I'm trying to read a part from the memory of a Notepad instance, but I'm always getting system error 299 when calling kernel32's ReadProcessMemory()
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This is the code I have so far:
package memreadtest;
import com.sun.jna.Memory;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinNT.HANDLE;
import com.sun.jna.ptr.IntByReference;
import com.sun.jna.win32.W32APIOptions;
public class MemReader {
private final static Kernel32 kernel32 = Native.load("kernel32", Kernel32.class, W32APIOptions.DEFAULT_OPTIONS);
private final static User32 user32 = Native.load("user32", User32.class, W32APIOptions.DEFAULT_OPTIONS);
private final static int PROCESS_VM_READ = 0x0010;
public static void main(String[] args) {
int bytesToRead = 1024;
Memory notepadDump = readProcessMemory("*Untitled - Notepad", bytesToRead);
Memory.disposeAll();
}
private static Memory readProcessMemory(String winTitle, int bytesToRead) {
Memory output = new Memory(bytesToRead);
IntByReference pid = new IntByReference(0);
user32.GetWindowThreadProcessId(user32.FindWindow(null, winTitle), pid);
HANDLE handle = kernel32.OpenProcess(PROCESS_VM_READ, true, pid.getValue());
if (!kernel32.ReadProcessMemory(handle, handle.getPointer(), output, bytesToRead, null)) {
System.err.println("Failed to read memory of process " + pid.getValue() + ". System Error Code: " + kernel32.GetLastError());
return null;
}
return output;
}
}
What am I doing wrong?
You are reading an address that there is no reason to expect is valid in the external process. A process handle is not expected to be a valid address in the process.
I'm not sure what you are trying to read from this process, but l whatever it is you will need to somehow find an appropriate address.
You clarify in comments that you want to read from the module base address. For instance see: Get base address of process