Question

On a tomcat, I have two webapplications i.e app1 and app2. I send URL from app1 in encrypted form (using below program) to app2 . I send the URL through response.sendRedirect(encryptedURL).Then at app2 I get this encrypted URL. I see there are some extra characters like +,space( ) in this encrypted URL at app2. I want the exact same URL at app2. I am not getting why these extra characters getting inserted?

Here is the URL at app1 after encryption

 Rc9mgB+18chPk6nk1+gzpws6dO5/TSkcOYy8rbuVVTmjE9YjLt5w0EMpuhh+QBKzReYO34pAquf9
 kmYOiwl99jo2kDCCkYHMh/+nxEgs1yrLYagsc/0p5KdYeMy1eWeUQB8KqmNlhtYysrHhOYVuunUi
 dTaEKUTSWd8lPg9/wZfHdBoJgaF40aUW3FeRODVL

Here is the value of this encrypted URL at app2 when I get it with req.getParameter(“encryptedURL”);

 Rc9mgB 18chPk6nk1 gzpws6dO5/TSkcOYy8rbuVVTmjE9YjLt5w0EMpuhh QBKzReYO34pAquf9  kmYOiwl99jo2kDCCkYHMh/ nxEgs1yrLYagsc/0p5KdYeMy1eWeUQB8KqmNlhtYysrHhOYVuunUi  dTaEKUTSWd8lPg9/wZfHdBoJgaF40aUW3FeRODVL

Here is the program for encryption

 import java.security.Key;
 import javax.crypto.Cipher;
 import javax.crypto.spec.SecretKeySpec;
 import sun.misc.BASE64Decoder;
 import sun.misc.BASE64Encoder;

 public class AESEncryptionDecryptionTest {

   private static final String ALGORITHM       = "AES";
   private static final String myEncryptionKey = "ThisIsFoundation";
   private static final String UNICODE_FORMAT  = "UTF8";

   public static String encrypt(String valueToEnc) throws Exception {
 Key key = generateKey();
 Cipher c = Cipher.getInstance(ALGORITHM);
 c.init(Cipher.ENCRYPT_MODE, key);  
 byte[] encValue = c.doFinal(valueToEnc.getBytes());
 String encryptedValue = new BASE64Encoder().encode(encValue);
 return encryptedValue;
   }


private static Key generateKey() throws Exception {
byte[] keyAsBytes;
keyAsBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
Key key = new SecretKeySpec(keyAsBytes, ALGORITHM);
return key;
}


}

EDIT:-Looks like very close to it. here is my new code and finding

This is the parameter I am encrypting at app1

 mySession=84088586B45317C3600978DF9F52A699&securityTok=44a2e4dd89ed1aad438d5e3c16ff528&myurl=https://10.205.112.83:8443

// encrypted as you suggested at app1 and sending encryptedParam as request parameter

//now getting the encryptedParam at app2 from request and decrypted as per your suggestion . As you can see below
everything is decrypted fine at app2 except my URL part(i.e =https://10.205 replaced with ½‡è˜�Àg¸l½.µbO’)

mySession=84088586B45317C3600978DF9F52A699&securityTok=44a2e4dd89ed1aad438d5e3c16ff528&myurl½‡è˜�Àg¸l½.µbO’112.83:8443

Code is

   public static String encrypt(String valueToEnc) throws Exception {
    Key key = generateKey();
    // Key key = buildKey();
    Cipher c = Cipher.getInstance(ALGORITHM);
    c.init(Cipher.ENCRYPT_MODE, key);
    byte[] encValue = c.doFinal(valueToEnc.getBytes(UNICODE_FORMAT));
    String encryptedValue1 = new BASE64Encoder().encode(encValue);
    String encryptedValue = URLEncoder.encode(encryptedValue1);
    return encryptedValue;
  }

  public static String decrypt(String encryptedValue) throws Exception {
    Key key = generateKey();
    // Key key = buildKey();
    Cipher c = Cipher.getInstance(ALGORITHM);
    c.init(Cipher.DECRYPT_MODE, key);
    String decordedValueStr = URLDecoder.decode(encryptedValue);
    byte[] decordedValue = new BASE64Decoder().decodeBuffer(decordedValueStr);
    byte[] decValue = c.doFinal(decordedValue);
    // String try1=new BASE64Encoder().encode(decValue);
    String decryptedValue = new String(decValue);
    return decryptedValue;
  }

Answer 1

In your encrypt method instead of:

return encryptedValue;

use this code:

return URLEncoder.encode(encryptedValue);

then on receiving side call URLDecoder#decode:

String tmpUrl = URLDecoder.decode(encryptedURL);
// call BASE64Decoder on tmpUrl
// call decrypt on return value of BASE64Decoder