Good for converting .dll files into Base64 strings, in order to embed .dll files into scripts. This allows you to either export the .dll to disk, or attempt to run from memory.

ConvertFileto-Base64.ps1

function ConvertFileTo-Base64 {
    param(
        [Parameter(Mandatory=$true)]
        [string] $SourceFilePath,

        [Parameter(Mandatory=$true)]
        [string] $TargetFilePath
    )
 
    $SourceFilePath = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($SourceFilePath)
    $TargetFilePath = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($TargetFilePath)
     
    $bufferSize = 9000 # should be a multiplier of 3
    $buffer = New-Object byte[] $bufferSize
     
    $reader = [System.IO.File]::OpenRead($SourceFilePath)
    $writer = [System.IO.File]::CreateText($TargetFilePath)
     
    $bytesRead = 0

    do {
        $bytesRead = $reader.Read($buffer, 0, $bufferSize);
        $writer.Write([Convert]::ToBase64String($buffer, 0, $bytesRead));
    } while ($bytesRead -eq $bufferSize);
     
    $reader.Dispose()
    $writer.Dispose()
}