1 // Copyright (c) 2013 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 "components/policy/core/common/cloud/component_cloud_policy_updater.h"
6
7 #include "base/bind.h"
8 #include "base/bind_helpers.h"
9 #include "base/logging.h"
10 #include "base/sequenced_task_runner.h"
11 #include "base/strings/string_number_conversions.h"
12 #include "components/policy/core/common/cloud/component_cloud_policy_store.h"
13 #include "components/policy/core/common/cloud/external_policy_data_fetcher.h"
14 #include "policy/proto/chrome_extension_policy.pb.h"
15 #include "policy/proto/device_management_backend.pb.h"
16
17 namespace em = enterprise_management;
18
19 namespace policy {
20
21 namespace {
22
23 // The maximum size of the serialized policy protobuf.
24 const size_t kPolicyProtoMaxSize = 16 * 1024;
25
26 // The maximum size of the downloaded policy data.
27 const int64 kPolicyDataMaxSize = 5 * 1024 * 1024;
28
29 // Tha maximum number of policy data fetches to run in parallel.
30 const int64 kMaxParallelPolicyDataFetches = 2;
31
32 } // namespace
33
ComponentCloudPolicyUpdater(scoped_refptr<base::SequencedTaskRunner> task_runner,scoped_ptr<ExternalPolicyDataFetcher> external_policy_data_fetcher,ComponentCloudPolicyStore * store)34 ComponentCloudPolicyUpdater::ComponentCloudPolicyUpdater(
35 scoped_refptr<base::SequencedTaskRunner> task_runner,
36 scoped_ptr<ExternalPolicyDataFetcher> external_policy_data_fetcher,
37 ComponentCloudPolicyStore* store)
38 : store_(store),
39 external_policy_data_updater_(task_runner,
40 external_policy_data_fetcher.Pass(),
41 kMaxParallelPolicyDataFetches) {
42 }
43
~ComponentCloudPolicyUpdater()44 ComponentCloudPolicyUpdater::~ComponentCloudPolicyUpdater() {
45 }
46
UpdateExternalPolicy(scoped_ptr<em::PolicyFetchResponse> response)47 void ComponentCloudPolicyUpdater::UpdateExternalPolicy(
48 scoped_ptr<em::PolicyFetchResponse> response) {
49 // Keep a serialized copy of |response|, to cache it later.
50 // The policy is also rejected if it exceeds the maximum size.
51 std::string serialized_response;
52 if (!response->SerializeToString(&serialized_response) ||
53 serialized_response.size() > kPolicyProtoMaxSize) {
54 return;
55 }
56
57 // Validate the policy before doing anything else.
58 PolicyNamespace ns;
59 em::ExternalPolicyData data;
60 if (!store_->ValidatePolicy(response.Pass(), &ns, &data)) {
61 LOG(ERROR) << "Failed to validate component policy fetched from DMServer";
62 return;
63 }
64
65 // Maybe the data for this hash has already been downloaded and cached.
66 const std::string& cached_hash = store_->GetCachedHash(ns);
67 if (!cached_hash.empty() && data.secure_hash() == cached_hash)
68 return;
69
70 // TODO(joaodasilva): implement the other two auth methods.
71 if (data.download_auth_method() != em::ExternalPolicyData::NONE)
72 return;
73
74 const std::string key = NamespaceToKey(ns);
75
76 if (data.download_url().empty() || !data.has_secure_hash()) {
77 // If there is no policy for this component or the policy has been removed,
78 // cancel any existing request to fetch policy for this component.
79 external_policy_data_updater_.CancelExternalDataFetch(key);
80
81 // Delete any existing policy for this component.
82 store_->Delete(ns);
83 } else {
84 // Make a request to fetch policy for this component. If another fetch
85 // request is already pending for the component, it will be canceled.
86 external_policy_data_updater_.FetchExternalData(
87 key,
88 ExternalPolicyDataUpdater::Request(data.download_url(),
89 data.secure_hash(),
90 kPolicyDataMaxSize),
91 base::Bind(&ComponentCloudPolicyStore::Store, base::Unretained(store_),
92 ns,
93 serialized_response,
94 data.secure_hash()));
95 }
96 }
97
CancelUpdate(const PolicyNamespace & ns)98 void ComponentCloudPolicyUpdater::CancelUpdate(const PolicyNamespace& ns) {
99 external_policy_data_updater_.CancelExternalDataFetch(NamespaceToKey(ns));
100 }
101
NamespaceToKey(const PolicyNamespace & ns)102 std::string ComponentCloudPolicyUpdater::NamespaceToKey(
103 const PolicyNamespace& ns) {
104 const std::string domain = base::IntToString(ns.domain);
105 const std::string size = base::IntToString(domain.size());
106 return size + ":" + domain + ":" + ns.component_id;
107 }
108
109 } // namespace policy
110