Land Recent QUIC changes

net/quic/crypto/cert_compressor.cc

 // Copyright (c) 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/cert_compressor.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/quic/quic_utils.h"
 #include "third_party/zlib/zlib.h"
 
 using base::StringPiece;
 using std::string;
 using std::vector;
 
 namespace net {
 
 namespace {
 
 // kCommonCertSubstrings contains ~1500 bytes of common certificate substrings
-// in order to help zlib.
+// in order to help zlib. This was generated via a fairly dumb algorithm from
+// the Alexa Top 5000 set - we could probably do better.
 static unsigned char kCommonCertSubstrings[] = {
   0x04, 0x02, 0x30, 0x00, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d, 0x25, 0x04,
   0x16, 0x30, 0x14, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03,
   0x01, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x02, 0x30,
   0x5f, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x86, 0xf8, 0x42, 0x04, 0x01,
   0x06, 0x06, 0x0b, 0x60, 0x86, 0x48, 0x01, 0x86, 0xfd, 0x6d, 0x01, 0x07,
   0x17, 0x01, 0x30, 0x33, 0x20, 0x45, 0x78, 0x74, 0x65, 0x6e, 0x64, 0x65,
   0x64, 0x20, 0x56, 0x61, 0x6c, 0x69, 0x64, 0x61, 0x74, 0x69, 0x6f, 0x6e,
   0x20, 0x53, 0x20, 0x4c, 0x69, 0x6d, 0x69, 0x74, 0x65, 0x64, 0x31, 0x34,
   0x20, 0x53, 0x53, 0x4c, 0x20, 0x43, 0x41, 0x30, 0x1e, 0x17, 0x0d, 0x31,
@@ skipping 119 matching lines @@
 struct CertEntry {
  public:
   enum Type {
     // COMPRESSED means that the certificate is included in the trailing zlib
     // data.
     COMPRESSED = 1,
     // CACHED means that the certificate is already known to the peer and will
     // be replaced by its 64-bit hash (in |hash|).
     CACHED = 2,
     // COMMON means that the certificate is in a common certificate set known
-    // to the peer with hash |set_hash| and index |index|.
+    // to the peer with hash |set_hash| and certificate index |index|.
     COMMON = 3,
   };
 
   Type type;
   uint64 hash;
   uint64 set_hash;
   uint32 index;
 };
 
 // MatchCerts returns a vector of CertEntries describing how to most
 // efficiently represent |certs| to a peer who has the common sets identified
 // by |client_common_set_hashes| and who has cached the certificates with the
-// 64-bit, FNV-1a hashes in |client_cached|.
+// 64-bit, FNV-1a hashes in |client_cached_cert_hashes|.
 vector<CertEntry> MatchCerts(const vector<string>& certs,
                              StringPiece client_common_set_hashes,
-                             StringPiece client_cached,
-                             CommonCertSet* common_set) {
+                             StringPiece client_cached_cert_hashes,
+                             const CommonCertSets* common_set) {
   vector<CertEntry> entries;
   entries.reserve(certs.size());
 
-  const bool cached_valid = client_cached.size() % sizeof(uint64) == 0 &&
-                            !client_cached.empty();
+  const bool cached_valid =
+      client_cached_cert_hashes.size() % sizeof(uint64) == 0 &&
+      !client_cached_cert_hashes.empty();
 
   for (vector<string>::const_iterator i = certs.begin();
        i != certs.end(); ++i) {
     CertEntry entry;
 
     if (cached_valid) {
       bool cached = false;
 
       uint64 hash = QuicUtils::FNV1a_64_Hash(i->data(), i->size());
       // This assumes that the machine is little-endian.
-      for (size_t i = 0; i < client_cached.size(); i += sizeof(uint64)) {
+      for (size_t i = 0; i < client_cached_cert_hashes.size();
+           i += sizeof(uint64)) {
         uint64 cached_hash;
-        memcpy(&cached_hash, client_cached.data() + i, sizeof(uint64));
+        memcpy(&cached_hash, client_cached_cert_hashes.data() + i,
+               sizeof(uint64));
         if (hash != cached_hash) {
           continue;
         }
 
         entry.type = CertEntry::CACHED;
         entry.hash = hash;
         entries.push_back(entry);
         cached = true;
         break;
       }
 
       if (cached) {
         continue;
       }
     }
 
-    if (common_set &&
-        common_set->MatchCert(*i, client_common_set_hashes, &entry.set_hash,
-                              &entry.index)) {
+    if (common_set && common_set->MatchCert(*i, client_common_set_hashes,
+                                            &entry.set_hash, &entry.index)) {
       entry.type = CertEntry::COMMON;
       entries.push_back(entry);
       continue;
     }
 
     entry.type = CertEntry::COMPRESSED;
     entries.push_back(entry);
   }
 
   return entries;
@@ skipping 96 matching lines @@
 
   return ret;
 }
 
 // ParseEntries parses the serialised form of a vector of CertEntries from
 // |in_out| and writes them to |out_entries|. CACHED and COMMON entries are
 // resolved using |cached_certs| and |common_set| and written to |out_certs|.
 // |in_out| is updated to contain the trailing data.
 bool ParseEntries(StringPiece* in_out,
                   const vector<string>& cached_certs,
-                  CommonCertSet* common_set,
+                  const CommonCertSets* common_set,
                   vector<CertEntry>* out_entries,
                   vector<string>* out_certs) {
   StringPiece in = *in_out;
   vector<uint64> cached_hashes;
 
   out_entries->clear();
   out_certs->clear();
 
   for (;;) {
     if (in.empty()) {
@@ skipping 69 matching lines @@
   return true;
 }
 
 class ScopedZLib {
  public:
   enum Type {
     INFLATE,
     DEFLATE,
   };
 
-  explicit ScopedZLib(Type type)
-      : z_(NULL),
-        type_(type) {
-  }
+  explicit ScopedZLib(Type type) : z_(NULL), type_(type) {}
 
-  void reset(z_stream* z) {
-    z_ = z;
-  }
+  void reset(z_stream* z) { z_ = z; }
 
   ~ScopedZLib() {
     if (z_) {
       if (type_ == DEFLATE) {
         deflateEnd(z_);
       } else {
         inflateEnd(z_);
       }
       z_ = NULL;
     }
   }
 
  private:
   z_stream* z_;
   const Type type_;
 };
 
 }  // anonymous namespace
 
 
 // static
 string CertCompressor::CompressChain(const vector<string>& certs,
                                      StringPiece client_common_set_hashes,
-                                     StringPiece client_cached,
-                                     CommonCertSet* common_set) {
+                                     StringPiece client_cached_cert_hashes,
+                                     const CommonCertSets* common_set) {
   const vector<CertEntry> entries = MatchCerts(
-      certs, client_common_set_hashes, client_cached, common_set);
+      certs, client_common_set_hashes, client_cached_cert_hashes, common_set);
   DCHECK_EQ(entries.size(), certs.size());
 
   size_t uncompressed_size = 0;
   for (size_t i = 0; i < entries.size(); i++) {
     if (entries[i].type == CertEntry::COMPRESSED) {
       uncompressed_size += 4 /* uint32 length */ + certs[i].size();
     }
   }
 
   size_t compressed_size = 0;
@@ skipping 77 matching lines @@
     return "";
   }
 
   result.resize(result.size() - z.avail_out);
   return result;
 }
 
 // static
 bool CertCompressor::DecompressChain(StringPiece in,
                                      const vector<string>& cached_certs,
-                                     CommonCertSet* common_set,
+                                     const CommonCertSets* common_set,
                                      vector<string>* out_certs) {
   vector<CertEntry> entries;
   if (!ParseEntries(&in, cached_certs, common_set, &entries, out_certs)) {
     return false;
   }
   DCHECK_EQ(entries.size(), out_certs->size());
 
   scoped_ptr<uint8[]> uncompressed_data;
   StringPiece uncompressed;
 
@@ skipping 28 matching lines @@
     int rv = inflate(&z, Z_FINISH);
     if (rv == Z_NEED_DICT) {
       string zlib_dict = ZlibDictForEntries(entries, *out_certs);
       const uint8* dict = reinterpret_cast<const uint8*>(zlib_dict.data());
       if (Z_OK != inflateSetDictionary(&z, dict, zlib_dict.size())) {
         return false;
       }
       rv = inflate(&z, Z_FINISH);
     }
 
-    if (Z_STREAM_END != rv ||
-        z.avail_out > 0 ||
-        z.avail_in > 0) {
+    if (Z_STREAM_END != rv || z.avail_out > 0 || z.avail_in > 0) {
       return false;
     }
 
     uncompressed = StringPiece(reinterpret_cast<char*>(uncompressed_data.get()),
                                uncompressed_size);
   }
 
   for (size_t i = 0; i < entries.size(); i++) {
     switch (entries[i].type) {
       case CertEntry::COMPRESSED:
@@ skipping 16 matching lines @@
   }
 
   if (!uncompressed.empty()) {
     return false;
   }
 
   return true;
 }
 
 }  // namespace net