Question

I have been able to use the algorithm to encrypt and decrypt files , but when I go to try and send a file from Android to a WAS server, it fails. Here is the encrypt side

    Security.addProvider(new BouncyCastleProvider());
    KeyGenerator keygen = KeyGenerator.getInstance("AES");
    SecureRandom random = new SecureRandom();
    keygen.init(random);
    SecretKey key = keygen.generateKey();

    // wrap with RSA public key
    ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream (getFileLocation(PUBLIC_KEY, localTest)));
    Key publicKey = (Key) keyIn.readObject();
    keyIn.close();

    Cipher cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.WRAP_MODE, publicKey);
    byte[] wrappedKey = cipher.wrap(key);
    DataOutputStream out = new DataOutputStream(new FileOutputStream(getFileLocation(SIGN_FILE, localTest)));
    out.writeInt(wrappedKey.length);
    out.write(wrappedKey);

    InputStream in = new ByteArrayInputStream(message.getBytes());
    cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, key);
    crypt(in, out, cipher);
    in.close();
    out.close();

    FileInputStream fis = new FileInputStream(getFileLocation(SIGN_FILE, localTest));
    byte[] buffer = new byte[fis.available()];
    int i =0;
    while (i< buffer.length ){
         buffer[i]= (byte)fis.read();
         i++;
    }
    String ss = encodeMsg(buffer);
    return ss;

Here is the decrypt side

        Security.addProvider(new BouncyCastleProvider());

        byte[] arr = decodeMsg(encrypted);

            DataInputStream in = new DataInputStream(new ByteArrayInputStream(arr));
            int length = in.readInt();
            byte[] wrappedKey = new byte[length];
            in.read(wrappedKey, 0, length);
            // unwrap with RSA private key
            ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream (getFileLocation(PRIVATE_KEY, localTest)));
            Key privateKey = (Key) keyIn.readObject();
            keyIn.close();
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.UNWRAP_MODE, privateKey);
            Key key = cipher.unwrap(wrappedKey, "AES", Cipher.SECRET_KEY);

            OutputStream out = new FileOutputStream(getFileLocation(DECRYPTED, localTest));
            cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, key);
            crypt(in, out, cipher);
            in.close();
            out.close();

            FileInputStream fis = new FileInputStream(getFileLocation(DECRYPTED, localTest));
            byte[] buffer = new byte[fis.available()];
            int i =0;
            while (i< buffer.length ){//!= 0) {
                 buffer[i]= (byte)fis.read();
                 i++;
            }
            String ss = new String(buffer);
            return ss;

Again, on my workstation, this works. When doing the mobile request to the WAS web server, it fails. At first, it argued with the object class and so I recreated the keys using Java 1.6. I have recompiled the war into Java 1.6 as well. It errors as below.

–cipher unwrap

java.security.InvalidKeyException com.ibm.crypto.provider.RSA.engineUnwrap(Unknown Source)
javax.crypto.Cipher.unwrap(Unknown Source)
com.webapp.web.security.RSAEncrypt.decrypt(RSAEncrypt.java:161)
com.webapp.web.MobileRequest.doPost(MobileRequest.java:81)
javax.servlet.http.HttpServlet.service(HttpServlet.java:738)
javax.servlet.http.HttpServlet.service(HttpServlet.java:831)

…

Does the WAS environment have to be updated to handle this? ideas?
UPDATE the keysize is set to 2048

Answer 1

The Unlimited Jurisdiciton policy might work, but I attempted to use the IBMJCE without success as well. Then, I switched to use the SunJCE provider (version Java 1.6) and now I am able to do the encryption and decryption in both Android and Websphere. I am having the administrators look into the policy files to see if BouncyCastle could be enabled, but I am ok with using the Sun provider files.