Private/GetEntropy.ps1
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<## # Copyright 2021 David Hollings. All rights reserved. # Use of this source code is governed by a BSD-style # license that can be found in the LICENSE file. #> # Import helper scripts . $PSScriptRoot/HelperFunctions.ps1 . $PSScriptRoot/vars.ps1 Function GetEntropy{ [CmdletBinding(DefaultParameterSetName = "Character")] param( # Password to check [Parameter(Mandatory)] [securestring] $Password, # Is it a word password? Will return seen entropy as well as blind if true [Parameter(Mandatory, ParameterSetName = "Word")] [switch] $Word, # Length of word list in use [Parameter(Mandatory, ParameterSetName = "Word")] [int32] $WordlistLength, # Number of Words [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $WordCount, # Prefix Symbols [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $PrefixSymbolCount, # Suffix Symbols [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $SuffixSymbolCount, # Number of padding symbols to choose from [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $SymbolSetSize, # Number of prefix digits [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $PrefixDigitCount, # Number of suffix digits [Parameter(Mandatory, ParameterSetName = "Word")] [byte] $SuffixDigitCount, # Number of separator symbols [Parameter(Mandatory, ParameterSetName= "Word")] [byte] $SeparatorCharacterCount ) if ($PSCmdlet.ParameterSetName -eq "Word"){ # Words $WordPermutations = [math]::Pow($WordlistLength,$WordCount) Write-Verbose "Word Permutations: $WordPermutations" # Cases $CasePermutations = [math]::Pow(2,$WordCount) Write-Verbose "Case Permutations: $CasePermutations" # Padding Characters $PaddingPermutations = ([math]::Pow($SymbolSetSize,($PrefixSymbolCount + $SuffixSymbolCount))) Write-Verbose "Padding Permutations: $PaddingPermutations" # Digits $DigitPermutations = [math]::Pow(10,($PrefixDigitCount + $SuffixDigitCount)) Write-Verbose "Digit Permutations: $DigitPermutations" # Separator Character if ($SeparatorCharacterCount -eq 0) { $SeparatorCharacterCount ++} $SeparatorPermutations = $SeparatorCharacterCount Write-Verbose "Separator Permutations: $SeparatorPermutations" $SeenPermutations = $WordPermutations * $CasePermutations * $PaddingPermutations * $DigitPermutations * $SeparatorPermutations $SeenEntropy = [math]::round([math]::log($SeenPermutations,2)) } # Unpack secure string to read password. If we are using Windows Powershell we need to use the BSTR method but this doesn't work on Linux # so for modern versions we use ConvertFrom-SecureString $PasswordPlain = SecureStringToPlainText -Password $Password if (StringContains -String $PasswordPlain -Characters $LowerCase){ $CharacterSet += $LowerCase } if (StringContains -String $PasswordPlain -Characters $UpperCase){ $CharacterSet += $UpperCase } if (StringContains -String $PasswordPlain -Characters $Numbers){ $CharacterSet += $Numbers } if (StringContains -String $PasswordPlain -Characters $Symbols){ $CharacterSet += $Symbols } $BlindPermutations = [math]::pow($CharacterSet.Length,$PasswordPlain.Length) $BlindEntropy = [math]::round([math]::log($BlindPermutations,2)) # Remove plain password variable and garbage collect Remove-Variable -Name PasswordPlain [System.GC]::Collect() if (!($SeenEntropy)){ # If not using a word format the seen entropy will be the same as blind entropy $SeenEntropy = $BlindEntropy } $TotalEntropy = [PSCustomObject]@{ SeenEntropy = $SeenEntropy BlindEntropy = $BlindEntropy } Write-Output $TotalEntropy } |