WKWebView(iOS9): correctly update SSL status for current navigation item

ios/web/web_state/ui/crw_wk_web_view_web_controller.mm

Index: ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
diff --git a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
index e5c88664c2057d26c56a89ea4e4b249886d6e8fb..6ea9922174a49bb85d8b43bec8842a3d1c2de792 100644
--- a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
+++ b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
@@ -11,6 +11,7 @@
 #include "base/json/json_reader.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/values.h"
 #import "ios/net/http_response_headers_util.h"
@@ -250,12 +251,30 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
 // Clears all activity indicator tasks for this web controller.
 - (void)clearActivityIndicatorTasks;
 
+// Updates |security_style| and |cert_status| for the NavigationItem with ID
+// |navigationItemID|, if URL and certificate chain still match |host| and
+// |certChain|.
+- (void)updateSSLStatusForNavigationItemWithID:(int)navigationItemID
+                                     certChain:(NSArray*)chain
+                                          host:(NSString*)host
+                             withSecurityStyle:(web::SecurityStyle)style
+                                    certStatus:(net::CertStatus)certStatus;
+
+// Asynchronously obtains SSL status from given |certChain| and |host| and
+// updates current navigation item. Before scheduling update changes SSLStatus'
+// cert_status and security_style to default.
+- (void)scheduleSSLStatusUpdateUsingCertChain:(NSArray*)chain
+                                         host:(NSString*)host;
+
 #if !defined(ENABLE_CHROME_NET_STACK_FOR_WKWEBVIEW)
 // Updates SSL status for the current navigation item based on the information
 // provided by web view.
 - (void)updateSSLStatusForCurrentNavigationItem;
 #endif
 
+// Reports "WebController.WKWebViewHasCertForSecureConnection" UMA.
+- (void)reportHasCertForSecureConnectionUMAWithValue:(bool)value;
+
 // Registers load request with empty referrer and link or client redirect
 // transition based on user interaction state.
 - (void)registerLoadRequest:(const GURL&)url;
@@ -864,12 +883,81 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
       clearNetworkTasksForGroup:[self activityIndicatorGroupID]];
 }
 
+- (void)updateSSLStatusForNavigationItemWithID:(int)navigationItemID
+                                     certChain:(NSArray*)chain
+                                          host:(NSString*)host
+                             withSecurityStyle:(web::SecurityStyle)style
+                                    certStatus:(net::CertStatus)certStatus {
+  web::NavigationManager* navigationManager =
+      self.webStateImpl->GetNavigationManager();
+
+  // The searched item almost always be the last one, so walk backward rather
+  // than forward.
+  for (int i = navigationManager->GetEntryCount() - 1; 0 <= i; i--) {
+    web::NavigationItem* item = navigationManager->GetItemAtIndex(i);
+    if (item->GetUniqueID() != navigationItemID)
+      continue;
+
+    // NavigationItem's UniqueID is preserved even after redirects, so
+    // checking that cert and URL match is necessary.
+    scoped_refptr<net::X509Certificate> cert(web::CreateCertFromChain(chain));
+    int certID =
+        web::CertStore::GetInstance()->StoreCert(cert.get(), self.certGroupID);
+    std::string GURLHost = base::SysNSStringToUTF8(host);
+    web::SSLStatus& SSLStatus = item->GetSSL();
+    if (SSLStatus.cert_id == certID && item->GetURL().host() == GURLHost) {
+      web::SSLStatus previousSSLStatus = item->GetSSL();
+      SSLStatus.cert_status = certStatus;
+      SSLStatus.security_style = style;
+      if (navigationManager->GetCurrentEntryIndex() == i &&
+          !previousSSLStatus.Equals(SSLStatus)) {
+        [self didUpdateSSLStatusForCurrentNavigationItem];
+      }
+    }
+    return;
+  }
+}
+
+- (void)scheduleSSLStatusUpdateUsingCertChain:(NSArray*)chain
+                                         host:(NSString*)host {
+  // Real SSL status is unknown, reset cert status and security style. Keep
+  // cert_id, which works as a guard to prevent re-entry into this method.

[davidben, 2015/10/15 17:46:12]

I don't understand what this comment is saying. By the time this code runs,
cert_id has already been set in line 982.

I think the invariant (SSLStatus *always* refers to the current state of the
world) would be much clearer if lines 927 and 928 were after line 987 or so.
That way you don't update half of SSLStatus one time and half another time.

[Eugene But (OOO till 7-30), 2015/10/15 22:59:34]

Moved the code.

+  web::NavigationItem* item =
+      self.webStateImpl->GetNavigationManager()->GetLastCommittedItem();
+  item->GetSSL().cert_status = net::CertStatus();
+  item->GetSSL().security_style = web::SECURITY_STYLE_UNKNOWN;
+
+  // Use Navigation Item's unique ID to locate requested item after
+  // obtaining cert status asynchronously.
+  int itemID = item->GetUniqueID();
+
+  base::WeakNSObject<CRWWKWebViewWebController> weakSelf(self);
+  void (^SSLStatusResponse)(web::SecurityStyle, net::CertStatus) =
+      ^(web::SecurityStyle style, net::CertStatus certStatus) {
+        base::scoped_nsobject<CRWWKWebViewWebController> strongSelf(
+            [weakSelf retain]);
+        if (!strongSelf || [strongSelf isBeingDestroyed]) {
+          return;
+        }
+        [strongSelf updateSSLStatusForNavigationItemWithID:itemID
+                                                 certChain:chain
+                                                      host:host
+                                         withSecurityStyle:style
+                                                certStatus:certStatus];
+      };
+
+  [_certVerificationController
+      querySSLStatusForTrust:web::CreateServerTrustFromChain(chain, host)
+                        host:host
+           completionHandler:SSLStatusResponse];
+}
+
 #if !defined(ENABLE_CHROME_NET_STACK_FOR_WKWEBVIEW)
+
 - (void)updateSSLStatusForCurrentNavigationItem {
   if ([self isBeingDestroyed])
     return;
 
-  DCHECK(self.webStateImpl);
   web::NavigationItem* item =
       self.webStateImpl->GetNavigationManagerImpl().GetLastCommittedItem();
   if (!item)
@@ -877,36 +965,59 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
 
   web::SSLStatus previousSSLStatus = item->GetSSL();
   web::SSLStatus& SSLStatus = item->GetSSL();
+
+  // Starting from iOS9 WKWebView blocks active mixed content, so if
+  // |hasOnlySecureContent| returns NO it means passive content.
+  SSLStatus.content_status = [_wkWebView hasOnlySecureContent]
+                                 ? web::SSLStatus::NORMAL_CONTENT
+                                 : web::SSLStatus::DISPLAYED_INSECURE_CONTENT;
+
+  // Try updating SSLStatus for current NavigationItem asynchronously.
+  scoped_refptr<net::X509Certificate> cert;
   if (item->GetURL().SchemeIsCryptographic()) {
-    // TODO(eugenebut): Do not set security style to authenticated once
-    // proceeding with bad ssl cert is implemented.
-    SSLStatus.security_style = web::SECURITY_STYLE_AUTHENTICATED;
-    SSLStatus.content_status = [_wkWebView hasOnlySecureContent]
-                                   ? web::SSLStatus::NORMAL_CONTENT
-                                   : web::SSLStatus::DISPLAYED_INSECURE_CONTENT;
-
-    if (base::ios::IsRunningOnIOS9OrLater()) {
-      scoped_refptr<net::X509Certificate> cert(web::CreateCertFromChain(
-          [_wkWebView performSelector:@selector(certificateChain)]));
-      if (cert) {
-        SSLStatus.cert_id = web::CertStore::GetInstance()->StoreCert(
-            cert.get(), self.certGroupID);
-      } else {
-        SSLStatus.security_style = web::SECURITY_STYLE_UNAUTHENTICATED;
-        SSLStatus.cert_id = 0;
+    NSArray* chain = [_wkWebView certificateChain];
+    cert = web::CreateCertFromChain(chain);
+    if (cert) {
+      int oldCertID = SSLStatus.cert_id;
+      SSLStatus.cert_id = web::CertStore::GetInstance()->StoreCert(
+          cert.get(), self.certGroupID);
+      // Only recompute the SSLStatus information if the certificate or host has
+      // since changed. Host can be changed in case of redirect.
+      if (oldCertID != SSLStatus.cert_id ||
+          item->GetURL().host() != _documentURL.host()) {
+        NSString* host = base::SysUTF8ToNSString(_documentURL.host());
+        [self scheduleSSLStatusUpdateUsingCertChain:chain host:host];
+        [self reportHasCertForSecureConnectionUMAWithValue:true];
       }
     }
-  } else {
-    SSLStatus.security_style = web::SECURITY_STYLE_UNAUTHENTICATED;
+  }
+
+  if (!cert) {
     SSLStatus.cert_id = 0;
+    if (!item->GetURL().SchemeIsCryptographic()) {
+      // HTTP or other non-secure connection.
+      SSLStatus.security_style = web::SECURITY_STYLE_UNAUTHENTICATED;
+    } else {
+      // HTTPS, no certificate (this use-case has not been observed).
+      SSLStatus.security_style = web::SECURITY_STYLE_UNKNOWN;
+      if (!previousSSLStatus.Equals(SSLStatus)) {
+        [self reportHasCertForSecureConnectionUMAWithValue:false];

[davidben, 2015/10/15 17:46:12]

If all that changed was hasSecureContent, this will still trigger, no?

I think you need to decide what are the points you want to sample and put it
there. A priori, I would think didCommitNavigation is the right place. Then you
sample exactly then.

[Eugene But (OOO till 7-30), 2015/10/15 22:59:34]

That's a good suggestion. Done.

+      }
+    }
   }
 
   if (!previousSSLStatus.Equals(SSLStatus)) {
     [self didUpdateSSLStatusForCurrentNavigationItem];
   }
 }
+
 #endif  // !defined(ENABLE_CHROME_NET_STACK_FOR_WKWEBVIEW)
 
+- (void)reportHasCertForSecureConnectionUMAWithValue:(bool)value {
+  UMA_HISTOGRAM_BOOLEAN("WebController.WKWebViewHasCertForSecureConnection",
+                        value);
+}
+
 - (void)registerLoadRequest:(const GURL&)url {
   // If load request is registered via WKWebViewWebController, assume transition
   // is link or client redirect as other transitions will already be registered
@@ -1389,6 +1500,7 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
 
   SecTrustRef trust = challenge.protectionSpace.serverTrust;
   scoped_refptr<net::X509Certificate> cert = web::CreateCertFromTrust(trust);
+  // TODO(eugenebut): pass SecTrustRef instead of cert.
   [_certVerificationController
       decidePolicyForCert:cert
                      host:challenge.protectionSpace.host