mcs/class/Mono.Security/Mono.Security.Protocol.Tls.Handshake.Client/TlsServerHello.cs

   1 /* Transport Security Layer (TLS)
   2  * Copyright (c) 2003-2004 Carlos Guzman Alvarez
   3  *
   4  * Permission is hereby granted, free of charge, to any person
   5  * obtaining a copy of this software and associated documentation
   6  * files (the "Software"), to deal in the Software without restriction,
   7  * including without limitation the rights to use, copy, modify, merge,
   8  * publish, distribute, sublicense, and/or sell copies of the Software,
   9  * and to permit persons to whom the Software is furnished to do so,
  10  * subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included
  13  * in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  17  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  19  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  20  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 using System;
  26
  27 namespace Mono.Security.Protocol.Tls.Handshake.Client
  28 {
  29         internal class TlsServerHello : TlsHandshakeMessage
  30         {
  31                 #region Fields
  32
  33                 private SecurityCompressionType compressionMethod;
  34                 private byte[]                                  random;
  35                 private byte[]                                  sessionId;
  36                 private CipherSuite     cipherSuite;
  37
  38                 #endregion
  39
  40                 #region Constructors
  41
  42                 public TlsServerHello(TlsContext context, byte[] buffer)
  43                         : base(context, TlsHandshakeType.ServerHello, buffer)
  44                 {
  45                 }
  46
  47                 #endregion
  48
  49                 #region Methods
  50
  51                 public override void Update()
  52                 {
  53                         base.Update();
  54
  55                         this.Context.SessionId                  = this.sessionId;
  56                         this.Context.ServerRandom               = this.random;
  57                         this.Context.Cipher                             = this.cipherSuite;
  58                         this.Context.CompressionMethod  = this.compressionMethod;
  59                         this.Context.Cipher.Context             = this.Context;
  60
  61                         // Compute ClientRandom + ServerRandom
  62                         TlsStream random = new TlsStream();
  63                         random.Write(this.Context.ClientRandom);
  64                         random.Write(this.Context.ServerRandom);
  65                         this.Context.RandomCS = random.ToArray();
  66
  67                         // Server Random + Client Random
  68                         random.Reset();
  69                         random.Write(this.Context.ServerRandom);
  70                         random.Write(this.Context.ClientRandom);
  71
  72                         this.Context.RandomSC = random.ToArray();
  73                         random.Reset();
  74                 }
  75
  76                 #endregion
  77
  78                 #region Protected Methods
  79
  80                 protected override void ProcessAsSsl3()
  81                 {
  82                         this.ProcessAsTls1();
  83                 }
  84
  85                 protected override void ProcessAsTls1()
  86                 {
  87                         // Read protocol version
  88                         this.processProtocol(this.ReadInt16());
  89
  90                         // Read random  - Unix time + Random bytes
  91                         this.random     = this.ReadBytes(32);
  92
  93                         // Read Session id
  94                         int length = (int)ReadByte();
  95                         if (length > 0)
  96                         {
  97                                 this.sessionId = this.ReadBytes(length);
  98                         }
  99
 100                         // Read cipher suite
 101                         short cipherCode = this.ReadInt16();
 102                         if (this.Context.SupportedCiphers.IndexOf(cipherCode) == -1)
 103                         {
 104                                 // The server has sent an invalid ciphersuite
 105                                 throw new TlsException("Invalid cipher suite received from server");
 106                         }
 107                         this.cipherSuite = this.Context.SupportedCiphers[cipherCode];
 108
 109                         // Read compression methods ( always 0 )
 110                         this.compressionMethod = (SecurityCompressionType)this.ReadByte();
 111                 }
 112
 113                 #endregion
 114
 115                 #region Private Methods
 116
 117                 private void processProtocol(short protocol)
 118                 {
 119                         SecurityProtocolType serverProtocol = this.Context.DecodeProtocolCode(protocol);
 120
 121                         if ((serverProtocol & this.Context.SecurityProtocolFlags) == serverProtocol)
 122                         {
 123                                 this.Context.SecurityProtocol = serverProtocol;
 124                                 this.Context.SupportedCiphers.Clear();
 125                                 this.Context.SupportedCiphers = null;
 126                                 this.Context.SupportedCiphers = TlsCipherSuiteFactory.GetSupportedCiphers(serverProtocol);
 127                         }
 128                         else
 129                         {
 130                                 throw this.Context.CreateException("Incorrect protocol version received from server");
 131                         }
 132                 }
 133
 134                 #endregion
 135         }
 136 }