#!/usr/local/bin/perl
# Copyright (C) 1994-1997 - pckizer@tamu.edu

# Change these to match best source of random data on your systems
# WARNING: On many systems, a 'ps' is just too slow to be usable,
#          these should be an option so users can pick their own data.
@random_seeds = ( "/dev/ksyms", "/etc/utmp", "/etc/utmpx",
                  "/etc/wtmp", "netstat -n|");

use Getopt::Std;
#require 'getopts.pl';

($iam = $0) =~ s,.*/,,;
&getopts('Hfrmnahpv:V') || &Usage;
&Usage if $opt_h;

sub Usage {
  $l=length($iam);
  print "Usage: $iam [-f] [-r] [-m] [-a] [-n] [-h] [-p] [pswds [chars]]\n";
  print ' 'x($l+8),"Generate random passwords.  The following options mean:\n";
  print ' 'x($l+8),"-r    means use a \"reasonable\" character set (default)\n";
  print ' 'x($l+8),"-f    means use the full printable character set\n";
  print ' 'x($l+8),"-H    means to use hexadecimal digits\n";
  print ' 'x($l+8),"-m    means use a minimal character set\n";
  print ' 'x($l+8),"-a    means use a just the alpha-numeric character set\n";
  print ' 'x($l+8),"-n    means use a just the numeric character set\n";
  print ' 'x($l+8),"-p    print character set to be used\n";
  print ' 'x($l+8),"-v #  <chars> is max, but allow # fewer characters\n";
  print ' 'x($l+8),"-V    allow 1 fewer characters (rand 7 or 8)\n";
  print ' 'x($l+8),"pswds is the number of random passwords to generate\n";
  print ' 'x($l+8),"chars is the max number of characters to generate\n";
  exit(0);
}

if (($opt_f+$opt_m+$opt_a+$opt_n+$opt_r)>1) {
  print "$iam: error: please spacify only one of: -f -r -m -a -n\n";
  exit(1);
}

# The "reasonable" character set
@char=('a'..'z','A'..'Z','0'..'9',',','.','/','-','=','!','@','#','$','%','&'); 

     if ($opt_f) { # Full
  @char=('a'..'z','A'..'Z','0'..'9','!','"','#','$','%','&','\'','(',')','*',
          '+',',','-','.','/',':',';','<','=','>','?','@','{','|','}','~'); 
} elsif ($opt_H) { # HEX
  @char=('a'..'f','0'..'9'); 
} elsif ($opt_m) { # Minimal
  @char=('a'..'z','0'..'9',',','.','/','-','=',';'); 
} elsif ($opt_a) { # Alphanumeric
  @char=('a'..'z','0'..'9'); 
} elsif ($opt_n) { # Numeric
  @char=('0'..'9'); 
}

if ($opt_p) {
  print join('',@char),"\n";
  exit(0);
}

$times=($#ARGV>=0 && $ARGV[0]>1)?$ARGV[0]:1;
$chars=($#ARGV>=1 && $ARGV[1]>0)?$ARGV[1]:8;
   if ($opt_V) {$opt_v=1}
elsif ($opt_v) {}
else           {$opt_v=0}

# Initialize random number generator with decent numbers, hopefully not
# guessable or replayable as the current time would be
$i = eval 'use MD5; 1';
if ($i == 1) {
  $hash = new MD5;
  $hash->reset();
  foreach $file ( @random_seeds ) {
    #print "Adding random data from: $file\n";
    open(FILE,$file) || next; $hash->addfile(FILE); close(FILE);
  }
  $digest = $hash->digest(); $hexdigest = unpack("H*",$digest);
  #$hash->add( time );
  foreach $value (unpack("I*",$digest)) {
    $init ^= $value;
  }
} else { # Normal, low-entropy, time/PID initialization
  print "Warning: using low-entropy initializer!\n";
  $init=time();
}
$init ^= $$;
#print "Initialized with: (", $hexdigest , ") => $init\n";
srand( $init );

#print "Generating $chars chars - $opt_v random chars\n";

for ($t=0;$t<$times;$t++) {
  $num= $chars - int(($opt_v+1)*rand);
  for ($i=0;$i<$num;$i++) {print $char[$#char*rand]}
  print "\n";
}