Password Masking

[Chathu]

I'm Taking User Name And Password From The User. Does Anyone Know How To Display Only Stars When User Enter The Password?

char pw[];
cout<<"Password: ";
cin>>pw; //Don't Want To Display The PW. Only Start Or Something Like That

Thank you

[bluecoder]

you have to get the length of the character in the pw array and then use the for loop to print the stars

[ZED0815]

you should have a look
here http://cplusplus.com/reference/clibrary/cstdio/getc/
and here http://cplusplus.com/reference/clibrary/cstring/strlen/

It's what I would do, I'm no expert though

ZED

[Chathu]

@bluecoder That Idea Was In My Head. It Didn't Work. I Tried.
@ZED0815 No Thats Not What I Want. Thanks Anyways
Oh I Got It

http://www.cplusplus.com/forum/general/3766/

But Is Their Any Other Ways To Do This ?

[Syuf]

MSVS2008:

#include <iostream>
#include <locale>
#include <conio.h>

using namespace std;


int main()
{
	const char symb = '*', space = ' ';
	const int chars_in_line = 80, max_pass_l = 32;
	// assert(max_pass_l + strlen("Input the password:   ") < chars_in_line)

	cout << "Input the password:   ";
	char ch, password[max_pass_l + 1] = {'\0'};
	for(int inp_ch = 0; ch = _getch(); )
	{
		// Enter
		if(ch == '\n' || ch == '\r')
			break;

		// Backspace
		else if(ch == '\b' && inp_ch > 0)
		{
			password[--inp_ch] = '\0';
			cout << '\r';
			for(int i = 0; i < chars_in_line - 1; i++)
				cout << space;
			cout << "\rInput the password:   ";
			for(int i = 0; i < inp_ch; i++)
				cout << symb;
		}

		// Next char
		else if(inp_ch < max_pass_l && isprint(ch, cout.getloc()))
		{
			password[inp_ch++] = ch;
			cout << symb;
		}
	}

	cout << endl << "Password:   \"" << password << "\"" << endl;

	return 0;
}

[Galik]

This is not possible using only standard C++. It is the terminal that is doing this which is external to your program. You would have to use a library such as ncurses: http://en.wikipedia.org/wiki/Ncurses

[Null]

#include <iostream>
#include <string>
#include <windows.h>
using namespace std;


string getpass(const char *prompt, bool show_asterisk=true)
{
  const char BACKSPACE=8;
  const char RETURN=13;

  string password;
  unsigned char ch=0;

  cout <<prompt<<endl;

  DWORD con_mode;
  DWORD dwRead;

  HANDLE hIn=GetStdHandle(STD_INPUT_HANDLE);

  GetConsoleMode( hIn, &con_mode );
  SetConsoleMode( hIn, con_mode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT) );

  while(ReadConsoleA( hIn, &ch, 1, &dwRead, NULL) && ch !=RETURN)
    {
       if(ch==BACKSPACE)
         {
            if(password.length()!=0)
              {
                 if(show_asterisk)
                     cout <<"\b \b";
                 password.resize(password.length()-1);
              }
         }
       else
         {
             password+=ch;
             if(show_asterisk)
                 cout <<'*';
         }
    }
  cout <<endl;
  return password;
}



int main()
{
  const char *correct_password="null";

  cout <<"Test 1: echoing enabled"<<endl;
  string password=getpass("Please enter the password: ",true); // Show asterisks
  if(password==correct_password)
      cout <<"Correct password"<<endl;
  else
      cout <<"Incorrect password. Try again"<<endl;

  cout <<"\nTest 2: echoing disabled"<<endl;
  password=getpass("Please enter the password: ",false); // Do not show asterisks
  if(password==correct_password)
      cout <<"Correct password"<<endl;
  else
      cout <<"Incorrect password. Try again"<<endl;

  return 0;
}

[Chathu]

this is part of my code. But it gives an error. encryption part i can do . I need to fix this error. it tells every time password not matching

#include<iostream>
#include<iomanip>
#include<conio.h>
#include<string>

using namespace std;
void encrypt(char*);

main()
{
     char uname[30],pw1[30],pw2[30],c=' ';
     char *pwPtr;
     cout<<"User Name: ";
     cin>>uname;
     cout<<"\nPassword: "<<endl;
     
     for(int i=0;c!=13;i++)
     {
          c=getch();
          pw1[i]=c;
          cout<<"*";            
     
     }
     
     c=' ';
     cout<<"\nReEnter Password: \n";
     
     for(int j=0;j<30,c!=13;j++)
     { 
          c=getch();
          pw2[j]=c;
          cout<<"*";               
     }
     
     if(pw1!=pw2)
     {
          cout<<"\n\nPasswords Entered Not Matching"<<endl;            
     }
     else
     {
          pwPtr=pw2;
          cout<<"Your Encripterd Password Is: ";
          encrypt(pwPtr);    
     }
     cin.ignore();
     cin.get();
}

[ZED0815]

It'll puzzle you, but you can't compare strings like so! Use strcmp or something similar! What you do just now is comparing some pointer address of string 1 and 2 -> these can't be the same unless string 1 is string 2 even in memory!

[ZED0815]

BTW: the comparison between two pointers is perfectly fine, just not what you want. That's the reason your compiler isn't bitching!

[Chathu]

Ah Yeah...Ill try strcmp.Thanks Youuu

[Chathu]

@ZED0thank 815 yes it works. Thanks Alot. As I'm New To This Language It Couldn't Figure It Out In The First Place. Thanks again.

But There Is Another Error. When I Enter 3 Chars It Display 4 Stars. Every time It Print One Extra Star.

This Is The Corrected Code

     if(strcmp(pw1,pw2)!=0)
     {
          cout<<"\n\nPasswords Entered Not Matching"<<endl;            
     }
     else
     {
          pwPtr=pw2;
          cout<<"Your Encripterd Password Is: ";
          encode(pwPtr);    
     }

[ZED0815]

yes of course...you print a star before checking whether input is '\n' or not....

So you enter like "bla"<RETURN> what your proggy does is:

b -> print * -> check return -> false go on...
l -> print * ->check return -> false go on...
a -> print * ->check return -> false go on...
return ->print *-> check return -> true stop...