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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
// Copyright (c) 2010 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 "webkit/glue/site_isolation_metrics.h"
#include <set>
#include "base/hash_tables.h"
#include "base/metrics/histogram.h"
#include "net/base/mime_sniffer.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebSecurityOrigin.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebURL.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebURLRequest.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebURLResponse.h"
using WebKit::WebFrame;
using WebKit::WebSecurityOrigin;
using WebKit::WebString;
using WebKit::WebURL;
using WebKit::WebURLRequest;
using WebKit::WebURLResponse;
namespace webkit_glue {
typedef base::hash_map<unsigned, WebURLRequest::TargetType> TargetTypeMap;
typedef base::hash_map<std::string, int> MimeTypeMap;
typedef std::set<std::string> CrossOriginTextHtmlResponseSet;
static TargetTypeMap* GetTargetTypeMap() {
static TargetTypeMap target_type_map_;
return &target_type_map_;
}
// Copied from net/base/mime_util.cc, supported_non_image_types[]
static const char* const kCrossOriginMimeTypesToLog[] = {
"text/cache-manifest",
"text/html",
"text/xml",
"text/xsl",
"text/plain",
"text/vnd.chromium.ftp-dir",
"text/",
"text/css",
"image/svg+xml",
"application/xml",
"application/xhtml+xml",
"application/rss+xml",
"application/atom+xml",
"application/json",
"application/x-x509-user-cert",
"multipart/x-mixed-replace",
"(NONE)" // Keep track of missing MIME types as well
};
static MimeTypeMap* GetMimeTypeMap() {
static MimeTypeMap mime_type_map_;
if (!mime_type_map_.size()) {
for (size_t i = 0; i < arraysize(kCrossOriginMimeTypesToLog); ++i)
mime_type_map_[kCrossOriginMimeTypesToLog[i]] = i;
}
return &mime_type_map_;
}
// This is set is used to keep track of the response urls that we want to
// sniff, since we will have to wait for the payload to arrive.
static CrossOriginTextHtmlResponseSet* GetCrossOriginTextHtmlResponseSet() {
static CrossOriginTextHtmlResponseSet cross_origin_text_html_response_set_;
return &cross_origin_text_html_response_set_;
}
static void LogVerifiedTextHtmlResponse() {
UMA_HISTOGRAM_COUNTS(
"SiteIsolation.CrossSiteNonFrameResponse_verified_texthtml_BLOCK", 1);
}
static void LogMislabeledTextHtmlResponse() {
UMA_HISTOGRAM_COUNTS(
"SiteIsolation.CrossSiteNonFrameResponse_mislabeled_texthtml", 1);
}
void SiteIsolationMetrics::AddRequest(unsigned identifier,
WebURLRequest::TargetType target_type) {
TargetTypeMap& target_type_map = *GetTargetTypeMap();
target_type_map[identifier] = target_type;
}
// Check whether the given response is allowed due to access control headers.
// This is basically a copy of the logic of passesAccessControlCheck() in
// WebCore/loader/CrossOriginAccessControl.cpp.
bool SiteIsolationMetrics::AllowedByAccessControlHeader(
WebFrame* frame, const WebURLResponse& response) {
WebString access_control_origin = response.httpHeaderField(
WebString::fromUTF8("Access-Control-Allow-Origin"));
WebSecurityOrigin security_origin =
WebSecurityOrigin::createFromString(access_control_origin);
return access_control_origin == WebString::fromUTF8("*") ||
frame->securityOrigin().canAccess(security_origin);
}
// We want to log any cross-site request that we don't think a renderer should
// be allowed to make. We can safely ignore frame requests (since we'd like
// those to be in a separate renderer) and plugin requests, even if they are
// cross-origin.
//
// For comparison, we keep counts of:
// - All requests made by a renderer
// - All cross-site requests
//
// Then, for cross-site non-frame/plugin requests, we keep track of:
// - Counts for MIME types of interest
// - Counts of those MIME types that carry CORS headers
// - Counts of mislabeled text/html responses (without CORS)
// As well as those we would block:
// - Counts of verified text/html responses (without CORS)
// - Counts of XML/JSON responses (without CORS)
//
// This will let us say what percentage of requests we would end up blocking.
void SiteIsolationMetrics::LogMimeTypeForCrossOriginRequest(
WebFrame* frame, unsigned identifier, const WebURLResponse& response) {
UMA_HISTOGRAM_COUNTS("SiteIsolation.Requests", 1);
TargetTypeMap& target_type_map = *GetTargetTypeMap();
TargetTypeMap::iterator iter = target_type_map.find(identifier);
if (iter != target_type_map.end()) {
WebURLRequest::TargetType target_type = iter->second;
target_type_map.erase(iter);
// Focus on cross-site requests.
if (!frame->securityOrigin().canAccess(
WebSecurityOrigin::create(response.url()))) {
UMA_HISTOGRAM_COUNTS("SiteIsolation.CrossSiteRequests", 1);
// Now focus on non-frame, non-plugin requests.
if (target_type != WebURLRequest::TargetIsMainFrame &&
target_type != WebURLRequest::TargetIsSubframe &&
target_type != WebURLRequest::TargetIsObject) {
// If it is part of a MIME type we might block, log the MIME type.
std::string mime_type = response.mimeType().utf8();
MimeTypeMap mime_type_map = *GetMimeTypeMap();
// Also track it if it lacks a MIME type.
// TODO(creis): 304 responses have no MIME type, so we don't handle
// them correctly. Can we look up their MIME type from the cache?
if (mime_type == "")
mime_type = "(NONE)";
MimeTypeMap::iterator mime_type_iter = mime_type_map.find(mime_type);
if (mime_type_iter != mime_type_map.end()) {
UMA_HISTOGRAM_ENUMERATION(
"SiteIsolation.CrossSiteNonFrameResponse_MIME_Type",
mime_type_iter->second,
arraysize(kCrossOriginMimeTypesToLog));
// We also check access control headers, in case this
// cross-origin request has been explicitly permitted.
if (AllowedByAccessControlHeader(frame, response)) {
UMA_HISTOGRAM_ENUMERATION(
"SiteIsolation.CrossSiteNonFrameResponse_With_CORS_MIME_Type",
mime_type_iter->second,
arraysize(kCrossOriginMimeTypesToLog));
} else {
// Without access control headers, we might block this request.
// Sometimes resources are mislabled as text/html, though, and we
// should only block them if we can verify that. To do so, we sniff
// the content once we have some of the payload.
if (mime_type == "text/html") {
// Remember the response until we can sniff its contents.
GetCrossOriginTextHtmlResponseSet()->insert(
response.url().spec());
} else if (mime_type == "text/xml" ||
mime_type == "text/xsl" ||
mime_type == "application/xml" ||
mime_type == "application/xhtml+xml" ||
mime_type == "application/rss+xml" ||
mime_type == "application/atom+xml" ||
mime_type == "application/json") {
// We will also block XML and JSON MIME types for cross-site
// non-frame requests without CORS headers.
UMA_HISTOGRAM_COUNTS(
"SiteIsolation.CrossSiteNonFrameResponse_xml_or_json_BLOCK",
1);
}
}
}
}
}
}
}
void SiteIsolationMetrics::SniffCrossOriginHTML(const WebURL& response_url,
const char* data,
int len) {
if (!response_url.isValid())
return;
// Look up the URL to see if it is a text/html request we are tracking.
CrossOriginTextHtmlResponseSet& cross_origin_text_html_response_set =
*GetCrossOriginTextHtmlResponseSet();
CrossOriginTextHtmlResponseSet::iterator request_iter =
cross_origin_text_html_response_set.find(response_url.spec());
if (request_iter != cross_origin_text_html_response_set.end()) {
// Log whether it actually looks like HTML.
std::string sniffed_mime_type;
bool successful = net::SniffMimeType(data, len, response_url,
"", &sniffed_mime_type);
if (successful && sniffed_mime_type == "text/html")
LogVerifiedTextHtmlResponse();
else
LogMislabeledTextHtmlResponse();
cross_origin_text_html_response_set.erase(request_iter);
}
}
void SiteIsolationMetrics::RemoveCompletedResponse(
const WebURL& response_url) {
if (!response_url.isValid())
return;
// Ensure we don't leave responses in the set after they've completed.
CrossOriginTextHtmlResponseSet& cross_origin_text_html_response_set =
*GetCrossOriginTextHtmlResponseSet();
CrossOriginTextHtmlResponseSet::iterator request_iter =
cross_origin_text_html_response_set.find(response_url.spec());
if (request_iter != cross_origin_text_html_response_set.end()) {
LogMislabeledTextHtmlResponse();
cross_origin_text_html_response_set.erase(request_iter);
}
}
} // namespace webkit_glue
|
