net/quic/test_tools/crypto_test_utils.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/test_tools/crypto_test_utils.h"
   6
   7 #include "net/quic/crypto/channel_id.h"
   8 #include "net/quic/crypto/common_cert_set.h"
   9 #include "net/quic/crypto/crypto_handshake.h"
  10 #include "net/quic/crypto/quic_crypto_server_config.h"
  11 #include "net/quic/crypto/quic_decrypter.h"
  12 #include "net/quic/crypto/quic_encrypter.h"
  13 #include "net/quic/crypto/quic_random.h"
  14 #include "net/quic/quic_clock.h"
  15 #include "net/quic/quic_crypto_client_stream.h"
  16 #include "net/quic/quic_crypto_server_stream.h"
  17 #include "net/quic/quic_crypto_stream.h"
  18 #include "net/quic/quic_server_id.h"
  19 #include "net/quic/test_tools/quic_connection_peer.h"
  20 #include "net/quic/test_tools/quic_framer_peer.h"
  21 #include "net/quic/test_tools/quic_test_utils.h"
  22 #include "net/quic/test_tools/simple_quic_framer.h"
  23
  24 using base::StringPiece;
  25 using std::make_pair;
  26 using std::pair;
  27 using std::string;
  28 using std::vector;
  29
  30 namespace net {
  31 namespace test {
  32
  33 namespace {
  34
  35 const char kServerHostname[] = "test.example.com";
  36 const uint16 kServerPort = 80;
  37
  38 // CryptoFramerVisitor is a framer visitor that records handshake messages.
  39 class CryptoFramerVisitor : public CryptoFramerVisitorInterface {
  40  public:
  41   CryptoFramerVisitor()
  42       : error_(false) {
  43   }
  44
  45   void OnError(CryptoFramer* framer) override { error_ = true; }
  46
  47   void OnHandshakeMessage(const CryptoHandshakeMessage& message) override {
  48     messages_.push_back(message);
  49   }
  50
  51   bool error() const {
  52     return error_;
  53   }
  54
  55   const vector<CryptoHandshakeMessage>& messages() const {
  56     return messages_;
  57   }
  58
  59  private:
  60   bool error_;
  61   vector<CryptoHandshakeMessage> messages_;
  62 };
  63
  64 // MovePackets parses crypto handshake messages from packet number
  65 // |*inout_packet_index| through to the last packet (or until a packet fails to
  66 // decrypt) and has |dest_stream| process them. |*inout_packet_index| is updated
  67 // with an index one greater than the last packet processed.
  68 void MovePackets(PacketSavingConnection* source_conn,
  69                  size_t *inout_packet_index,
  70                  QuicCryptoStream* dest_stream,
  71                  PacketSavingConnection* dest_conn) {
  72   SimpleQuicFramer framer(source_conn->supported_versions());
  73   CryptoFramer crypto_framer;
  74   CryptoFramerVisitor crypto_visitor;
  75
  76   // In order to properly test the code we need to perform encryption and
  77   // decryption so that the crypters latch when expected. The crypters are in
  78   // |dest_conn|, but we don't want to try and use them there. Instead we swap
  79   // them into |framer|, perform the decryption with them, and then swap them
  80   // back.
  81   QuicConnectionPeer::SwapCrypters(dest_conn, framer.framer());
  82
  83   crypto_framer.set_visitor(&crypto_visitor);
  84
  85   size_t index = *inout_packet_index;
  86   for (; index < source_conn->encrypted_packets_.size(); index++) {
  87     if (!framer.ProcessPacket(*source_conn->encrypted_packets_[index])) {
  88       // The framer will be unable to decrypt forward-secure packets sent after
  89       // the handshake is complete. Don't treat them as handshake packets.
  90       break;
  91     }
  92
  93     for (vector<QuicStreamFrame>::const_iterator
  94          i =  framer.stream_frames().begin();
  95          i != framer.stream_frames().end(); ++i) {
  96       scoped_ptr<string> frame_data(i->GetDataAsString());
  97       ASSERT_TRUE(crypto_framer.ProcessInput(*frame_data));
  98       ASSERT_FALSE(crypto_visitor.error());
  99     }
 100   }
 101   *inout_packet_index = index;
 102
 103   QuicConnectionPeer::SwapCrypters(dest_conn, framer.framer());
 104
 105   ASSERT_EQ(0u, crypto_framer.InputBytesRemaining());
 106
 107   for (vector<CryptoHandshakeMessage>::const_iterator
 108        i = crypto_visitor.messages().begin();
 109        i != crypto_visitor.messages().end(); ++i) {
 110     dest_stream->OnHandshakeMessage(*i);
 111   }
 112 }
 113
 114 // HexChar parses |c| as a hex character. If valid, it sets |*value| to the
 115 // value of the hex character and returns true. Otherwise it returns false.
 116 bool HexChar(char c, uint8* value) {
 117   if (c >= '0' && c <= '9') {
 118     *value = c - '0';
 119     return true;
 120   }
 121   if (c >= 'a' && c <= 'f') {
 122     *value = c - 'a' + 10;
 123     return true;
 124   }
 125   if (c >= 'A' && c <= 'F') {
 126     *value = c - 'A' + 10;
 127     return true;
 128   }
 129   return false;
 130 }
 131
 132 // A ChannelIDSource that works in asynchronous mode unless the |callback|
 133 // argument to GetChannelIDKey is nullptr.
 134 class AsyncTestChannelIDSource : public ChannelIDSource,
 135                                  public CryptoTestUtils::CallbackSource {
 136  public:
 137   // Takes ownership of |sync_source|, a synchronous ChannelIDSource.
 138   explicit AsyncTestChannelIDSource(ChannelIDSource* sync_source)
 139       : sync_source_(sync_source) {}
 140   ~AsyncTestChannelIDSource() override {}
 141
 142   // ChannelIDSource implementation.
 143   QuicAsyncStatus GetChannelIDKey(const string& hostname,
 144                                   scoped_ptr<ChannelIDKey>* channel_id_key,
 145                                   ChannelIDSourceCallback* callback) override {
 146     // Synchronous mode.
 147     if (!callback) {
 148       return sync_source_->GetChannelIDKey(hostname, channel_id_key, nullptr);
 149     }
 150
 151     // Asynchronous mode.
 152     QuicAsyncStatus status =
 153         sync_source_->GetChannelIDKey(hostname, &channel_id_key_, nullptr);
 154     if (status != QUIC_SUCCESS) {
 155       return QUIC_FAILURE;
 156     }
 157     callback_.reset(callback);
 158     return QUIC_PENDING;
 159   }
 160
 161   // CallbackSource implementation.
 162   void RunPendingCallbacks() override {
 163     if (callback_.get()) {
 164       callback_->Run(&channel_id_key_);
 165       callback_.reset();
 166     }
 167   }
 168
 169  private:
 170   scoped_ptr<ChannelIDSource> sync_source_;
 171   scoped_ptr<ChannelIDSourceCallback> callback_;
 172   scoped_ptr<ChannelIDKey> channel_id_key_;
 173 };
 174
 175 }  // anonymous namespace
 176
 177 CryptoTestUtils::FakeClientOptions::FakeClientOptions()
 178     : dont_verify_certs(false),
 179       channel_id_enabled(false),
 180       channel_id_source_async(false) {
 181 }
 182
 183 // static
 184 int CryptoTestUtils::HandshakeWithFakeServer(
 185     PacketSavingConnection* client_conn,
 186     QuicCryptoClientStream* client) {
 187   PacketSavingConnection* server_conn = new PacketSavingConnection(
 188       Perspective::IS_SERVER, client_conn->supported_versions());
 189   TestSession server_session(server_conn, DefaultQuicConfig());
 190   server_session.InitializeSession();
 191   QuicCryptoServerConfig crypto_config(QuicCryptoServerConfig::TESTING,
 192                                        QuicRandom::GetInstance());
 193
 194   SetupCryptoServerConfigForTest(
 195       server_session.connection()->clock(),
 196       server_session.connection()->random_generator(),
 197       server_session.config(), &crypto_config);
 198
 199   QuicCryptoServerStream server(&crypto_config, &server_session);
 200   server_session.SetCryptoStream(&server);
 201
 202   // The client's handshake must have been started already.
 203   CHECK_NE(0u, client_conn->encrypted_packets_.size());
 204
 205   CommunicateHandshakeMessages(client_conn, client, server_conn, &server);
 206
 207   CompareClientAndServerKeys(client, &server);
 208
 209   return client->num_sent_client_hellos();
 210 }
 211
 212 // static
 213 int CryptoTestUtils::HandshakeWithFakeClient(
 214     PacketSavingConnection* server_conn,
 215     QuicCryptoServerStream* server,
 216     const FakeClientOptions& options) {
 217   PacketSavingConnection* client_conn =
 218       new PacketSavingConnection(Perspective::IS_CLIENT);
 219   // Advance the time, because timers do not like uninitialized times.
 220   client_conn->AdvanceTime(QuicTime::Delta::FromSeconds(1));
 221   TestClientSession client_session(client_conn, DefaultQuicConfig());
 222   QuicCryptoClientConfig crypto_config;
 223
 224   if (!options.dont_verify_certs) {
 225     // TODO(wtc): replace this with ProofVerifierForTesting() when we have
 226     // a working ProofSourceForTesting().
 227     crypto_config.SetProofVerifier(FakeProofVerifierForTesting());
 228   }
 229   bool is_https = false;
 230   AsyncTestChannelIDSource* async_channel_id_source = nullptr;
 231   if (options.channel_id_enabled) {
 232     is_https = true;
 233
 234     ChannelIDSource* source = ChannelIDSourceForTesting();
 235     if (options.channel_id_source_async) {
 236       async_channel_id_source = new AsyncTestChannelIDSource(source);
 237       source = async_channel_id_source;
 238     }
 239     crypto_config.SetChannelIDSource(source);
 240   }
 241   QuicServerId server_id(kServerHostname, kServerPort, is_https,
 242                          PRIVACY_MODE_DISABLED);
 243   QuicCryptoClientStream client(server_id, &client_session,
 244                                 ProofVerifyContextForTesting(),
 245                                 &crypto_config);
 246   client_session.SetCryptoStream(&client);
 247
 248   client.CryptoConnect();
 249   CHECK_EQ(1u, client_conn->encrypted_packets_.size());
 250
 251   CommunicateHandshakeMessagesAndRunCallbacks(
 252       client_conn, &client, server_conn, server, async_channel_id_source);
 253
 254   CompareClientAndServerKeys(&client, server);
 255
 256   if (options.channel_id_enabled) {
 257     scoped_ptr<ChannelIDKey> channel_id_key;
 258     QuicAsyncStatus status = crypto_config.channel_id_source()->GetChannelIDKey(
 259         kServerHostname, &channel_id_key, nullptr);
 260     EXPECT_EQ(QUIC_SUCCESS, status);
 261     EXPECT_EQ(channel_id_key->SerializeKey(),
 262               server->crypto_negotiated_params().channel_id);
 263     EXPECT_EQ(options.channel_id_source_async,
 264               client.WasChannelIDSourceCallbackRun());
 265   }
 266
 267   return client.num_sent_client_hellos();
 268 }
 269
 270 // static
 271 void CryptoTestUtils::SetupCryptoServerConfigForTest(
 272     const QuicClock* clock,
 273     QuicRandom* rand,
 274     QuicConfig* config,
 275     QuicCryptoServerConfig* crypto_config) {
 276   QuicCryptoServerConfig::ConfigOptions options;
 277   options.channel_id_enabled = true;
 278   scoped_ptr<CryptoHandshakeMessage> scfg(
 279       crypto_config->AddDefaultConfig(rand, clock, options));
 280 }
 281
 282 // static
 283 void CryptoTestUtils::CommunicateHandshakeMessages(
 284     PacketSavingConnection* a_conn,
 285     QuicCryptoStream* a,
 286     PacketSavingConnection* b_conn,
 287     QuicCryptoStream* b) {
 288   CommunicateHandshakeMessagesAndRunCallbacks(a_conn, a, b_conn, b, nullptr);
 289 }
 290
 291 // static
 292 void CryptoTestUtils::CommunicateHandshakeMessagesAndRunCallbacks(
 293     PacketSavingConnection* a_conn,
 294     QuicCryptoStream* a,
 295     PacketSavingConnection* b_conn,
 296     QuicCryptoStream* b,
 297     CallbackSource* callback_source) {
 298   size_t a_i = 0, b_i = 0;
 299   while (!a->handshake_confirmed()) {
 300     ASSERT_GT(a_conn->encrypted_packets_.size(), a_i);
 301     VLOG(1) << "Processing " << a_conn->encrypted_packets_.size() - a_i
 302             << " packets a->b";
 303     MovePackets(a_conn, &a_i, b, b_conn);
 304     if (callback_source) {
 305       callback_source->RunPendingCallbacks();
 306     }
 307
 308     ASSERT_GT(b_conn->encrypted_packets_.size(), b_i);
 309     VLOG(1) << "Processing " << b_conn->encrypted_packets_.size() - b_i
 310             << " packets b->a";
 311     MovePackets(b_conn, &b_i, a, a_conn);
 312     if (callback_source) {
 313       callback_source->RunPendingCallbacks();
 314     }
 315   }
 316 }
 317
 318 // static
 319 pair<size_t, size_t> CryptoTestUtils::AdvanceHandshake(
 320     PacketSavingConnection* a_conn,
 321     QuicCryptoStream* a,
 322     size_t a_i,
 323     PacketSavingConnection* b_conn,
 324     QuicCryptoStream* b,
 325     size_t b_i) {
 326   VLOG(1) << "Processing " << a_conn->encrypted_packets_.size() - a_i
 327           << " packets a->b";
 328   MovePackets(a_conn, &a_i, b, b_conn);
 329
 330   VLOG(1) << "Processing " << b_conn->encrypted_packets_.size() - b_i
 331           << " packets b->a";
 332   if (b_conn->encrypted_packets_.size() - b_i == 2) {
 333     VLOG(1) << "here";
 334   }
 335   MovePackets(b_conn, &b_i, a, a_conn);
 336
 337   return std::make_pair(a_i, b_i);
 338 }
 339
 340 // static
 341 string CryptoTestUtils::GetValueForTag(const CryptoHandshakeMessage& message,
 342                                        QuicTag tag) {
 343   QuicTagValueMap::const_iterator it = message.tag_value_map().find(tag);
 344   if (it == message.tag_value_map().end()) {
 345     return string();
 346   }
 347   return it->second;
 348 }
 349
 350 class MockCommonCertSets : public CommonCertSets {
 351  public:
 352   MockCommonCertSets(StringPiece cert, uint64 hash, uint32 index)
 353       : cert_(cert.as_string()),
 354         hash_(hash),
 355         index_(index) {
 356   }
 357
 358   StringPiece GetCommonHashes() const override {
 359     CHECK(false) << "not implemented";
 360     return StringPiece();
 361   }
 362
 363   StringPiece GetCert(uint64 hash, uint32 index) const override {
 364     if (hash == hash_ && index == index_) {
 365       return cert_;
 366     }
 367     return StringPiece();
 368   }
 369
 370   bool MatchCert(StringPiece cert,
 371                  StringPiece common_set_hashes,
 372                  uint64* out_hash,
 373                  uint32* out_index) const override {
 374     if (cert != cert_) {
 375       return false;
 376     }
 377
 378     if (common_set_hashes.size() % sizeof(uint64) != 0) {
 379       return false;
 380     }
 381     bool client_has_set = false;
 382     for (size_t i = 0; i < common_set_hashes.size(); i += sizeof(uint64)) {
 383       uint64 hash;
 384       memcpy(&hash, common_set_hashes.data() + i, sizeof(hash));
 385       if (hash == hash_) {
 386         client_has_set = true;
 387         break;
 388       }
 389     }
 390
 391     if (!client_has_set) {
 392       return false;
 393     }
 394
 395     *out_hash = hash_;
 396     *out_index = index_;
 397     return true;
 398   }
 399
 400  private:
 401   const string cert_;
 402   const uint64 hash_;
 403   const uint32 index_;
 404 };
 405
 406 CommonCertSets* CryptoTestUtils::MockCommonCertSets(StringPiece cert,
 407                                                     uint64 hash,
 408                                                     uint32 index) {
 409   return new class MockCommonCertSets(cert, hash, index);
 410 }
 411
 412 void CryptoTestUtils::CompareClientAndServerKeys(
 413     QuicCryptoClientStream* client,
 414     QuicCryptoServerStream* server) {
 415   QuicFramer* client_framer =
 416       QuicConnectionPeer::GetFramer(client->session()->connection());
 417   QuicFramer* server_framer =
 418       QuicConnectionPeer::GetFramer(server->session()->connection());
 419   const QuicEncrypter* client_encrypter(
 420       QuicFramerPeer::GetEncrypter(client_framer, ENCRYPTION_INITIAL));
 421   const QuicDecrypter* client_decrypter(
 422       client->session()->connection()->decrypter());
 423   const QuicEncrypter* client_forward_secure_encrypter(
 424       QuicFramerPeer::GetEncrypter(client_framer, ENCRYPTION_FORWARD_SECURE));
 425   const QuicDecrypter* client_forward_secure_decrypter(
 426       client->session()->connection()->alternative_decrypter());
 427   const QuicEncrypter* server_encrypter(
 428       QuicFramerPeer::GetEncrypter(server_framer, ENCRYPTION_INITIAL));
 429   const QuicDecrypter* server_decrypter(
 430       server->session()->connection()->decrypter());
 431   const QuicEncrypter* server_forward_secure_encrypter(
 432       QuicFramerPeer::GetEncrypter(server_framer, ENCRYPTION_FORWARD_SECURE));
 433   const QuicDecrypter* server_forward_secure_decrypter(
 434       server->session()->connection()->alternative_decrypter());
 435
 436   StringPiece client_encrypter_key = client_encrypter->GetKey();
 437   StringPiece client_encrypter_iv = client_encrypter->GetNoncePrefix();
 438   StringPiece client_decrypter_key = client_decrypter->GetKey();
 439   StringPiece client_decrypter_iv = client_decrypter->GetNoncePrefix();
 440   StringPiece client_forward_secure_encrypter_key =
 441       client_forward_secure_encrypter->GetKey();
 442   StringPiece client_forward_secure_encrypter_iv =
 443       client_forward_secure_encrypter->GetNoncePrefix();
 444   StringPiece client_forward_secure_decrypter_key =
 445       client_forward_secure_decrypter->GetKey();
 446   StringPiece client_forward_secure_decrypter_iv =
 447       client_forward_secure_decrypter->GetNoncePrefix();
 448   StringPiece server_encrypter_key = server_encrypter->GetKey();
 449   StringPiece server_encrypter_iv = server_encrypter->GetNoncePrefix();
 450   StringPiece server_decrypter_key = server_decrypter->GetKey();
 451   StringPiece server_decrypter_iv = server_decrypter->GetNoncePrefix();
 452   StringPiece server_forward_secure_encrypter_key =
 453       server_forward_secure_encrypter->GetKey();
 454   StringPiece server_forward_secure_encrypter_iv =
 455       server_forward_secure_encrypter->GetNoncePrefix();
 456   StringPiece server_forward_secure_decrypter_key =
 457       server_forward_secure_decrypter->GetKey();
 458   StringPiece server_forward_secure_decrypter_iv =
 459       server_forward_secure_decrypter->GetNoncePrefix();
 460
 461   StringPiece client_subkey_secret =
 462       client->crypto_negotiated_params().subkey_secret;
 463   StringPiece server_subkey_secret =
 464       server->crypto_negotiated_params().subkey_secret;
 465
 466
 467   const char kSampleLabel[] = "label";
 468   const char kSampleContext[] = "context";
 469   const size_t kSampleOutputLength = 32;
 470   string client_key_extraction;
 471   string server_key_extraction;
 472   EXPECT_TRUE(client->ExportKeyingMaterial(kSampleLabel,
 473                                            kSampleContext,
 474                                            kSampleOutputLength,
 475                                            &client_key_extraction));
 476   EXPECT_TRUE(server->ExportKeyingMaterial(kSampleLabel,
 477                                            kSampleContext,
 478                                            kSampleOutputLength,
 479                                            &server_key_extraction));
 480
 481   CompareCharArraysWithHexError("client write key",
 482                                 client_encrypter_key.data(),
 483                                 client_encrypter_key.length(),
 484                                 server_decrypter_key.data(),
 485                                 server_decrypter_key.length());
 486   CompareCharArraysWithHexError("client write IV",
 487                                 client_encrypter_iv.data(),
 488                                 client_encrypter_iv.length(),
 489                                 server_decrypter_iv.data(),
 490                                 server_decrypter_iv.length());
 491   CompareCharArraysWithHexError("server write key",
 492                                 server_encrypter_key.data(),
 493                                 server_encrypter_key.length(),
 494                                 client_decrypter_key.data(),
 495                                 client_decrypter_key.length());
 496   CompareCharArraysWithHexError("server write IV",
 497                                 server_encrypter_iv.data(),
 498                                 server_encrypter_iv.length(),
 499                                 client_decrypter_iv.data(),
 500                                 client_decrypter_iv.length());
 501   CompareCharArraysWithHexError("client forward secure write key",
 502                                 client_forward_secure_encrypter_key.data(),
 503                                 client_forward_secure_encrypter_key.length(),
 504                                 server_forward_secure_decrypter_key.data(),
 505                                 server_forward_secure_decrypter_key.length());
 506   CompareCharArraysWithHexError("client forward secure write IV",
 507                                 client_forward_secure_encrypter_iv.data(),
 508                                 client_forward_secure_encrypter_iv.length(),
 509                                 server_forward_secure_decrypter_iv.data(),
 510                                 server_forward_secure_decrypter_iv.length());
 511   CompareCharArraysWithHexError("server forward secure write key",
 512                                 server_forward_secure_encrypter_key.data(),
 513                                 server_forward_secure_encrypter_key.length(),
 514                                 client_forward_secure_decrypter_key.data(),
 515                                 client_forward_secure_decrypter_key.length());
 516   CompareCharArraysWithHexError("server forward secure write IV",
 517                                 server_forward_secure_encrypter_iv.data(),
 518                                 server_forward_secure_encrypter_iv.length(),
 519                                 client_forward_secure_decrypter_iv.data(),
 520                                 client_forward_secure_decrypter_iv.length());
 521   CompareCharArraysWithHexError("subkey secret",
 522                                 client_subkey_secret.data(),
 523                                 client_subkey_secret.length(),
 524                                 server_subkey_secret.data(),
 525                                 server_subkey_secret.length());
 526   CompareCharArraysWithHexError("sample key extraction",
 527                                 client_key_extraction.data(),
 528                                 client_key_extraction.length(),
 529                                 server_key_extraction.data(),
 530                                 server_key_extraction.length());
 531 }
 532
 533 // static
 534 QuicTag CryptoTestUtils::ParseTag(const char* tagstr) {
 535   const size_t len = strlen(tagstr);
 536   CHECK_NE(0u, len);
 537
 538   QuicTag tag = 0;
 539
 540   if (tagstr[0] == '#') {
 541     CHECK_EQ(static_cast<size_t>(1 + 2*4), len);
 542     tagstr++;
 543
 544     for (size_t i = 0; i < 8; i++) {
 545       tag <<= 4;
 546
 547       uint8 v = 0;
 548       CHECK(HexChar(tagstr[i], &v));
 549       tag |= v;
 550     }
 551
 552     return tag;
 553   }
 554
 555   CHECK_LE(len, 4u);
 556   for (size_t i = 0; i < 4; i++) {
 557     tag >>= 8;
 558     if (i < len) {
 559       tag |= static_cast<uint32>(tagstr[i]) << 24;
 560     }
 561   }
 562
 563   return tag;
 564 }
 565
 566 // static
 567 CryptoHandshakeMessage CryptoTestUtils::Message(const char* message_tag, ...) {
 568   va_list ap;
 569   va_start(ap, message_tag);
 570
 571   CryptoHandshakeMessage message = BuildMessage(message_tag, ap);
 572   va_end(ap);
 573   return message;
 574 }
 575
 576 // static
 577 CryptoHandshakeMessage CryptoTestUtils::BuildMessage(const char* message_tag,
 578                                                      va_list ap) {
 579   CryptoHandshakeMessage msg;
 580   msg.set_tag(ParseTag(message_tag));
 581
 582   for (;;) {
 583     const char* tagstr = va_arg(ap, const char*);
 584     if (tagstr == nullptr) {
 585       break;
 586     }
 587
 588     if (tagstr[0] == '$') {
 589       // Special value.
 590       const char* const special = tagstr + 1;
 591       if (strcmp(special, "padding") == 0) {
 592         const int min_bytes = va_arg(ap, int);
 593         msg.set_minimum_size(min_bytes);
 594       } else {
 595         CHECK(false) << "Unknown special value: " << special;
 596       }
 597
 598       continue;
 599     }
 600
 601     const QuicTag tag = ParseTag(tagstr);
 602     const char* valuestr = va_arg(ap, const char*);
 603
 604     size_t len = strlen(valuestr);
 605     if (len > 0 && valuestr[0] == '#') {
 606       valuestr++;
 607       len--;
 608
 609       CHECK_EQ(0u, len % 2);
 610       scoped_ptr<uint8[]> buf(new uint8[len/2]);
 611
 612       for (size_t i = 0; i < len/2; i++) {
 613         uint8 v = 0;
 614         CHECK(HexChar(valuestr[i*2], &v));
 615         buf[i] = v << 4;
 616         CHECK(HexChar(valuestr[i*2 + 1], &v));
 617         buf[i] |= v;
 618       }
 619
 620       msg.SetStringPiece(
 621           tag, StringPiece(reinterpret_cast<char*>(buf.get()), len/2));
 622       continue;
 623     }
 624
 625     msg.SetStringPiece(tag, valuestr);
 626   }
 627
 628   // The CryptoHandshakeMessage needs to be serialized and parsed to ensure
 629   // that any padding is included.
 630   scoped_ptr<QuicData> bytes(CryptoFramer::ConstructHandshakeMessage(msg));
 631   scoped_ptr<CryptoHandshakeMessage> parsed(
 632       CryptoFramer::ParseMessage(bytes->AsStringPiece()));
 633   CHECK(parsed.get());
 634
 635   return *parsed;
 636 }
 637
 638 }  // namespace test
 639 }  // namespace net