WKWebView: Implemented recoverable SSL interstitials.

ios/web/net/crw_cert_verification_controller.mm

 // 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.
 
 #import "ios/web/net/crw_cert_verification_controller.h"
 
 #include "base/logging.h"
 #include "base/mac/bind_objc_block.h"
 #import "base/memory/ref_counted.h"
 #import "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/worker_pool.h"
 #include "ios/web/net/cert_verifier_block_adapter.h"
 #include "ios/web/public/browser_state.h"
+#include "ios/web/public/certificate_policy_cache.h"
 #include "ios/web/public/web_thread.h"
 #import "ios/web/web_state/wk_web_view_security_util.h"
 #include "net/cert/cert_verify_result.h"
 #include "net/ssl/ssl_config_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 
 namespace {
 
 // This class takes ownership of block and releases it on UI thread, even if
@@ skipping 28 matching lines @@
       web::WebThread::PostTask(web::WebThread::UI, FROM_HERE,
                                base::Bind(&BlockHolder::ReleaseBlock, block_));
     }
   }
 
   T block_;
 };
 
 }  // namespace
 
+using web::CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_ACCEPTED_BY_USER;
+using web::CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_NOT_ACCEPTED_BY_USER;
+
 @interface CRWCertVerificationController () {
   // Cert verification object which wraps |net::CertVerifier|. Must be created,
   // used and destroyed on IO Thread.
   scoped_ptr<web::CertVerifierBlockAdapter> _certVerifier;
 
   // URLRequestContextGetter for obtaining net layer objects.
   net::URLRequestContextGetter* _contextGetter;
+
+  // Used to remember decisions about how to handle problematic certs.
+  scoped_refptr<web::CertificatePolicyCache> _certPolicyCache;
 }
 
 // Cert verification flags. Must be used on IO Thread.
 @property(nonatomic, readonly) int certVerifyFlags;
 
 // Creates _certVerifier object on IO thread.
 - (void)createCertVerifier;
 
 // Verifies the given |cert| for the given |host| using |net::CertVerifier| and
 // calls |completionHandler| on completion. |completionHandler| cannot be null
@@ skipping 26 matching lines @@
   return nil;
 }
 
 - (instancetype)initWithBrowserState:(web::BrowserState*)browserState {
   DCHECK(browserState);
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
   self = [super init];
   if (self) {
     _contextGetter = browserState->GetRequestContext();
     DCHECK(_contextGetter);
+    _certPolicyCache =
+        web::BrowserState::GetCertificatePolicyCache(browserState);
+
     [self createCertVerifier];
   }
   return self;
 }
 
-- (void)decidePolicyForCert:(const scoped_refptr<net::X509Certificate>&)cert
-                       host:(NSString*)host
-          completionHandler:(web::PolicyDecisionHandler)completionHandler {
+- (void)decideLoadPolicyForTrust:(SecTrustRef)serverTrust
+                            host:(NSString*)host
+               completionHandler:(web::PolicyDecisionHandler)completionHandler {
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
   // completionHandler of |verifyCert:forHost:completionHandler:| is called on
   // IO thread and then bounces back to UI thread. As a result all objects
   // captured by completionHandler may be released on either UI or IO thread.
   // Since |completionHandler| can potentially capture multiple thread unsafe
   // objects (like Web Controller) |completionHandler| itself should never be
   // released on background thread and |BlockHolder| ensures that.
   __block scoped_refptr<BlockHolder<web::PolicyDecisionHandler>> handlerHolder(
       new BlockHolder<web::PolicyDecisionHandler>(completionHandler));
-  [self verifyCert:cert
-                forHost:host
-      completionHandler:^(net::CertVerifyResult result, int error) {
-        web::CertAcceptPolicy policy =
-            web::CERT_ACCEPT_POLICY_NON_RECOVERABLE_ERROR;
-        if (error == net::OK) {
-          policy = web::CERT_ACCEPT_POLICY_ALLOW;
-        } else if (net::IsCertStatusError(result.cert_status)) {
-          policy = net::IsCertStatusMinorError(result.cert_status)
-                       ? web::CERT_ACCEPT_POLICY_ALLOW
-                       : web::CERT_ACCEPT_POLICY_RECOVERABLE_ERROR;
-        }
 
+  web::WebThread::PostTask(web::WebThread::IO, FROM_HERE, base::BindBlock(^{
+    base::ScopedCFTypeRef<SecTrustRef> trust(
+        serverTrust, base::scoped_policy::RETAIN);
+    [self verifyTrust:trust completionHandler:^(SecTrustResultType result) {
+      if (result == kSecTrustResultProceed ||
+          result == kSecTrustResultUnspecified) {
+        // SecTrust API considers this cert as valid.
         dispatch_async(dispatch_get_main_queue(), ^{
-          handlerHolder->call(policy, result.cert_status);
+          handlerHolder->call(web::CERT_ACCEPT_POLICY_ALLOW, net::CertStatus());
         });
-      }];
+        return;
+      }
+
+      // SecTrust API considers this cert as invalid. Check the reason and
+      // whether or not user has decided to proceed with this bad cert.
+      scoped_refptr<net::X509Certificate> cert(web::CreateCertFromTrust(trust));
+      [self verifyCert:cert
+                    forHost:host
+          completionHandler:^(net::CertVerifyResult certVerifierResult, int) {
+            web::CertAcceptPolicy policy =
+                web::CERT_ACCEPT_POLICY_NON_RECOVERABLE_ERROR;
+            scoped_refptr<net::X509Certificate> leafCert;
+            if (result == kSecTrustResultRecoverableTrustFailure &&
+                SecTrustGetCertificateCount(trust)) {
+              // Check if user has decided to proceed with this bad cert.
+              leafCert = web::CreateCertFromChain(@[
+                static_cast<id>(SecTrustGetCertificateAtIndex(trust, 0))
+              ]);
+
+              web::CertPolicy::Judgment judgment =
+                  _certPolicyCache->QueryPolicy(
+                      leafCert.get(), base::SysNSStringToUTF8(host),
+                      certVerifierResult.cert_status);
+
+              policy = (judgment == web::CertPolicy::ALLOWED)
+                  ? CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_ACCEPTED_BY_USER
+                  : CERT_ACCEPT_POLICY_RECOVERABLE_ERROR_NOT_ACCEPTED_BY_USER;
+            }
+
+            dispatch_async(dispatch_get_main_queue(), ^{
+              handlerHolder->call(policy, certVerifierResult.cert_status);
+            });
+          }];
+    }];
+  }));
 }
 
 - (void)querySSLStatusForCertChain:(NSArray*)certChain
                               host:(NSString*)host
                  completionHandler:(web::StatusQueryHandler)completionHandler {
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
   DCHECK(certChain.count);
 
   // Completion handler of |verifyCert:forHost:completionHandler:| will be
   // deallocated on IO thread. |completionHandler| itself should never be
   // released on background thread and |BlockHolder| ensures that.
   __block scoped_refptr<BlockHolder<web::StatusQueryHandler>> handlerHolder(
       new BlockHolder<web::StatusQueryHandler>(completionHandler));
-  scoped_refptr<net::X509Certificate> cert(web::CreateCertFromChain(certChain));
-  // Retrieve the net::CertStatus to allow Chromium-specific policies to be
-  // enacted. This is called for all certificates (valid and invalid alike),
-  // since the net::CertVerifier may reject or downgrade certificates that
-  // SecTrust accepts.
-  [self verifyCert:cert
-                forHost:host
-      completionHandler:^(net::CertVerifyResult certVerifierResult, int) {
-        [self verifyTrust:web::CreateServerTrustFromChain(certChain, host)
-            completionHandler:^(SecTrustResultType trustResult) {
-              // If SecTrust has accepted a certificate, clear any error
-              // statuses returned by net::CertVerifier, since the CertVerifier
-              // may not have access to the same trust information
-              // (e.g. custom-installed roots). Note, this also disables
-              // net::CertVerifier's ability to reject certificates, such as via
-              // CRLSets. However, copy any supplemental status bits over, since
-              // those may be used as part of policy logic, such as deprecating
-              // SHA-1 or requiring Certificate Transparency.
-              web::SecurityStyle security_style =
-                  web::GetSecurityStyleFromTrustResult(trustResult);
-              net::CertStatus cert_status = certVerifierResult.cert_status;
-              if (security_style == web::SECURITY_STYLE_AUTHENTICATED) {
-                cert_status &= ~net::CERT_STATUS_ALL_ERRORS;
-              }
+  web::WebThread::PostTask(web::WebThread::IO, FROM_HERE, base::BindBlock(^{
+    scoped_refptr<net::X509Certificate> cert(
+        web::CreateCertFromChain(certChain));
+    // Retrieve the net::CertStatus to allow Chromium-specific policies to
+    // be enacted. This is called for all certificates (valid and invalid
+    // alike), since the net::CertVerifier may reject or downgrade certificates
+    // that SecTrust accepts.
+    [self verifyCert:cert
+                  forHost:host
+        completionHandler:^(net::CertVerifyResult certVerifierResult, int) {
+          [self verifyTrust:web::CreateServerTrustFromChain(certChain, host)
+              completionHandler:^(SecTrustResultType trustResult) {
+                // If SecTrust has accepted a certificate, clear any error
+                // statuses returned by net::CertVerifier, since the
+                // CertVerifier may not have access to the same trust
+                // information (e.g. custom-installed roots). Note, this also
+                // disables net::CertVerifier's ability to reject certificates,
+                // such as via CRLSets. However, copy any supplemental status
+                // bits over, since those may be used as part of policy logic,
+                // such as deprecating SHA-1 or requiring Certificate
+                // Transparency.
+                web::SecurityStyle security_style =
+                    web::GetSecurityStyleFromTrustResult(trustResult);
+                net::CertStatus cert_status =
+                    certVerifierResult.cert_status;
+                if (security_style == web::SECURITY_STYLE_AUTHENTICATED) {
+                  cert_status &= ~net::CERT_STATUS_ALL_ERRORS;
+                }
 
-              dispatch_async(dispatch_get_main_queue(), ^{
-                handlerHolder->call(security_style, cert_status);
-              });
-            }];
-      }];
+                dispatch_async(dispatch_get_main_queue(), ^{
+                  handlerHolder->call(security_style, cert_status);
+                });
+              }];
+        }];
+  }));
+}
+
+- (void)allowCert:(scoped_refptr<net::X509Certificate>)cert
+          forHost:(NSString*)host
+           status:(net::CertStatus)status {
+  DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
+  DCHECK(cert);
+  DCHECK_EQ(0U, cert->GetIntermediateCertificates().size());
+  web::WebThread::PostTask(web::WebThread::IO, FROM_HERE, base::BindBlock(^{
+    _certPolicyCache->AllowCertForHost(
+        cert.get(), base::SysNSStringToUTF8(host), status);
+  }));
 }
 
 - (void)shutDown {
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
   web::WebThread::PostTask(web::WebThread::IO, FROM_HERE, base::BindBlock(^{
     // This block captures |self| delaying its deallocation and causing dealloc
     // to happen on either IO or UI thread (which is fine for this class).
     _certVerifier.reset();
   }));
 }
@@ skipping 18 matching lines @@
   web::WebThread::PostTask(web::WebThread::IO, FROM_HERE, base::BindBlock(^{
     net::URLRequestContext* context = _contextGetter->GetURLRequestContext();
     _certVerifier.reset(new web::CertVerifierBlockAdapter(
         context->cert_verifier(), context->net_log()));
   }));
 }
 
 - (void)verifyCert:(const scoped_refptr<net::X509Certificate>&)cert
               forHost:(NSString*)host
     completionHandler:(void (^)(net::CertVerifyResult, int))completionHandler {
+  DCHECK(web::WebThread::CurrentlyOn(web::WebThread::IO));
   DCHECK(completionHandler);
-  __block scoped_refptr<net::X509Certificate> blockCert = cert;
-  web::WebThread::PostTask(
-      web::WebThread::IO, FROM_HERE, base::BindBlock(^{
-        // WeakNSObject does not work across different threads, hence this block
-        // retains self.
-        if (!_certVerifier) {
-          completionHandler(net::CertVerifyResult(), net::ERR_FAILED);
-          return;
-        }
+  if (!_certVerifier) {
+    completionHandler(net::CertVerifyResult(), net::ERR_FAILED);
+    return;
+  }
 
-        web::CertVerifierBlockAdapter::Params params(
-            blockCert.Pass(), base::SysNSStringToUTF8(host));
-        params.flags = self.certVerifyFlags;
-        params.crl_set = net::SSLConfigService::GetCRLSet();
-        // OCSP response is not provided by iOS API.
-        _certVerifier->Verify(params, completionHandler);
-      }));
+  web::CertVerifierBlockAdapter::Params params(
+      cert, base::SysNSStringToUTF8(host));
+  params.flags = self.certVerifyFlags;
+  params.crl_set = net::SSLConfigService::GetCRLSet();
+  // OCSP response is not provided by iOS API.
+  _certVerifier->Verify(params, completionHandler);
 }
 
 - (void)verifyTrust:(base::ScopedCFTypeRef<SecTrustRef>)trust
     completionHandler:(void (^)(SecTrustResultType))completionHandler {
   DCHECK(web::WebThread::CurrentlyOn(web::WebThread::IO));
   DCHECK(completionHandler);
   bool result = base::WorkerPool::PostTask(FROM_HERE, base::BindBlock(^{
     SecTrustResultType trustResult = kSecTrustResultInvalid;
     if (SecTrustEvaluate(trust.get(), &trustResult) != errSecSuccess) {
       trustResult = kSecTrustResultInvalid;
     }
     web::WebThread::PostTask(web::WebThread::IO, FROM_HERE,base::BindBlock(^{
       completionHandler(trustResult);
     }));
   }), false /* task_is_slow */);
 
   if (!result) {
     completionHandler(kSecTrustResultInvalid);
   }
 }
 
 @end