Generate IOTA seed in Powershell using RNGCryptoServiceProvider

GenerateIotaSeed.ps1

# PowerShell script to generate IOTA seed.
# See https://matthewwinstonjohnson.gitbooks.io/iota-guide-and-faq/getting-started/dl-wallet/what-is-my-seed.html 
#   for seed requirements.
# See https://msdn.microsoft.com/en-us/library/system.security.cryptography.rngcryptoserviceprovider(v=vs.110).aspx
#   for the reasoning behind IsFairRoll.

function IsFairRoll($roll, $sides)
{
    $fullSetsOfValues = [Byte]::MaxValue / $sides
    return $roll -lt $sides * $fullSetsOfValues
}

$chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ9"
$rngCsp = New-Object System.Security.Cryptography.RNGCryptoServiceProvider
$totalRolls = 81
$numSides = $chars.Length
$seed = ""
for ($x = 0; $x -lt $totalRolls; $x++)
{
    [byte[]]$randomNumber = @(0)
    do
    {
        $rngCsp.GetBytes($randomNumber)
    }
    while (-not (IsFairRoll $randomNumber[0] $numSides))

    $roll = $randomNumber[0] % $numSides
    $seed += $chars[$roll]
}

$rngCsp.Dispose()
$seed