#!/usr/bin/perl

#srand( time() ^ ($$ + ($$ << 15)) );

my $gVERSION     = "1.4";
my $gAlpha       = "aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ";
my $gNumeric     = "0123456789";
my $gSymbol      = "\!\@\#\$\^\-\.\*";
my $gUserPattern = 0;
my $gQuiet       = 0;
my $gRunTimes    = 1; 	# how many passwords to generate
my $gPopulation  = "AAA000!!";
my $gChoice      = int(rand($gNumPatterns));
my $gMyPattern   = &GeneratePattern; 

&ParseCommandLine(@ARGV);

die "\nMaximum pattern length is 8 characters\n\n" if (length($gMyPattern) > 8);

for ($mastercount = 1; $mastercount < $gRunTimes + 1; $mastercount++) {
	$gMyPattern = &GeneratePattern if ($gUserPattern == 0);

	print "\n(" . $mastercount . "/" . $gRunTimes . ") " if ($gQuiet == 0);
	&GeneratePassword;
}

sub GeneratePassword {
	my $Password, $Hash, $Salt;

	for ($count = 0; $count < length($gMyPattern); $count++) {
		if (substr($gMyPattern,$count,1) eq "?") {
			$rand = int(rand(3));
			substr($gMyPattern,$count,1) = substr("A0!",$rand,1);
		}
	
		if (substr($gMyPattern,$count,1) eq "A") {
			$Password = $Password . substr($gAlpha,int(rand(length($gAlpha))),1);
			next;
		}
		if (substr($gMyPattern,$count,1) eq "0") {
			$Password = $Password . substr($gNumeric,int(rand(length($gNumeric))),1);
			next;
		}
		if (substr($gMyPattern,$count,1) eq "!") {
			$Password =  $Password . substr($gSymbol,int(rand(length($gSymbol))),1);
			next;
		}

		# We should never reach this point
		die "\n" . substr($gMyPattern,$count,1) . " - patterns may only contain A, 0 or ! (" . $gMyPattern . ")\n\n";
	}

	$Salt = substr($gAlpha,int(rand(length($gAlpha))),1) . substr($gNumeric,int(rand(length($gNumeric))),1);

	$Hash = crypt($Password,$Salt);

	if ($gQuiet == 0) {
		print "Pattern: " . $gMyPattern . "   Password: " . $Password . "   Hash: " . $Hash . "\n\n";
	} elsif ($gQuiet == 1) {
		print $Password . "\n";
	} elsif ($gQuiet == 2) {
		print "$Password $Hash\n";
	}
}

sub GeneratePattern {
	local $a, $r, $done, $count, $string;
    my (@Places);

	$string = "-" x length($gPopulation);

    for ($count = 0 ; $count < length($gPopulation); $count++) {
    	$Places[$count] = $count;
    }

    for ($count = 0 ; $count < length($gPopulation); $count++) {
        $a = substr($gPopulation,$count,1);
        
        $r = int(rand(scalar(@Places)));
        
        substr($string,$Places[$r],1) = $a;
        splice(@Places,$r,1);
    }
	return($string);
}

sub ParseCommandLine {
	local @CommandLine = @_;
	local $count, $string;

	for ($count = 0; $count < @CommandLine; $count++) {
		$string = $CommandLine[$count];
		$string =~ tr/A-Z/a-z/;

		if ($string eq "-h") {			## Version
			&ShowHelp;
		} elsif ($string eq "-q") {		## Quiet Mode, only print password
			$gQuiet = 1;
		} elsif ($string eq "-r") {		## Quiet Mode, only print hash
			$gQuiet = 2;
		} elsif ($string eq "-p") {		## User Supplied Password 
			$gMyPattern = $CommandLine[$count+1];
			$gUserPattern = 1;
			$count++;
		} elsif ($string eq "-t") {		## How many passwords to generate? 
			$gRunTimes = $CommandLine[$count+1];
			$count++;
		} else {
			print "\n** Unknown option: $string, use -h for help\n\n";
			exit;
		} 
	}
}

sub ShowHelp {
	print "passgen.pl (v. $gVERSION)\n\n";
	print "passgen.pl [-h] [-q] [-p pattern] [-t num]\n";
	print "           -h         : help\n";
	print "           -q         : quiet mode ... only display password\n";
	print "           -r         : quiet mode ... only display password & hash\n";
	print "           -p pattern : help\n";
	print "           -t num     : generate <num> passwords\n\n";
	exit;
}