1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
// 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 "chrome/browser/safe_browsing/unverified_download_policy.h"
#include <algorithm>
#include "base/bind.h"
#include "base/callback.h"
#include "base/files/file_path.h"
#include "base/metrics/sparse_histogram.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/safe_browsing/safe_browsing_service.h"
#include "chrome/browser/safe_browsing/unverified_download_field_trial.h"
#include "chrome/common/safe_browsing/download_protection_util.h"
#include "components/rappor/rappor_service.h"
#include "components/rappor/rappor_utils.h"
#include "components/safe_browsing_db/database_manager.h"
#include "content/public/browser/browser_thread.h"
namespace safe_browsing {
namespace {
using content::BrowserThread;
// Record the uma_file_type to UMA as an enum, and the URL's eTLD+1 to Rappor.
void RecordPolicyMetricOnUIThread(const std::string& metric_name,
int uma_file_type,
const GURL& requestor) {
DCHECK_CURRENTLY_ON(BrowserThread::UI);
UMA_HISTOGRAM_SPARSE_SLOWLY(metric_name, uma_file_type);
rappor::RapporService* rappor_service = g_browser_process->rappor_service();
if (rappor_service && requestor.is_valid()) {
rappor_service->RecordSample(
metric_name, rappor::SAFEBROWSING_RAPPOR_TYPE,
rappor::GetDomainAndRegistrySampleFromGURL(requestor));
}
}
void RecordPolicyMetric(const std::string& metric_name,
int uma_file_type,
const GURL& requestor) {
BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
base::Bind(&RecordPolicyMetricOnUIThread, metric_name,
uma_file_type, requestor));
}
void RespondWithPolicy(
const base::FilePath& file,
const UnverifiedDownloadCheckCompletionCallback& callback,
const GURL& requestor,
UnverifiedDownloadPolicy policy) {
int uma_file_type =
download_protection_util::GetSBClientDownloadExtensionValueForUMA(file);
if (policy == UnverifiedDownloadPolicy::ALLOWED) {
RecordPolicyMetric("SafeBrowsing.UnverifiedDownloads.Allowed",
uma_file_type, requestor);
} else {
RecordPolicyMetric("SafeBrowsing.UnverifiedDownloads.Blocked",
uma_file_type, requestor);
}
BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
base::Bind(callback, policy));
}
void CheckFieldTrialOnAnyThread(
const base::FilePath& file,
const std::vector<base::FilePath::StringType>& alternate_extensions,
const GURL& requestor,
const UnverifiedDownloadCheckCompletionCallback& callback) {
if (!IsUnverifiedDownloadAllowedByFieldTrial(file)) {
RespondWithPolicy(file, callback, requestor,
UnverifiedDownloadPolicy::DISALLOWED);
return;
}
for (const auto& extension : alternate_extensions) {
base::FilePath alternate_filename = file.AddExtension(extension);
if (!IsUnverifiedDownloadAllowedByFieldTrial(alternate_filename)) {
RespondWithPolicy(alternate_filename, callback, requestor,
UnverifiedDownloadPolicy::DISALLOWED);
return;
}
}
RespondWithPolicy(file, callback, requestor,
UnverifiedDownloadPolicy::ALLOWED);
}
void CheckWhitelistOnIOThread(
scoped_refptr<SafeBrowsingService> service,
const GURL& requestor,
const base::FilePath& file,
const std::vector<base::FilePath::StringType>& alternate_extensions,
const UnverifiedDownloadCheckCompletionCallback& callback) {
DCHECK_CURRENTLY_ON(BrowserThread::IO);
int uma_file_type =
download_protection_util::GetSBClientDownloadExtensionValueForUMA(file);
if (!service || !service->enabled()) {
// If the SafeBrowsing service was disabled, don't try to check against the
// field trial list. Instead allow the download. We are assuming that if the
// SafeBrowsing service was disabled for this user, then we shouldn't
// interefere with unverified downloads.
RecordPolicyMetric(
"SafeBrowsing.UnverifiedDownloads.AllowedDueToDisabledService",
uma_file_type, requestor);
RespondWithPolicy(file, callback, requestor,
UnverifiedDownloadPolicy::ALLOWED);
return;
}
if (service->database_manager() &&
service->database_manager()->MatchDownloadWhitelistUrl(requestor)) {
RecordPolicyMetric("SafeBrowsing.UnverifiedDownloads.AllowedByWhitelist",
uma_file_type, requestor);
RespondWithPolicy(file, callback, requestor,
UnverifiedDownloadPolicy::ALLOWED);
return;
}
CheckFieldTrialOnAnyThread(file, alternate_extensions, requestor, callback);
}
} // namespace
void CheckUnverifiedDownloadPolicy(
const GURL& requestor,
const base::FilePath& file,
const std::vector<base::FilePath::StringType>& alternate_extensions,
const UnverifiedDownloadCheckCompletionCallback& callback) {
// Record a count of alternate extensions. The count is capped so that it
// won't be unbounded. In practice, it's expected that numbers above 3 are
// rare.
int alternate_extension_count =
std::min<int>(alternate_extensions.size(), 16);
UMA_HISTOGRAM_SPARSE_SLOWLY(
"SafeBrowsing.UnverifiedDownloads.AlternateExtensionCount",
alternate_extension_count);
if (requestor.is_valid()) {
scoped_refptr<SafeBrowsingService> service =
g_browser_process->safe_browsing_service();
BrowserThread::PostTask(
BrowserThread::IO, FROM_HERE,
base::Bind(&CheckWhitelistOnIOThread, service, requestor, file,
alternate_extensions, callback));
return;
}
CheckFieldTrialOnAnyThread(file, alternate_extensions, GURL(), callback);
}
} // namespace safe_browsing
|
