栈溢出

 1 #include <stdio.h>
 2 #define PASSWORD "1234567"
 3 int verify_password (char *password)
 4 {
 5     int authenticated;
 6     char buffer[8];
 7     authenticated=strcmp(password,PASSWORD);
 8     strcpy(buffer,password);//over flowed here!    
 9     return authenticated;
10 }
11 void main(void)
12 {
13     int valid_flag=0;
14     char password[1024];
15     FILE * fp;
16     if(!(fp=fopen("password.txt","rw+")))
17     {
18         exit(0);
19     }
20     fscanf(fp,"%s",password);
21     valid_flag = verify_password(password);
22     if(valid_flag)
23     {
24         printf("incorrect password!\n");
25     }
26     else
27     {
28         printf("You have passed the verification!\n");
29     }
30     fclose(fp);
31 }