The problem is that I have to jump to the administrative fun

 The problem is that I have to jump to the administrative function using buffer overflow but it is disabled in the code. I have to figure out how to bypass #undef ADMINISTRATIVE and get inside the function somehow.    #include <stdio.h> #include <stdlib.h> #include <string.h>  // define to allow administrative access, undef to restrict #undef ADMINISTRATIVE  //#define ADMINISTRATIVE  // function prototypes for \"main.c\" functions  int main (int argc, char *argv[]); void list(void); void add(void); void quit(void); void delete(void); void deleteall(void); void normal(char *user); void administrative(char *nothing); void debug(char *nothing); void rot13(char *user, char *rot13pwd);  typedef void (*menufunctype)(char *); typedef void (*userfunctype)(void); typedef void (*adminfunctype)(void);  // jump table for non-administrative functions userfunctype userfunc[3] = {add, list, quit};  // jump table for administrative functions adminfunctype adminfunc[5] = {delete, deleteall, add, list, quit};   int main (int argc, char *argv[]) {    menufunctype menufunc[3]={debug, administrative, normal};   char rot13pwd[20];   char user[20];   char pwd[20];    printf(\"Enter authorization code: \"); fflush(stdout);   gets(pwd);   printf(\"Enter username or \\\"admin\\\" for admin functions: \"); fflush(stdout);   gets(user);    // authenticate user   rot13(user, rot13pwd);    if (strcmp(pwd, rot13pwd)) {     puts(\"Authentication FAILED.  Access denied.\ \");     exit(1);   }    // passed authentication, now display debug, normal or   // administrative menu.  If administrative access is prohibited by   // compile-time \"ADMINISTRATIVE\" symbol, then don\'t allow admin   // under any circumstances.    if (! strncmp(\"debug\", user, 5)) {     (*menufunc[0])(user);   }   else if (! strncmp(\"admin\", user, 5)) { #if defined(ADMINISTRATIVE)     (*menufunc[1])(0); #else     puts(\"NO ADMINSTRATIVE ACCESS AVAILABLE--SEE YOUR SYSTEMS ADMINISTRATOR.\"); #endif   }   else {     (*menufunc[2])(user);   } }  // menu for users with non-administrative access void normal(char *user) {   char buf[40];   char normalaccessfile[20]=\".normal_access\";   char choice[2];   int ch;    // audit trail   sprintf(buf, \"echo %s >> %s\", user, normalaccessfile);   system(buf);      while (1) {     puts(\"\ ##### MENU ######\ \");     puts(\"[0] Add a record\");     puts(\"[1] List all records\");     puts(\"[2] Exit\ \");     printf(\"Choice: \"); fflush(stdout);     gets(choice);      // audit trail     sprintf(buf, \"echo %c >> %s\", choice[0], normalaccessfile);     system(buf);      ch = atoi(choice);     if (ch < 0 || ch > 2) {       puts(\"Invalid choice.\ \");     }     else {       (*userfunc[ch])();     }   } }  // menu for administrators void administrative(char *nothing) {   char buf[80];   char administrativeaccessfile[80]=\".admin_access\";   char choice[2];   int ch;    while (1) {     puts(\"\ ----- RESTRICTED ADMIN MENU -----\ \");     puts(\"[0] Delete a record\");     puts(\"[1] Delete all records\");     puts(\"[2] Add a record\");     puts(\"[3] List all records\");     puts(\"[4] Exit\ \");      printf(\"Choice: \"); fflush(stdout);     gets(choice);      // audit trail     sprintf(buf, \"echo %c >> %s\", choice[0], administrativeaccessfile);     system(buf);      ch = atoi(choice);     if (ch < 0 || ch > 4) {       puts(\"Invalid choice.\ \");     }     else {       (*adminfunc[ch])();     }    } }   // menu for debug account void debug(char *nothing) {    // implement debug menu later...      // Marjorie: CHANGE THIS BEFORE RELEASE: MAJOR SECURITY HOLE!   system(nothing); }   // USER FUNCTIONS  // list all records void list() {   puts(\"*** LIST ***\"); }  // add a record void add() {   puts(\"*** ADD ***\"); }   // ADMINISTRATIVE FUNCTIONS  // delete a record void delete() {   puts(\"*** ADMIN: DELETE ***\"); }  // delete all record void deleteall() {   puts(\"*** ADMIN: DELETE ALL ***\"); }   // UNRESTRICTED  // quit void quit() {   puts(\"*** BYE ***\");   exit(1); }         // ROT13 calculation void  rot13(char *user, char *rot13pwd) {   int i;   char cap;    for (i=0; i < 20; i++) {     rot13pwd[i] = user[i];     cap = rot13pwd[i] & 32;     rot13pwd[i] &= ~cap;     rot13pwd[i] = ((rot13pwd[i] >= \'A\') && (rot13pwd[i] <= \'Z\') ?                     ((rot13pwd[i] - \'A\' + 13) % 26 + \'A\') : rot13pwd[i]) | cap;   }   rot13pwd[20]=0; }