Revert "Certificate Transparency: Code for unpacking EV cert hashes whitelist"

net/cert/ct_ev_whitelist.cc

-// Copyright 2014 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/cert/ct_ev_whitelist.h"
-
-#include <set>
-
-#include "base/big_endian.h"
-#include "base/file_util.h"
-#include "base/lazy_instance.h"
-#include "base/logging.h"
-
-namespace net {
-
-namespace ct {
-
-namespace {
-base::LazyInstance<std::set<std::string> >::Leaky g_current_ev_whitelist =
-    LAZY_INSTANCE_INITIALIZER;
-
-const uint8 kCertHashLengthBits = 64;     // 8 bytes
-const uint64 kGolombMParameterBits = 47;  // 2^47
-}  // namespace
-
-namespace internal {
-
-BitStreamReader::BitStreamReader(const char* source, size_t length)
-    : source_(source), length_(length), current_byte_(0), current_bit_(7) {
-}
-
-bool BitStreamReader::ReadUnaryEncoding(uint64* out) {
-  uint64 res = 0;
-  if (BitsLeft() == 0)
-    return false;
-
-  while ((BitsLeft() > 0) && ReadBit())
-    res++;
-
-  *out = res;
-  return true;
-}
-
-bool BitStreamReader::ReadBits(uint8 num_bits, uint64* out) {
-  if (num_bits > 64)
-    return false;
-
-  if (BitsLeft() < num_bits)
-    return false;
-
-  uint64 res = 0;
-  for (uint8 i = 0; i < num_bits; ++i)
-    res |= (static_cast<uint64>(ReadBit()) << (num_bits - (i + 1)));
-
-  *out = res;
-  return true;
-}
-
-uint64 BitStreamReader::BitsLeft() const {
-  if (current_byte_ == length_)
-    return 0;
-  return (length_ - (current_byte_ + 1)) * 8 + current_bit_ + 1;
-}
-
-uint8 BitStreamReader::ReadBit() {
-  DCHECK_GT(BitsLeft(), 0u);
-  DCHECK(current_bit_ < 8 && current_bit_ >= 0);
-  uint8 res = (source_[current_byte_] & (1 << current_bit_)) >> current_bit_;
-  current_bit_--;
-  if (current_bit_ < 0) {
-    current_byte_++;
-    current_bit_ = 7;
-  }
-
-  return res;
-}
-
-bool UncompressEVWhitelist(const std::string& compressed_whitelist,
-                           std::set<std::string>* uncompressed_list) {
-  BitStreamReader reader(compressed_whitelist.data(),
-                         compressed_whitelist.size());
-  std::set<std::string> result;
-
-  VLOG(1) << "Uncompressing EV whitelist of size "
-          << compressed_whitelist.size();
-  uint64 curr_hash(0);
-  if (!reader.ReadBits(kCertHashLengthBits, &curr_hash)) {
-    VLOG(1) << "Failed reading first hash.";
-    return false;
-  }
-  char hash_bytes[8];
-  base::WriteBigEndian(hash_bytes, curr_hash);
-  result.insert(std::string(hash_bytes, 8));
-  static const uint64 M = static_cast<uint64>(1) << kGolombMParameterBits;
-
-  while (reader.BitsLeft() > kGolombMParameterBits) {
-    uint64 read_prefix = 0;
-    if (!reader.ReadUnaryEncoding(&read_prefix)) {
-      VLOG(1) << "Failed reading unary-encoded prefix.";
-      return false;
-    }
-
-    uint64 r = 0;
-    if (!reader.ReadBits(kGolombMParameterBits, &r)) {
-      VLOG(1) << "Failed reading " << kGolombMParameterBits << " bits.";
-      return false;
-    }
-
-    uint64 curr_diff = read_prefix * M + r;
-    curr_hash += curr_diff;
-
-    base::WriteBigEndian(hash_bytes, curr_hash);
-    result.insert(std::string(hash_bytes, 8));
-  }
-
-  uncompressed_list->swap(result);
-  return true;
-}
-
-void SetEVWhitelistData(std::set<std::string>& ev_whitelist) {
-  g_current_ev_whitelist.Get().swap(ev_whitelist);
-}
-
-}  // namespace internal
-
-void SetEVWhitelistFromFile(const base::FilePath& compressed_whitelist_file) {
-  VLOG(1) << "Setting EV whitelist from file: "
-          << compressed_whitelist_file.value();
-  std::string compressed_list;
-  if (!base::ReadFileToString(compressed_whitelist_file, &compressed_list)) {
-    VLOG(1) << "Failed reading from " << compressed_whitelist_file.value();
-    return;
-  }
-
-  std::set<std::string> uncompressed_list;
-  if (!internal::UncompressEVWhitelist(compressed_list, &uncompressed_list)) {
-    VLOG(1) << "Failed uncompressing.";
-    return;
-  }
-  VLOG(1) << "Uncompressing succeeded, hashes: " << uncompressed_list.size();
-
-  internal::SetEVWhitelistData(uncompressed_list);
-}
-
-bool IsCertificateHashInWhitelist(const std::string& certificate_hash) {
-  const std::set<std::string>& current_ev_whitelist =
-      g_current_ev_whitelist.Get();
-  return current_ev_whitelist.find(certificate_hash) !=
-         current_ev_whitelist.end();
-}
-
-bool HasValidEVWhitelist() {
-  return !g_current_ev_whitelist.Get().empty();
-}
-
-}  // namespace ct
-
-}  // namespace net