The Web Application Hacker’s Handbook Discovering and Exploiting Security Flaws

478

Chapter 13 

■

Automating Bespoke Attacks

70779c13.qxd:WileyRed  9/14/07  3:14 PM  Page 478

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The 

nextPayload

method can be used to advance the state of the source, and

returns 

true

until all of its payloads are used up. The 

reset

method returns

the state to its initial point. The 

getPayload

method returns the value of the

current payload.

In the document enumeration example, the parameter we want to vary con-

tains a numeric value, and so our first implementation of the 

PayloadSource

interface is a class to generate numeric payloads. This class allows us to spec-

ify the range of numbers which we want to test:

class PSNumbers implements PayloadSource

{

int from, to, step, current;

PSNumbers(int from, int to, int step)

{

this.from = from;

this.to = to;

this.step = step;

reset();

}

public boolean nextPayload()

{

current += step;

return current <= to;

}

public void reset()

{

current = from - step;

}

public String getPayload()

{

return Integer.toString(current);

}

}

Equipped with the concept of a request parameter and a payload source, we

have sufficient resources to generate actual requests and process the server’s

responses. First, let’s specify some configuration for our first attack:

class JAttack

{

// attack config

String host = “wahh-app.com”;

int port = 80;

String method = “GET”;

String url = “/ShowDoc.jsp”;