ConvertFrom-Base64String.ps1
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<#
.SYNOPSIS Convert Base64 String to Byte Array or Plain Text String. .DESCRIPTION .EXAMPLE PS C:\>ConvertFrom-Base64String "QSBzdHJpbmcgd2l0aCBiYXNlNjQgZW5jb2Rpbmc=" Convert Base64 String to String with Default Encoding. .EXAMPLE PS C:\>"QVNDSUkgc3RyaW5nIHdpdGggYmFzZTY0dXJsIGVuY29kaW5n" | ConvertFrom-Base64String -Base64Url -Encoding Ascii Convert Base64Url String to String with Ascii Encoding. .EXAMPLE PS C:\>[guid](ConvertFrom-Base64String "5oIhNbCaFUGAe8NsiAKfpA==" -RawBytes) Convert Base64 String to GUID. .INPUTS System.String #> function ConvertFrom-Base64String { [CmdletBinding()] [OutputType([byte[]],[string])] param ( # Value to convert [Parameter(Mandatory=$true, Position=0, ValueFromPipeline=$true)] [string[]] $InputObjects, # Use base64url variant [Parameter (Mandatory=$false)] [switch] $Base64Url, # Output raw byte array [Parameter (Mandatory=$false)] [switch] $RawBytes, # Encoding to use for text strings [Parameter (Mandatory=$false)] [ValidateSet('Ascii', 'UTF32', 'UTF7', 'UTF8', 'BigEndianUnicode', 'Unicode')] [string] $Encoding = 'Default' ) process { foreach ($InputObject in $InputObjects) { [string] $strBase64 = $InputObject if (!$PSBoundParameters.ContainsValue('Base64Url') -and ($strBase64.Contains('-') -or $strBase64.Contains('_'))) { $Base64Url = $true } if ($Base64Url) { $strBase64 = $strBase64.Replace('-','+').Replace('_','/').PadRight($strBase64.Length + (4 - $strBase64.Length % 4) % 4, '=') } [byte[]] $outBytes = [System.Convert]::FromBase64String($strBase64) if ($RawBytes) { Write-Output $outBytes -NoEnumerate } else { [string] $outString = ([Text.Encoding]::$Encoding.GetString($outBytes)) Write-Output $outString } } } } |