BattleFaction2019.psm1
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function Get-CaesarCipher { [CmdletBinding()] param ( [parameter(Mandatory = $true)] [string]$Text, [parameter(Mandatory = $true)] [int]$SecretNumber, [string]$RootString = $([char[]]$(32..126) -join ''), [switch]$Encode, [switch]$Decode ) begin { # If you are decoding, you need to reverse the lookup if ($Decode) { $SecretNumber = -$SecretNumber } # Modulus is used to keep the values inside array of possible positions $Modulus = $RootString.length Write-Verbose "Modulus: $Modulus" If ($SecretNumber -lt 0) { $SecretNumber = $Modulus + ($SecretNumber % $Modulus) } Write-Verbose $SecretNumber } process { # Build 2 hashtables. One for looking a letter based on poition in the string and one for looking up the position in the string based on the letter $Counter = @{ } $Letter = @{ } $i = 0 [int[]][char[]]$RootString | ForEach-Object { $Counter.add($i, $_); $Letter.Add($_, $i); $i++ } # Convert original chars to the char ints matching the secret number $Converted = [int[]][char[]]$Text | ForEach-Object { try { if ($_ -eq 10 -or $_ -eq 13) { $_ } else { $no = $letter[$_] $Counter[$($($no + $SecretNumber) % $Modulus)] } } catch { Write-Warning "Error on $_" } } } end { # Just joining the string would remove new line carriage return, formatting a string allows them to expand correctly $str = "" for ($j = 0; $j -le $Converted.count - 1; $j++) { $str += "{$j}" } $str -f $($Converted.foreach{ [char]$_ }) } } function Protect-Message { [CmdletBinding()] param ( $Message, [securestring]$Password, [System.IO.FileInfo]$File ) begin { $certPath = "$env:Temp\BattleCert.pfx" $UserInfo = @{ User = $env:USERNAME Computer = $env:COMPUTERNAME Date = (Get-Date).ToString() } | ConvertTo-Json } process { $certName = 'BattleFaction' + ((Get-Random -InputObject (0..9) -count 4) -join '') $battleCert = New-SelfSignedCertificate -DnsName $certName -CertStoreLocation "Cert:\CurrentUser\My" -KeyUsage KeyEncipherment, DataEncipherment, KeyAgreement -Type DocumentEncryptionCert $Message | Protect-CmsMessage -To $battleCert.Subject -OutFile $File.FullName $Exported = $battleCert | Export-PfxCertificate -FilePath $certPath -Password $Password $fileContentBytes = get-content $certPath -Encoding Byte $certString = [System.Convert]::ToBase64String($fileContentBytes) Add-Content -value $certString -Path $File.FullName -Stream Cert Add-Content -value $UserInfo -Path $File.FullName -Stream UserInfo } end { Get-Childitem -Path Cert:\CurrentUser\My -DocumentEncryptionCert | where { $_.Subject -eq $battleCert.subject } | Remove-Item Remove-item $certPath } } function Unprotect-Message { [CmdletBinding()] param ( [System.IO.FileInfo]$MessageFile, [SecureString]$Password, [switch]$ThisMessageWillSelfDestruct ) begin { $cert = Get-Content $MessageFile.FullName -Stream Cert $userInfo = Get-Content $MessageFile.FullName -Stream UserInfo | convertfrom-json $certPath = "$env:Temp\BattleCert.pfx" } process { [IO.File]::WriteAllBytes($certPath, [Convert]::FromBase64String($cert)) $battleCert = Import-PfxCertificate -CertStoreLocation "Cert:\CurrentUser\My" -FilePath $certPath -Password $Password $Message = Unprotect-CmsMessage -Path $MessageFile.FullName $userMessageString = "Message was generated on {0} by {1} at {2}" -f $userInfo.Computer, $userInfo.User, $userInfo.Date Write-Verbose $userMessageString $Message } end { Get-Childitem -Path Cert:\CurrentUser\My -DocumentEncryptionCert | where { $_.Subject -eq $battleCert.subject } | Remove-Item Remove-item $certPath if ($ThisMessageWillSelfDestruct){Remove-Item $MessageFile} } } |