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package buzzerproxy;

//import java.math.BigInteger;
import java.security.SecureRandom;
//import java.util.UUID;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.bouncycastle.util.encoders.Hex;
import org.bouncycastle.crypto.BufferedBlockCipher;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.engines.AESEngine;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.CryptoException;

/**
 *
 * @author Enger
 */
public class Crypto {

    private byte[] cipherText = null;
    public SecureRandom random = new SecureRandom();
    private int len = 256;
    private long sessionIDLenght = 32;

    public final long generateSessionID() {
     
        //   return UUID.randomUUID().toString()+new BigInteger(130, random).toString(len);
        //  return new BigInteger(130, random).longValue();
        SecureRandom randomr = new SecureRandom();
        return randomr.nextLong();

    } // public final String generateSessionID(){

    public final String performEncrypt(byte[] key, String plainText) {

        if (plainText == null || !(plainText instanceof String) || key == null || !(key instanceof byte[])) {
            Exception e = new Exception();
            Logger.getLogger(Crypto.class.getName()).log(Level.SEVERE, null, e);
            System.exit(1);
        } // if ( str == null || !(str instanceof String)){

        byte[] ptBytes = plainText.getBytes();

        BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new AESEngine()));
        String name = cipher.getUnderlyingCipher().getAlgorithmName();
        cipher.init(true, new KeyParameter(key));
        byte[] rv = new byte[cipher.getOutputSize(ptBytes.length)];
        int oLen = cipher.processBytes(ptBytes, 0, ptBytes.length, rv, 0);

        try {
            cipher.doFinal(rv, oLen);
        } catch (CryptoException ce) {
            System.out.println(ce.toString());
            Logger.getLogger(Crypto.class.getName()).log(Level.SEVERE, null, ce);
        }
        return new String(Hex.encode(rv));
        //return new String(rv).trim();
    } //  public final String performEncrypt(byte[] key, String plainText) {

    public final String performDecrypt(byte[] key, String st) {

        if (st == null || !(st instanceof String) || key == null || !(key instanceof byte[])) {
            Exception e = new Exception();
            Logger.getLogger(Crypto.class.getName()).log(Level.SEVERE, null, e);
            System.exit(1);
        } // if ( str == null || !(str instanceof String)){

        cipherText = Hex.decode(st);
        BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new AESEngine()));
        cipher.init(false, new KeyParameter(key));

        byte[] rv = new byte[cipher.getOutputSize(cipherText.length)];

        int oLen = cipher.processBytes(cipherText, 0, cipherText.length, rv, 0);
        try {
            cipher.doFinal(rv, oLen);
        } catch (CryptoException ce) {
            System.out.println(ce.toString());
            Logger.getLogger(Crypto.class.getName()).log(Level.SEVERE, null, ce);
        }
        return new String(rv).trim();
    } //  public final String performDecrypt(byte[] key, String st) {
} // public class Crypto {