static async Task <GeminiResponse> ReadMessage(SslStream sslStream)
{
// Read the message sent by the server.
// The end of the message is signaled using the
// "<EOF>" marker.
byte[] buffer = new byte[2048];
int bytes = -1;
bytes = await sslStream.ReadAsync(buffer, 0, buffer.Length);
GeminiResponse resp = new GeminiResponse(buffer.ToList(), bytes);
while (bytes != 0)
{
bytes = await sslStream.ReadAsync(buffer, 0, buffer.Length);
resp.pyld.AddRange(buffer.Take(bytes));
}
return(resp);
}
public async static Task <IResponse> Fetch(Uri hostURL)
{
int refetchCount = 0;
Refetch:
// Stop unbounded redirects
if (refetchCount >= 5)
{
return(new GeminiResponse {
codeMajor = '3',
codeMinor = '9',
meta = "",
pyld = Encoding.UTF8.GetBytes("Too many redirects!").ToList(),
mime = "text/plain",
encoding = "UTF-8"
});
}
refetchCount += 1;
// Set remote port
int port = hostURL.Port;
if (port == -1)
{
port = DefaultPort;
}
// Create a TCP/IP client socket.
// machineName is the host running the server application.
TcpClient client;
try {
client = new TcpClient(hostURL.Host, port);
} catch (Exception e) {
Log.Error(e, "Connection failure");
throw e;
}
// Create an SSL stream that will close the client's stream.
SslStream sslStream = new SslStream(
client.GetStream(),
false,
new RemoteCertificateValidationCallback(ValidateServerCertificate),
null
);
// The server name must match the name on the server certificate.
try {
await sslStream.AuthenticateAsClientAsync(hostURL.Host);
} catch (AuthenticationException e) {
Log.Error(e, "Authentication failure");
client.Close();
throw e;
}
// Gemini request format: URI\r\n
byte[] messsage = Encoding.UTF8.GetBytes(hostURL.ToString() + "\r\n");
await sslStream.WriteAsync(messsage, 0, messsage.Count());
await sslStream.FlushAsync();
// Read message from the server.
GeminiResponse resp = await ReadMessage(sslStream);
// Close the client connection.
client.Close();
// Determine what to do w/ that
switch (resp.codeMajor)
{
//case '1': // Text input
// TODO
//break;
case '2': // OK
break;
case '3': // Redirect
hostURL = new Uri(resp.meta);
goto Refetch;
case '4': // Temporary failure
case '5': // Permanent failure
case '6': // Client cert required
Log.Error(resp.ToString());
resp.pyld = Encoding.UTF8.GetBytes(resp.ToString()).ToList();
break;
default:
throw new Exception(
string.Format("Invalid response code {0}", resp.codeMajor)
);
}
return(resp);
}