Base64.psm1
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# Add 'ToBase64String' method to System.String Update-TypeData -TypeName System.String -MemberType ScriptMethod -MemberName ToBase64String -Value { param( [Parameter()] [ValidateSet('ASCII', 'BigEndianUnicode', 'Default', 'Unicode', 'UTF32', 'UTF7', 'UTF8')] [string] $Encoding = 'Default' ) $ErrorActionPreference = 'Stop' try { [System.Convert]::ToBase64String([System.Text.Encoding]::$Encoding.GetBytes($this)) } catch { $_.Exception.Message | Write-Warning } } # Add 'FromBase64String' method to System.String Update-TypeData -TypeName System.String -MemberType ScriptMethod -MemberName FromBase64String -Value { param( [Parameter()] [ValidateSet('ASCII', 'BigEndianUnicode', 'Default', 'Unicode', 'UTF32', 'UTF7', 'UTF8')] [string] $Encoding = 'Default' ) $ErrorActionPreference = 'Stop' try { [System.Text.Encoding]::$Encoding.GetString([System.Convert]::FromBase64String($this)) } catch { $_.Exception.Message | Write-Warning } } function ConvertTo-Base64String { <# .SYNOPSIS Converts the given text to a Base64 string. .EXAMPLE $encodedCommand = ConvertTo-Base64String 'Get-ChildItem $env:TEMP | ?{$_.LastWriteTime -lt (Get-Date).AddDays(-1)}' This example creates a Base64 encoded powershell command. This can be used with powershell.exe's -encodedcommand parameter. .EXAMPLE 'Get-ChildItem $env:TEMP | ?{$_.LastWriteTime -lt (Get-Date).AddDays(-1)}' | ConvertTo-Base64String .INPUTS System.String .OUTPUTS System.String #> [OutputType([String])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [ValidateNotNullOrEmpty()] [String] $Text, [Parameter()] [ValidateSet('ASCII', 'BigEndianUnicode', 'Default', 'Unicode', 'UTF32', 'UTF7', 'UTF8')] [string] $Encoding = 'Default' ) process { $Text.ToBase64String($Encoding) } } function ConvertFrom-Base64String { <# .SYNOPSIS Converts the given Base64 encoded text to the original text. .EXAMPLE $Command = ConvertFrom-Base64String $encodedCommand This example reverse engineers a previously encoded text. .EXAMPLE $encodedCommand | ConvertFrom-Base64String .INPUTS System.String .OUTPUTS System.String #> [OutputType([String])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [ValidateNotNullOrEmpty()] [String] $Text, [Parameter()] [ValidateSet('ASCII', 'BigEndianUnicode', 'Default', 'Unicode', 'UTF32', 'UTF7', 'UTF8')] [string] $Encoding = 'Default' ) process { $Text.FromBase64String($Encoding) } } function ConvertFrom-BinaryFile { <# .SYNOPSIS Convert a given binary file to Base64 string. .DESCRIPTION Base64-encodes binary data. The resulting textual representation can be encrypted with Protect-CmsMessage, for exmaple. .EXAMPLE dir .\secret.exe | ConvertFrom-BinaryFile | Protect-CmsMessage -To .\pubkey.cer -OutFile OutputFile.cms Convert the binary file to Base64 strings, then encrypt: .INPUTS System.IO.FileInfo .OUTPUTS System.String #> [CmdletBinding()] Param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] $Path, [switch] $InsertLineBreaks ) if ($InsertLineBreaks) { $option = [System.Base64FormattingOptions]::InsertLineBreaks } else { $option = [System.Base64FormattingOptions]::None } $content = Get-Content -ReadCount 0 -Encoding Byte -Path $Path [System.Convert]::ToBase64String($content, $option) } function ConvertTo-BinaryFile { <# .SYNOPSIS Convert a given Base64 string to binary file. .DESCRIPTION Converts Base64-encoded data to a binary file. .EXAMPLE Unprotect-CmsMessage -Path .\OutputFile.cms | ConvertTo-BinaryFile -OutputFilePath .\RestoredFile.exe Decrypt CMS message, and convert the resulting Base64 back into a binary file. .INPUTS System.String #> [CmdletBinding()] Param( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] $String, [Parameter(Mandatory = $true)] $Destination ) [System.Convert]::FromBase64String($String) | Set-Content -Path $Destination -Encoding Byte } |