// example by Stian Lavik Stokkenes oct 2005
// INF329 - University of Bergen
// Demonstrates the "Throwing Dice for password" example 
// in chapter 13 in Building secure Software.
//
import java.util.Random ;

public class Dices {
  
  public static Random rand = new Random() ;
  public static String [][][]table;
  protected static String password = "";
  
  /**
   * Generates a random number between 1 and 6
   */
  public static int throw_dice () {
	  int dice = rand.nextInt();
	  dice = Math.abs(dice);
	  dice = dice % 6;
	  dice += 1;
	  return dice;
    
  }
  /**
   * Init the table of chars
   */
  public static void init(){
	  table = new String[7][7][7];
	  table[1][1][1]="a";table[1][1][2]="b";table[1][1][3]="c";table[1][1][4]="d";
	  table[1][1][5]="e";table[1][1][6]="f";table[1][2][1]="g";table[1][2][2]="h";
	  table[1][2][3]="i";table[1][2][4]="j";table[1][2][5]="k";table[1][2][6]="l";
	  table[1][3][1]="m";table[1][3][2]="n";table[1][3][3]="o";table[1][3][4]="p";
	  table[1][3][5]="q";table[1][3][6]="r";table[1][4][1]="s";table[1][4][2]="t";
	  table[1][4][3]="u";table[1][4][4]="v";table[1][4][5]="w";table[1][4][6]="x";
	  table[1][5][1]="y";table[1][5][2]="z";table[1][5][3]="A";table[1][5][4]="B";
	  table[1][5][5]="C";table[1][5][6]="D";table[1][6][1]="E";table[1][6][2]="F";
	  table[1][6][3]="G";table[1][6][4]="H";table[1][6][5]="I";table[1][6][6]="J";
	  table[3][1][1]="K";table[3][1][2]="L";table[3][1][3]="M";table[3][1][4]="N";
	  table[3][1][5]="O";table[3][1][6]="P";table[3][2][1]="Q";table[3][2][2]="R";
	  table[3][2][3]="S";table[3][2][4]="T";table[3][2][5]="U";table[3][2][6]="V";
	  table[3][3][1]="W";table[3][3][2]="X";table[3][3][3]="Y";table[3][3][4]="Z";
	  table[3][3][5]="0";table[3][3][6]="1";table[3][4][1]="2";table[3][4][2]="3";
	  table[3][4][3]="4";table[3][4][4]="5";table[3][4][5]="6";table[3][4][6]="7";
	  table[3][5][1]="8";table[3][5][2]="9";table[3][5][3]="'";table[3][5][4]="~";
	  table[3][5][5]="!";table[3][5][6]="@";table[3][6][1]="#";table[3][6][2]="$";
	  table[3][6][3]="%";table[3][6][4]="^";table[3][6][5]="&";table[3][6][6]="*";
	  table[5][1][1]="(";table[5][1][2]=")";table[5][1][3]="_";table[5][1][4]="-";
	  table[5][1][5]="+";table[5][1][6]="=";table[5][2][1]="{";table[5][2][2]="[";
	  table[5][2][3]="}";table[5][2][4]="]";table[5][2][5]="|";table[5][2][6]="\\";
	  table[5][3][1]=":";table[5][3][2]=";";table[5][3][3]="\"";table[5][3][4]=",";
	  table[5][3][5]="?";table[5][3][6]="/";table[5][4][1]="2";table[5][4][2]="3";
	  table[5][4][3]="4";table[5][4][4]="5";table[5][4][5]="6";table[5][4][6]="7";
	  table[5][5][1]="8";table[5][5][2]="9";table[5][5][3]="'";table[5][5][4]="~";
	  table[5][5][5]="!";table[5][5][6]="@";table[5][6][1]="#";table[5][6][2]="$";
	  table[5][6][3]="%";table[5][6][4]="^";table[5][6][5]="&";table[5][6][6]="*";
  	}
  
  
  public static String gen_password(int length){
	  int dice1;
	  int dice2;
	  int dice3;
	  for(int i=0;i<length;i++){
		  dice1 = throw_dice();
		  dice2 = throw_dice();
		  dice3 = throw_dice();
		  //Since the table output the same value in row one for (1and2),(3and4),(5and6) 
		  if(dice1==2)
			  dice1=1;
		  if(dice1==4)
			  dice1=3;
		  if(dice1==6)
			  dice1=5;
		  password+=table[dice1][dice2][dice3];
	  }
	  return password;
  }
  
  public static void main (String[ ] args) {
	  init();	//init the char table
	  int password_length = 8;
  	  int nPasswords = 9;
	
	  System.out.println("Starting generating "+nPasswords+" passwords..\n");
	
	  for(int i=1;i<=nPasswords;i++){
		  System.out.println("Password "+i+" is: "+gen_password(password_length));
		  //after echoed the password out, wipe from memory
		  password="";  
	  }
	  
    
	
  }
}