private static NatsServerInfo VerifyConnection(Host host, ConnectionInfo connectionInfo, Socket socket, Func <IOp> readOne)
{
if (!socket.Connected)
{
throw NatsException.FailedToConnectToHost(host, "No connection could be established.");
}
var op = readOne();
if (op == null)
{
throw NatsException.FailedToConnectToHost(host, "Expected to get INFO after establishing connection. Got nothing.");
}
var infoOp = op as InfoOp;
if (infoOp == null)
{
throw NatsException.FailedToConnectToHost(host, $"Expected to get INFO after establishing connection. Got {op.GetType().Name}.");
}
Logger.Debug($"Got INFO during connect. {infoOp.GetAsString()}");
var serverInfo = NatsServerInfo.Parse(infoOp.Message);
var credentials = host.HasNonEmptyCredentials() ? host.Credentials : connectionInfo.Credentials;
if (serverInfo.AuthRequired && (credentials == null || credentials == Credentials.Empty))
{
throw NatsException.MissingCredentials(host);
}
socket.Send(ConnectCmd.Generate(connectionInfo.Verbose, credentials));
socket.Send(PingCmd.Generate());
op = readOne();
if (op == null)
{
throw NatsException.FailedToConnectToHost(host, "Expected to read something after CONNECT and PING. Got nothing.");
}
if (op is ErrOp)
{
throw NatsException.FailedToConnectToHost(host, $"Expected to get PONG after sending CONNECT and PING. Got {op.GetAsString()}.");
}
if (!socket.Connected)
{
throw NatsException.FailedToConnectToHost(host, "No connection could be established.");
}
return(serverInfo);
}
private async Task <(INatsConnection connection, IList <IOp> consumedOps)> EstablishConnectionAsync(
Host host,
ConnectionInfo connectionInfo,
CancellationToken cancellationToken)
{
var serverCertificateValidation = connectionInfo.ServerCertificateValidation ?? DefaultServerCertificateValidation;
bool RemoteCertificateValidationCallback(object _, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
=> serverCertificateValidation(certificate, chain, errors);
var consumedOps = new List <IOp>();
Socket socket = null;
Stream stream = null;
try
{
socket = _socketFactory.Create(connectionInfo.SocketOptions);
await socket.ConnectAsync(
host,
connectionInfo.SocketOptions.ConnectTimeoutMs,
cancellationToken).ConfigureAwait(false);
stream = socket.CreateReadWriteStream();
var reader = new NatsOpStreamReader(stream);
var op = reader.ReadOneOp();
if (op == null)
{
throw NatsException.FailedToConnectToHost(host,
"Expected to get INFO after establishing connection. Got nothing.");
}
if (!(op is InfoOp infoOp))
{
throw NatsException.FailedToConnectToHost(host,
$"Expected to get INFO after establishing connection. Got {op.GetType().Name}.");
}
var serverInfo = NatsServerInfo.Parse(infoOp.Message);
var credentials = host.HasNonEmptyCredentials() ? host.Credentials : connectionInfo.Credentials;
if (serverInfo.AuthRequired && (credentials == null || credentials == Credentials.Empty))
{
throw NatsException.MissingCredentials(host);
}
if (serverInfo.TlsVerify && connectionInfo.ClientCertificates.Count == 0)
{
throw NatsException.MissingClientCertificates(host);
}
consumedOps.Add(op);
if (serverInfo.TlsRequired)
{
await stream.DisposeAsync();
stream = new SslStream(socket.CreateReadWriteStream(), false, RemoteCertificateValidationCallback, null, EncryptionPolicy.RequireEncryption);
var ssl = (SslStream)stream;
var clientAuthOptions = new SslClientAuthenticationOptions
{
RemoteCertificateValidationCallback = RemoteCertificateValidationCallback,
AllowRenegotiation = true,
CertificateRevocationCheckMode = X509RevocationMode.Online,
ClientCertificates = connectionInfo.ClientCertificates,
EnabledSslProtocols = SslProtocols.Tls12,
EncryptionPolicy = EncryptionPolicy.RequireEncryption,
TargetHost = host.Address
};
await ssl.AuthenticateAsClientAsync(clientAuthOptions, cancellationToken).ConfigureAwait(false);
reader = new NatsOpStreamReader(ssl);
}
stream.Write(ConnectCmd.Generate(connectionInfo.Verbose, credentials, connectionInfo.Name));
stream.Write(PingCmd.Bytes.Span);
await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
op = reader.ReadOneOp();
if (op == null)
{
throw NatsException.FailedToConnectToHost(host,
"Expected to read something after CONNECT and PING. Got nothing.");
}
if (op is ErrOp)
{
throw NatsException.FailedToConnectToHost(host,
$"Expected to get PONG after sending CONNECT and PING. Got {op.GetAsString()}.");
}
if (!socket.Connected)
{
throw NatsException.FailedToConnectToHost(host, "No connection could be established.");
}
consumedOps.Add(op);
return(
new NatsConnection(
serverInfo,
socket,
stream,
cancellationToken),
consumedOps);
}
catch
{
Swallow.Everything(
() =>
{
stream?.Dispose();
stream = null;
},
() =>
{
if (socket == null)
{
return;
}
if (socket.Connected)
{
socket.Shutdown(SocketShutdown.Both);
}
socket.Dispose();
socket = null;
});
throw;
}
}
