package org.owasp.webgoat.lessons;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import org.apache.ecs.Element;
import org.apache.ecs.ElementContainer;
import org.apache.ecs.StringElement;
import org.apache.ecs.html.Input;
import org.apache.ecs.html.P;
import org.owasp.webgoat.session.DatabaseUtilities;
import org.owasp.webgoat.session.ECSFactory;
import org.owasp.webgoat.session.WebSession;


/***************************************************************************************************
 * 
 * 
 * This file is part of WebGoat, an Open Web Application Security Project utility. For details,
 * please see http://www.owasp.org/
 * 
 * Copyright (c) 2002 - 2007 Bruce Mayhew
 * 
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along with this program; if
 * not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 * 
 * Getting Source ==============
 * 
 * Source for this application is maintained at code.google.com, a repository for free software
 * projects.
 * 
 * For details, please see http://code.google.com/p/webgoat/
 * 
 * @author Chuck Willis <a href="http://www.securityfoundry.com">Chuck's web site</a> (this lesson
 *         is heavily based on Bruce Mayhews' SQL Injection lesson
 * @created January 14, 2005
 */
public class BlindSqlInjection extends LessonAdapter
{

	private final static String ACCT_NUM = "account_number";

	private final static int TARGET_ACCT_NUM = 15613;

	/**
	 * Description of the Method
	 * 
	 * @param s
	 *            Description of the Parameter
	 * @return Description of the Return Value
	 */
	protected Element createContent(WebSession s)
	{
		ElementContainer ec = new ElementContainer();

		try
		{
			Connection connection = DatabaseUtilities.getConnection(s);

			ec.addElement(new P().addElement("Enter your Account Number: "));

			String accountNumber = s.getParser().getRawParameter(ACCT_NUM, "101");
			Input input = new Input(Input.TEXT, ACCT_NUM, accountNumber.toString());
			ec.addElement(input);

			Element b = ECSFactory.makeButton("Go!");
			ec.addElement(b);

			String query = "SELECT * FROM user_data WHERE userid = " + accountNumber;
			String answer_query;
			if (runningOnWindows())
			{
				answer_query = "SELECT TOP 1 first_name FROM user_data WHERE userid = " + TARGET_ACCT_NUM;
			}
			else
			{
				answer_query = "SELECT first_name FROM user_data WHERE userid = " + TARGET_ACCT_NUM;
			}

			try
			{
				Statement answer_statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
																		ResultSet.CONCUR_READ_ONLY);
				ResultSet answer_results = answer_statement.executeQuery(answer_query);
				answer_results.first();
				System.out.println("Account: " + accountNumber);
				System.out.println("Answer : " + answer_results.getString(1));
				if (accountNumber.toString().equals(answer_results.getString(1)))
				{
					makeSuccess(s);
				}
				else
				{

					Statement statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
																		ResultSet.CONCUR_READ_ONLY);
					ResultSet results = statement.executeQuery(query);

					if ((results != null) && (results.first() == true))
					{
						ec.addElement(new P().addElement("Account number is valid"));
					}
					else
					{
						ec.addElement(new P().addElement("Invalid account number"));
					}
				}
			} catch (SQLException sqle)
			{
				ec.addElement(new P().addElement("An error occurred, please try again."));
			}
		} catch (Exception e)
		{
			s.setMessage("Error generating " + this.getClass().getName());
			e.printStackTrace();
		}

		return (ec);
	}

	/**
	 * Gets the category attribute of the SqlInjection object
	 * 
	 * @return The category value
	 */
	protected Category getDefaultCategory()
	{
		return Category.INJECTION;
	}

	/**
	 * Gets the credits attribute of the AbstractLesson object
	 * 
	 * @return The credits value
	 */
	public Element getCredits()
	{
		return new StringElement("By Chuck Willis");
	}

	/**
	 * 
	 * Determines the OS that WebGoat is running on. Needed because different DB backends are used
	 * on the different OSes (Access on Windows, InstantDB on others)
	 * 
	 * @return true if running on Windows, false otherwise
	 */
	private boolean runningOnWindows()
	{
		String os = System.getProperty("os.name", "Windows");
		if (os.toLowerCase().indexOf("window") != -1)
		{
			return true;
		}
		else
		{
			return false;
		}
	}

	/**
	 * Gets the hints attribute of the DatabaseFieldScreen object
	 * 
	 * @return The hints value
	 */
	protected List<String> getHints(WebSession s)
	{
		List<String> hints = new ArrayList<String>();
		if (runningOnWindows())
		{
			hints
					.add("Compound SQL statements can be made by joining multiple tests with keywords like AND and OR. "
							+ "Create a SQL statement that you can use as a true/false test and then "
							+ "select the first character of the target element and do a start narrowing "
							+ "down the character using > and <"
							+ "<br><br>The backend database is Microsoft Access.  Keep that in mind if you research SQL functions "
							+ "on the Internet since different databases use some different functions and syntax.");
			hints.add("This is the code for the query being built and issued by WebGoat:<br><br> "
					+ "\"SELECT * FROM user_data WHERE userid = \" + accountNumber ");
			hints.add("The application is taking your input and inserting it at the end of a pre-formed SQL command. "
					+ "You will need to make use of the following SQL functions: "
					+ "<br><br>SELECT - query for your target data and get a string "
					+ "<br><br>mid(string, start, length) - returns a "
					+ "substring of string starting at the start character and going for length characters "
					+ "<br><br>asc(string) will return the ascii value of the first character in string "
					+ "<br><br>&gt and &lt - once you have a character's value, compare it to a choosen one");
			hints.add("Example: is the first character of the first_name of userid " + TARGET_ACCT_NUM
					+ " less than 'M' (ascii 77)? "
					+ "<br><br>101 AND (asc( mid((SELECT first_name FROM user_data WHERE userid=" + TARGET_ACCT_NUM
					+ ") , 1 , 1) ) < 77 ); "
					+ "<br><br>If you get back that account number is valid, then yes.  If get back that the number is"
					+ "invalid then answer is no.");
			hints
					.add("Another example: is the second character of the first_name of userid "
							+ TARGET_ACCT_NUM
							+ " greater than 'm' (ascii 109)? "
							+ "<br><br>101 AND (asc( mid((SELECT first_name FROM user_data WHERE userid="
							+ TARGET_ACCT_NUM
							+ ") , 2 , 1) ) > 109 ); "
							+ "<br><br>If you get back that account number is valid, then yes.  If get back that the number is "
							+ "invalid then answer is no.");
		}
		else
		{
			hints.add("Compound SQL statements can be made by joining multiple tests with keywords like AND and OR. "
					+ "Create a SQL statement that you can use as a true/false test and then "
					+ "select the first character of the target element and do a start narrowing "
					+ "down the character using > and <");

			hints
					.add("The database backend is InstantDB.  Here is a reference guide : <a href=\"http://www.instantdb.com/doc/syntax.html\" target=\"_blank\">http://www.instantdb.com/doc/syntax.html</a>");
			hints.add("This is the code for the query being built and issued by WebGoat:<br><br> "
					+ "\"SELECT * FROM user_data WHERE userid = \" + accountNumber ");
			hints
					.add("THIS HINT IS FOR THE MS ACCESS DB.  IT NEEDS TO BE ALTERED FOR THE INSTANTDB BACKEND. <br><br>The application is taking your input and inserting it at the end of a pre-formed SQL command. "
							+ "You will need to make use of the following SQL functions: "
							+ "<br><br>SELECT - query for your target data and get a string "
							+ "<br><br>mid(string, start, length) - returns a "
							+ "substring of string starting at the start character and going for length characters "
							+ "<br><br>asc(string) will return the ascii value of the first character in string "
							+ "<br><br>&gt and &lt - once you have a character's value, compare it to a choosen one");
			hints
					.add("THIS HINT IS FOR THE MS ACCESS DB.  IT NEEDS TO BE ALTERED FOR THE INSTANTDB BACKEND. <br><br>Example: is the first character of the first_name of userid "
							+ TARGET_ACCT_NUM
							+ " less than 'M' (ascii 77)? "
							+ "<br><br>101 AND (asc( mid((SELECT first_name FROM user_data WHERE userid="
							+ TARGET_ACCT_NUM
							+ ") , 1 , 1) ) < 77 ); "
							+ "<br><br>If you get back that account number is valid, then yes.  If get back that the number is"
							+ "invalid then answer is no.");
			hints
					.add("THIS HINT IS FOR THE MS ACCESS DB.  IT NEEDS TO BE ALTERED FOR THE INSTANTDB BACKEND. <br><br> example: is the second character of the first_name of userid "
							+ TARGET_ACCT_NUM
							+ " greater than 'm' (ascii 109)? "
							+ "<br><br>101 AND (asc( mid((SELECT first_name FROM user_data WHERE userid="
							+ TARGET_ACCT_NUM
							+ ") , 2 , 1) ) > 109 ); "
							+ "<br><br>If you get back that account number is valid, then yes.  If get back that the number is "
							+ "invalid then answer is no.");
		}
		return hints;
	}

	/**
	 * Gets the instructions attribute of the SqlInjection object
	 * 
	 * @return The instructions value
	 */
	public String getInstructions(WebSession s)
	{
		String instructions = "The form below allows a user to enter an account number and determine if "
				+ "it is valid or not.  Use this form to develop a true / false test check other entries in the database.  "
				+ "<br><br>Reference Ascii Values: 'A' = 65   'Z' = 90   'a' = 97   'z' = 122 "
				+ "<br><br>The goal is to find the value of " + "the first_name in table user_data for userid "
				+ TARGET_ACCT_NUM
				+ ".  Put the discovered name in the form to pass the lesson.  Only the discovered name "
				+ "should be put into the form field, paying close attention to the spelling and capitalization.";

		return (instructions);
	}

	private final static Integer DEFAULT_RANKING = new Integer(70);

	protected Integer getDefaultRanking()
	{
		return DEFAULT_RANKING;
	}

	/**
	 * Gets the title attribute of the DatabaseFieldScreen object
	 * 
	 * @return The title value
	 */
	public String getTitle()
	{
		return ("Blind SQL Injection");
	}

	/**
	 * Constructor for the DatabaseFieldScreen object
	 * 
	 * @param s
	 *            Description of the Parameter
	 */
	public void handleRequest(WebSession s)
	{
		try
		{
			super.handleRequest(s);
		} catch (Exception e)
		{
			System.out.println("Exception caught: " + e);
			e.printStackTrace(System.out);
		}
	}
}