Reverse Engineering for Beginners

CHAPTER 54. JAVA CHAPTER 54. JAVA

Perhaps, JVM has some other checks related to the stack maps.

OK, let’s patch it differently by removing the call tonag():

Figure 54.3:IDA

0 is the opcode forNOP.

Now that works!

54.17.2 Second example

Another simple crackme example:

public class password
{
public static void main(String[] args)
{
System.out.println("Please enter the password");
String input = System.console().readLine();
if (input.equals("secret"))
System.out.println("password is correct");
else
System.out.println("password is not correct");
}
}

Let’s load it in IDA: