예제 #1
0
        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);
        }
예제 #2
0
        // IDictionary is (Int32 -> byte[])
        public virtual IDictionary GetServerExtensions()
        {
            if (this.mEncryptThenMacOffered && AllowEncryptThenMac)
            {
                /*
                 * RFC 7366 3. If a server receives an encrypt-then-MAC request extension from a client
                 * and then selects a stream or Authenticated Encryption with Associated Data (AEAD)
                 * ciphersuite, it MUST NOT send an encrypt-then-MAC response extension back to the
                 * client.
                 */
                if (TlsUtilities.IsBlockCipherSuite(this.mSelectedCipherSuite))
                {
                    TlsExtensionsUtilities.AddEncryptThenMacExtension(CheckServerExtensions());
                }
            }

            if (this.mMaxFragmentLengthOffered >= 0 &&
                TlsUtilities.IsValidUint8(mMaxFragmentLengthOffered) &&
                MaxFragmentLength.IsValid((byte)mMaxFragmentLengthOffered))
            {
                TlsExtensionsUtilities.AddMaxFragmentLengthExtension(CheckServerExtensions(), (byte)mMaxFragmentLengthOffered);
            }

            if (this.mTruncatedHMacOffered && AllowTruncatedHMac)
            {
                TlsExtensionsUtilities.AddTruncatedHMacExtension(CheckServerExtensions());
            }

            if (this.mClientECPointFormats != null && TlsEccUtilities.IsEccCipherSuite(this.mSelectedCipherSuite))
            {
                /*
                 * RFC 4492 5.2. A server that selects an ECC cipher suite in response to a ClientHello
                 * message including a Supported Point Formats Extension appends this extension (along
                 * with others) to its ServerHello message, enumerating the point formats it can parse.
                 */
                this.mServerECPointFormats = new byte[] { ECPointFormat.uncompressed,
                                                          ECPointFormat.ansiX962_compressed_prime, ECPointFormat.ansiX962_compressed_char2, };

                TlsEccUtilities.AddSupportedPointFormatsExtension(CheckServerExtensions(), mServerECPointFormats);
            }

            return(mServerExtensions);
        }