bluetooth: Implement allowed devices map

content/browser/bluetooth/bluetooth_allowed_devices_map.cc

+// Copyright 2015 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 "content/browser/bluetooth/bluetooth_allowed_devices_map.h"
+
+#include <vector>
+
+#include "base/base64.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/strings/string_util.h"
+#include "content/common/bluetooth/bluetooth_scan_filter.h"
+#include "crypto/random.h"
+#include "device/bluetooth/bluetooth_uuid.h"
+
+using device::BluetoothUUID;
+
+namespace content {
+
+namespace {
+const size_t kIdLength = 16 /* 128bits */;

[palmer, 2016/01/15 01:13:59]

Nit: I don't know if these comments are strictly necessary. (But also they don't
hurt anything.)

+
+std::string GetBase64Id() {
+  std::string bytes(
+      kIdLength + 1 /* to avoid bytes being reallocated by WriteInto */, '\0');
+
+  crypto::RandBytes(
+      base::WriteInto(&bytes /* str */, kIdLength + 1 /* length_with_null */),
+      kIdLength);
+
+  base::Base64Encode(bytes, &bytes);
+
+  return bytes;
+}
+}  // namespace
+
+BluetoothAllowedDevicesMap::BluetoothAllowedDevicesMap() {}
+BluetoothAllowedDevicesMap::~BluetoothAllowedDevicesMap() {}
+
+const std::string& BluetoothAllowedDevicesMap::AddDevice(
+    const url::Origin& origin,
+    const std::string& device_address,
+    const std::vector<BluetoothScanFilter>& filters,
+    const std::vector<BluetoothUUID>& optional_services) {
+  VLOG(1) << "Adding a device to Map of Allowed Devices.";
+
+  // "Unique" Origins generate the same key in maps. The set of "unique"
+  // Origins that generate the same key does not intersect the set of
+  // trustworthy origins; since Bluetooth is only available for trustworthy

[palmer, 2016/01/15 01:13:59]

Nit: The correct terminology might be "potentially-trustworthy"? Not sure.

[ortuno, 2016/01/15 02:52:21]

Done.

+  // origins we should never receive a request from a "unique" Origin.
+  // See url::Origin for what constitutes a "unique" Origin and the
+  // Secure Contexts spec for what constitutes a Trusworthy Origin:
+  // https://w3c.github.io/webappsec-secure-contexts/
+  CHECK(!origin.unique());
+
+  if (ContainsKey(origin_to_device_address_to_id_map_[origin],
+                  device_address)) {
+    VLOG(1) << "Device already in map of allowed devices.";
+    return origin_to_device_address_to_id_map_[origin][device_address];
+  }
+  const std::string device_id = GenerateDeviceId(origin);
+  VLOG(1) << "Id generated for device: " << device_id;
+
+  origin_to_device_address_to_id_map_[origin][device_address] = device_id;
+  origin_to_device_id_to_address_map_[origin][device_id] = device_address;
+  origin_to_device_id_to_services_map_[origin][device_id] =
+      UnionOfServices(filters, optional_services);
+
+  return origin_to_device_address_to_id_map_[origin][device_address];
+}
+
+void BluetoothAllowedDevicesMap::RemoveDevice(
+    const url::Origin& origin,
+    const std::string& device_address) {
+  const std::string device_id = GetDeviceId(origin, device_address);
+  DCHECK(!device_id.empty());
+
+  // 1. Remove from all three maps.
+  CHECK(origin_to_device_address_to_id_map_[origin].erase(device_address));
+  CHECK(origin_to_device_id_to_address_map_[origin].erase(device_id));
+  CHECK(origin_to_device_id_to_services_map_[origin].erase(device_id));
+
+  // 2. Remove empty map for origin.
+  if (origin_to_device_address_to_id_map_[origin].empty()) {
+    CHECK(origin_to_device_address_to_id_map_.erase(origin));
+    CHECK(origin_to_device_id_to_address_map_.erase(origin));
+    CHECK(origin_to_device_id_to_services_map_.erase(origin));
+  }
+}
+
+const std::string& BluetoothAllowedDevicesMap::GetDeviceId(
+    const url::Origin& origin,
+    const std::string& device_address) {
+  auto address_map_iter = origin_to_device_address_to_id_map_.find(origin);
+  if (address_map_iter == origin_to_device_address_to_id_map_.end()) {
+    return base::EmptyString();
+  }
+
+  const auto& device_address_to_id_map = address_map_iter->second;
+
+  auto id_iter = device_address_to_id_map.find(device_address);
+  if (id_iter == device_address_to_id_map.end()) {
+    return base::EmptyString();
+  }
+  return id_iter->second;
+}
+
+const std::string& BluetoothAllowedDevicesMap::GetDeviceAddress(
+    const url::Origin& origin,
+    const std::string& device_id) {
+  auto id_map_iter = origin_to_device_id_to_address_map_.find(origin);
+  if (id_map_iter == origin_to_device_id_to_address_map_.end()) {
+    return base::EmptyString();
+  }
+
+  const auto& device_id_to_address_map = id_map_iter->second;
+
+  auto id_iter = device_id_to_address_map.find(device_id);
+
+  return id_iter == device_id_to_address_map.end() ? base::EmptyString()
+                                                   : id_iter->second;
+}
+
+std::string BluetoothAllowedDevicesMap::GenerateDeviceId(
+    const url::Origin& origin) {
+  std::string device_id = GetBase64Id();
+  auto id_map_iter = origin_to_device_id_to_address_map_.find(origin);
+  if (id_map_iter == origin_to_device_id_to_address_map_.end()) {
+    return device_id;
+  }
+  while (ContainsKey(id_map_iter->second, device_id)) {
+    LOG(WARNING) << "Generated repeated id.";
+    device_id = GetBase64Id();
+  }
+  return device_id;
+}
+
+std::set<std::string> BluetoothAllowedDevicesMap::UnionOfServices(
+    const std::vector<BluetoothScanFilter>& filters,
+    const std::vector<BluetoothUUID>& optional_services) {
+  std::set<std::string> unionOfServices;
+  for (const auto& filter : filters) {
+    for (const BluetoothUUID& uuid : filter.services) {
+      unionOfServices.insert(uuid.canonical_value());
+    }
+  }
+  for (const BluetoothUUID& uuid : optional_services) {
+    unionOfServices.insert(uuid.canonical_value());
+  }
+  return unionOfServices;
+}
+
+}  // namespace content