C++ Account Creation Program Crashing - c++

Question

I am hitting a bit of a roadblock and don't know what to do. I am attempting to write a program that creates an account with username and password and stores it to a text file. However, while using the program and inputting the username and password data, the program crashes as it moves to the encryption function. Thank you for your time.
bool processNewAccount (string username, string password)
{
ofstream outFile;
string outFileName = "creds.txt";
outFile.open(outFileName.c_str(), fstream::app);
if (!outFile)
return false;
outFile << username << ":" << password << endl;
outFile.close();
return true;
}
void encrypt(string& s, int key)
{
for (int i = 0; i < s.length(); i++)
{
s[i] = (s[i] + key) % 127;
if (s[i] < 33)
{
s[i] = s[i] + 33;
}
}
}
string createAccount()
{
string firstName;
string lastName;
cout << "Creating an Account:" << endl;
cout << "First Name: ";
cin >> firstName;
cout << "Last Name: ";
cin >> lastName;
cout << endl;
string username;
if (lastName.length() <5)
{
for (int i = 0; username.length() <5; i++)
username = lastName + firstName.substr(0,i);
}
else
username = lastName.substr(0,4) + firstName.at(0);
for (int i = 0; i < 5; i++)
username.at(i) = tolower(username[i]);
}
string createPass ()
{
string password1;
string password2;
cout << "Create a Password that:" << endl << endl << "-Is at least 10 characters" << endl << "-Contains no spaces" << endl << endl << "Password: ";
cin >> password1;
if (password1.length() < 10)
{
cout << "Password is not secure enough" << endl;
cout << "Enter a password at least 10 characters: " << endl << endl;
createPass();
}
if (password1.length() >= 10)
cout << "Confirm Password: ";
cin >> password2;
if (password2 != password1)
{
cout << "Passwords do not match!" << endl << endl;
createPass();
}
}
int main()
{
string user;
string pass;
char menuOption;
do
{
printMenu();
cin >> menuOption;
switch (menuOption)
{
case '1': login();
break;
case '2':
user = createAccount();
pass = createPass();
encrypt(pass, 13);
processNewAccount (user, pass);
cout << "Welcome " << "Username: " << user << endl << "Email: " << user << "#student.edu" << endl;
break;
case '3': break;
default : cout << "\nInvalid entry. Please choose from the menu.|n";
break;
}
}
while (menuOption != 3);
cout << "\n Goodbye.\n\n";
return 0;
}

Answer 1

Here's a better version of createPass. It actually returns the password, and also uses a loop to avoid the recursive calls that you make.
string createPass ()
{
string password1;
bool password_ok = false;
do
{
cout << "Create a Password that:" << endl << endl << "-Is at least 10 characters" << endl << "-Contains no spaces" << endl << endl << "Password: ";
cin >> password1;
if (password1.length() < 10)
{
cout << "Password is not secure enough" << endl;
cout << "Enter a password at least 10 characters: " << endl << endl;
}
else
{
cout << "Confirm Password: ";
string password2;
cin >> password2;
if (password2 != password1)
{
cout << "Passwords do not match!" << endl << endl;
}
else
{
password_ok = true;
}
}
}
while (!password_ok);
return password1;
}
And as Lightness Races in Orbit points out you need to fix createAccount in a similar way.
Untested code of course.

Answer 2

Neither createAccount() nor createPass() returns a value, despite having a non-void return type. This means your program has undefined behaviour. Likely the stack is in "a bit of a way" after calling those functions, resulting in the crash you've observed. Your compiler should have warned you about this: heed your compiler's warnings, then you'll know what to do.
Ensure that you have a return statement so that you can pass your functions' results back to the caller. These statements might look like this:
std::string createAccount()
{
// ...
return username;
}
std::string createPass()
{
// ...
return password1;
}
In the case of createPass(), you'll also have to change your recursive calls:
if (password1.length() < 10) {
cout << "Password is not secure enough" << endl;
cout << "Enter a password at least 10 characters: " << endl << endl;
return createPass();
}
// ...
if (password2 != password1) {
cout << "Passwords do not match!" << endl << endl;
return createPass();
}
… but I agree with John that you'd be better off replacing this recursion with a nice loop.