#$links = .\get-downloadlinkswithhash.ps1 -UpdateId "244bab40-f647-4394-bee0-b03f897404d8"
#$links.URL
#$links.FILENAME

Param($UpdateId)
if ($PSBoundParameters.Count -ne 1)  { Write-host "Error: -UpdateId <GUID>" ;exit 1}

$PostJson = @{size = 0; UpdateID = $UpdateId; UpdateIDInfo = $UpdateId} | ConvertTo-Json -Compress
$Body = @{UpdateIDs = "[$PostJson]"}
$ret = Invoke-WebRequest `
    -Uri 'https://www.catalog.update.microsoft.com/DownloadDialog.aspx' `
    -UseBasicParsing `
    -Method Post `
    -ContentType 'application/x-www-form-urlencoded' `
    -Body $body
$pattern = "files\[(\d+)\]\.(url|digest|sha256)\s*=\s*'([^']+)'"

$map = @{}
foreach ($m in [regex]::Matches($ret, $pattern)) {
    $idx = [int]$m.Groups[1].Value
    $key = $m.Groups[2].Value
    $val = $m.Groups[3].Value

    if (-not $map.ContainsKey($idx)) {
        $map[$idx] = [ordered]@{
            Index = $idx
            url = $null
            digest = $null
            sha256 = $null
            fileName = $null
        }
    }
    $map[$idx][$key] = $val
    if ($key -eq 'url') {
        $map[$idx]['fileName'] = [System.IO.Path]::GetFileName($val)
    }
}

$items = $map.GetEnumerator() |
          Sort-Object Key |
          ForEach-Object { [pscustomobject]$_.Value }
$items