AES_Killer_v4.0.java

package burp;

import java.io.PrintWriter;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * @author bugzy
 */
public class BurpExtender implements IBurpExtender, IProxyListener, IHttpListener{

    public String ExtensionName =  "AES_Killer v4.0";
    
    public IBurpExtenderCallbacks callbacks;
    public IExtensionHelpers helpers;
    public PrintWriter stdout;
    public PrintWriter stderr;
    public Boolean isDebug = false;
    
    public String _key01 = "<Base64 encoded key>";      // key used to encrypt complete request & response body
    public String _key02 = "<Base64 encoded key>";      // key used to encrypt specific parameters within the request
    
    public Cipher cipher;
    public SecretKey sec_key;
    
    public String[] Hosts = { "https://<HOST URL>:443/", "https://<HOST2 URL>:443/"};

    // encrypted parameters
    public String[] params = { "username", "password", "account", "amount" };

    
    @Override
    public void registerExtenderCallbacks(IBurpExtenderCallbacks callbacks) {
        this.callbacks = callbacks;
        this.helpers = callbacks.getHelpers();
        this.stdout = new PrintWriter(callbacks.getStdout(), true);
        this.callbacks.setExtensionName(this.ExtensionName);
        
        
       
        
        this.callbacks.registerHttpListener(this);
        this.callbacks.registerProxyListener(this);
        this.stdout.println("AES_Killer - v4.0 Installed !!!");
    }

    private void print_output(String _src, String str){
        if(! isDebug){ return; }
        this.stdout.println(_src + " :: " + str);
    }
    
    private void print_error(String _src, String str){
        if(! isDebug){ return; }
        this.stdout.println(_src + " :: " + str);
    }
    
       
    private String do_Decrypt(String _key, String paramString){
        try{
            String temp_params = paramString;
            cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            sec_key = new SecretKeySpec(this.helpers.base64Decode(_key), "AES");
            cipher.init(2, sec_key);
            temp_params = new String (cipher.doFinal(this.helpers.base64Decode(temp_params)));
            return temp_params;
        }catch(Exception ex){
            print_error("do_Decrypt", ex.getMessage());
            return paramString;
        }
    }
        
    private String do_Encrypt(String _key, String paramString){
        try{
            String temp_params = paramString;
            cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            sec_key = new SecretKeySpec(this.helpers.base64Decode(_key), "AES");
            cipher.init(1, sec_key);
            temp_params = new String (this.helpers.base64Encode(cipher.doFinal(temp_params.getBytes())));
            return temp_params;
        }catch(Exception ex){
            print_error("do_Encryp", ex.getMessage());
            return paramString;
        }
    }
    
    
    private String decrypt_parameters(String _reqBody){
        String _str = _reqBody;
        for(int i=0; i< this.params.length; i++){
            int _fi = _str.indexOf(params[i]);
            if(_fi == -1){ continue; }
            
            _fi = _fi + params[i].length() + 2;
            int _si = _str.indexOf("</end-del>", _fi);
            
            String _enc_param = _str.substring(_fi, _si);
            if(_enc_param.contains("null")){ continue; } // null value check
            
            String _dec_param = do_Decrypt(_key02, _enc_param);
            _str = _str.substring(0, _fi) + _dec_param + _str.substring(_si, _str.length());
        }
        return _str;
    }
    
    
    
    private String encrypt_parameters(String _reqBody){
        String _str = _reqBody;
        for(int i=0; i< this.params.length; i++){
            int _fi = _str.indexOf(params[i]);
            if(_fi == -1){ continue; }
            
            _fi = _fi + params[i].length() + 2;
            int _si = _str.indexOf("</<end-del>>", _fi);
            
            String _enc_param = _str.substring(_fi, _si);
            if(_enc_param.contains("null")){ continue; } // null value check
            
            String _dec_param = do_Encrypt(_key02, _enc_param);
            _str = _str.substring(0, _fi) + _dec_param + _str.substring(_si, _str.length());
        }
        return _str;
    }
    
    
    
    @Override
    public void processProxyMessage(boolean messageIsRequest, IInterceptedProxyMessage message) {
        if(messageIsRequest){
            IHttpRequestResponse messageInfo = message.getMessageInfo();
            IRequestInfo reqInfo = helpers.analyzeRequest(messageInfo);
            String URL = new String(reqInfo.getUrl().toString());
            List headers = reqInfo.getHeaders();


            if((URL.contains(this.Hosts[0]) || URL.contains(this.Hosts[1])) && reqInfo.getMethod().toLowerCase().contains("post")){                
                String tmpreq = new String(messageInfo.getRequest());
                String messageBody = new String(tmpreq.substring(reqInfo.getBodyOffset())).trim();
                String decValue = do_Decrypt(_key01, messageBody);
                decValue = decrypt_parameters(decValue);
                headers.add(new String("AES-Killer: v4.0"));
                byte[] updateMessage = helpers.buildHttpMessage(headers, decValue.getBytes());
                messageInfo.setRequest(updateMessage);
                print_output("PPM", "Decrypted request\n" + new String(updateMessage));
            }
            
        }else {
            IHttpRequestResponse messageInfo = message.getMessageInfo();
            IRequestInfo reqInfo = helpers.analyzeRequest(messageInfo);
            IResponseInfo resInfo = helpers.analyzeResponse(messageInfo.getResponse());
            String URL = new String(reqInfo.getUrl().toString());
            List headers = resInfo.getHeaders();
            
//            if(!headers.contains("AES-Killer: DecryptedResponse")){
//                return;
//            }
            
            if((URL.contains(this.Hosts[0]) || URL.contains(this.Hosts[1])) && reqInfo.getMethod().toLowerCase().contains("post")){
                String tmpreq = new String(messageInfo.getResponse());
                String messageBody = new String(tmpreq.substring(resInfo.getBodyOffset())).trim();
                messageBody = do_Encrypt(_key01, messageBody);
                byte[] updateMessage = helpers.buildHttpMessage(headers, messageBody.getBytes());
                messageInfo.setResponse(updateMessage);
                print_output("PPM","Final Encrypted Response\n" + new String(updateMessage));
            }
        }
    }


    @Override
    public void processHttpMessage(int toolFlag, boolean messageIsRequest, IHttpRequestResponse messageInfo) {
        if(messageIsRequest){
            IRequestInfo reqInfo = helpers.analyzeRequest(messageInfo);
            String URL = new String(reqInfo.getUrl().toString());
            List headers = reqInfo.getHeaders();
            
//            if(!headers.contains("AES-Killer: v4.0")){
//                return;
//            }
            
            if((URL.contains(this.Hosts[0]) || URL.contains(this.Hosts[1])) && reqInfo.getMethod().toLowerCase().contains("post")){
                String tmpreq = new String(messageInfo.getRequest());
                String messageBody = new String(tmpreq.substring(reqInfo.getBodyOffset())).trim();
                messageBody = encrypt_parameters(messageBody);
                messageBody = do_Encrypt(_key01, messageBody);
                byte[] updateMessage = helpers.buildHttpMessage(headers, messageBody.getBytes());
                messageInfo.setRequest(updateMessage);
                print_output("PHTM", "Final Encrypted Request\n" + new String(updateMessage));
            }
            
        }
        else{
            IRequestInfo reqInfo = helpers.analyzeRequest(messageInfo);
            IResponseInfo resInfo = helpers.analyzeResponse(messageInfo.getResponse());
            String URL = new String(reqInfo.getUrl().toString());
            List headers = resInfo.getHeaders();
            
            if((URL.contains(this.Hosts[0]) || URL.contains(this.Hosts[1])) && reqInfo.getMethod().toLowerCase().contains("post")){
                String tmpreq = new String(messageInfo.getResponse());
                String messageBody = new String(tmpreq.substring(resInfo.getBodyOffset())).trim();
                messageBody = do_Decrypt(_key01, messageBody);
                headers.add("AES-Killer: DecryptedResponse");
                byte[] updateMessage = helpers.buildHttpMessage(headers, messageBody.getBytes());
                messageInfo.setResponse(updateMessage);
                print_output("PHTM", "Decrypted Response\n" + new String(updateMessage));
            }
        }
    }
    
}