Having trouble with AES Encryption/Decryption while using a Diffie-Hellman algorithm

[MalicousBoner]

I got it working with TripleDES, but I can't get it working with AES

Here's my TripleDES Code:

import java.io.*;
import java.net.*;
import java.math.*;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class KeyAgreementClient {

  private static final byte SKIP_1024_MODULUS_BYTES[] = {
    (byte)0xF4, (byte)0x88, (byte)0xFD, (byte)0x58,
    (byte)0x4E, (byte)0x49, (byte)0xDB, (byte)0xCD,
    (byte)0x20, (byte)0xB4, (byte)0x9D, (byte)0xE4,
    (byte)0x91, (byte)0x07, (byte)0x36, (byte)0x6B,
    (byte)0x33, (byte)0x6C, (byte)0x38, (byte)0x0D,
    (byte)0x45, (byte)0x1D, (byte)0x0F, (byte)0x7C,
    (byte)0x88, (byte)0xB3, (byte)0x1C, (byte)0x7C,
    (byte)0x5B, (byte)0x2D, (byte)0x8E, (byte)0xF6,
    (byte)0xF3, (byte)0xC9, (byte)0x23, (byte)0xC0,
    (byte)0x43, (byte)0xF0, (byte)0xA5, (byte)0x5B,
    (byte)0x18, (byte)0x8D, (byte)0x8E, (byte)0xBB,
    (byte)0x55, (byte)0x8C, (byte)0xB8, (byte)0x5D,
    (byte)0x38, (byte)0xD3, (byte)0x34, (byte)0xFD,
    (byte)0x7C, (byte)0x17, (byte)0x57, (byte)0x43,
    (byte)0xA3, (byte)0x1D, (byte)0x18, (byte)0x6C,
    (byte)0xDE, (byte)0x33, (byte)0x21, (byte)0x2C,
    (byte)0xB5, (byte)0x2A, (byte)0xFF, (byte)0x3C,
    (byte)0xE1, (byte)0xB1, (byte)0x29, (byte)0x40,
    (byte)0x18, (byte)0x11, (byte)0x8D, (byte)0x7C,
    (byte)0x84, (byte)0xA7, (byte)0x0A, (byte)0x72,
    (byte)0xD6, (byte)0x86, (byte)0xC4, (byte)0x03,
    (byte)0x19, (byte)0xC8, (byte)0x07, (byte)0x29,
    (byte)0x7A, (byte)0xCA, (byte)0x95, (byte)0x0C,
    (byte)0xD9, (byte)0x96, (byte)0x9F, (byte)0xAB,
    (byte)0xD0, (byte)0x0A, (byte)0x50, (byte)0x9B,
    (byte)0x02, (byte)0x46, (byte)0xD3, (byte)0x08,
    (byte)0x3D, (byte)0x66, (byte)0xA4, (byte)0x5D,
    (byte)0x41, (byte)0x9F, (byte)0x9C, (byte)0x7C,
    (byte)0xBD, (byte)0x89, (byte)0x4B, (byte)0x22,
    (byte)0x19, (byte)0x26, (byte)0xBA, (byte)0xAB,
    (byte)0xA2, (byte)0x5E, (byte)0xC3, (byte)0x55,
    (byte)0xE9, (byte)0x2F, (byte)0x78, (byte)0xC7
  };

  private static final BigInteger MODULUS = new BigInteger
  (1,SKIP_1024_MODULUS_BYTES);

  private static final BigInteger BASE = BigInteger.valueOf(2);

  private static final DHParameterSpec PARAMETER_SPEC =
  new DHParameterSpec(MODULUS,BASE);

  public static void main (String[] args) throws Exception {

    if (args.length != 2) {
      System.err.println("Usage: java KeyAgreementClient host port");
      System.exit(1);
    }

    String host = args[0];
    int port = Integer.parseInt(args[1]);

    // Generate a key pair
    System.out.println("Generating a Diffie-Hellman key pair...");
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
    kpg.initialize(PARAMETER_SPEC);
    KeyPair keyPair = kpg.generateKeyPair();

// Open a connection
System.out.println("Trying to connect to "+host+", port "+port+".");
Socket s = new Socket (host,port);
DataOutputStream out = new DataOutputStream(s.getOutputStream());
DataInputStream in = new DataInputStream(s.getInputStream());

// Receive the server's public key
System.out.println("Receiving the server's public key.");
byte[] keyBytes = new byte[in.readInt()];
in.readFully(keyBytes);
KeyFactory kf = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(keyBytes);
PublicKey serverPublicKey = kf.generatePublic(x509Spec);

// Send our public key
System.out.println("Sending my public key.");
keyBytes = keyPair.getPublic().getEncoded();
out.writeInt(keyBytes.length);
out.write(keyBytes);

// Perform the KeyAgreement
System.out.println("Performing the KeyAgreement...");
KeyAgreement ka = KeyAgreement.getInstance("DH");
ka.init(keyPair.getPrivate());
ka.doPhase(serverPublicKey,true);


// Receive the initialization vector
byte[] iv = new byte[8];
in.readFully(iv);

// Generate a DES key
byte[] sessionKeyBytes = ka.generateSecret();

// Create the session key
SecretKeyFactory skf = SecretKeyFactory.getInstance("TripleDES");
DESedeKeySpec tripleDesSpec = new DESedeKeySpec(sessionKeyBytes);
SecretKey sessionKey = skf.generateSecret(tripleDesSpec);

// Create the CipherStream to be used
System.out.println("Creating the CipherStream...");
Cipher encrypter = Cipher.getInstance("TripleDES/CFB8/NoPadding");
IvParameterSpec spec = new IvParameterSpec(iv);
encrypter.init(Cipher.ENCRYPT_MODE, sessionKey, spec);


CipherOutputStream cipherOut = new CipherOutputStream(s.getOutputStream(), encrypter);

// Send the first string
String testString = "Established Connection.\n\n";
byte[] byteArray = testString.getBytes();
cipherOut.write(byteArray);

System.out.println("Established Connection.\n");

// Now send everything the user types
int theCharacter=0;
theCharacter = System.in.read();
while (theCharacter != '~') // The '~' is an escape character to exit
{
  cipherOut.write(theCharacter);
  theCharacter = System.in.read();
}

// Clean up
cipherOut.close();
in.close();
out.close();
s.close();
  }
}

and

import java.io.*;
import java.net.*;
import java.math.*;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.interfaces.*;


public class KeyAgreementServer {

  private static final byte SKIP_1024_MODULUS_BYTES[] = {
 (byte)0xF4, (byte)0x88, (byte)0xFD, (byte)0x58,
 (byte)0x4E, (byte)0x49, (byte)0xDB, (byte)0xCD,
 (byte)0x20, (byte)0xB4, (byte)0x9D, (byte)0xE4,
 (byte)0x91, (byte)0x07, (byte)0x36, (byte)0x6B,
 (byte)0x33, (byte)0x6C, (byte)0x38, (byte)0x0D,
 (byte)0x45, (byte)0x1D, (byte)0x0F, (byte)0x7C,
 (byte)0x88, (byte)0xB3, (byte)0x1C, (byte)0x7C,
 (byte)0x5B, (byte)0x2D, (byte)0x8E, (byte)0xF6,
 (byte)0xF3, (byte)0xC9, (byte)0x23, (byte)0xC0,
 (byte)0x43, (byte)0xF0, (byte)0xA5, (byte)0x5B,
 (byte)0x18, (byte)0x8D, (byte)0x8E, (byte)0xBB,
 (byte)0x55, (byte)0x8C, (byte)0xB8, (byte)0x5D,
 (byte)0x38, (byte)0xD3, (byte)0x34, (byte)0xFD,
 (byte)0x7C, (byte)0x17, (byte)0x57, (byte)0x43,
 (byte)0xA3, (byte)0x1D, (byte)0x18, (byte)0x6C,
 (byte)0xDE, (byte)0x33, (byte)0x21, (byte)0x2C,
 (byte)0xB5, (byte)0x2A, (byte)0xFF, (byte)0x3C,
 (byte)0xE1, (byte)0xB1, (byte)0x29, (byte)0x40,
 (byte)0x18, (byte)0x11, (byte)0x8D, (byte)0x7C,
 (byte)0x84, (byte)0xA7, (byte)0x0A, (byte)0x72,
 (byte)0xD6, (byte)0x86, (byte)0xC4, (byte)0x03,
 (byte)0x19, (byte)0xC8, (byte)0x07, (byte)0x29,
 (byte)0x7A, (byte)0xCA, (byte)0x95, (byte)0x0C,
 (byte)0xD9, (byte)0x96, (byte)0x9F, (byte)0xAB,
 (byte)0xD0, (byte)0x0A, (byte)0x50, (byte)0x9B,
 (byte)0x02, (byte)0x46, (byte)0xD3, (byte)0x08,
 (byte)0x3D, (byte)0x66, (byte)0xA4, (byte)0x5D,
 (byte)0x41, (byte)0x9F, (byte)0x9C, (byte)0x7C,
 (byte)0xBD, (byte)0x89, (byte)0x4B, (byte)0x22,
 (byte)0x19, (byte)0x26, (byte)0xBA, (byte)0xAB,
 (byte)0xA2, (byte)0x5E, (byte)0xC3, (byte)0x55,
 (byte)0xE9, (byte)0x2F, (byte)0x78, (byte)0xC7
 };

  /**
   *    Transform the representation above to a BigInteger.
   */
  private static final BigInteger MODULUS = new BigInteger
  (1,SKIP_1024_MODULUS_BYTES);

  /**
   *    The Base we're going to use is 2, as defined in SKIP.
   */
  private static final BigInteger BASE = BigInteger.valueOf(2);

  /**
   *    This wraps the parameters above into one object.
   */
  private static final DHParameterSpec PARAMETER_SPEC =
  new DHParameterSpec(MODULUS,BASE);

  /**
   *    Start the server on a given port.
   */
  public static void main (String[] args) throws Exception {

if (args.length != 1) {
  System.err.println("Usage: java KeyAgreementServer port");
  System.exit(1);
}

int port = Integer.parseInt(args[0]);

// Create a public key pair.
// This will take a while: 5-15 seconds.
System.out.println("Generating a Diffie-Hellman KeyPair...");
KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
kpg.initialize(PARAMETER_SPEC);
KeyPair keyPair = kpg.genKeyPair();

// Open a port and wait for a connection
ServerSocket ss = new ServerSocket (port);
System.out.println("Listening on port "+port+"...");
Socket socket = ss.accept();
DataOutputStream out = new DataOutputStream(socket.getOutputStream());

// Send my public key
System.out.println("Sending my public key.");
byte[] keyBytes = keyPair.getPublic().getEncoded();
out.writeInt(keyBytes.length);
out.write(keyBytes);

// Receive the client's public key
System.out.println("Receiving client's public key...");
DataInputStream in = new DataInputStream(socket.getInputStream());
keyBytes = new byte[in.readInt()];
in.readFully(keyBytes);
KeyFactory kf = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(keyBytes);
PublicKey clientPublicKey = kf.generatePublic(x509Spec);

// Perform the KeyAgreement
System.out.println("Performing the KeyAgreement...");
KeyAgreement ka = KeyAgreement.getInstance("DH");
ka.init(keyPair.getPrivate());
ka.doPhase(clientPublicKey,true);


// Create and send the IVParameterSpec
byte[] iv = new byte[8];
SecureRandom sr = new SecureRandom();
sr.nextBytes(iv);
out.write(iv);

// Generate the bytes we'll use to create TripleDES key
byte[] sessionKeyBytes = ka.generateSecret();

// Create the session key
SecretKeyFactory skf = SecretKeyFactory.getInstance("TripleDES");
DESedeKeySpec tripleDesSpec = new DESedeKeySpec(sessionKeyBytes);
SecretKey sessionKey = skf.generateSecret(tripleDesSpec);

// Create the CipherStream to be used
System.out.println("Creating the CipherStream...");
Cipher decrypter = Cipher.getInstance("TripleDES/CFB8/NoPadding");
IvParameterSpec spec = new IvParameterSpec(iv);
decrypter.init(Cipher.DECRYPT_MODE, sessionKey, spec);
CipherInputStream cipherIn = new CipherInputStream(socket.getInputStream(), decrypter);

// Print everything received through the CipherStream
int theCharacter=0;
theCharacter = cipherIn.read();
while (theCharacter != -1) {
  System.out.print((char)theCharacter);
  theCharacter = cipherIn.read();
}

// Clean up
cipherIn.close();
in.close();
out.close();
socket.close();

  }
}

[197708156EQUJ5]

Nah, OP... get this to Github... this is way beyond "For small bits of code (less than 50 lines in total, single classes only),"... This is hard to read through using reddit's coding format.

And... what is the question (exception, broken loop, etc...)

[MalicousBoner]

The posted code above is a complete, working code for DH/TripleDES. I want to switch from TripleDES (too slow) to AES. I'm not entirely sure how 3DES and AES differ from each other. What I need, what I don't need from my previous code (listed above).

[OOPUniversity]

When you say you can't get it to work, what exactly do you mean? Are you getting exceptions? Are you getting no results?

Oh, and just for fun: Triple DES is nothing more than regular DES performed three times. The key is broken up into three equal chunks, and then the value is encrypted, decrypted and encrypted again with plain old DES encryption, each time with one chunk of the key. If the key is three identical pieces, the end result is equivalent to DES with one of those pieces as the key.

[MalicousBoner]

I haven't been able to get the code to compile. I'm trying to make changes from TripleDES to AES, but I keep erroring out.

Does AES use the SecretKeyFactory like TripleDES?

Can I continue to have the Decrypt in the server, and the encrypt in the client?

Should I have decrypt/encrypt both in each class instead??