/* TEMPLATE GENERATED TESTCASE FILE
Filename: CWE129_Improper_Validation_of_Array_Index__getQueryString_Servlet_array_read_check_min_42.java
Label Definition File: CWE129_Improper_Validation_of_Array_Index.label.xml
Template File: sources-sinks-42.tmpl.java
*/
/*
 * @description
 * CWE: 129 Improper Validation of Array Index
 * BadSource: getQueryString_Servlet Parse id param out of the URL query string (without using getParameter())
 * GoodSource: A hardcoded non-zero, non-min, non-max, even number
 * Sinks: array_read_check_min
 *    GoodSink: Read from array after verifying that data is at least 0 and less than array.length
 *    BadSink : Read from array after verifying that data is at least 0 (but not verifying that data less than array.length)
 * Flow Variant: 42 Data flow: data returned from one method to another in the same class
 *
 * */




import javax.servlet.http.*;


import java.util.StringTokenizer;
import java.util.logging.Level;

public class CWE129_Improper_Validation_of_Array_Index__getQueryString_Servlet_array_read_check_min_42 extends AbstractTestCaseServlet
{
    private int badSource(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data;

        data = Integer.MIN_VALUE; /* initialize data in case id is not in query string */

        /* POTENTIAL FLAW: Parse id param out of the URL querystring (without using getParam) */
        {
            StringTokenizer tokenizer = new StringTokenizer(request.getQueryString(), "&");

            while (tokenizer.hasMoreTokens())
            {
                String token = tokenizer.nextToken(); /* a token will be like "id=33" */
                if(token.startsWith("id=")) /* check if we have the "id" parameter" */
                {
                    try
                    {
                        data = Integer.parseInt(token.substring(3)); /* set data to the int 33 */
                    }
                    catch(NumberFormatException exceptNumberFormat)
                    {
                        IO.logger.log(Level.WARNING, "Number format exception reading id from query string", exceptNumberFormat);
                    }
                    break; /* exit while loop */
                }
            }
        }

        return data;
    }

    public void bad(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data = badSource(request, response);

        /* Need to ensure that the array is of size > 3  and < 101 due to the GoodSource and the large_fixed BadSource */
        int array[] = { 0, 1, 2, 3, 4 };

        /* POTENTIAL FLAW: Verify that data >= 0, but don't verify that data < array.length, so may be attempting to read out of the array bounds */
        if (data >= 0)
        {
            IO.writeLine(array[data]);
        }
        else
        {
            IO.writeLine("Array index out of bounds");
        }

    }

    /* goodG2B() - use goodsource and badsink */
    private int goodG2BSource(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data;

        /* FIX: Use a hardcoded number that won't cause underflow, overflow, divide by zero, or loss-of-precision issues */
        data = 2;

        return data;
    }

    private void goodG2B(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data = goodG2BSource(request, response);

        /* Need to ensure that the array is of size > 3  and < 101 due to the GoodSource and the large_fixed BadSource */
        int array[] = { 0, 1, 2, 3, 4 };

        /* POTENTIAL FLAW: Verify that data >= 0, but don't verify that data < array.length, so may be attempting to read out of the array bounds */
        if (data >= 0)
        {
            IO.writeLine(array[data]);
        }
        else
        {
            IO.writeLine("Array index out of bounds");
        }

    }

    /* goodB2G() - use badsource and goodsink */
    private int goodB2GSource(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data;

        data = Integer.MIN_VALUE; /* initialize data in case id is not in query string */

        /* POTENTIAL FLAW: Parse id param out of the URL querystring (without using getParam) */
        {
            StringTokenizer tokenizer = new StringTokenizer(request.getQueryString(), "&");

            while (tokenizer.hasMoreTokens())
            {
                String token = tokenizer.nextToken(); /* a token will be like "id=33" */
                if(token.startsWith("id=")) /* check if we have the "id" parameter" */
                {
                    try
                    {
                        data = Integer.parseInt(token.substring(3)); /* set data to the int 33 */
                    }
                    catch(NumberFormatException exceptNumberFormat)
                    {
                        IO.logger.log(Level.WARNING, "Number format exception reading id from query string", exceptNumberFormat);
                    }
                    break; /* exit while loop */
                }
            }
        }

        return data;
    }

    private void goodB2G(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        int data = goodB2GSource(request, response);

        /* Need to ensure that the array is of size > 3  and < 101 due to the GoodSource and the large_fixed BadSource */
        int array[] = { 0, 1, 2, 3, 4 };

        /* FIX: Fully verify data before reading from array at location data */
        if (data >= 0 && data < array.length)
        {
            IO.writeLine(array[data]);
        }
        else
        {
            IO.writeLine("Array index out of bounds");
        }

    }

    public void good(HttpServletRequest request, HttpServletResponse response) throws Throwable
    {
        goodG2B(request, response);
        goodB2G(request, response);
    }

    /* Below is the main(). It is only used when building this testcase on
     * its own for testing or for building a binary to use in testing binary
     * analysis tools. It is not used when compiling all the testcases as one
     * application, which is how source code analysis tools are tested.
     */
    public static void main(String[] args) throws ClassNotFoundException,
           InstantiationException, IllegalAccessException
    {
        mainFromParent(args);
    }
}
