A super quick and super dirty shellcode emulator

Using JPC, it gives something like this:


import java.io.IOException;
import org.jpc.emulator.PC;
import org.jpc.emulator.processor.Processor;
import org.jpc.j2se.VirtualClock;

public class EmulateShellcode {
    public static void main(String[] args) throws IOException {
	VirtualClock clock = new VirtualClock();
	PC pc = new PC(clock, args);
	Processor cpu = pc.getProcessor();
	cpu.cs.setSelector(0);
	cpu.eip = 0;

	if(args.length == 0) {
	    System.out.println("Usage: java EmulateShellcode ");
	    System.out.println("*** examples:");
	    System.out.println("* add al, 0x42:\n\tjava EmulateShellcode 04 42");
	    System.out.println("* nop:\n\tjava EmulateShellcode 0x90");
	    System.out.println("* inc edx:\n\tjava EmulateShellcode 42h");
	    System.exit(1);
	}

	System.out.println("Loading shellcode in memory...");
	for(int i=0; i<args.length; i++) {
	    String str = args[i];
	    if(args[i].startsWith("0x"))
		str = args[i].substring(2);
	    else if(args[i].startsWith("\\x"))
		str = args[i].substring(2);
	    else if(args[i].endsWith("h"))
		str = args[i].substring(0, args[i].length()-1);

            <strong>// the byte at address i is the argument at position i cpu.linearMemory.setByte(i, (byte)Integer.parseInt(str, 16));</strong>
	}

	System.out.println("Before execution:");
	cpu.printState();
        <strong>// execute starting at address 0 cpu.linearMemory.executeProtected(cpu, 0);</strong>
	System.out.println("\nAfter execution:");
	cpu.printState();
    }
}

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