public virtual IDictionary GetClientExtensions()
{
IDictionary clientExtensions = null;
ProtocolVersion clientVersion = mContext.ClientVersion;
/*
* RFC 5246 7.4.1.4.1. Note: this extension is not meaningful for TLS versions prior to 1.2.
* Clients MUST NOT offer it if they are offering prior versions.
*/
if (TlsUtilities.IsSignatureAlgorithmsExtensionAllowed(clientVersion))
{
// TODO Provide a way for the user to specify the acceptable hash/signature algorithms.
this.mSupportedSignatureAlgorithms = TlsUtilities.GetDefaultSupportedSignatureAlgorithms();
clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(clientExtensions);
TlsUtilities.AddSignatureAlgorithmsExtension(clientExtensions, mSupportedSignatureAlgorithms);
}
if (TlsEccUtilities.ContainsEccCipherSuites(GetCipherSuites()))
{
/*
* RFC 4492 5.1. A client that proposes ECC cipher suites in its ClientHello message
* appends these extensions (along with any others), enumerating the curves it supports
* and the point formats it can parse. Clients SHOULD send both the Supported Elliptic
* Curves Extension and the Supported Point Formats Extension.
*/
/*
* TODO Could just add all the curves since we support them all, but users may not want
* to use unnecessarily large fields. Need configuration options.
*/
this.mNamedCurves = new int[] { NamedCurve.secp256r1, NamedCurve.secp384r1 };
this.mClientECPointFormats = new byte[] { ECPointFormat.uncompressed,
ECPointFormat.ansiX962_compressed_prime, ECPointFormat.ansiX962_compressed_char2, };
clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(clientExtensions);
TlsEccUtilities.AddSupportedEllipticCurvesExtension(clientExtensions, mNamedCurves);
TlsEccUtilities.AddSupportedPointFormatsExtension(clientExtensions, mClientECPointFormats);
}
return(clientExtensions);
}