private static async Task <Record> HandleResponse(NetworkStream s, TlsRequestParameters requestParameters)
{
byte[] buffer = new byte[1024];
int bytesRead = await s.ReadAsync(buffer, 0, 1024);
if (bytesRead <= 0)
{
Console.WriteLine("Not enough data! :O ");
return(null);
}
return(RecordFactory.Create(new Span <byte>(buffer)));
}
private const int ServerReadTimeoutInSeconds = 3; // TODO: Have this configurable in case this isn't big enough.
public static async Task <IEnumerable <ProtocolVersion> > GetSupportedProtocolVersionsAsync(string hostName, int port = 443)
{
List <ProtocolVersion> supportedVersions = new List <ProtocolVersion>();
foreach (var version in Enum.GetValues(typeof(ProtocolVersion)).Cast <ProtocolVersion>())
{
Record response = await SendClientHelloAsync(TlsRequestParameters.Create(hostName, port, version, version, null));
bool supported = response.ContentType == RecordContentTypes.Handshake;
if (supported)
{
supportedVersions.Add(version);
}
}
return(supportedVersions);
}
private static async Task <Record> SendClientHelloAsync(TlsRequestParameters requestParameters)
{
if (requestParameters.CipherSuites == null)
{
requestParameters.CipherSuites = new CipherSuites[]
{
Tls.CipherSuites.TLS_AES_128_GCM_SHA256,
Tls.CipherSuites.TLS_AES_256_GCM_SHA384,
Tls.CipherSuites.TLS_CHACHA20_POLY1305_SHA256,
Tls.CipherSuites.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
Tls.CipherSuites.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
Tls.CipherSuites.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
Tls.CipherSuites.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
Tls.CipherSuites.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
Tls.CipherSuites.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
Tls.CipherSuites.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
Tls.CipherSuites.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
Tls.CipherSuites.TLS_RSA_WITH_AES_128_GCM_SHA256,
Tls.CipherSuites.TLS_RSA_WITH_AES_256_GCM_SHA384,
Tls.CipherSuites.TLS_RSA_WITH_AES_128_CBC_SHA,
Tls.CipherSuites.TLS_RSA_WITH_AES_256_CBC_SHA,
Tls.CipherSuites.TLS_RSA_WITH_3DES_EDE_CBC_SHA
};
}
using (TcpClient client = new TcpClient())
{
await client.ConnectAsync(requestParameters.Host, requestParameters.Port);
NetworkStream s = client.GetStream();
s.ReadTimeout = ServerReadTimeoutInSeconds * 1000;
ClientHello hello = new ClientHello(
requestParameters.HandshakeVersion,
requestParameters.CipherSuites,
requestParameters.RecordVersion);
await WriteRecordToStreamAsync(hello, s);
return(await HandleResponse(s, requestParameters));
}
}
public static async Task <IEnumerable <CipherSuites> > GetSupportedCipherSuitesAsync(string hostName, int port = 443, ProtocolVersion protocolVersion = ProtocolVersion.Tls12)
{
List <CipherSuites> supportedCipherSuites = new List <CipherSuites>();
foreach (CipherSuites suite in Enum.GetValues(typeof(CipherSuites)).Cast <CipherSuites>())
{
Record response = await SendClientHelloAsync(TlsRequestParameters.Create(hostName, port, protocolVersion, protocolVersion, new CipherSuites[] { suite }));
if (response == null)
{
throw new Exception("No response received from server. Check the host name and port number.");
}
bool supported = response.ContentType == RecordContentTypes.Handshake;
if (supported)
{
supportedCipherSuites.Add(suite);
}
}
return(supportedCipherSuites);
}
