1 // Transport Security Layer (TLS)
2 // Copyright (c) 2003-2004 Carlos Guzman Alvarez
3 // Copyright (C) 2006 Novell, Inc (http://www.novell.com)
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:
13 // The above copyright notice and this permission notice shall be
14 // included in all copies or substantial portions of the Software.
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.
27 using System.Security.Cryptography;
29 namespace Mono.Security.Protocol.Tls
31 internal class TlsCipherSuite : CipherSuite
33 private const int MacHeaderLength = 13;
34 private byte[] header;
38 public TlsCipherSuite(
39 short code, string name, CipherAlgorithmType cipherAlgorithmType,
40 HashAlgorithmType hashAlgorithmType, ExchangeAlgorithmType exchangeAlgorithmType,
41 bool exportable, bool blockMode, byte keyMaterialSize,
42 byte expandedKeyMaterialSize, short effectiveKeyBytes,
43 byte ivSize, byte blockSize)
44 :base(code, name, cipherAlgorithmType, hashAlgorithmType,
45 exchangeAlgorithmType, exportable, blockMode, keyMaterialSize,
46 expandedKeyMaterialSize, effectiveKeyBytes, ivSize, blockSize)
52 #region MAC Generation Methods
54 public override byte[] ComputeServerRecordMAC(ContentType contentType, byte[] fragment)
57 header = new byte [MacHeaderLength];
59 ulong seqnum = (Context is ClientContext) ? Context.ReadSequenceNumber : Context.WriteSequenceNumber;
60 Write (header, 0, seqnum);
61 header [8] = (byte) contentType;
62 Write (header, 9, this.Context.Protocol);
63 Write (header, 11, (short)fragment.Length);
65 HashAlgorithm mac = this.ServerHMAC;
66 mac.TransformBlock (header, 0, header.Length, header, 0);
67 mac.TransformBlock (fragment, 0, fragment.Length, fragment, 0);
68 // hack, else the method will allocate a new buffer of the same length (negative half the optimization)
69 mac.TransformFinalBlock (CipherSuite.EmptyArray, 0, 0);
73 public override byte[] ComputeClientRecordMAC(ContentType contentType, byte[] fragment)
76 header = new byte [MacHeaderLength];
78 ulong seqnum = (Context is ClientContext) ? Context.WriteSequenceNumber : Context.ReadSequenceNumber;
79 Write (header, 0, seqnum);
80 header [8] = (byte) contentType;
81 Write (header, 9, this.Context.Protocol);
82 Write (header, 11, (short)fragment.Length);
84 HashAlgorithm mac = this.ClientHMAC;
85 mac.TransformBlock (header, 0, header.Length, header, 0);
86 mac.TransformBlock (fragment, 0, fragment.Length, fragment, 0);
87 // hack, else the method will allocate a new buffer of the same length (negative half the optimization)
88 mac.TransformFinalBlock (CipherSuite.EmptyArray, 0, 0);
94 #region Key Generation Methods
96 public override void ComputeMasterSecret(byte[] preMasterSecret)
98 // Create master secret
99 this.Context.MasterSecret = new byte[preMasterSecret.Length];
100 this.Context.MasterSecret = this.PRF(
101 preMasterSecret, "master secret", this.Context.RandomCS, 48);
103 DebugHelper.WriteLine(">>>> MasterSecret", this.Context.MasterSecret);
106 public override void ComputeKeys()
109 TlsStream keyBlock = new TlsStream(
111 this.Context.MasterSecret,
113 this.Context.RandomSC,
116 this.Context.Negotiating.ClientWriteMAC = keyBlock.ReadBytes(this.HashSize);
117 this.Context.Negotiating.ServerWriteMAC = keyBlock.ReadBytes(this.HashSize);
118 this.Context.ClientWriteKey = keyBlock.ReadBytes(this.KeyMaterialSize);
119 this.Context.ServerWriteKey = keyBlock.ReadBytes(this.KeyMaterialSize);
121 if (!this.IsExportable)
123 if (this.IvSize != 0)
125 this.Context.ClientWriteIV = keyBlock.ReadBytes(this.IvSize);
126 this.Context.ServerWriteIV = keyBlock.ReadBytes(this.IvSize);
130 this.Context.ClientWriteIV = CipherSuite.EmptyArray;
131 this.Context.ServerWriteIV = CipherSuite.EmptyArray;
136 // Generate final write keys
137 byte[] finalClientWriteKey = PRF(this.Context.ClientWriteKey, "client write key", this.Context.RandomCS, this.ExpandedKeyMaterialSize);
138 byte[] finalServerWriteKey = PRF(this.Context.ServerWriteKey, "server write key", this.Context.RandomCS, this.ExpandedKeyMaterialSize);
140 this.Context.ClientWriteKey = finalClientWriteKey;
141 this.Context.ServerWriteKey = finalServerWriteKey;
146 byte[] ivBlock = PRF(CipherSuite.EmptyArray, "IV block", this.Context.RandomCS, this.IvSize*2);
149 this.Context.ClientWriteIV = new byte[this.IvSize];
150 Buffer.BlockCopy(ivBlock, 0, this.Context.ClientWriteIV, 0, this.Context.ClientWriteIV.Length);
152 this.Context.ServerWriteIV = new byte[this.IvSize];
153 Buffer.BlockCopy(ivBlock, this.IvSize, this.Context.ServerWriteIV, 0, this.Context.ServerWriteIV.Length);
157 this.Context.ClientWriteIV = CipherSuite.EmptyArray;
158 this.Context.ServerWriteIV = CipherSuite.EmptyArray;
162 DebugHelper.WriteLine(">>>> KeyBlock", keyBlock.ToArray());
163 DebugHelper.WriteLine(">>>> ClientWriteKey", this.Context.ClientWriteKey);
164 DebugHelper.WriteLine(">>>> ClientWriteIV", this.Context.ClientWriteIV);
165 DebugHelper.WriteLine(">>>> ClientWriteMAC", this.Context.Negotiating.ClientWriteMAC);
166 DebugHelper.WriteLine(">>>> ServerWriteKey", this.Context.ServerWriteKey);
167 DebugHelper.WriteLine(">>>> ServerWriteIV", this.Context.ServerWriteIV);
168 DebugHelper.WriteLine(">>>> ServerWriteMAC", this.Context.Negotiating.ServerWriteMAC);
170 ClientSessionCache.SetContextInCache (this.Context);
171 // Clear no more needed data