Thread: Password generator

Characters (numbers, letters, etc.) can be treated as numerical values. For example, if you say
char c = 'G';
cout << (int)c;
you'll get 71 printed out. You can also declare an integer as
int n = 'A';
and n will now be 65.

The most easiest way to accomplish what you try to do is to make a loop that goes on until randomized value is number or a letter (mind the case). This loop would, of course, be nested in another loop that assigns each cell in a string:

Code:

char pw[10], c;
for(int i = 0;  i < 10;  i++)
{
  for(c = 0;  isdigit(c) == 0;)
    c = '0'+(rand()%('z'+1-'0'));
  pw[i] = c;
}

for(c = 0; isalnu,(c) == 0
goes through until c is a number/letter

c = '0'+(rand()%('z'+1-'0'));
c can now be anything between '0' and 'z'. '0' is the smallest from digits and letters what comes to numerical value and 'z' is the highest (we need to add 1 to 'z' to include 'z' itself and substract '0' because we already have it in the beginning of the statement - alternatively you could write: c = 48+rand()%75).

Hope I wasn't too complicated :-)

Replace that annoying yellow ball with ;)

I did a bit a code for this problem in an old project, but you'll have to modify it so it does 8.

void RandomizePasswords(char Passwords[MAX_LEVEL][PASSWORD_LENGTH])
{
const int Letters=25, Numbers=9, LettersBase=97, NumbersBase=48;

int i=0,Temp,Index=0;

randomize();

while(Index < MAX_LEVEL)
{
i=0; //Reinitalise i for next password randomization
for(i; i < PASSWORD_LENGTH-1; i++)
{
if(i <= 1)
{
Temp = LettersBase + random(Letters+1);
Passwords[Index][i]= (char)Temp;
}
else
{
Temp = NumbersBase + random(Numbers+1);
Passwords[Index][i]= (char)Temp;
if(i==5) //Put end of string on
Passwords[Index][i+1]='\0';
}
}
Index++;
}

Here there are some functions I have made. Hope this helps too.

Code:

#include <iostream.h>
#include <windows.h>
#include <stdlib.h>

/* Generates one random letter */
char gen_letter(void)
{
  char ch = (rand() % 26) + 'a';

  return ch;
}

/* Generates one alphanumeric character */
char gen_alphanum(void)
{
  char vAlpha[] = "0123456789abcdefghijklmnopqrstuvwxyz";
  char ch = vAlpha[ rand() % 36 ];
  
  return ch;
}

/* Use this to generate the password of length 'iSize' */
void gen_pass(char *sPassWord, int iSize)
{
   if (iSize < 1)
   {
     sPassWord[0] = '\0';
     return;
   }
  
   /* First must be a letter */
   sPassWord[0] = gen_letter();

   for (int i=1; i < iSize; i++)
     sPassWord[i] = gen_alphanum();

   /* Terminates the string */
   sPassWord[iSize] = '\0';
}

int main(void)
{
    char password[9];
  
    /* Get a seed number */
    srand((unsigned int) (GetTickCount() / 100) );

    gen_pass(password, 8);
    cout << "\nPassword: '" << password;

    return 0;
}

As it was said: Letters can be treated as numbers (ASCII code).

Use: rand() % Num
to generate a random number between 0 and Num-1.

#include "iostream.h"
#include "stdio.h"
#include "stdlib.h" // rand()

Code:

int main()
{
	int i, c, d, num_chars, num_passwds;
	static char *letters[] = { "a","b","c","d","e","f","g","h","i","j","k","l","m",
			                   "n","o","p","q","r","s","t","u","v","w","x","y","z" };
	char FileName[30];

	cout << "\n How many Chars?     : ";
	cin >> num_chars;

	cout << " How many Passwords? : ";
	cin >> num_passwds;

	cout << "         Output File : ";
	cin >> FileName;
	
	FILE *wordfile;
	wordfile = fopen(FileName,"w");

	d = 1;
	fflush(wordfile);

	while(d <= num_passwds)
	{
		d++;
		c = 1;
		
		while(c <= num_chars)
		{
			c++;
			i = rand() % 26;
			fprintf(wordfile, "%s", letters[i]);
		}
		fputs("\n", wordfile);
	}
	
	fclose(wordfile);

	return 0;
}

Yes, i know.. this is some wierd'ed-out code(not clean looking). I didn't spend much time on it, and its very simple stuff.

Heres an Idea.
----
I just thought about this ...
Instead of programming a "random" password generator(because there is already enough out there), why not program a "real" word generator? Heres how it could work.

----
Pass an actual document on something familiar(maybe a real dictionary)through the program, then have it split up everyword and check for repeats of the same word ... this way, you would have real words, and not random characters. And if You know what your victim is into, what he or she likes, but you don't know what words to use, pass a document on whatever they like and you would have "real" words on that subject without ever knowing anything on it.

Would go something like this
----
- Get a file that talks about something
- Split everyword up and write it to a file
- Read-in the file that you wrote to, and check for repeats - if any repeats, take them out and re-write

kinda interesting ...