package src;

import java.io.*;

import javax.crypto.spec.*;
import javax.crypto.*;

public class AESDecryption {

	public static void main(String[] args) {
		try {

			String afterEncrypt = "cipher.txt";
			String afterDecrypt = "final.txt";
			byte[] cipherkey = KeyCipher.loadKey(afterEncrypt);
			byte[] b = new byte[64];
			System.arraycopy(cipherkey, 0, b, 0, 64);
			byte[] aesKey = RSADecryption.decrypt(GetRSAKey.GetPrivateKey(), b);

			SecretKey aks = new SecretKeySpec(aesKey, "AES");

			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.DECRYPT_MODE, aks);
			BufferedOutputStream out = new BufferedOutputStream(
					new FileOutputStream(afterDecrypt));
			CipherInputStream in = new CipherInputStream(
					new BufferedInputStream(new FileInputStream(afterEncrypt)),
					cipher);

			int i;
			do {
				i = in.read();
				if (i != -1)
					out.write(i);
			} while (i != -1);

			in.close();
			out.close();
			byte[] fss = KeyCipher.readFile(afterDecrypt);
			int length = fss.length;
			byte[] cut = new byte[length-64];
			System.arraycopy(fss, 64, cut, 0, length-64);
			String s = new String(cut);
			FileWriter fw = null;
			fw = new FileWriter(afterDecrypt); 
			fw.write(s); 
			fw.close();
			
			System.out.println("Decryption is successful!");
		} catch (Exception e) {
			e.printStackTrace();
		}

	}
}