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// Transport Security Layer (TLS)
// Copyright (c) 2003-2004 Carlos Guzman Alvarez
// Copyright (C) 2006 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
namespace Mono.Security.Protocol.Tls.Handshake.Client
{
internal class TlsServerHello : HandshakeMessage
{
#region Fields
private SecurityCompressionType compressionMethod;
private byte[] random;
private byte[] sessionId;
private CipherSuite cipherSuite;
#endregion
#region Constructors
public TlsServerHello(Context context, byte[] buffer)
: base(context, HandshakeType.ServerHello, buffer)
{
}
#endregion
#region Methods
public override void Update()
{
base.Update();
this.Context.SessionId = this.sessionId;
this.Context.ServerRandom = this.random;
this.Context.Negotiating.Cipher = this.cipherSuite;
this.Context.CompressionMethod = this.compressionMethod;
this.Context.ProtocolNegotiated = true;
DebugHelper.WriteLine("Selected Cipher Suite {0}", this.cipherSuite.Name);
DebugHelper.WriteLine("Client random", this.Context.ClientRandom);
DebugHelper.WriteLine("Server random", this.Context.ServerRandom);
// Compute ClientRandom + ServerRandom
int clen = this.Context.ClientRandom.Length;
int slen = this.Context.ServerRandom.Length;
int rlen = clen + slen;
byte[] cs = new byte[rlen];
Buffer.BlockCopy (this.Context.ClientRandom, 0, cs, 0, clen);
Buffer.BlockCopy (this.Context.ServerRandom, 0, cs, clen, slen);
this.Context.RandomCS = cs;
// Server Random + Client Random
byte[] sc = new byte[rlen];
Buffer.BlockCopy (this.Context.ServerRandom, 0, sc, 0, slen);
Buffer.BlockCopy (this.Context.ClientRandom, 0, sc, slen, clen);
this.Context.RandomSC = sc;
}
#endregion
#region Protected Methods
protected override void ProcessAsSsl3()
{
this.ProcessAsTls1();
}
protected override void ProcessAsTls1()
{
// Read protocol version
this.processProtocol(this.ReadInt16());
// Read random - Unix time + Random bytes
this.random = this.ReadBytes(32);
// Read Session id
int length = (int) ReadByte ();
if (length > 0)
{
this.sessionId = this.ReadBytes(length);
ClientSessionCache.Add (this.Context.ClientSettings.TargetHost, this.sessionId);
this.Context.AbbreviatedHandshake = Compare (this.sessionId, this.Context.SessionId);
}
else
{
this.Context.AbbreviatedHandshake = false;
}
// Read cipher suite
short cipherCode = this.ReadInt16();
if (this.Context.SupportedCiphers.IndexOf(cipherCode) == -1)
{
// The server has sent an invalid ciphersuite
throw new TlsException(AlertDescription.InsuficientSecurity, "Invalid cipher suite received from server");
}
this.cipherSuite = this.Context.SupportedCiphers[cipherCode];
// Read compression methods ( always 0 )
this.compressionMethod = (SecurityCompressionType)this.ReadByte();
}
#endregion
#region Private Methods
private void processProtocol(short protocol)
{
SecurityProtocolType serverProtocol = this.Context.DecodeProtocolCode(protocol);
if ((serverProtocol & this.Context.SecurityProtocolFlags) == serverProtocol ||
(this.Context.SecurityProtocolFlags & SecurityProtocolType.Default) == SecurityProtocolType.Default)
{
this.Context.SecurityProtocol = serverProtocol;
this.Context.SupportedCiphers.Clear();
this.Context.SupportedCiphers = null;
this.Context.SupportedCiphers = CipherSuiteFactory.GetSupportedCiphers(serverProtocol);
DebugHelper.WriteLine("Selected protocol {0}", serverProtocol);
}
else
{
throw new TlsException(
AlertDescription.ProtocolVersion,
"Incorrect protocol version received from server");
}
}
#endregion
}
}
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