2008 Scripting Games - Advanced Event 5

Event 5: You Call That a Strong Password?

param(
  [string]$pwd = $(throw "Please specify password"),
  [string]$wordList = "c:\scripts\WordList.txt"

)

$score=13

$ptrn6 = '(.*).{10,20}' ; if($pwd -notmatch $ptrn6) {$score-=1; "Password is less than 10 characters or less than 20 characters"}


$ptrn7 = '\d' ; if($pwd -notmatch $ptrn7) {$score-=1; "Password must contain at least one number"}
$ptrn8 = '[A-Z]' ; if($pwd -cnotmatch $ptrn8) {$score-=1; "No uppercase letters in password."}
$ptrn9 = '[a-z]' ; if($pwd -cnotmatch $ptrn9) {$score-=1; "No lowercase letters in password."}
$ptrn10 = '(?=.*[^A-Za-z0-9])' ; if($pwd -notmatch $ptrn10) {$score-=1; "Password must contain at least one symbol"}
$ptrn11 = '[a-z]{4,}' ; if($pwd -cmatch $ptrn11) {$score-=1; "Four consecutive lowercase letters in password."}
$ptrn12 = '[A-Z]{4,}' ; if($pwd -cmatch $ptrn12) {$score-=1; "Four consecutive uppercase letters in password."}
if ($pwd.ToCharArray() | group | where {$_.count -gt 1}) {$score-=1; "Duplicate letters in password."}

$words = cat $wordList
if($words -contains $pwd) {$score-=1; "Password can't be an actual word"}
if($words -contains $pwd.substring(0,($pwd.length-1))) {$score-=1; "Password minus the last letter, is an actual word"}
if($words -contains $pwd.substring(1)) {$score-=11; "Password minus the first letter, is an actual word"}
if($words -contains ($pwd  -replace 'O','0')) {$score-=1; "Password substitute 0 (zero) for the letter o (either an uppercase O or a lowercase o)"}
if($words -contains ($pwd  -replace 'L','1')) {$score-=1; "Password does not simply substitute 1 (one) for the letter l (either an uppercase L or a lowercase l)"}

Write-Host
switch($score){
  {$_ -lt 7} {"A password score of $score indicates a weak password."; break}
  {($_ -ge 7) -and ($_ -le 10)} {"A password score of $score indicates a moderately-strong password"; break}
  {$_ -ge 11} {"A password score of $score indicates a strong password."; break}
}