Fun Little Cryptogram

There’s an interesting site https://ironscripter.us/ which creates powershell based scripting challenges for practicing DevOps thinking and continual learning. It’s kind of like a kata website with a funny “Battle for the Iron Throne” feel to it.

A few days ago they posted a really small cryptogram to find a hidden message within some text. I say really small because I have a coworker that is active in crypto games and the stuff he does is mind blowing (https://op011.com/).

Ironscripter’s challenge is more light hearted and just a quick game to help you think about powershell, string manipulation, visualizing data to make it useful and so on. So, here’s my solution to the challenge.

(I think I might go back later and use a language file to try and match the text in the possible solutions; instead of trying to look through them manually.)

(Thanks to David Carroll for pointing this site out: His solution)

	# $crypto = @"
	# g - 2 5 R e t o p c 7 -
	# h v 1 Q n e l b e d E p
	# "@
	$crypto = @"
	P k T r 2 s z 2 * c F -
	r a z 7 G u D 4 w 6 U #
	g c t K 3 E @ B t 1 a Y
	Q P i c % 7 0 5 Z v A e
	W 6 j e P R f p m I ) H
	y ^ L o o w C n b J d O
	S i 9 M b e r # ) i e U
	* f 2 Z 6 M S h 7 V u D
	5 a ( h s v 8 e l 1 o W
	Z O 7 l p K y J l D z $
	- j I @ t T 2 3 R a i k
	q = F & w B 6 c % H l y
	"@
	# using language files to automate testing the results
	# https://sites.google.com/site/cryptocrackprogram/download/language-files
	$dictFolder = "C:\Program Files\WindowsPowerShell\Modules\IronScriptor-20190702-Cryptogram\EnglishDict"
	$dictFiles = dir -Path $dictFolder -Recurse *.* -File
	$allwords = $dictFiles |% { Get-Content -Path $_.FullName }
	function Test-DictionaryWords ([string] $Possible) {
	$Possible = $Possible -replace "-", ""
	$Possible = $Possible.ToUpper()
	foreach($word in $allwords) {
	if($Possible.StartsWith($word)) {
	if($Possible.Length -eq $word.Length) {
	return $true
	}
	$newPossible = $Possible.Substring($word.Length)
	$results = Test-DictionaryWords -Possible $newPossible
	if($results -eq $true) {
	return $true
	}
	}
	}
	return $false
	}
	$crypto = $crypto -replace " ", ""
	$crypto = $crypto -replace "`r", ""
	$crypto = $crypto -replace "`n", ""
	$cryptolen = $crypto.Length
	$results = @()
	for($x = 1; $x -lt 20; $x++) {
	$props = [PSCustomObject] @{}
	for($y = 1; $y -lt 20; $y++) {
	$plaintext = ""
	for($j = 0; ((($x + $y) * $j) + $x) -le $cryptolen; $j++) {
	$cx = (($x + $y) * $j) + $x
	$plaintext += $crypto[$cx - 1]
	$cy = (($x + $y) * $j) + $x + $y
	if($cy -le $cryptolen) {
	$plaintext += $crypto[$cy - 1]
	}
	}
	$props = [PSCustomObject] @{
	X = $x
	Y = $y
	PlainText = $plaintext
	PlainTextL = $plaintext.ToLower()
	DictionaryMatch = Test-DictionaryWords -Possible $plaintext
	}
	$results += @($props)
	if($props.DictionaryMatch) {
	$props | ft X, Y, PlainText -AutoSize
	break
	}
	}
	if($props.DictionaryMatch) {
	break
	}
	}
	#$results | ft X, Y, PlainTextL -AutoSize
	#$results |? { $_.plaintext -match "-" } | ft X, Y, PlainText -AutoSize
	#$results |? { $_.plaintextl -notmatch "[^a-zA-z\-]" } | ft X, Y, PlainTextL -AutoSize
	#$results |? { $_.X -eq 1 -and $_.Y -eq 12 }

view raw IronScripter-2019-06-28.ps1 hosted with ❤ by GitHub