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  *
   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 using System.IO;
  27 using System.Security.Cryptography;
  28
  29 using Mono.Security.Cryptography;
  30
  31 namespace Mono.Security.Protocol.Tls.Handshake.Client
  32 {
  33         internal class TlsClientKeyExchange : HandshakeMessage
  34         {
  35                 #region Constructors
  36
  37                 public TlsClientKeyExchange (Context context) :
  38                         base(context, HandshakeType.ClientKeyExchange)
  39                 {
  40                 }
  41
  42                 #endregion
  43
  44                 #region Protected Methods
  45
  46                 protected override void ProcessAsSsl3()
  47                 {
  48                         // Compute pre master secret
  49                         byte[] preMasterSecret = this.Context.Cipher.CreatePremasterSecret();
  50
  51                         // Create a new RSA key
  52                         RSA rsa = null;
  53                         if (this.Context.ServerSettings.ServerKeyExchange)
  54                         {
  55                                 // this is the case for "exportable" ciphers
  56                                 rsa = new RSAManaged ();
  57                                 rsa.ImportParameters (this.Context.ServerSettings.RsaParameters);
  58                         }
  59                         else
  60                         {
  61                                 rsa = this.Context.ServerSettings.CertificateRSA;
  62                         }
  63
  64                         // Encrypt premaster_sercret
  65                         RSAPKCS1KeyExchangeFormatter formatter = new RSAPKCS1KeyExchangeFormatter(rsa);
  66
  67                         // Write the preMasterSecret encrypted
  68                         byte[] buffer = formatter.CreateKeyExchange(preMasterSecret);
  69                         this.Write(buffer);
  70
  71                         // Create master secret
  72                         this.Context.Cipher.ComputeMasterSecret(preMasterSecret);
  73
  74                         // Create keys
  75                         this.Context.Cipher.ComputeKeys();
  76
  77                         // Clear resources
  78                         rsa.Clear();
  79                 }
  80
  81                 protected override void ProcessAsTls1()
  82                 {
  83                         // Compute pre master secret
  84                         byte[] preMasterSecret = this.Context.Cipher.CreatePremasterSecret();
  85
  86                         // Create a new RSA key
  87                         RSA rsa = null;
  88                         if (this.Context.ServerSettings.ServerKeyExchange)
  89                         {
  90                                 // this is the case for "exportable" ciphers
  91                                 rsa = new RSAManaged ();
  92                                 rsa.ImportParameters (this.Context.ServerSettings.RsaParameters);
  93                         }
  94                         else
  95                         {
  96                                 rsa = this.Context.ServerSettings.CertificateRSA;
  97                         }
  98
  99                         // Encrypt premaster_sercret
 100                         RSAPKCS1KeyExchangeFormatter formatter = new RSAPKCS1KeyExchangeFormatter(rsa);
 101
 102                         // Write the preMasterSecret encrypted
 103                         byte[] buffer = formatter.CreateKeyExchange(preMasterSecret);
 104                         this.Write((short)buffer.Length);
 105                         this.Write(buffer);
 106
 107                         // Create master secret
 108                         this.Context.Cipher.ComputeMasterSecret(preMasterSecret);
 109
 110                         // Create keys
 111                         this.Context.Cipher.ComputeKeys();
 112
 113                         // Clear resources
 114                         rsa.Clear();
 115                 }
 116
 117                 #endregion
 118         }
 119 }