b_overflow.c

/* Vunlerable program: stack.c */
/* You can get this program from the lab’s website */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

/* Changing this size will change the layout of the stack.
 * Instructors can change this value each year, so students
 * won’t be able to use the solutions from the past.
 * Suggested value: between 0 and 400 */
#ifndef BUF_SIZE
#define BUF_SIZE 24
#endif

int bof(char * str)
{
  char buffer[BUF_SIZE];

  /* The following statement has a buffer overflow problem */
  strcpy(buffer, str);➀

  return 1;
}
int main(int argc, char ** argv)
{
  char str[517];
  FILE * badfile;
  /* Change the size of the dummy array to randomize the parameters
  for this lab. Need to use the array at least once */
  char dummy[BUF_SIZE];
  memset(dummy, 0, BUF_SIZE);

  badfile = fopen("badfile", "r");
  fread(str, sizeof(char), 517, badfile);
  bof(str);
  printf("Returned Properly\n");
  return 1;
}