JRAT - layer 2 decryptor

kyl.java

package w;

import java.security.GeneralSecurityException;
import java.security.Key;
import java.security.interfaces.RSAPrivateKey;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class kyl {
    private byte[] encryptedAesKey;
    private byte[] encryptedBuffer;
    private static int mode = javax.crypto.Cipher.DECRYPT_MODE;

    public kyl() {
    }
    
    public void setEncryptedBuffer(byte[] value) {
    	this.encryptedBuffer = value;
    }
    
    public void setEncryptedAesKey(byte[] value) {
    	this.encryptedAesKey = value;
    }
    
    public byte[] decryptContent(Object object2) throws GeneralSecurityException {

        Cipher object = Cipher.getInstance("RSA");
        object.init(2, (RSAPrivateKey)object2);
        
        Cipher cipher2 = Cipher.getInstance("AES");
        byte []aesDecrypted = object.doFinal(this.encryptedAesKey);
        
        SecretKeySpec sKey = new SecretKeySpec(aesDecrypted, "AES");
        Cipher arrby = cipher2;
        arrby.init(mode, (Key)sKey);

        return arrby.doFinal(this.encryptedBuffer);
    }
}

main.java

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.security.GeneralSecurityException;
import java.security.interfaces.RSAPrivateKey;

import w.kyl;

public class main {
	
    public static byte[] readFromStream(InputStream param1) throws IOException {
        int n;
        ByteArrayOutputStream kyqa2 = new ByteArrayOutputStream();
        byte[] arrby = new byte[2048];
        InputStream inputStream = param1;
        while ((n = inputStream.read(arrby)) > -1) {
            inputStream = param1;
            kyqa2.write(arrby, 0, n);
        }
        ByteArrayOutputStream kyqa3 = kyqa2;
        kyqa3.close();
        return kyqa3.toByteArray();
    }
    
    public static byte [] decrypt(String encData, String aesKey, String rsaKey, String outFile) throws IOException, ClassNotFoundException, GeneralSecurityException
    {
        byte []dataPath = readFromStream(new FileInputStream(encData));
        byte []pPassCrypted = readFromStream(new FileInputStream(aesKey));
		

        ObjectInputStream objPrivatePass = new ObjectInputStream(new FileInputStream(rsaKey));
        RSAPrivateKey rKey = (RSAPrivateKey) objPrivatePass.readObject();
		
        kyl kyl2 = new kyl();
        kyl2.setEncryptedAesKey((byte[])pPassCrypted);
        kyl2.setEncryptedBuffer((byte[])dataPath);
        
        byte []decrypted = kyl2.decryptContent(rKey);
        
        FileOutputStream fos = new FileOutputStream(outFile);
        fos.write(decrypted);
        fos.close();
        return decrypted;
    }
    
    public static void main(String []args) throws IOException, ClassNotFoundException, GeneralSecurityException
    {
        if (args.length < 4){
            System.out.println("Args: <encData> <aesKey> <rsaKey> <outFile>");
            return;
        }
        decrypt(args[0], args[1], args[2], args[3]);
    }
}