net/quic/quic_crypto_client_stream.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/quic/quic_crypto_client_stream.h"
   6
   7 #include "net/quic/crypto/crypto_protocol.h"
   8 #include "net/quic/crypto/crypto_utils.h"
   9 #include "net/quic/crypto/null_encrypter.h"
  10 #include "net/quic/quic_client_session_base.h"
  11 #include "net/quic/quic_protocol.h"
  12 #include "net/quic/quic_session.h"
  13
  14 namespace net {
  15
  16 QuicCryptoClientStream::ChannelIDSourceCallbackImpl::
  17 ChannelIDSourceCallbackImpl(QuicCryptoClientStream* stream)
  18     : stream_(stream) {}
  19
  20 QuicCryptoClientStream::ChannelIDSourceCallbackImpl::
  21 ~ChannelIDSourceCallbackImpl() {}
  22
  23 void QuicCryptoClientStream::ChannelIDSourceCallbackImpl::Run(
  24     scoped_ptr<ChannelIDKey>* channel_id_key) {
  25   if (stream_ == NULL) {
  26     return;
  27   }
  28
  29   stream_->channel_id_key_.reset(channel_id_key->release());
  30   stream_->channel_id_source_callback_run_ = true;
  31   stream_->channel_id_source_callback_ = NULL;
  32   stream_->DoHandshakeLoop(NULL);
  33
  34   // The ChannelIDSource owns this object and will delete it when this method
  35   // returns.
  36 }
  37
  38 void QuicCryptoClientStream::ChannelIDSourceCallbackImpl::Cancel() {
  39   stream_ = NULL;
  40 }
  41
  42 QuicCryptoClientStream::ProofVerifierCallbackImpl::ProofVerifierCallbackImpl(
  43     QuicCryptoClientStream* stream)
  44     : stream_(stream) {}
  45
  46 QuicCryptoClientStream::ProofVerifierCallbackImpl::
  47 ~ProofVerifierCallbackImpl() {}
  48
  49 void QuicCryptoClientStream::ProofVerifierCallbackImpl::Run(
  50     bool ok,
  51     const string& error_details,
  52     scoped_ptr<ProofVerifyDetails>* details) {
  53   if (stream_ == NULL) {
  54     return;
  55   }
  56
  57   stream_->verify_ok_ = ok;
  58   stream_->verify_error_details_ = error_details;
  59   stream_->verify_details_.reset(details->release());
  60   stream_->proof_verify_callback_ = NULL;
  61   stream_->DoHandshakeLoop(NULL);
  62
  63   // The ProofVerifier owns this object and will delete it when this method
  64   // returns.
  65 }
  66
  67 void QuicCryptoClientStream::ProofVerifierCallbackImpl::Cancel() {
  68   stream_ = NULL;
  69 }
  70
  71 QuicCryptoClientStream::QuicCryptoClientStream(
  72     const QuicServerId& server_id,
  73     QuicClientSessionBase* session,
  74     ProofVerifyContext* verify_context,
  75     QuicCryptoClientConfig* crypto_config)
  76     : QuicCryptoStream(session),
  77       next_state_(STATE_IDLE),
  78       num_client_hellos_(0),
  79       crypto_config_(crypto_config),
  80       server_id_(server_id),
  81       generation_counter_(0),
  82       channel_id_sent_(false),
  83       channel_id_source_callback_run_(false),
  84       channel_id_source_callback_(NULL),
  85       verify_context_(verify_context),
  86       proof_verify_callback_(NULL) {
  87 }
  88
  89 QuicCryptoClientStream::~QuicCryptoClientStream() {
  90   if (channel_id_source_callback_) {
  91     channel_id_source_callback_->Cancel();
  92   }
  93   if (proof_verify_callback_) {
  94     proof_verify_callback_->Cancel();
  95   }
  96 }
  97
  98 void QuicCryptoClientStream::OnHandshakeMessage(
  99     const CryptoHandshakeMessage& message) {
 100   QuicCryptoStream::OnHandshakeMessage(message);
 101
 102   if (message.tag() == kSCUP) {
 103     if (!handshake_confirmed()) {
 104       CloseConnection(QUIC_CRYPTO_UPDATE_BEFORE_HANDSHAKE_COMPLETE);
 105       return;
 106     }
 107
 108     // |message| is an update from the server, so we treat it differently from a
 109     // handshake message.
 110     HandleServerConfigUpdateMessage(message);
 111     return;
 112   }
 113
 114   // Do not process handshake messages after the handshake is confirmed.
 115   if (handshake_confirmed()) {
 116     CloseConnection(QUIC_CRYPTO_MESSAGE_AFTER_HANDSHAKE_COMPLETE);
 117     return;
 118   }
 119
 120   DoHandshakeLoop(&message);
 121 }
 122
 123 bool QuicCryptoClientStream::CryptoConnect() {
 124   next_state_ = STATE_INITIALIZE;
 125   DoHandshakeLoop(NULL);
 126   return true;
 127 }
 128
 129 int QuicCryptoClientStream::num_sent_client_hellos() const {
 130   return num_client_hellos_;
 131 }
 132
 133 bool QuicCryptoClientStream::WasChannelIDSent() const {
 134   return channel_id_sent_;
 135 }
 136
 137 bool QuicCryptoClientStream::WasChannelIDSourceCallbackRun() const {
 138   return channel_id_source_callback_run_;
 139 }
 140
 141 void QuicCryptoClientStream::HandleServerConfigUpdateMessage(
 142     const CryptoHandshakeMessage& server_config_update) {
 143   DCHECK(server_config_update.tag() == kSCUP);
 144   string error_details;
 145   QuicCryptoClientConfig::CachedState* cached =
 146       crypto_config_->LookupOrCreate(server_id_);
 147   QuicErrorCode error = crypto_config_->ProcessServerConfigUpdate(
 148       server_config_update,
 149       session()->connection()->clock()->WallNow(),
 150       cached,
 151       &crypto_negotiated_params_,
 152       &error_details);
 153
 154   if (error != QUIC_NO_ERROR) {
 155     CloseConnectionWithDetails(
 156         error, "Server config update invalid: " + error_details);
 157     return;
 158   }
 159 }
 160
 161 // kMaxClientHellos is the maximum number of times that we'll send a client
 162 // hello. The value 3 accounts for:
 163 //   * One failure due to an incorrect or missing source-address token.
 164 //   * One failure due the server's certificate chain being unavailible and the
 165 //     server being unwilling to send it without a valid source-address token.
 166 static const int kMaxClientHellos = 3;
 167
 168 void QuicCryptoClientStream::DoHandshakeLoop(
 169     const CryptoHandshakeMessage* in) {
 170   CryptoHandshakeMessage out;
 171   QuicErrorCode error;
 172   string error_details;
 173   QuicCryptoClientConfig::CachedState* cached =
 174       crypto_config_->LookupOrCreate(server_id_);
 175
 176   for (;;) {
 177     const State state = next_state_;
 178     next_state_ = STATE_IDLE;
 179     switch (state) {
 180       case STATE_INITIALIZE: {
 181         if (!cached->IsEmpty() && !cached->signature().empty() &&
 182             server_id_.is_https()) {
 183           // Note that we verify the proof even if the cached proof is valid.
 184           // This allows us to respond to CA trust changes or certificate
 185           // expiration because it may have been a while since we last verified
 186           // the proof.
 187           DCHECK(crypto_config_->proof_verifier());
 188           // If the cached state needs to be verified, do it now.
 189           next_state_ = STATE_VERIFY_PROOF;
 190         } else {
 191           next_state_ = STATE_GET_CHANNEL_ID;
 192         }
 193         break;
 194       }
 195       case STATE_SEND_CHLO: {
 196         // Send the client hello in plaintext.
 197         session()->connection()->SetDefaultEncryptionLevel(ENCRYPTION_NONE);
 198         if (num_client_hellos_ > kMaxClientHellos) {
 199           CloseConnection(QUIC_CRYPTO_TOO_MANY_REJECTS);
 200           return;
 201         }
 202         num_client_hellos_++;
 203
 204         if (!cached->IsComplete(session()->connection()->clock()->WallNow())) {
 205           crypto_config_->FillInchoateClientHello(
 206               server_id_,
 207               session()->connection()->supported_versions().front(),
 208               cached, &crypto_negotiated_params_, &out);
 209           // Pad the inchoate client hello to fill up a packet.
 210           const size_t kFramingOverhead = 50;  // A rough estimate.
 211           const size_t max_packet_size =
 212               session()->connection()->max_packet_length();
 213           if (max_packet_size <= kFramingOverhead) {
 214             DLOG(DFATAL) << "max_packet_length (" << max_packet_size
 215                          << ") has no room for framing overhead.";
 216             CloseConnection(QUIC_INTERNAL_ERROR);
 217             return;
 218           }
 219           if (kClientHelloMinimumSize > max_packet_size - kFramingOverhead) {
 220             DLOG(DFATAL) << "Client hello won't fit in a single packet.";
 221             CloseConnection(QUIC_INTERNAL_ERROR);
 222             return;
 223           }
 224           out.set_minimum_size(max_packet_size - kFramingOverhead);
 225           next_state_ = STATE_RECV_REJ;
 226           SendHandshakeMessage(out);
 227           return;
 228         }
 229         session()->config()->ToHandshakeMessage(&out);
 230         error = crypto_config_->FillClientHello(
 231             server_id_,
 232             session()->connection()->connection_id(),
 233             session()->connection()->supported_versions().front(),
 234             cached,
 235             session()->connection()->clock()->WallNow(),
 236             session()->connection()->random_generator(),
 237             channel_id_key_.get(),
 238             &crypto_negotiated_params_,
 239             &out,
 240             &error_details);
 241         if (error != QUIC_NO_ERROR) {
 242           // Flush the cached config so that, if it's bad, the server has a
 243           // chance to send us another in the future.
 244           cached->InvalidateServerConfig();
 245           CloseConnectionWithDetails(error, error_details);
 246           return;
 247         }
 248         channel_id_sent_ = (channel_id_key_.get() != NULL);
 249         if (cached->proof_verify_details()) {
 250           client_session()->OnProofVerifyDetailsAvailable(
 251               *cached->proof_verify_details());
 252         }
 253         next_state_ = STATE_RECV_SHLO;
 254         SendHandshakeMessage(out);
 255         // Be prepared to decrypt with the new server write key.
 256         session()->connection()->SetAlternativeDecrypter(
 257             crypto_negotiated_params_.initial_crypters.decrypter.release(),
 258             ENCRYPTION_INITIAL,
 259             true /* latch once used */);
 260         // Send subsequent packets under encryption on the assumption that the
 261         // server will accept the handshake.
 262         session()->connection()->SetEncrypter(
 263             ENCRYPTION_INITIAL,
 264             crypto_negotiated_params_.initial_crypters.encrypter.release());
 265         session()->connection()->SetDefaultEncryptionLevel(
 266             ENCRYPTION_INITIAL);
 267         if (!encryption_established_) {
 268           encryption_established_ = true;
 269           session()->OnCryptoHandshakeEvent(
 270               QuicSession::ENCRYPTION_FIRST_ESTABLISHED);
 271         } else {
 272           session()->OnCryptoHandshakeEvent(
 273               QuicSession::ENCRYPTION_REESTABLISHED);
 274         }
 275         return;
 276       }
 277       case STATE_RECV_REJ:
 278         // We sent a dummy CHLO because we didn't have enough information to
 279         // perform a handshake, or we sent a full hello that the server
 280         // rejected. Here we hope to have a REJ that contains the information
 281         // that we need.
 282         if (in->tag() != kREJ) {
 283           CloseConnectionWithDetails(QUIC_INVALID_CRYPTO_MESSAGE_TYPE,
 284                                      "Expected REJ");
 285           return;
 286         }
 287         error = crypto_config_->ProcessRejection(
 288             *in, session()->connection()->clock()->WallNow(), cached,
 289             server_id_.is_https(), &crypto_negotiated_params_, &error_details);
 290         if (error != QUIC_NO_ERROR) {
 291           CloseConnectionWithDetails(error, error_details);
 292           return;
 293         }
 294         if (!cached->proof_valid()) {
 295           if (!server_id_.is_https()) {
 296             // We don't check the certificates for insecure QUIC connections.
 297             SetCachedProofValid(cached);
 298           } else if (!cached->signature().empty()) {
 299             // Note that we only verify the proof if the cached proof is not
 300             // valid. If the cached proof is valid here, someone else must have
 301             // just added the server config to the cache and verified the proof,
 302             // so we can assume no CA trust changes or certificate expiration
 303             // has happened since then.
 304             next_state_ = STATE_VERIFY_PROOF;
 305             break;
 306           }
 307         }
 308         next_state_ = STATE_GET_CHANNEL_ID;
 309         break;
 310       case STATE_VERIFY_PROOF: {
 311         ProofVerifier* verifier = crypto_config_->proof_verifier();
 312         DCHECK(verifier);
 313         next_state_ = STATE_VERIFY_PROOF_COMPLETE;
 314         generation_counter_ = cached->generation_counter();
 315
 316         ProofVerifierCallbackImpl* proof_verify_callback =
 317             new ProofVerifierCallbackImpl(this);
 318
 319         verify_ok_ = false;
 320
 321         QuicAsyncStatus status = verifier->VerifyProof(
 322             server_id_.host(),
 323             cached->server_config(),
 324             cached->certs(),
 325             cached->signature(),
 326             verify_context_.get(),
 327             &verify_error_details_,
 328             &verify_details_,
 329             proof_verify_callback);
 330
 331         switch (status) {
 332           case QUIC_PENDING:
 333             proof_verify_callback_ = proof_verify_callback;
 334             DVLOG(1) << "Doing VerifyProof";
 335             return;
 336           case QUIC_FAILURE:
 337             delete proof_verify_callback;
 338             break;
 339           case QUIC_SUCCESS:
 340             delete proof_verify_callback;
 341             verify_ok_ = true;
 342             break;
 343         }
 344         break;
 345       }
 346       case STATE_VERIFY_PROOF_COMPLETE:
 347         if (!verify_ok_) {
 348           client_session()->OnProofVerifyDetailsAvailable(*verify_details_);
 349           CloseConnectionWithDetails(
 350               QUIC_PROOF_INVALID, "Proof invalid: " + verify_error_details_);
 351           return;
 352         }
 353         // Check if generation_counter has changed between STATE_VERIFY_PROOF
 354         // and STATE_VERIFY_PROOF_COMPLETE state changes.
 355         if (generation_counter_ != cached->generation_counter()) {
 356           next_state_ = STATE_VERIFY_PROOF;
 357         } else {
 358           SetCachedProofValid(cached);
 359           cached->SetProofVerifyDetails(verify_details_.release());
 360           next_state_ = STATE_GET_CHANNEL_ID;
 361         }
 362         break;
 363       case STATE_GET_CHANNEL_ID: {
 364         next_state_ = STATE_GET_CHANNEL_ID_COMPLETE;
 365         channel_id_key_.reset();
 366         if (!RequiresChannelID(cached)) {
 367           next_state_ = STATE_SEND_CHLO;
 368           break;
 369         }
 370
 371         ChannelIDSourceCallbackImpl* channel_id_source_callback =
 372             new ChannelIDSourceCallbackImpl(this);
 373         QuicAsyncStatus status =
 374             crypto_config_->channel_id_source()->GetChannelIDKey(
 375                 server_id_.host(), &channel_id_key_,
 376                 channel_id_source_callback);
 377
 378         switch (status) {
 379           case QUIC_PENDING:
 380             channel_id_source_callback_ = channel_id_source_callback;
 381             DVLOG(1) << "Looking up channel ID";
 382             return;
 383           case QUIC_FAILURE:
 384             delete channel_id_source_callback;
 385             CloseConnectionWithDetails(QUIC_INVALID_CHANNEL_ID_SIGNATURE,
 386                                        "Channel ID lookup failed");
 387             return;
 388           case QUIC_SUCCESS:
 389             delete channel_id_source_callback;
 390             break;
 391         }
 392         break;
 393       }
 394       case STATE_GET_CHANNEL_ID_COMPLETE:
 395         if (!channel_id_key_.get()) {
 396           CloseConnectionWithDetails(QUIC_INVALID_CHANNEL_ID_SIGNATURE,
 397                                      "Channel ID lookup failed");
 398           return;
 399         }
 400         next_state_ = STATE_SEND_CHLO;
 401         break;
 402       case STATE_RECV_SHLO: {
 403         // We sent a CHLO that we expected to be accepted and now we're hoping
 404         // for a SHLO from the server to confirm that.
 405         if (in->tag() == kREJ) {
 406           // alternative_decrypter will be NULL if the original alternative
 407           // decrypter latched and became the primary decrypter. That happens
 408           // if we received a message encrypted with the INITIAL key.
 409           if (session()->connection()->alternative_decrypter() == NULL) {
 410             // The rejection was sent encrypted!
 411             CloseConnectionWithDetails(QUIC_CRYPTO_ENCRYPTION_LEVEL_INCORRECT,
 412                                        "encrypted REJ message");
 413             return;
 414           }
 415           next_state_ = STATE_RECV_REJ;
 416           break;
 417         }
 418         if (in->tag() != kSHLO) {
 419           CloseConnectionWithDetails(QUIC_INVALID_CRYPTO_MESSAGE_TYPE,
 420                                      "Expected SHLO or REJ");
 421           return;
 422         }
 423         // alternative_decrypter will be NULL if the original alternative
 424         // decrypter latched and became the primary decrypter. That happens
 425         // if we received a message encrypted with the INITIAL key.
 426         if (session()->connection()->alternative_decrypter() != NULL) {
 427           // The server hello was sent without encryption.
 428           CloseConnectionWithDetails(QUIC_CRYPTO_ENCRYPTION_LEVEL_INCORRECT,
 429                                      "unencrypted SHLO message");
 430           return;
 431         }
 432         error = crypto_config_->ProcessServerHello(
 433             *in, session()->connection()->connection_id(),
 434             session()->connection()->server_supported_versions(),
 435             cached, &crypto_negotiated_params_, &error_details);
 436
 437         if (error != QUIC_NO_ERROR) {
 438           CloseConnectionWithDetails(
 439               error, "Server hello invalid: " + error_details);
 440           return;
 441         }
 442         error =
 443             session()->config()->ProcessPeerHello(*in, SERVER, &error_details);
 444         if (error != QUIC_NO_ERROR) {
 445           CloseConnectionWithDetails(
 446               error, "Server hello invalid: " + error_details);
 447           return;
 448         }
 449         session()->OnConfigNegotiated();
 450
 451         CrypterPair* crypters =
 452             &crypto_negotiated_params_.forward_secure_crypters;
 453         // TODO(agl): we don't currently latch this decrypter because the idea
 454         // has been floated that the server shouldn't send packets encrypted
 455         // with the FORWARD_SECURE key until it receives a FORWARD_SECURE
 456         // packet from the client.
 457         session()->connection()->SetAlternativeDecrypter(
 458             crypters->decrypter.release(), ENCRYPTION_FORWARD_SECURE,
 459             false /* don't latch */);
 460         session()->connection()->SetEncrypter(
 461             ENCRYPTION_FORWARD_SECURE, crypters->encrypter.release());
 462         session()->connection()->SetDefaultEncryptionLevel(
 463             ENCRYPTION_FORWARD_SECURE);
 464
 465         handshake_confirmed_ = true;
 466         session()->OnCryptoHandshakeEvent(QuicSession::HANDSHAKE_CONFIRMED);
 467         session()->connection()->OnHandshakeComplete();
 468         return;
 469       }
 470       case STATE_IDLE:
 471         // This means that the peer sent us a message that we weren't expecting.
 472         CloseConnection(QUIC_INVALID_CRYPTO_MESSAGE_TYPE);
 473         return;
 474     }
 475   }
 476 }
 477
 478 void QuicCryptoClientStream::SetCachedProofValid(
 479     QuicCryptoClientConfig::CachedState* cached) {
 480   cached->SetProofValid();
 481   client_session()->OnProofValid(*cached);
 482 }
 483
 484 bool QuicCryptoClientStream::RequiresChannelID(
 485     QuicCryptoClientConfig::CachedState* cached) {
 486   if (!server_id_.is_https() ||
 487       server_id_.privacy_mode() == PRIVACY_MODE_ENABLED ||
 488       !crypto_config_->channel_id_source()) {
 489     return false;
 490   }
 491   const CryptoHandshakeMessage* scfg = cached->GetServerConfig();
 492   if (!scfg) {  // scfg may be null when we send an inchoate CHLO.
 493     return false;
 494   }
 495   const QuicTag* their_proof_demands;
 496   size_t num_their_proof_demands;
 497   if (scfg->GetTaglist(kPDMD, &their_proof_demands,
 498                        &num_their_proof_demands) != QUIC_NO_ERROR) {
 499     return false;
 500   }
 501   for (size_t i = 0; i < num_their_proof_demands; i++) {
 502     if (their_proof_demands[i] == kCHID) {
 503       return true;
 504     }
 505   }
 506   return false;
 507 }
 508
 509 QuicClientSessionBase* QuicCryptoClientStream::client_session() {
 510   return reinterpret_cast<QuicClientSessionBase*>(session());
 511 }
 512
 513 }  // namespace net