Landing Recent QUIC changes until: Fri Oct 30 22:23:58 2015 +0000

net/quic/crypto/quic_crypto_client_config.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/crypto/quic_crypto_client_config.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
@@ skipping 755 matching lines @@
 QuicErrorCode QuicCryptoClientConfig::ProcessServerHello(
     const CryptoHandshakeMessage& server_hello,
     QuicConnectionId connection_id,
     QuicVersion version,
     const QuicVersionVector& negotiated_versions,
     CachedState* cached,
     QuicCryptoNegotiatedParameters* out_params,
     string* error_details) {
   DCHECK(error_details != nullptr);
 
-  if (server_hello.tag() != kSHLO) {
-    *error_details = "Bad tag";
-    return QUIC_INVALID_CRYPTO_MESSAGE_TYPE;
-  }
-
-  const QuicTag* supported_version_tags;
-  size_t num_supported_versions;
-
-  if (server_hello.GetTaglist(kVER, &supported_version_tags,
-                              &num_supported_versions) != QUIC_NO_ERROR) {
-    *error_details = "server hello missing version list";
-    return QUIC_INVALID_CRYPTO_MESSAGE_PARAMETER;
-  }
-  if (!negotiated_versions.empty()) {
-    bool mismatch = num_supported_versions != negotiated_versions.size();
-    for (size_t i = 0; i < num_supported_versions && !mismatch; ++i) {
-      mismatch = QuicTagToQuicVersion(supported_version_tags[i]) !=
-          negotiated_versions[i];
-    }
-    // The server sent a list of supported versions, and the connection
-    // reports that there was a version negotiation during the handshake.
-      // Ensure that these two lists are identical.
-    if (mismatch) {
-      *error_details = "Downgrade attack detected";
-      return QUIC_VERSION_NEGOTIATION_MISMATCH;
-    }
+  QuicErrorCode valid = CryptoUtils::ValidateServerHello(
+      server_hello, negotiated_versions, error_details);
+  if (valid != QUIC_NO_ERROR) {
+    return valid;
   }
 
   // Learn about updated source address tokens.
   StringPiece token;
   if (server_hello.GetStringPiece(kSourceAddressTokenTag, &token)) {
     cached->set_source_address_token(token);
   }
 
   StringPiece shlo_nonce;
   if (version > QUIC_VERSION_26 &&
@@ skipping 130 matching lines @@
   }
 
   // Update canonical version to point at the "most recent" entry.
   canonical_server_map_[suffix_server_id] = server_id;
 
   server_state->InitializeFrom(*canonical_state);
   return true;
 }
 
 }  // namespace net