# RouterOS script: GeneratePSK
# Copyright (c) 2013-2018 Christian Hesse <mail@eworm.de>
#
# return pseudo-random string for PSK

:local date [ / system clock get date ];

# 0-30 for days of month
:local
secret1 { "Abusive"; "Aggressive"; "Bored"; "Chemical"; "Cold"; "Cruel";
  "Curved"; "Delightful"; "Discreet"; "Elite"; "Evasive"; "Faded"; "Flat";
  "Future"; "Grandiose"; "Hanging"; "Humorous"; "Interesting"; "Magenta";
  "Magnificent"; "Numerous"; "Optimal"; "Pathetic"; "Possessive";
  "Remarkable"; "Rightful"; "Ruthless"; "Stale"; "Unusual"; "Useless";
  "Various" };
# 0-11 for month of year
:local secret2 { "Adhesive"; "Amusing"; "Astonishing"; "Frantic";
  "Kindhearted"; "Limping"; "Roasted"; "Robust"; "Staking"; "Thundering";
  "Ultra"; "Unusual" };
# 0-6 for days of week
:local secret3 { "Belief"; "Button"; "Curtain"; "Edge"; "Jewel"; "String";
  "Whistle" };

:local months { "jan"; "feb"; "mar"; "apr"; "may"; "jun"; "jul"; "aug"; "sep";
  "oct"; "nov"; "dec" };
:local monthtbl { 0; 3; 3; 6; 1; 4; 6; 2; 5; 0; 3; 5 };

:local monthstr [ :pick $date 0 3 ];
:local month;
:local day [ :pick $date 4 6 ];
:local century [ :pick $date 7 9 ];
:local year [ :pick $date 9 11 ];

# get numeric value for month
:for mindex from=0 to=[ :len $months ] do={
  :if ([ :pick $months $mindex ] = $monthstr) do={
    :set month $mindex;
  };
};

# calculate day of week
:local sum 0;
:set sum ($sum + (2 * (3 - ($century - (($century / 4) * 4)))));
:set sum ($sum + ($year / 4));
:set sum ($sum + $year + $day);
:set sum ($sum + $month);
:set sum ($sum - (($sum / 7) * 7));

:local return ([ :pick $secret1 ($day - 1) ] . [ :pick $secret2 $month ] . [ :pick $secret3 $sum ]);

:return $return;