Common Name Mismatch Handler For WWW Subdomain Mismatch case

chrome/browser/ssl/ssl_error_handler.cc

 // Copyright 2014 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/ssl/ssl_error_handler.h"
 
 #include "base/callback_helpers.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ssl/ssl_blocking_page.h"
 #include "chrome/browser/ssl/ssl_cert_reporter.h"
+#include "chrome/browser/ssl/ssl_error_classification.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
 
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
 #include "chrome/browser/captive_portal/captive_portal_service.h"
 #include "chrome/browser/captive_portal/captive_portal_service_factory.h"
 #include "chrome/browser/captive_portal/captive_portal_tab_helper.h"
 #include "chrome/browser/ssl/captive_portal_blocking_page.h"
 #endif
 
 namespace {
 
 // The type of the delay before displaying the SSL interstitial. This can be
 // changed in tests.
 SSLErrorHandler::InterstitialDelayType g_interstitial_delay_type =
     SSLErrorHandler::NORMAL;
 
 // Callback to call when the interstitial timer is started. Used for testing.
 SSLErrorHandler::TimerStartedCallback* g_timer_started_callback = nullptr;
 
 // Events for UMA.
 enum SSLErrorHandlerEvent {
   HANDLE_ALL,
   SHOW_CAPTIVE_PORTAL_INTERSTITIAL_NONOVERRIDABLE,
   SHOW_CAPTIVE_PORTAL_INTERSTITIAL_OVERRIDABLE,
   SHOW_SSL_INTERSTITIAL_NONOVERRIDABLE,
   SHOW_SSL_INTERSTITIAL_OVERRIDABLE,
+  SHOW_COMMON_NAME_MISMATCH_INTERSTITIAL_NONOVERRIDABLE,
+  SHOW_COMMON_NAME_MISMATCH_INTERSTITIAL_OVERRIDABLE,
   SSL_ERROR_HANDLER_EVENT_COUNT
 };
 
 void RecordUMA(SSLErrorHandlerEvent event) {
   UMA_HISTOGRAM_ENUMERATION("interstitial.ssl_error_handler",
                             event,
                             SSL_ERROR_HANDLER_EVENT_COUNT);
 }
 
-#if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
 // The delay before displaying the SSL interstitial for cert errors.
-// - If a "captive portal detected" result arrives in this many seconds,
-//   a captive portal interstitial is displayed.
+// - If a "captive portal detected" or "suggested URL valid" result
+//   arrives in this many seconds, then a captive portal interstitial
+//   or a common name mismatch interstitial is displayed.
 // - Otherwise, an SSL interstitial is displayed.
 const int kDefaultInterstitialDisplayDelayInSeconds = 2;
 
 base::TimeDelta GetInterstitialDisplayDelay(
     SSLErrorHandler::InterstitialDelayType delay) {
   switch (delay) {
     case SSLErrorHandler::LONG:
       return base::TimeDelta::FromHours(1);
 
     case SSLErrorHandler::NONE:
       return base::TimeDelta();
 
     case SSLErrorHandler::NORMAL:
       return base::TimeDelta::FromSeconds(
           kDefaultInterstitialDisplayDelayInSeconds);
 
     default:
       NOTREACHED();
   }
   return base::TimeDelta();
 }
 
+#if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
 bool IsCaptivePortalInterstitialEnabled() {
   return base::FieldTrialList::FindFullName("CaptivePortalInterstitial") ==
          "Enabled";
 }
 #endif
 
 }  // namespace
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(SSLErrorHandler);
 
 void SSLErrorHandler::HandleSSLError(
     content::WebContents* web_contents,
     int cert_error,
     const net::SSLInfo& ssl_info,
     const GURL& request_url,
     int options_mask,
     scoped_ptr<SSLCertReporter> ssl_cert_reporter,
     const base::Callback<void(bool)>& callback) {
-#if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
-  CaptivePortalTabHelper* captive_portal_tab_helper =
-      CaptivePortalTabHelper::FromWebContents(web_contents);
-  if (captive_portal_tab_helper) {
-    captive_portal_tab_helper->OnSSLCertError(ssl_info);
-  }
-#endif
   DCHECK(!FromWebContents(web_contents));
   web_contents->SetUserData(
       UserDataKey(),
       new SSLErrorHandler(web_contents, cert_error, ssl_info, request_url,
                           options_mask, ssl_cert_reporter.Pass(), callback));
 
   SSLErrorHandler* error_handler =
       SSLErrorHandler::FromWebContents(web_contents);
   error_handler->StartHandlingError();
 }
@@ skipping 18 matching lines @@
                                  int options_mask,
                                  scoped_ptr<SSLCertReporter> ssl_cert_reporter,
                                  const base::Callback<void(bool)>& callback)
     : content::WebContentsObserver(web_contents),
       web_contents_(web_contents),
       cert_error_(cert_error),
       ssl_info_(ssl_info),
       request_url_(request_url),
       options_mask_(options_mask),
       callback_(callback),
-      ssl_cert_reporter_(ssl_cert_reporter.Pass()) {
-#if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
-  Profile* profile = Profile::FromBrowserContext(
-      web_contents->GetBrowserContext());
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_CAPTIVE_PORTAL_CHECK_RESULT,
-                 content::Source<Profile>(profile));
-#endif
-}
+      profile_(Profile::FromBrowserContext(web_contents->GetBrowserContext())),
+      ssl_cert_reporter_(ssl_cert_reporter.Pass()) {}
 
 SSLErrorHandler::~SSLErrorHandler() {
 }
 
 void SSLErrorHandler::StartHandlingError() {
   RecordUMA(HANDLE_ALL);
 
+  std::vector<std::string> dns_names;
+  ssl_info_.cert->GetDNSNames(&dns_names);
+  DCHECK(!dns_names.empty());
+  GURL suggested_url;
+  if (GetSuggestedUrl(dns_names, &suggested_url)) {
+    net::CertStatus extra_cert_errors =
+        ssl_info_.cert_status ^ net::CERT_STATUS_COMMON_NAME_INVALID;
+
+    // Show the SSL intersitial if |CERT_STATUS_COMMON_NAME_INVALID| is not
+    // the only error. Need not check for captive portal in this case.
+    // (See the comment below).
+    if (extra_cert_errors) {

[Ryan Sleevi, 2015/08/14 00:40:17]

This is not correct. CertStatus contains errors _and_ informational status bits.

Our preferred idiom is to look at both IsCertStatusError and
IsCertStatusMinorError to make a decision.

[Bhanu Dev, 2015/08/15 00:18:54]

Done. Thanks for pointing this out. This might have resulted in false negatives.

+      ShowSSLInterstitial();
+      return;
+    }
+    CheckSuggestedUrl(suggested_url);
+    timer_.Start(FROM_HERE,
+                 GetInterstitialDisplayDelay(g_interstitial_delay_type), this,
+                 &SSLErrorHandler::OnTimerExpired);
+    if (g_timer_started_callback)
+      g_timer_started_callback->Run(web_contents_);
+
+    // Do not check for a captive portal in this case, because a captive
+    // portal most likely cannot serve a valid certificate which passes the
+    // similarity check.
+    return;
+  }
+
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
+  CaptivePortalTabHelper* captive_portal_tab_helper =
+      CaptivePortalTabHelper::FromWebContents(web_contents_);
+  if (captive_portal_tab_helper) {
+    captive_portal_tab_helper->OnSSLCertError(ssl_info_);
+  }
+
+  registrar_.Add(this, chrome::NOTIFICATION_CAPTIVE_PORTAL_CHECK_RESULT,
+                 content::Source<Profile>(profile_));
+
   if (IsCaptivePortalInterstitialEnabled()) {
     CheckForCaptivePortal();
     timer_.Start(FROM_HERE,
                  GetInterstitialDisplayDelay(g_interstitial_delay_type),
                  this, &SSLErrorHandler::OnTimerExpired);
     if (g_timer_started_callback)
       g_timer_started_callback->Run(web_contents_);
     return;
   }
 #endif
   // Display an SSL interstitial.
   ShowSSLInterstitial();
 }
 
 void SSLErrorHandler::OnTimerExpired() {
   ShowSSLInterstitial();
 }
 
+bool SSLErrorHandler::GetSuggestedUrl(const std::vector<std::string>& dns_names,
+                                      GURL* suggested_url) const {
+  return CommonNameMismatchHandler::GetSuggestedUrl(request_url_, dns_names,
+                                                    suggested_url);
+}
+
+void SSLErrorHandler::CheckSuggestedUrl(const GURL& suggested_url) {
+  scoped_refptr<net::URLRequestContextGetter> request_context(
+      profile_->GetRequestContext());
+  common_name_mismatch_handler_.reset(
+      new CommonNameMismatchHandler(request_url_, request_context));
+
+  common_name_mismatch_handler_->CheckSuggestedUrl(
+      suggested_url,
+      base::Bind(&SSLErrorHandler::CommonNameMismatchHandlerCallback,
+                 base::Unretained(this)));

[Ryan Sleevi, 2015/08/14 00:40:17]

This seems incredibly dangerous - base::Unretained() is almost universally a red
flag that signals "carefully review the threading contracts", and I don't see
code that guarantees this is safe.

[Bhanu Dev, 2015/08/15 00:18:53]

Done. Added a method |Cancel()| in CommonNameMismatchHandler and it is called
before the SSLErrorHandler gets deleted. 

+}
+
+void SSLErrorHandler::NavigateToSuggestedURL(const GURL& suggested_url) {
+  content::NavigationController::LoadURLParams load_params(suggested_url);
+  load_params.transition_type = ui::PAGE_TRANSITION_TYPED;
+  web_contents()->GetController().LoadURLWithParams(load_params);
+}
+
 void SSLErrorHandler::CheckForCaptivePortal() {
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
-  Profile* profile = Profile::FromBrowserContext(
-      web_contents_->GetBrowserContext());
   CaptivePortalService* captive_portal_service =
-      CaptivePortalServiceFactory::GetForProfile(profile);
+      CaptivePortalServiceFactory::GetForProfile(profile_);
   captive_portal_service->DetectCaptivePortal();
 #else
   NOTREACHED();
 #endif
 }
 
 void SSLErrorHandler::ShowCaptivePortalInterstitial(const GURL& landing_url) {
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
   // Show captive portal blocking page. The interstitial owns the blocking page.
-  const Profile* const profile =
-      Profile::FromBrowserContext(web_contents_->GetBrowserContext());
-  RecordUMA(SSLBlockingPage::IsOverridable(options_mask_, profile)
+  RecordUMA(SSLBlockingPage::IsOverridable(options_mask_, profile_)
                 ? SHOW_CAPTIVE_PORTAL_INTERSTITIAL_OVERRIDABLE
                 : SHOW_CAPTIVE_PORTAL_INTERSTITIAL_NONOVERRIDABLE);
   (new CaptivePortalBlockingPage(web_contents_, request_url_, landing_url,
                                  ssl_cert_reporter_.Pass(), ssl_info_,
                                  callback_))->Show();
   // Once an interstitial is displayed, no need to keep the handler around.
   // This is the equivalent of "delete this".
   web_contents_->RemoveUserData(UserDataKey());
 #else
   NOTREACHED();
 #endif
 }
 
 void SSLErrorHandler::ShowSSLInterstitial() {
   // Show SSL blocking page. The interstitial owns the blocking page.
-  const Profile* const profile =
-      Profile::FromBrowserContext(web_contents_->GetBrowserContext());
-  RecordUMA(SSLBlockingPage::IsOverridable(options_mask_, profile)
+  RecordUMA(SSLBlockingPage::IsOverridable(options_mask_, profile_)
                 ? SHOW_SSL_INTERSTITIAL_OVERRIDABLE
                 : SHOW_SSL_INTERSTITIAL_NONOVERRIDABLE);
+
   (new SSLBlockingPage(web_contents_, cert_error_, ssl_info_, request_url_,
                        options_mask_, base::Time::NowFromSystemTime(),
-                       ssl_cert_reporter_.Pass(), callback_))->Show();
+                       ssl_cert_reporter_.Pass(), callback_))
+      ->Show();
   // Once an interstitial is displayed, no need to keep the handler around.
   // This is the equivalent of "delete this".
   web_contents_->RemoveUserData(UserDataKey());
 }
 
 void SSLErrorHandler::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
@@ skipping 24 matching lines @@
 }
 
 void SSLErrorHandler::DeleteSSLErrorHandler() {
   // Need to explicity deny the certificate via the callback, otherwise memory
   // is leaked.
   if (!callback_.is_null()) {
     base::ResetAndReturn(&callback_).Run(false);
   }
   web_contents_->RemoveUserData(UserDataKey());
 }
+
+void SSLErrorHandler::CommonNameMismatchHandlerCallback(
+    const CommonNameMismatchHandler::Results& results) {
+  timer_.Stop();
+  if (results.result == CommonNameMismatchHandler::SuggestedUrlCheckResult::
+                            SUGGESTED_URL_AVAILABLE) {
+    NavigateToSuggestedURL(results.suggested_url);
+  } else {
+    ShowSSLInterstitial();
+  }
+}