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    receivedConnectionEnd;
  80                 private bool    sentConnectionEnd;
  81                 private bool    protocolNegotiated;
  82
  83                 // Sequence numbers
  84                 private ulong   writeSequenceNumber;
  85                 private ulong   readSequenceNumber;
  86
  87                 // Random data
  88                 private byte[]  clientRandom;
  89                 private byte[]  serverRandom;
  90                 private byte[]  randomCS;
  91                 private byte[]  randomSC;
  92
  93                 // Key information
  94                 private byte[]  masterSecret;
  95                 private byte[]  clientWriteKey;
  96                 private byte[]  serverWriteKey;
  97                 private byte[]  clientWriteIV;
  98                 private byte[]  serverWriteIV;
  99
 100                 // Handshake hashes
 101                 private TlsStream handshakeMessages;
 102
 103                 // Secure Random generator
 104                 private RandomNumberGenerator random;
 105
 106                 // Record protocol
 107                 private RecordProtocol recordProtocol;
 108
 109                 #endregion
 110
 111                 #region Properties
 112
 113                 public bool AbbreviatedHandshake
 114                 {
 115                         get { return abbreviatedHandshake; }
 116                         set { abbreviatedHandshake = value; }
 117                 }
 118
 119                 public bool     ProtocolNegotiated
 120                 {
 121                         get { return this.protocolNegotiated; }
 122                         set { this.protocolNegotiated = value; }
 123                 }
 124
 125                 public SecurityProtocolType SecurityProtocol
 126                 {
 127                         get
 128                         {
 129                                 if ((this.securityProtocol & SecurityProtocolType.Tls) == SecurityProtocolType.Tls ||
 130                                         (this.securityProtocol & SecurityProtocolType.Default) == SecurityProtocolType.Default)
 131                                 {
 132                                         return SecurityProtocolType.Tls;
 133                                 }
 134                                 else
 135                                 {
 136                                         if ((this.securityProtocol & SecurityProtocolType.Ssl3) == SecurityProtocolType.Ssl3)
 137                                         {
 138                                                 return SecurityProtocolType.Ssl3;
 139                                         }
 140                                 }
 141
 142                                 throw new NotSupportedException("Unsupported security protocol type");
 143                         }
 144
 145                         set { this.securityProtocol = value; }
 146                 }
 147
 148                 public SecurityProtocolType SecurityProtocolFlags
 149                 {
 150                         get { return this.securityProtocol; }
 151                 }
 152
 153                 public short Protocol
 154                 {
 155                         get
 156                         {
 157                                 switch (this.SecurityProtocol)
 158                                 {
 159                                         case SecurityProtocolType.Tls:
 160                                         case SecurityProtocolType.Default:
 161                                                 return Context.TLS1_PROTOCOL_CODE;
 162
 163                                         case SecurityProtocolType.Ssl3:
 164                                                 return Context.SSL3_PROTOCOL_CODE;
 165
 166                                         case SecurityProtocolType.Ssl2:
 167                                         default:
 168                                                 throw new NotSupportedException("Unsupported security protocol type");
 169                                 }
 170                         }
 171                 }
 172
 173                 public byte[] SessionId
 174                 {
 175                         get { return this.sessionId; }
 176                         set { this.sessionId = value; }
 177                 }
 178
 179                 public SecurityCompressionType CompressionMethod
 180                 {
 181                         get { return this.compressionMethod; }
 182                         set { this.compressionMethod = value; }
 183                 }
 184
 185                 public TlsServerSettings ServerSettings
 186                 {
 187                         get { return this.serverSettings; }
 188                 }
 189
 190                 public TlsClientSettings ClientSettings
 191                 {
 192                         get { return this.clientSettings; }
 193                 }
 194
 195                 public HandshakeType LastHandshakeMsg
 196                 {
 197                         get { return this.lastHandshakeMsg; }
 198                         set { this.lastHandshakeMsg = value; }
 199                 }
 200
 201                 public  HandshakeState HandshakeState
 202                 {
 203                         get { return this.handshakeState; }
 204                         set { this.handshakeState = value; }
 205                 }
 206
 207                 public bool ReceivedConnectionEnd
 208                 {
 209                         get { return this.receivedConnectionEnd; }
 210                         set { this.receivedConnectionEnd = value; }
 211                 }
 212
 213                 public bool SentConnectionEnd
 214                 {
 215                         get { return this.sentConnectionEnd; }
 216                         set { this.sentConnectionEnd = value; }
 217                 }
 218
 219                 public CipherSuiteCollection SupportedCiphers
 220                 {
 221                         get { return supportedCiphers; }
 222                         set { supportedCiphers = value; }
 223                 }
 224
 225                 public TlsStream HandshakeMessages
 226                 {
 227                         get { return this.handshakeMessages; }
 228                 }
 229
 230                 public ulong WriteSequenceNumber
 231                 {
 232                         get { return this.writeSequenceNumber; }
 233                         set { this.writeSequenceNumber = value; }
 234                 }
 235
 236                 public ulong ReadSequenceNumber
 237                 {
 238                         get { return this.readSequenceNumber; }
 239                         set { this.readSequenceNumber = value; }
 240                 }
 241
 242                 public byte[] ClientRandom
 243                 {
 244                         get { return this.clientRandom; }
 245                         set { this.clientRandom = value; }
 246                 }
 247
 248                 public byte[] ServerRandom
 249                 {
 250                         get { return this.serverRandom; }
 251                         set { this.serverRandom = value; }
 252                 }
 253
 254                 public byte[] RandomCS
 255                 {
 256                         get { return this.randomCS; }
 257                         set { this.randomCS = value; }
 258                 }
 259
 260                 public byte[] RandomSC
 261                 {
 262                         get { return this.randomSC; }
 263                         set { this.randomSC = value; }
 264                 }
 265
 266                 public byte[] MasterSecret
 267                 {
 268                         get { return this.masterSecret; }
 269                         set { this.masterSecret = value; }
 270                 }
 271
 272                 public byte[] ClientWriteKey
 273                 {
 274                         get { return this.clientWriteKey; }
 275                         set { this.clientWriteKey = value; }
 276                 }
 277
 278                 public byte[] ServerWriteKey
 279                 {
 280                         get { return this.serverWriteKey; }
 281                         set { this.serverWriteKey = value; }
 282                 }
 283
 284                 public byte[] ClientWriteIV
 285                 {
 286                         get { return this.clientWriteIV; }
 287                         set { this.clientWriteIV = value; }
 288                 }
 289
 290                 public byte[] ServerWriteIV
 291                 {
 292                         get { return this.serverWriteIV; }
 293                         set { this.serverWriteIV = value; }
 294                 }
 295
 296                 public RecordProtocol RecordProtocol
 297                 {
 298                         get { return this.recordProtocol; }
 299                         set { this.recordProtocol = value; }
 300                 }
 301
 302                 #endregion
 303
 304                 #region Constructors
 305
 306                 public Context(SecurityProtocolType securityProtocolType)
 307                 {
 308                         this.SecurityProtocol   = securityProtocolType;
 309                         this.compressionMethod  = SecurityCompressionType.None;
 310                         this.serverSettings             = new TlsServerSettings();
 311                         this.clientSettings             = new TlsClientSettings();
 312                         this.handshakeMessages  = new TlsStream();
 313                         this.sessionId                  = null;
 314                         this.handshakeState             = HandshakeState.None;
 315                         this.random                             = RandomNumberGenerator.Create();
 316                 }
 317
 318                 #endregion
 319
 320                 #region Methods
 321
 322                 public int GetUnixTime()
 323                 {
 324                         DateTime now = DateTime.UtcNow;
 325
 326                         return (int)((now.Ticks - UNIX_BASE_TICKS) / TimeSpan.TicksPerSecond);
 327                 }
 328
 329                 public byte[] GetSecureRandomBytes(int count)
 330                 {
 331                         byte[] secureBytes = new byte[count];
 332
 333                         this.random.GetNonZeroBytes(secureBytes);
 334
 335                         return secureBytes;
 336                 }
 337
 338                 public virtual void Clear()
 339                 {
 340                         this.compressionMethod  = SecurityCompressionType.None;
 341                         this.serverSettings             = new TlsServerSettings();
 342                         this.clientSettings             = new TlsClientSettings();
 343                         this.handshakeMessages  = new TlsStream();
 344                         this.sessionId                  = null;
 345                         this.handshakeState             = HandshakeState.None;
 346
 347                         this.ClearKeyInfo();
 348                 }
 349
 350                 public virtual void ClearKeyInfo()
 351                 {
 352                         // Clear Master Secret
 353                         if (masterSecret != null) {
 354                                 Array.Clear (masterSecret, 0, masterSecret.Length);
 355                                 masterSecret = null;
 356                         }
 357
 358                         // Clear client and server random
 359                         if (clientRandom != null) {
 360                                 Array.Clear (clientRandom, 0, clientRandom.Length);
 361                                 clientRandom = null;
 362                         }
 363                         if (serverRandom != null) {
 364                                 Array.Clear (serverRandom, 0, serverRandom.Length);
 365                                 serverRandom = null;
 366                         }
 367                         if (randomCS != null) {
 368                                 Array.Clear (randomCS, 0, randomCS.Length);
 369                                 randomCS = null;
 370                         }
 371                         if (randomSC != null) {
 372                                 Array.Clear (randomSC, 0, randomSC.Length);
 373                                 randomSC = null;
 374                         }
 375
 376                         // Clear client keys
 377                         if (clientWriteKey != null) {
 378                                 Array.Clear (clientWriteKey, 0, clientWriteKey.Length);
 379                                 clientWriteKey = null;
 380                         }
 381                         if (clientWriteIV != null) {
 382                                 Array.Clear (clientWriteIV, 0, clientWriteIV.Length);
 383                                 clientWriteIV = null;
 384                         }
 385
 386                         // Clear server keys
 387                         if (serverWriteKey != null) {
 388                                 Array.Clear (serverWriteKey, 0, serverWriteKey.Length);
 389                                 serverWriteKey = null;
 390                         }
 391                         if (serverWriteIV != null) {
 392                                 Array.Clear (serverWriteIV, 0, serverWriteIV.Length);
 393                                 serverWriteIV = null;
 394                         }
 395
 396                         // Reset handshake messages
 397                         this.handshakeMessages.Reset();
 398
 399                         // Clear MAC keys if protocol is different than Ssl3
 400                         // SSLv3 needs them inside Mono.Security.Protocol.Tls.SslCipherSuite.Compute[Client|Server]RecordMAC
 401                         if (this.securityProtocol != SecurityProtocolType.Ssl3)
 402                         {
 403 //                              this.clientWriteMAC = null;
 404 //                              this.serverWriteMAC = null;
 405                         }
 406                 }
 407
 408                 public SecurityProtocolType DecodeProtocolCode(short code)
 409                 {
 410                         switch (code)
 411                         {
 412                                 case Context.TLS1_PROTOCOL_CODE:
 413                                         return SecurityProtocolType.Tls;
 414
 415                                 case Context.SSL3_PROTOCOL_CODE:
 416                                         return SecurityProtocolType.Ssl3;
 417
 418                                 default:
 419                                         throw new NotSupportedException("Unsupported security protocol type");
 420                         }
 421                 }
 422
 423                 public void ChangeProtocol(short protocol)
 424                 {
 425                         SecurityProtocolType protocolType = this.DecodeProtocolCode(protocol);
 426
 427                         if ((protocolType & this.SecurityProtocolFlags) == protocolType ||
 428                                 (this.SecurityProtocolFlags & SecurityProtocolType.Default) == SecurityProtocolType.Default)
 429                         {
 430                                 this.SecurityProtocol = protocolType;
 431                                 this.SupportedCiphers.Clear();
 432                                 this.SupportedCiphers = null;
 433                                 this.SupportedCiphers = CipherSuiteFactory.GetSupportedCiphers(protocolType);
 434                         }
 435                         else
 436                         {
 437                                 throw new TlsException(AlertDescription.ProtocolVersion, "Incorrect protocol version received from server");
 438                         }
 439                 }
 440
 441
 442                 public SecurityParameters Current
 443                 {
 444                         get
 445                         {
 446                                 if (current == null)
 447                                         current = new SecurityParameters ();
 448                                 if (current.Cipher != null)
 449                                         current.Cipher.Context = this;
 450                                 return current;
 451                         }
 452                 }
 453
 454                 public SecurityParameters Negotiating
 455                 {
 456                         get
 457                         {
 458                                 if (negotiating == null)
 459                                         negotiating = new SecurityParameters ();
 460                                 if (negotiating.Cipher != null)
 461                                         negotiating.Cipher.Context = this;
 462                                 return negotiating;
 463                         }
 464                 }
 465
 466                 public SecurityParameters Read
 467                 {
 468                         get { return read; }
 469                 }
 470
 471                 public SecurityParameters Write
 472                 {
 473                         get { return write; }
 474                 }
 475
 476                 public void StartSwitchingSecurityParameters (bool client)
 477                 {
 478                         if (client) {
 479                                 // everything we write from now on is encrypted
 480                                 write = negotiating;
 481                                 // but we still read with the older cipher until we
 482                                 // receive the ChangeCipherSpec message
 483                                 read = current;
 484                         } else {
 485                                 // everything we read from now on is encrypted
 486                                 read = negotiating;
 487                                 // but we still write with the older cipher until we
 488                                 // receive the ChangeCipherSpec message
 489                                 write = current;
 490                         }
 491                         current = negotiating;
 492                 }
 493
 494                 public void EndSwitchingSecurityParameters (bool client)
 495                 {
 496                         SecurityParameters temp;
 497                         if (client) {
 498                                 temp = read;
 499                                 // we now read with the new, negotiated, security parameters
 500                                 read = current;
 501                         } else {
 502                                 temp = write;
 503                                 // we now write with the new, negotiated, security parameters
 504                                 write = current;
 505                         }
 506                         // so we clear the old one (last reference)
 507                         if (temp != null)
 508                                 temp.Clear ();
 509                         negotiating = temp;
 510                         // and are now ready for a future renegotiation
 511                 }
 512
 513                 #endregion
 514         }
 515 }