Yupp, I meant with that code you won't need a temp-file
I'm better in speaking with code ;)
var webClient = new WebClient();
string myKey = webClient.DownloadString("https://10.1.1.45/pk.php?pk=joes_pk");
var privatekeybytes = new MemoryStream(Encoding.Default.GetBytes(myKey));
PrivateKeyFile privatekey = new PrivateKeyFile(privatekeybytes);
Sorry, english is not my native language.I'm better in speaking with code ;)