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

   1 // Transport Security Layer (TLS)
   2 // Copyright (c) 2003-2004 Carlos Guzman Alvarez
   3 // Copyright (C) 2006 Novell, Inc (http://www.novell.com)
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining
   6 // a copy of this software and associated documentation files (the
   7 // "Software"), to deal in the Software without restriction, including
   8 // without limitation the rights to use, copy, modify, merge, publish,
   9 // distribute, sublicense, and/or sell copies of the Software, and to
  10 // permit persons to whom the Software is furnished to do so, subject to
  11 // the following conditions:
  12 //
  13 // The above copyright notice and this permission notice shall be
  14 // included in all copies or substantial portions of the Software.
  15 //
  16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  20 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23 //
  24
  25 using System;
  26 using System.Security.Cryptography;
  27
  28 using Mono.Security.Cryptography;
  29
  30 namespace Mono.Security.Protocol.Tls.Handshake.Client
  31 {
  32         internal class TlsClientKeyExchange : HandshakeMessage
  33         {
  34                 #region Constructors
  35
  36                 public TlsClientKeyExchange (Context context) :
  37                         base(context, HandshakeType.ClientKeyExchange)
  38                 {
  39                 }
  40
  41                 #endregion
  42
  43                 #region Protected Methods
  44
  45                 protected override void ProcessAsSsl3()
  46                 {
  47                         // a large chunk of code is common to both SSL3 and TLS1
  48                         // SSL3 doesn't send the length of the buffer
  49                         ProcessCommon (false);
  50                 }
  51
  52                 protected override void ProcessAsTls1()
  53                 {
  54                         // a large chunk of code is common to both SSL3 and TLS1
  55                         // TLS1 does send the length of the buffer
  56                         ProcessCommon (true);
  57                 }
  58
  59                 public void ProcessCommon (bool sendLength)
  60                 {
  61                         // Compute pre master secret
  62                         byte[] preMasterSecret = this.Context.Negotiating.Cipher.CreatePremasterSecret ();
  63
  64                         // Create a new RSA key
  65                         RSA rsa = null;
  66                         if (this.Context.ServerSettings.ServerKeyExchange)
  67                         {
  68                                 // this is the case for "exportable" ciphers
  69                                 rsa = new RSAManaged ();
  70                                 rsa.ImportParameters (this.Context.ServerSettings.RsaParameters);
  71                         }
  72                         else
  73                         {
  74                                 rsa = this.Context.ServerSettings.CertificateRSA;
  75                         }
  76
  77                         // Encrypt premaster_sercret
  78                         RSAPKCS1KeyExchangeFormatter formatter = new RSAPKCS1KeyExchangeFormatter (rsa);
  79
  80                         // Write the preMasterSecret encrypted
  81                         byte[] buffer = formatter.CreateKeyExchange (preMasterSecret);
  82                         if (sendLength)
  83                                 this.Write ((short) buffer.Length);
  84                         this.Write (buffer);
  85
  86                         // Create master secret
  87                         this.Context.Negotiating.Cipher.ComputeMasterSecret (preMasterSecret);
  88
  89                         // Create keys
  90                         this.Context.Negotiating.Cipher.ComputeKeys ();
  91
  92                         // Clear resources
  93                         rsa.Clear ();
  94                 }
  95
  96                 #endregion
  97         }
  98 }