Data commit

Task/Vigen-re-cipher/PowerShell/vigen-re-cipher.psh

@@ -0,0 +1,85 @@
+# Author: D. Cudnohufsky
+function Get-VigenereCipher
+{
+    Param
+    (
+        [Parameter(Mandatory=$true)]
+        [string] $Text,
+
+        [Parameter(Mandatory=$true)]
+        [string] $Key,
+
+        [switch] $Decode
+    )
+
+    begin
+    {
+        $map = [char]'A'..[char]'Z'
+    }
+
+    process
+    {
+        $Key = $Key -replace '[^a-zA-Z]',''
+        $Text = $Text -replace '[^a-zA-Z]',''
+
+        $keyChars = $Key.toUpper().ToCharArray()
+        $Chars = $Text.toUpper().ToCharArray()
+
+        function encode
+        {
+
+            param
+            (
+                $Char,
+                $keyChar,
+                $Alpha = [char]'A'..[char]'Z'
+            )
+
+            $charIndex = $Alpha.IndexOf([int]$Char)
+            $keyIndex = $Alpha.IndexOf([int]$keyChar)
+            $NewIndex = ($charIndex + $KeyIndex) - $Alpha.Length
+            $Alpha[$NewIndex]
+
+        }
+
+        function decode
+        {
+
+            param
+            (
+                $Char,
+                $keyChar,
+                $Alpha = [char]'A'..[char]'Z'
+            )
+
+            $charIndex = $Alpha.IndexOf([int]$Char)
+            $keyIndex = $Alpha.IndexOf([int]$keyChar)
+            $int = $charIndex - $keyIndex
+            if ($int -lt 0) { $NewIndex = $int + $Alpha.Length }
+            else { $NewIndex = $int }
+            $Alpha[$NewIndex]
+        }
+
+        while ( $keyChars.Length -lt $Chars.Length )
+        {
+            $keyChars = $keyChars + $keyChars
+        }
+
+        for ( $i = 0; $i -lt $Chars.Length; $i++ )
+        {
+
+            if ( [int]$Chars[$i] -in $map -and [int]$keyChars[$i] -in $map )
+            {
+                if ($Decode) {$Chars[$i] = decode $Chars[$i] $keyChars[$i] $map}
+                else {$Chars[$i] = encode $Chars[$i] $keyChars[$i] $map}
+
+                $Chars[$i] = [char]$Chars[$i]
+                [string]$OutText += $Chars[$i]
+            }
+
+        }
+
+        $OutText
+        $OutText = $null
+    }
+}