mcs/class/Mono.Security/Mono.Security.Protocol.Tls/Context.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.Text;
  27 using System.Collections;
  28 using System.Security.Cryptography;
  29 using System.Security.Cryptography.X509Certificates;
  30
  31 using Mono.Security.Cryptography;
  32 using Mono.Security.Protocol.Tls.Handshake;
  33
  34 namespace Mono.Security.Protocol.Tls
  35 {
  36         internal abstract class Context
  37         {
  38                 #region Internal Constants
  39
  40                 internal const short MAX_FRAGMENT_SIZE  = 16384; // 2^14
  41                 internal const short TLS1_PROTOCOL_CODE = (0x03 << 8) | 0x01;
  42                 internal const short SSL3_PROTOCOL_CODE = (0x03 << 8) | 0x00;
  43                 internal const long  UNIX_BASE_TICKS    = 621355968000000000;
  44
  45                 #endregion
  46
  47                 #region Fields
  48
  49                 // Protocol version
  50                 private SecurityProtocolType securityProtocol;
  51
  52                 // Sesison ID
  53                 private byte[] sessionId;
  54
  55                 // Compression method
  56                 private SecurityCompressionType compressionMethod;
  57
  58                 // Information sent and request by the server in the Handshake protocol
  59                 private TlsServerSettings serverSettings;
  60
  61                 // Client configuration
  62                 private TlsClientSettings clientSettings;
  63
  64                 // Cipher suite information
  65                 private SecurityParameters current;
  66                 private SecurityParameters negotiating;
  67                 private SecurityParameters read;
  68                 private SecurityParameters write;
  69                 private CipherSuiteCollection supportedCiphers;
  70
  71                 // Last handshake message received
  72                 private HandshakeType lastHandshakeMsg;
  73
  74                 // Handshake negotiation state
  75                 private HandshakeState handshakeState;
  76
  77                 // Misc
  78                 private bool    abbreviatedHandshake;
  79                 private bool    connectionEnd;
  80                 private bool    protocolNegotiated;
  81
  82                 // Sequence numbers
  83                 private ulong   writeSequenceNumber;
  84                 private ulong   readSequenceNumber;
  85
  86                 // Random data
  87                 private byte[]  clientRandom;
  88                 private byte[]  serverRandom;
  89                 private byte[]  randomCS;
  90                 private byte[]  randomSC;
  91
  92                 // Key information
  93                 private byte[]  masterSecret;
  94                 private byte[]  clientWriteKey;
  95                 private byte[]  serverWriteKey;
  96                 private byte[]  clientWriteIV;
  97                 private byte[]  serverWriteIV;
  98
  99                 // Handshake hashes
 100                 private TlsStream handshakeMessages;
 101
 102                 // Secure Random generator
 103                 private RandomNumberGenerator random;
 104
 105                 // Record protocol
 106                 private RecordProtocol recordProtocol;
 107
 108                 #endregion
 109
 110                 #region Properties
 111
 112                 public bool AbbreviatedHandshake
 113                 {
 114                         get { return abbreviatedHandshake; }
 115                         set { abbreviatedHandshake = value; }
 116                 }
 117
 118                 public bool     ProtocolNegotiated
 119                 {
 120                         get { return this.protocolNegotiated; }
 121                         set { this.protocolNegotiated = value; }
 122                 }
 123
 124                 public SecurityProtocolType SecurityProtocol
 125                 {
 126                         get
 127                         {
 128                                 if ((this.securityProtocol & SecurityProtocolType.Tls) == SecurityProtocolType.Tls ||
 129                                         (this.securityProtocol & SecurityProtocolType.Default) == SecurityProtocolType.Default)
 130                                 {
 131                                         return SecurityProtocolType.Tls;
 132                                 }
 133                                 else
 134                                 {
 135                                         if ((this.securityProtocol & SecurityProtocolType.Ssl3) == SecurityProtocolType.Ssl3)
 136                                         {
 137                                                 return SecurityProtocolType.Ssl3;
 138                                         }
 139                                 }
 140
 141                                 throw new NotSupportedException("Unsupported security protocol type");
 142                         }
 143
 144                         set { this.securityProtocol = value; }
 145                 }
 146
 147                 public SecurityProtocolType SecurityProtocolFlags
 148                 {
 149                         get { return this.securityProtocol; }
 150                 }
 151
 152                 public short Protocol
 153                 {
 154                         get
 155                         {
 156                                 switch (this.SecurityProtocol)
 157                                 {
 158                                         case SecurityProtocolType.Tls:
 159                                         case SecurityProtocolType.Default:
 160                                                 return Context.TLS1_PROTOCOL_CODE;
 161
 162                                         case SecurityProtocolType.Ssl3:
 163                                                 return Context.SSL3_PROTOCOL_CODE;
 164
 165                                         case SecurityProtocolType.Ssl2:
 166                                         default:
 167                                                 throw new NotSupportedException("Unsupported security protocol type");
 168                                 }
 169                         }
 170                 }
 171
 172                 public byte[] SessionId
 173                 {
 174                         get { return this.sessionId; }
 175                         set { this.sessionId = value; }
 176                 }
 177
 178                 public SecurityCompressionType CompressionMethod
 179                 {
 180                         get { return this.compressionMethod; }
 181                         set { this.compressionMethod = value; }
 182                 }
 183
 184                 public TlsServerSettings ServerSettings
 185                 {
 186                         get { return this.serverSettings; }
 187                 }
 188
 189                 public TlsClientSettings ClientSettings
 190                 {
 191                         get { return this.clientSettings; }
 192                 }
 193
 194                 public HandshakeType LastHandshakeMsg
 195                 {
 196                         get { return this.lastHandshakeMsg; }
 197                         set { this.lastHandshakeMsg = value; }
 198                 }
 199
 200                 public  HandshakeState HandshakeState
 201                 {
 202                         get { return this.handshakeState; }
 203                         set { this.handshakeState = value; }
 204                 }
 205
 206                 public bool ConnectionEnd
 207                 {
 208                         get { return this.connectionEnd; }
 209                         set { this.connectionEnd = value; }
 210                 }
 211
 212                 public CipherSuiteCollection SupportedCiphers
 213                 {
 214                         get { return supportedCiphers; }
 215                         set { supportedCiphers = value; }
 216                 }
 217
 218                 public TlsStream HandshakeMessages
 219                 {
 220                         get { return this.handshakeMessages; }
 221                 }
 222
 223                 public ulong WriteSequenceNumber
 224                 {
 225                         get { return this.writeSequenceNumber; }
 226                         set { this.writeSequenceNumber = value; }
 227                 }
 228
 229                 public ulong ReadSequenceNumber
 230                 {
 231                         get { return this.readSequenceNumber; }
 232                         set { this.readSequenceNumber = value; }
 233                 }
 234
 235                 public byte[] ClientRandom
 236                 {
 237                         get { return this.clientRandom; }
 238                         set { this.clientRandom = value; }
 239                 }
 240
 241                 public byte[] ServerRandom
 242                 {
 243                         get { return this.serverRandom; }
 244                         set { this.serverRandom = value; }
 245                 }
 246
 247                 public byte[] RandomCS
 248                 {
 249                         get { return this.randomCS; }
 250                         set { this.randomCS = value; }
 251                 }
 252
 253                 public byte[] RandomSC
 254                 {
 255                         get { return this.randomSC; }
 256                         set { this.randomSC = value; }
 257                 }
 258
 259                 public byte[] MasterSecret
 260                 {
 261                         get { return this.masterSecret; }
 262                         set { this.masterSecret = value; }
 263                 }
 264
 265                 public byte[] ClientWriteKey
 266                 {
 267                         get { return this.clientWriteKey; }
 268                         set { this.clientWriteKey = value; }
 269                 }
 270
 271                 public byte[] ServerWriteKey
 272                 {
 273                         get { return this.serverWriteKey; }
 274                         set { this.serverWriteKey = value; }
 275                 }
 276
 277                 public byte[] ClientWriteIV
 278                 {
 279                         get { return this.clientWriteIV; }
 280                         set { this.clientWriteIV = value; }
 281                 }
 282
 283                 public byte[] ServerWriteIV
 284                 {
 285                         get { return this.serverWriteIV; }
 286                         set { this.serverWriteIV = value; }
 287                 }
 288
 289                 public RecordProtocol RecordProtocol
 290                 {
 291                         get { return this.recordProtocol; }
 292                         set { this.recordProtocol = value; }
 293                 }
 294
 295                 #endregion
 296
 297                 #region Constructors
 298
 299                 public Context(SecurityProtocolType securityProtocolType)
 300                 {
 301                         this.SecurityProtocol   = securityProtocolType;
 302                         this.compressionMethod  = SecurityCompressionType.None;
 303                         this.serverSettings             = new TlsServerSettings();
 304                         this.clientSettings             = new TlsClientSettings();
 305                         this.handshakeMessages  = new TlsStream();
 306                         this.sessionId                  = null;
 307                         this.handshakeState             = HandshakeState.None;
 308                         this.random                             = RandomNumberGenerator.Create();
 309                 }
 310
 311                 #endregion
 312
 313                 #region Methods
 314
 315                 public int GetUnixTime()
 316                 {
 317                         DateTime now = DateTime.UtcNow;
 318
 319                         return (int)(now.Ticks - UNIX_BASE_TICKS / TimeSpan.TicksPerSecond);
 320                 }
 321
 322                 public byte[] GetSecureRandomBytes(int count)
 323                 {
 324                         byte[] secureBytes = new byte[count];
 325
 326                         this.random.GetNonZeroBytes(secureBytes);
 327
 328                         return secureBytes;
 329                 }
 330
 331                 public virtual void Clear()
 332                 {
 333                         this.compressionMethod  = SecurityCompressionType.None;
 334                         this.serverSettings             = new TlsServerSettings();
 335                         this.clientSettings             = new TlsClientSettings();
 336                         this.handshakeMessages  = new TlsStream();
 337                         this.sessionId                  = null;
 338                         this.handshakeState             = HandshakeState.None;
 339
 340                         this.ClearKeyInfo();
 341                 }
 342
 343                 public virtual void ClearKeyInfo()
 344                 {
 345                         // Clear Master Secret
 346                         this.masterSecret       = null;
 347
 348                         // Clear client and server random
 349                         this.clientRandom       = null;
 350                         this.serverRandom       = null;
 351                         this.randomCS           = null;
 352                         this.randomSC           = null;
 353
 354                         // Clear client keys
 355                         this.clientWriteKey     = null;
 356                         this.clientWriteIV      = null;
 357
 358                         // Clear server keys
 359                         this.serverWriteKey     = null;
 360                         this.serverWriteIV      = null;
 361
 362                         // Reset handshake messages
 363                         this.handshakeMessages.Reset();
 364
 365                         // Clear MAC keys if protocol is different than Ssl3
 366                         // SSLv3 needs them inside Mono.Security.Protocol.Tls.SslCipherSuite.Compute[Client|Server]RecordMAC
 367                         if (this.securityProtocol != SecurityProtocolType.Ssl3)
 368                         {
 369 //                              this.clientWriteMAC = null;
 370 //                              this.serverWriteMAC = null;
 371                         }
 372                 }
 373
 374                 public SecurityProtocolType DecodeProtocolCode(short code)
 375                 {
 376                         switch (code)
 377                         {
 378                                 case Context.TLS1_PROTOCOL_CODE:
 379                                         return SecurityProtocolType.Tls;
 380
 381                                 case Context.SSL3_PROTOCOL_CODE:
 382                                         return SecurityProtocolType.Ssl3;
 383
 384                                 default:
 385                                         throw new NotSupportedException("Unsupported security protocol type");
 386                         }
 387                 }
 388
 389                 public void ChangeProtocol(short protocol)
 390                 {
 391                         SecurityProtocolType protocolType = this.DecodeProtocolCode(protocol);
 392
 393                         if ((protocolType & this.SecurityProtocolFlags) == protocolType ||
 394                                 (this.SecurityProtocolFlags & SecurityProtocolType.Default) == SecurityProtocolType.Default)
 395                         {
 396                                 this.SecurityProtocol = protocolType;
 397                                 this.SupportedCiphers.Clear();
 398                                 this.SupportedCiphers = null;
 399                                 this.SupportedCiphers = CipherSuiteFactory.GetSupportedCiphers(protocolType);
 400                         }
 401                         else
 402                         {
 403                                 throw new TlsException(AlertDescription.ProtocolVersion, "Incorrect protocol version received from server");
 404                         }
 405                 }
 406
 407
 408                 public SecurityParameters Current
 409                 {
 410                         get
 411                         {
 412                                 if (current == null)
 413                                         current = new SecurityParameters ();
 414                                 if (current.Cipher != null)
 415                                         current.Cipher.Context = this;
 416                                 return current;
 417                         }
 418                 }
 419
 420                 public SecurityParameters Negotiating
 421                 {
 422                         get
 423                         {
 424                                 if (negotiating == null)
 425                                         negotiating = new SecurityParameters ();
 426                                 if (negotiating.Cipher != null)
 427                                         negotiating.Cipher.Context = this;
 428                                 return negotiating;
 429                         }
 430                 }
 431
 432                 public SecurityParameters Read
 433                 {
 434                         get { return read; }
 435                 }
 436
 437                 public SecurityParameters Write
 438                 {
 439                         get { return write; }
 440                 }
 441
 442                 public void StartSwitchingSecurityParameters (bool client)
 443                 {
 444                         if (client) {
 445                                 // everything we write from now on is encrypted
 446                                 write = negotiating;
 447                                 // but we still read with the older cipher until we
 448                                 // receive the ChangeCipherSpec message
 449                                 read = current;
 450                         } else {
 451                                 // everything we read from now on is encrypted
 452                                 read = negotiating;
 453                                 // but we still write with the older cipher until we
 454                                 // receive the ChangeCipherSpec message
 455                                 write = current;
 456                         }
 457                         current = negotiating;
 458                 }
 459
 460                 public void EndSwitchingSecurityParameters (bool client)
 461                 {
 462                         SecurityParameters temp;
 463                         if (client) {
 464                                 temp = read;
 465                                 // we now read with the new, negotiated, security parameters
 466                                 read = current;
 467                         } else {
 468                                 temp = write;
 469                                 // we now write with the new, negotiated, security parameters
 470                                 write = current;
 471                         }
 472                         // so we clear the old one (last reference)
 473                         if (temp != null)
 474                                 temp.Clear ();
 475                         negotiating = temp;
 476                         // and are now ready for a future renegotiation
 477                 }
 478
 479                 #endregion
 480         }
 481 }