumentException( "encryption key was null" );
if ( encryptionKey.trim().length() < 24 )
throw new IllegalArgumentException(
"encryption key was less than 24 characters" );
try
{
byte[] keyAsBytes = encryptionKey.getBytes( UNICODE_FORMAT );
if ( encryptionScheme.equals( DESEDE_ENCRYPTION_SCHEME) )
{
keySpec = new DESedeKeySpec( keyAsBytes );
}
else if ( encryptionScheme.equals( DES_ENCRYPTION_SCHEME ) )
{
keySpec = new DESKeySpec( keyAsBytes );
}
else
{
throw new IllegalArgumentException( "Encryption scheme not supported: "
+ encryptionScheme );
}
keyFactory = SecretKeyFactory.getInstance( encryptionScheme );
cipher = Cipher.getInstance( encryptionScheme );
}
catch (InvalidKeyException e)
{
throw new EncryptionException( e );
}
catch (UnsupportedEncodingException e)
{
throw new EncryptionException( e );
}
catch (NoSuchAlgorithmException e)
{
throw new EncryptionException( e );
}
catch (NoSuchPaddingException e)
{
throw new EncryptionException( e );
}
}
public String encrypt( String unencryptedString ) throws EncryptionException
{
if ( unencryptedString == null || unencryptedString.trim().length() == 0 )
throw new IllegalArgumentException(
"unencrypted string was null or empty" );
try
{
SecretKey key = keyFactory.generateSecret( keySpec );
cipher.init( Cipher.ENCRYPT_MODE, key );
byte[] cleartext = unencryptedString.getBytes( UNICODE_FORMAT );
byte[] ciphertext = cipher.doFinal( cleartext );
BASE64Encoder base64encoder = new BASE64Encoder();
return base64encoder.encode( ciphertext );
}
catch (Exception e)
{
throw new EncryptionException( e );
}
}
public String decrypt( String encryptedString ) throws EncryptionException
{
if ( encryptedString == null || encryptedString.trim().length() <= 0 )
throw new IllegalArgumentException( "encrypted string was null or empty" );
try
{
SecretKey key = keyFactory.generateSecret( keySpec );
cipher.init( Cipher.DECRYPT_MODE, key );
BASE64Decoder base64decoder = new BASE64Decoder();
byte[] cleartext = base64decoder.decodeBuffer( encryptedString );
byte[] ciphertext = cipher.doFinal( cleartext );
return bytes2String( ciphertext );
}
catch (Exception e)
{
throw new EncryptionException( e );
}
}
private static String bytes2String( byte[] bytes )
{
StringBuffer stringBuffer = new StringBuffer();
for (int i = 0; i < bytes.length; i++)
{
stringBuffer.append( (char) bytes[i] );
}
return stringBuffer.toString();
}
public static class EncryptionException extends Exception
{
public EncryptionException( Throwable t )
{
super( t );
}
}
}