UMA data collector for cross-site documents(XSD)

webkit/child/site_isolation_policy.h

+// Copyright (c) 2013 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.
+
+#ifndef WEBKIT_CHILD_SITE_ISOLATION_POLICY_H_
+#define WEBKIT_CHILD_SITE_ISOLATION_POLICY_H_
+
+#include <map>
+#include <utility>
+
+#include "base/gtest_prod_util.h"
+#include "third_party/WebKit/public/platform/WebURLRequest.h"
+#include "third_party/WebKit/public/platform/WebURLResponse.h"
+#include "third_party/WebKit/public/web/WebFrame.h"
+#include "webkit/child/webkit_child_export.h"
+
+using WebKit::WebFrame;
+using WebKit::WebURLResponse;
+using WebKit::WebURLRequest;
+
+namespace webkit_glue {
+
+// SiteIsolationPolicy implements the cross-site document blocking policy (XSDP)
+// for Site Isolation. XSDP will monitor network responses to a renderer and
+// block illegal responses so that a compromised renderer cannot steal private
+// information from other sites. For now SiteIsolationPolicy monitors responses
+// to gather various UMA stats to see the compatibility impact of actual
+// deployment of the policy. The UMA stat categories SiteIsolationPolicy gathers
+// are as follows:
+//
+// SiteIsolation.AllResponses : # of all network responses.
+// SiteIsolation.XSD.DataLength : the length of the first packet of a response.
+// SiteIsolation.XSD.MimeType (enum):
+//   # of responses from other sites, tagged with a document mime type.
+//   0:HTML, 1:XML, 2:JSON, 3:Plain, 4:Others
+// SiteIsolation.XSD.[%MIMETYPE].Blocked :
+//   blocked # of cross-site document responses grouped by sniffed MIME type.
+// SiteIsolation.XSD.[%MIMETYPE].Blocked.RenderableStatusCode :
+//   # of responses with renderable status code,
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].Blocked.NonRenderableStatusCode :
+//   # of responses with non-renderable status code,
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NoSniffBlocked.RenderableStatusCode :
+//   # of responses failed to be sniffed for its MIME type, but blocked by
+//   "X-Content-Type-Options: nosniff" header, and with renderable status code
+//   out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NoSniffBlocked.NonRenderableStatusCode :
+//   # of responses failed to be sniffed for its MIME type, but blocked by
+//   "X-Content-Type-Options: nosniff" header, and with non-renderable status
+//   code out of SiteIsolation.XSD.[%MIMETYPE].Blocked.
+// SiteIsolation.XSD.[%MIMETYPE].NotBlocked :
+//   # of responses, but not blocked due to failure of mime sniffing.
+// SiteIsolation.XSD.[%MIMETYPE].NotBlocked.MaybeJS :
+//   # of responses that are plausibly sniffed to be JavaScript?

[Charlie Reis, 2013/08/13 21:09:03]

nit: End with period, not question mark.

[dsjang, 2013/08/13 21:49:52]

Done.

+
+struct ResponseMetaData {
+
+  enum CanonicalMimeType {
+    HTML = 0,
+    XML = 1,
+    JSON = 2,
+    Plain = 3,
+    Others = 4,
+    MaxCanonicalMimeType,
+  };
+
+  static const char* CanonicalMimeTypeToString(CanonicalMimeType mime_type) {
+    const char* mime_type_names[] = {"HTML", "XML", "JSON", "Plain", "Others"};
+    return mime_type_names[mime_type];
+  };
+
+  static const char* TargetTypeToString(WebURLRequest::TargetType target_type) {
+    const char* target_type_names[] = {
+        "MainFrame", "Subframe", "Subresource", "StyleSheet", "Script",
+        "FontResource", "Image", "Object", "Media", "Worker", "SharedWorker",
+        "Prefetch", "Favicon", "XHR", "TextTrack", "Unspecified"};
+    return target_type_names[target_type];
+  };
+
+  ResponseMetaData();
+
+  std::string frame_origin;
+  GURL response_url;
+  unsigned request_identifier;
+  WebURLRequest::TargetType target_type;
+  CanonicalMimeType canonical_mime_type;
+  int http_status_code;
+  bool no_sniff;
+};
+
+typedef std::map<unsigned, WebURLRequest::TargetType> TargetTypeMap;
+typedef std::map<GURL, ResponseMetaData> UrlResponseMetaDataMap;
+typedef std::map<unsigned, GURL> IdUrlMap;
+
+class WEBKIT_CHILD_EXPORT SiteIsolationPolicy {
+ public:
+  // Registers |target_type| for |identifier| which identifies a specific
+  // request. In case HTTP redirection happens, this function is called multiple
+  // times for the same identifier. We do not depend on |target_type| to decide
+  // if a request is for navigation or not due to the redirection behavior.
+  static void WillSendRequest(unsigned identifier,
+                              WebURLRequest::TargetType target_type);
+
+  // Registers the header information of |response|. This function obtains the
+  // target_type set by |WillSendRequest|. We have to make sure to call either
+  // SiteIsolationPolicy::DidFinishResourceLoad(identifier)| or
+  // SiteIsolationPolicy::DidFinishResourceLoadForURL(response.url()) to free
+  // the bookkepping data.
+  // TODO(dsjang): There's a possibility that two distinct responses (identified
+  // by different identifiers) are from the same url, and this results in
+  // overwriting one of the two responses' bookkeeping data. For example, when
+  // there are <iframe src="urlA" /> and <img src="urlA"> on the same page,
+  // there will be two calls of |DidReceiveResponse| with the same url, but
+  // different identifiers. This can deteriorate our UMA data. Even though we
+  // expect that this rarely happens, find a way to use identifier throughout
+  // the entire HTTP transaction here.
+  static void DidReceiveResponse(WebFrame* frame,
+                                 unsigned identifier,
+                                 const WebURLResponse& response);
+
+  // Examines the first network packet in case response_url is
+  // registered as a cross-site document by DidReceiveResponse().
+  // This records various kinds of UMA data stats. This function is
+  // called only if the length of received data is non-zero.
+  static void DidReceiveData(const char* payload,
+                             int length,
+                             WebKit::WebURL& response_url);
+
+  // TODO(dsjang): Either of the following two functions must be called at the
+  // end of thetransaction.  WebURLLoaderImpl::didReceivedData() is not a place

[Charlie Reis, 2013/08/13 21:09:03]

nit: the transaction

[dsjang, 2013/08/13 21:49:52]

Done.

+  // where this can be called since it is not guaranteed that the function is
+  // called in case of network error. Instead,
+  // RenderFrameImpl::didFinishResourceLoad(identifier) and didFailLoad() are
+  // used for successful loading and failed loading, respectively.
+  static void DidFinishResourceLoad(unsigned identifier);
+
+  // Does the same thing as DidFinishResourceLoad(), but accepts response_url.
+  static void DidFinishResourceLoadForUrl(const WebKit::WebURL& response_url);
+
+private:
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsBlockableScheme);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsSameSite);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, IsValidCorsHeaderSet);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForHTML);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForXML);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForJSON);
+  FRIEND_TEST_ALL_PREFIXES(SiteIsolationPolicyTest, SniffForJS);
+
+  // Returns the representative mime type enum value of the mime type of
+  // response. For example, this returns the same value for all text/xml mime
+  // type families such as application/xml, application/rss+xml.
+  static ResponseMetaData::CanonicalMimeType GetCanonicalMimeType(
+      const WebURLResponse& response);
+
+  // Returns whether this scheme is a target of cross-site document
+  // policy(XSDP). This returns true only for http://* and https://* urls.
+  static bool IsBlockableScheme(const GURL& frame_origin);
+
+  // Returns whether the two urls belong to the same sites.
+  static bool IsSameSite(const GURL& frame_origin, const GURL& response_url);
+
+  // Returns whether there's a valid CORS header for frame_origin.  This is
+  // simliar to CrossOriginAccessControl::passesAccessControlCheck(), but we use
+  // sites as our security domain, not origins.
+  // TODO(dsjang): this must be improved to be more accurate to the actual CORS
+  // specification. For now, this works conservatively, allowing XSDs that are
+  // not allowed by actual CORS rules by ignoring 1) credentials and 2)
+  // methods. Preflight requests don't matter here since they are not used to
+  // decide whether to block a document or not on the client side.
+  static bool IsValidCorsHeaderSet(GURL& frame_origin,
+                                   GURL& website_origin,
+                                   std::string access_control_origin);
+
+  // Returns whether the given frame is navigating. When this is true, the frame
+  // is requesting is a web page to be loaded.
+  static bool IsFrameNavigating(WebFrame* frame);
+
+  static bool SniffForHTML(const char* data, size_t length);
+  static bool SniffForXML(const char* data, size_t length);
+  static bool SniffForJSON(const char* data, size_t length);
+
+  static bool MatchesSignature(const char* data,
+                               size_t length,
+                               const char* signatures[],
+                               size_t arr_size);
+
+  // TODO(dsjang): this is only needed for collecting UMA stat. Will be deleted
+  // when this class is used for actual blocking.
+  static bool SniffForJS(const char* data, size_t length);
+
+  // TODO(dsjang): this is only needed for collecting UMA stat. Will be deleted
+  // when this class is used for actual blocking.
+  static bool IsRenderableStatusCodeForDocument(int status_code);
+
+  // Maintain bookkeeping data between WillSendRequest() and
+  // DidReceiveResponse(). The key is the identifier of response.
+  static TargetTypeMap* GetIdTargetMap();
+
+  // Maintain data between DidReceiveResponse() and DidReceiveData().  The key
+  // is the url of response. We can't use identifier anymore from here since
+  // that information is no longer available for DidReceiveData().
+  static UrlResponseMetaDataMap* GetUrlResponseMetaDataMap();
+
+  // This maps the identifier of a response to the response's url. This is used
+  // to free ResponseMetaData in url_responsedata_map_, when DidReceiveData() is
+  // never called.
+  static IdUrlMap* GetIdUrlMap();
+
+  // Never needs to be constructed/destructed.
+  SiteIsolationPolicy() {}
+  ~SiteIsolationPolicy() {}
+
+  DISALLOW_COPY_AND_ASSIGN(SiteIsolationPolicy);
+};
+
+}  // namespace content
+
+#endif  // WEBKIT_CHILD_SITE_ISOLATION_POLICY_H_