The Tor Browser: caps/src/nsScriptSecurityManager.cpp@97036ab72558 (annotated)

caps/src/nsScriptSecurityManager.cpp@97036ab72558 (annotated)

caps/src/nsScriptSecurityManager.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* vim: set ts=4 et sw=4 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "nsScriptSecurityManager.h"
 #include "mozilla/ArrayUtils.h"
 #include "js/OldDebugAPI.h"
 #include "xpcprivate.h"
 #include "XPCWrapper.h"
 #include "nsIServiceManager.h"
 #include "nsIScriptObjectPrincipal.h"
 #include "nsIScriptContext.h"
 #include "nsIURL.h"
 #include "nsINestedURI.h"
 #include "nspr.h"
 #include "nsJSPrincipals.h"
 #include "nsSystemPrincipal.h"
 #include "nsPrincipal.h"
 #include "nsNullPrincipal.h"
 #include "DomainPolicy.h"
 #include "nsXPIDLString.h"
 #include "nsCRT.h"
 #include "nsCRTGlue.h"
 #include "nsError.h"
 #include "nsDOMCID.h"
 #include "nsIXPConnect.h"
 #include "nsIXPCSecurityManager.h"
 #include "nsTextFormatter.h"
 #include "nsIStringBundle.h"
 #include "nsNetUtil.h"
 #include "nsIEffectiveTLDService.h"
 #include "nsIProperties.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsIFile.h"
 #include "nsIFileURL.h"
 #include "nsIZipReader.h"
 #include "nsIXPConnect.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsPIDOMWindow.h"
 #include "nsIDocShell.h"
 #include "nsIPrompt.h"
 #include "nsIWindowWatcher.h"
 #include "nsIConsoleService.h"
 #include "nsIJSRuntimeService.h"
 #include "nsIObserverService.h"
 #include "nsIContent.h"
 #include "nsAutoPtr.h"
 #include "nsDOMJSUtils.h"
 #include "nsAboutProtocolUtils.h"
 #include "nsIClassInfo.h"
 #include "nsIURIFixup.h"
 #include "nsCDefaultURIFixup.h"
 #include "nsIChromeRegistry.h"
 #include "nsIContentSecurityPolicy.h"
 #include "nsIAsyncVerifyRedirectCallback.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/BindingUtils.h"
 #include <stdint.h>
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/StaticPtr.h"
 #include "nsContentUtils.h"
 #include "nsCxPusher.h"
 #include "nsJSUtils.h"
 // This should be probably defined on some other place... but I couldn't find it
 #define WEBAPPS_PERM_NAME "webapps-manage"
 using namespace mozilla;
 using namespace mozilla::dom;
 static NS_DEFINE_CID(kZipReaderCID, NS_ZIPREADER_CID);
 nsIIOService    *nsScriptSecurityManager::sIOService = nullptr;
 nsIStringBundle *nsScriptSecurityManager::sStrBundle = nullptr;
 JSRuntime       *nsScriptSecurityManager::sRuntime   = 0;
 bool nsScriptSecurityManager::sStrictFileOriginPolicy = true;
 bool
 nsScriptSecurityManager::SubjectIsPrivileged()
 {
     JSContext *cx = GetCurrentJSContext();
     if (cx && xpc::IsUniversalXPConnectEnabled(cx))
         return true;
     bool isSystem = false;
     return NS_SUCCEEDED(SubjectPrincipalIsSystem(&isSystem)) && isSystem;
 }
 ///////////////////////////
 // Convenience Functions //
 ///////////////////////////
 // Result of this function should not be freed.
 static inline const char16_t *
 IDToString(JSContext *cx, jsid id_)
 {
     JS::RootedId id(cx, id_);
     if (JSID_IS_STRING(id))
         return JS_GetInternedStringChars(JSID_TO_STRING(id));
     JS::Rooted<JS::Value> idval(cx);
     if (!JS_IdToValue(cx, id, &idval))
         return nullptr;
     JSString *str = JS::ToString(cx, idval);
     if(!str)
         return nullptr;
     return JS_GetStringCharsZ(cx, str);
 }
 class nsAutoInPrincipalDomainOriginSetter {
 public:
     nsAutoInPrincipalDomainOriginSetter() {
         ++sInPrincipalDomainOrigin;
     }
     ~nsAutoInPrincipalDomainOriginSetter() {
         --sInPrincipalDomainOrigin;
     }
     static uint32_t sInPrincipalDomainOrigin;
 };
 uint32_t nsAutoInPrincipalDomainOriginSetter::sInPrincipalDomainOrigin;
 static
 nsresult
 GetOriginFromURI(nsIURI* aURI, nsACString& aOrigin)
 {
   if (nsAutoInPrincipalDomainOriginSetter::sInPrincipalDomainOrigin > 1) {
       // Allow a single recursive call to GetPrincipalDomainOrigin, since that
       // might be happening on a different principal from the first call.  But
       // after that, cut off the recursion; it just indicates that something
       // we're doing in this method causes us to reenter a security check here.
       return NS_ERROR_NOT_AVAILABLE;
   }
   nsAutoInPrincipalDomainOriginSetter autoSetter;
   nsCOMPtr<nsIURI> uri = NS_GetInnermostURI(aURI);
   NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);
   nsAutoCString hostPort;
   nsresult rv = uri->GetHostPort(hostPort);
   if (NS_SUCCEEDED(rv)) {
     nsAutoCString scheme;
     rv = uri->GetScheme(scheme);
     NS_ENSURE_SUCCESS(rv, rv);
     aOrigin = scheme + NS_LITERAL_CSTRING("://") + hostPort;
   }
   else {
     // Some URIs (e.g., nsSimpleURI) don't support host. Just
     // get the full spec.
     rv = uri->GetSpec(aOrigin);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   return NS_OK;
 }
 static
 nsresult
 GetPrincipalDomainOrigin(nsIPrincipal* aPrincipal,
                          nsACString& aOrigin)
 {
   nsCOMPtr<nsIURI> uri;
   aPrincipal->GetDomain(getter_AddRefs(uri));
   if (!uri) {
     aPrincipal->GetURI(getter_AddRefs(uri));
   }
   NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);
   return GetOriginFromURI(uri, aOrigin);
 }
 inline void SetPendingException(JSContext *cx, const char *aMsg)
 {
     JS_ReportError(cx, "%s", aMsg);
 }
 inline void SetPendingException(JSContext *cx, const char16_t *aMsg)
 {
     JS_ReportError(cx, "%hs", aMsg);
 }
 // Helper class to get stuff from the ClassInfo and not waste extra time with
 // virtual method calls for things it has already gotten
 class ClassInfoData
 {
 public:
     ClassInfoData(nsIClassInfo *aClassInfo, const char *aName)
         : mClassInfo(aClassInfo),
           mName(const_cast<char *>(aName)),
           mDidGetFlags(false),
           mMustFreeName(false)
     {
     }
     ~ClassInfoData()
     {
         if (mMustFreeName)
             nsMemory::Free(mName);
     }
     uint32_t GetFlags()
     {
         if (!mDidGetFlags) {
             if (mClassInfo) {
                 nsresult rv = mClassInfo->GetFlags(&mFlags);
                 if (NS_FAILED(rv)) {
                     mFlags = 0;
                 }
             } else {
                 mFlags = 0;
             }
             mDidGetFlags = true;
         }
         return mFlags;
     }
     bool IsDOMClass()
     {
         return !!(GetFlags() & nsIClassInfo::DOM_OBJECT);
     }
     const char* GetName()
     {
         if (!mName) {
             if (mClassInfo) {
                 mClassInfo->GetClassDescription(&mName);
             }
             if (mName) {
                 mMustFreeName = true;
             } else {
                 mName = const_cast<char *>("UnnamedClass");
             }
         }
         return mName;
     }
 private:
     nsIClassInfo *mClassInfo; // WEAK
     uint32_t mFlags;
     char *mName;
     bool mDidGetFlags;
     bool mMustFreeName;
 };
 JSContext *
 nsScriptSecurityManager::GetCurrentJSContext()
 {
     // Get JSContext from stack.
     return nsXPConnect::XPConnect()->GetCurrentJSContext();
 }
 JSContext *
 nsScriptSecurityManager::GetSafeJSContext()
 {
     // Get JSContext from stack.
     return nsXPConnect::XPConnect()->GetSafeJSContext();
 }
 /* static */
 bool
 nsScriptSecurityManager::SecurityCompareURIs(nsIURI* aSourceURI,
                                              nsIURI* aTargetURI)
 {
     return NS_SecurityCompareURIs(aSourceURI, aTargetURI, sStrictFileOriginPolicy);
 }
 // SecurityHashURI is consistent with SecurityCompareURIs because NS_SecurityHashURI
 // is consistent with NS_SecurityCompareURIs.  See nsNetUtil.h.
 uint32_t
 nsScriptSecurityManager::SecurityHashURI(nsIURI* aURI)
 {
     return NS_SecurityHashURI(aURI);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetChannelPrincipal(nsIChannel* aChannel,
                                              nsIPrincipal** aPrincipal)
 {
     NS_PRECONDITION(aChannel, "Must have channel!");
     nsCOMPtr<nsISupports> owner;
     aChannel->GetOwner(getter_AddRefs(owner));
     if (owner) {
         CallQueryInterface(owner, aPrincipal);
         if (*aPrincipal) {
             return NS_OK;
         }
     }
     // OK, get the principal from the URI.  Make sure this does the same thing
     // as nsDocument::Reset and XULDocument::StartDocumentLoad.
     nsCOMPtr<nsIURI> uri;
     nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
     NS_ENSURE_SUCCESS(rv, rv);
     nsCOMPtr<nsIDocShell> docShell;
     NS_QueryNotificationCallbacks(aChannel, docShell);
     if (docShell) {
         return GetDocShellCodebasePrincipal(uri, docShell, aPrincipal);
     }
     return GetCodebasePrincipalInternal(uri, UNKNOWN_APP_ID,
         /* isInBrowserElement */ false, aPrincipal);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::IsSystemPrincipal(nsIPrincipal* aPrincipal,
                                            bool* aIsSystem)
 {
     *aIsSystem = (aPrincipal == mSystemPrincipal);
     return NS_OK;
 }
 NS_IMETHODIMP_(nsIPrincipal *)
 nsScriptSecurityManager::GetCxSubjectPrincipal(JSContext *cx)
 {
     NS_ASSERTION(cx == GetCurrentJSContext(),
                  "Uh, cx is not the current JS context!");
     nsresult rv = NS_ERROR_FAILURE;
     nsIPrincipal *principal = GetSubjectPrincipal(cx, &rv);
     if (NS_FAILED(rv))
         return nullptr;
     return principal;
 }
 /////////////////////////////
 // nsScriptSecurityManager //
 /////////////////////////////
 ////////////////////////////////////
 // Methods implementing ISupports //
 ////////////////////////////////////
 NS_IMPL_ISUPPORTS(nsScriptSecurityManager,
                   nsIScriptSecurityManager,
                   nsIXPCSecurityManager,
                   nsIChannelEventSink,
                   nsIObserver)
 ///////////////////////////////////////////////////
 // Methods implementing nsIScriptSecurityManager //
 ///////////////////////////////////////////////////
 ///////////////// Security Checks /////////////////
 bool
 nsScriptSecurityManager::ContentSecurityPolicyPermitsJSAction(JSContext *cx)
 {
     // Get the security manager
     nsScriptSecurityManager *ssm =
         nsScriptSecurityManager::GetScriptSecurityManager();
     NS_ASSERTION(ssm, "Failed to get security manager service");
     if (!ssm)
         return false;
     nsresult rv;
     nsIPrincipal* subjectPrincipal = ssm->GetSubjectPrincipal(cx, &rv);
     NS_ASSERTION(NS_SUCCEEDED(rv), "CSP: Failed to get nsIPrincipal from js context");
     if (NS_FAILED(rv))
         return false; // Not just absence of principal, but failure.
     if (!subjectPrincipal)
         return true;
     nsCOMPtr<nsIContentSecurityPolicy> csp;
     rv = subjectPrincipal->GetCsp(getter_AddRefs(csp));
     NS_ASSERTION(NS_SUCCEEDED(rv), "CSP: Failed to get CSP from principal.");
     // don't do anything unless there's a CSP
     if (!csp)
         return true;
     bool evalOK = true;
     bool reportViolation = false;
     rv = csp->GetAllowsEval(&reportViolation, &evalOK);
     if (NS_FAILED(rv))
     {
         NS_WARNING("CSP: failed to get allowsEval");
         return true; // fail open to not break sites.
     }
     if (reportViolation) {
         nsAutoString fileName;
         unsigned lineNum = 0;
         NS_NAMED_LITERAL_STRING(scriptSample, "call to eval() or related function blocked by CSP");
         JS::AutoFilename scriptFilename;
         if (JS::DescribeScriptedCaller(cx, &scriptFilename, &lineNum)) {
             if (const char *file = scriptFilename.get()) {
                 CopyUTF8toUTF16(nsDependentCString(file), fileName);
             }
         }
         csp->LogViolationDetails(nsIContentSecurityPolicy::VIOLATION_TYPE_EVAL,
                                  fileName,
                                  scriptSample,
                                  lineNum,
                                  EmptyString(),
                                  EmptyString());
     }
     return evalOK;
 }
 // static
 bool
 nsScriptSecurityManager::JSPrincipalsSubsume(JSPrincipals *first,
                                              JSPrincipals *second)
 {
     return nsJSPrincipals::get(first)->Subsumes(nsJSPrincipals::get(second));
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CheckSameOrigin(JSContext* cx,
                                          nsIURI* aTargetURI)
 {
     nsresult rv;
     // Get a context if necessary
     if (!cx)
     {
         cx = GetCurrentJSContext();
         if (!cx)
             return NS_OK; // No JS context, so allow access
     }
     // Get a principal from the context
     nsIPrincipal* sourcePrincipal = GetSubjectPrincipal(cx, &rv);
     if (NS_FAILED(rv))
         return rv;
     if (!sourcePrincipal)
     {
         NS_WARNING("CheckSameOrigin called on script w/o principals; should this happen?");
         return NS_OK;
     }
     if (sourcePrincipal == mSystemPrincipal)
     {
         // This is a system (chrome) script, so allow access
         return NS_OK;
     }
     // Get the original URI from the source principal.
     // This has the effect of ignoring any change to document.domain
     // which must be done to avoid DNS spoofing (bug 154930)
     nsCOMPtr<nsIURI> sourceURI;
     sourcePrincipal->GetDomain(getter_AddRefs(sourceURI));
     if (!sourceURI) {
       sourcePrincipal->GetURI(getter_AddRefs(sourceURI));
       NS_ENSURE_TRUE(sourceURI, NS_ERROR_FAILURE);
     }
     // Compare origins
     if (!SecurityCompareURIs(sourceURI, aTargetURI))
     {
          ReportError(cx, NS_LITERAL_STRING("CheckSameOriginError"), sourceURI, aTargetURI);
          return NS_ERROR_DOM_BAD_URI;
     }
     return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CheckSameOriginURI(nsIURI* aSourceURI,
                                             nsIURI* aTargetURI,
                                             bool reportError)
 {
     if (!SecurityCompareURIs(aSourceURI, aTargetURI))
     {
          if (reportError) {
             ReportError(nullptr, NS_LITERAL_STRING("CheckSameOriginError"),
                      aSourceURI, aTargetURI);
          }
          return NS_ERROR_DOM_BAD_URI;
     }
     return NS_OK;
 }
 /*static*/ uint32_t
 nsScriptSecurityManager::HashPrincipalByOrigin(nsIPrincipal* aPrincipal)
 {
     nsCOMPtr<nsIURI> uri;
     aPrincipal->GetDomain(getter_AddRefs(uri));
     if (!uri)
         aPrincipal->GetURI(getter_AddRefs(uri));
     return SecurityHashURI(uri);
 }
 /* static */ bool
 nsScriptSecurityManager::AppAttributesEqual(nsIPrincipal* aFirst,
                                             nsIPrincipal* aSecond)
 {
     MOZ_ASSERT(aFirst && aSecond, "Don't pass null pointers!");
     uint32_t firstAppId = nsIScriptSecurityManager::UNKNOWN_APP_ID;
     if (!aFirst->GetUnknownAppId()) {
         firstAppId = aFirst->GetAppId();
     }
     uint32_t secondAppId = nsIScriptSecurityManager::UNKNOWN_APP_ID;
     if (!aSecond->GetUnknownAppId()) {
         secondAppId = aSecond->GetAppId();
     }
     return ((firstAppId == secondAppId) &&
             (aFirst->GetIsInBrowserElement() == aSecond->GetIsInBrowserElement()));
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CheckLoadURIFromScript(JSContext *cx, nsIURI *aURI)
 {
     // Get principal of currently executing script.
     nsresult rv;
     nsIPrincipal* principal = GetSubjectPrincipal(cx, &rv);
     if (NS_FAILED(rv))
         return rv;
     // Native code can load all URIs.
     if (!principal)
         return NS_OK;
     rv = CheckLoadURIWithPrincipal(principal, aURI,
                                    nsIScriptSecurityManager::STANDARD);
     if (NS_SUCCEEDED(rv)) {
         // OK to load
         return NS_OK;
     }
     // See if we're attempting to load a file: URI. If so, let a
     // UniversalXPConnect capability trump the above check.
     bool isFile = false;
     bool isRes = false;
     if (NS_FAILED(aURI->SchemeIs("file", &isFile)) ||
         NS_FAILED(aURI->SchemeIs("resource", &isRes)))
         return NS_ERROR_FAILURE;
     if (isFile || isRes)
     {
         if (SubjectIsPrivileged())
             return NS_OK;
     }
     // Report error.
     nsAutoCString spec;
     if (NS_FAILED(aURI->GetAsciiSpec(spec)))
         return NS_ERROR_FAILURE;
     nsAutoCString msg("Access to '");
     msg.Append(spec);
     msg.AppendLiteral("' from script denied");
     SetPendingException(cx, msg.get());
     return NS_ERROR_DOM_BAD_URI;
 }
 /**
  * Helper method to handle cases where a flag passed to
  * CheckLoadURIWithPrincipal means denying loading if the given URI has certain
  * nsIProtocolHandler flags set.
  * @return if success, access is allowed. Otherwise, deny access
  */
 static nsresult
 DenyAccessIfURIHasFlags(nsIURI* aURI, uint32_t aURIFlags)
 {
     NS_PRECONDITION(aURI, "Must have URI!");
     bool uriHasFlags;
     nsresult rv =
         NS_URIChainHasFlags(aURI, aURIFlags, &uriHasFlags);
     NS_ENSURE_SUCCESS(rv, rv);
     if (uriHasFlags) {
         return NS_ERROR_DOM_BAD_URI;
     }
     return NS_OK;
 }
 static bool
 EqualOrSubdomain(nsIURI* aProbeArg, nsIURI* aBase)
 {
     // Make a clone of the incoming URI, because we're going to mutate it.
     nsCOMPtr<nsIURI> probe;
     nsresult rv = aProbeArg->Clone(getter_AddRefs(probe));
     NS_ENSURE_SUCCESS(rv, false);
     nsCOMPtr<nsIEffectiveTLDService> tldService = do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);
     NS_ENSURE_TRUE(tldService, false);
     while (true) {
         if (nsScriptSecurityManager::SecurityCompareURIs(probe, aBase)) {
             return true;
         }
         nsAutoCString host, newHost;
         nsresult rv = probe->GetHost(host);
         NS_ENSURE_SUCCESS(rv, false);
         rv = tldService->GetNextSubDomain(host, newHost);
         if (rv == NS_ERROR_INSUFFICIENT_DOMAIN_LEVELS) {
             return false;
         }
         NS_ENSURE_SUCCESS(rv, false);
         rv = probe->SetHost(newHost);
         NS_ENSURE_SUCCESS(rv, false);
     }
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CheckLoadURIWithPrincipal(nsIPrincipal* aPrincipal,
                                                    nsIURI *aTargetURI,
                                                    uint32_t aFlags)
 {
     NS_PRECONDITION(aPrincipal, "CheckLoadURIWithPrincipal must have a principal");
     // If someone passes a flag that we don't understand, we should
     // fail, because they may need a security check that we don't
     // provide.
     NS_ENSURE_FALSE(aFlags & ~(nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT |
                                nsIScriptSecurityManager::ALLOW_CHROME |
                                nsIScriptSecurityManager::DISALLOW_SCRIPT |
                                nsIScriptSecurityManager::DISALLOW_INHERIT_PRINCIPAL |
                                nsIScriptSecurityManager::DONT_REPORT_ERRORS),
                     NS_ERROR_UNEXPECTED);
     NS_ENSURE_ARG_POINTER(aPrincipal);
     NS_ENSURE_ARG_POINTER(aTargetURI);
     // If DISALLOW_INHERIT_PRINCIPAL is set, we prevent loading of URIs which
     // would do such inheriting. That would be URIs that do not have their own
     // security context. We do this even for the system principal.
     if (aFlags & nsIScriptSecurityManager::DISALLOW_INHERIT_PRINCIPAL) {
         nsresult rv =
             DenyAccessIfURIHasFlags(aTargetURI,
                                     nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT);
         NS_ENSURE_SUCCESS(rv, rv);
     }
     if (aPrincipal == mSystemPrincipal) {
         // Allow access
         return NS_OK;
     }
     nsCOMPtr<nsIURI> sourceURI;
     aPrincipal->GetURI(getter_AddRefs(sourceURI));
     if (!sourceURI) {
         nsCOMPtr<nsIExpandedPrincipal> expanded = do_QueryInterface(aPrincipal);
         if (expanded) {
             nsTArray< nsCOMPtr<nsIPrincipal> > *whiteList;
             expanded->GetWhiteList(&whiteList);
             for (uint32_t i = 0; i < whiteList->Length(); ++i) {
                 nsresult rv = CheckLoadURIWithPrincipal((*whiteList)[i],
                                                         aTargetURI,
                                                         aFlags);
                 if (NS_SUCCEEDED(rv)) {
                     // Allow access if it succeeded with one of the white listed principals
                     return NS_OK;
                 }
             }
             // None of our whitelisted principals worked.
             return NS_ERROR_DOM_BAD_URI;
         }
         NS_ERROR("Non-system principals or expanded principal passed to CheckLoadURIWithPrincipal "
                  "must have a URI!");
         return NS_ERROR_UNEXPECTED;
     }
     // Automatic loads are not allowed from certain protocols.
     if (aFlags & nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT) {
         nsresult rv =
             DenyAccessIfURIHasFlags(sourceURI,
                                     nsIProtocolHandler::URI_FORBIDS_AUTOMATIC_DOCUMENT_REPLACEMENT);
         NS_ENSURE_SUCCESS(rv, rv);
     }
     // If either URI is a nested URI, get the base URI
     nsCOMPtr<nsIURI> sourceBaseURI = NS_GetInnermostURI(sourceURI);
     nsCOMPtr<nsIURI> targetBaseURI = NS_GetInnermostURI(aTargetURI);
     //-- get the target scheme
     nsAutoCString targetScheme;
     nsresult rv = targetBaseURI->GetScheme(targetScheme);
     if (NS_FAILED(rv)) return rv;
     //-- Some callers do not allow loading javascript:
     if ((aFlags & nsIScriptSecurityManager::DISALLOW_SCRIPT) &&
          targetScheme.EqualsLiteral("javascript"))
     {
        return NS_ERROR_DOM_BAD_URI;
     }
     NS_NAMED_LITERAL_STRING(errorTag, "CheckLoadURIError");
     bool reportErrors = !(aFlags & nsIScriptSecurityManager::DONT_REPORT_ERRORS);
     // Check for uris that are only loadable by principals that subsume them
     bool hasFlags;
     rv = NS_URIChainHasFlags(targetBaseURI,
                              nsIProtocolHandler::URI_LOADABLE_BY_SUBSUMERS,
                              &hasFlags);
     NS_ENSURE_SUCCESS(rv, rv);
     if (hasFlags) {
         return aPrincipal->CheckMayLoad(targetBaseURI, true, false);
     }
     //-- get the source scheme
     nsAutoCString sourceScheme;
     rv = sourceBaseURI->GetScheme(sourceScheme);
     if (NS_FAILED(rv)) return rv;
     if (sourceScheme.LowerCaseEqualsLiteral(NS_NULLPRINCIPAL_SCHEME)) {
         // A null principal can target its own URI.
         if (sourceURI == aTargetURI) {
             return NS_OK;
         }
     }
     else if (targetScheme.Equals(sourceScheme,
                                  nsCaseInsensitiveCStringComparator()))
     {
         // every scheme can access another URI from the same scheme,
         // as long as they don't represent null principals...
         // Or they don't require an special permission to do so
         // See bug#773886
         bool hasFlags;
         rv = NS_URIChainHasFlags(targetBaseURI,
                                  nsIProtocolHandler::URI_CROSS_ORIGIN_NEEDS_WEBAPPS_PERM,
                                  &hasFlags);
         NS_ENSURE_SUCCESS(rv, rv);
         if (hasFlags) {
             // In this case, we allow opening only if the source and target URIS
             // are on the same domain, or the opening URI has the webapps
             // permision granted
             if (!SecurityCompareURIs(sourceBaseURI,targetBaseURI) &&
                 !nsContentUtils::IsExactSitePermAllow(aPrincipal,WEBAPPS_PERM_NAME)){
                 return NS_ERROR_DOM_BAD_URI;
             }
         }
         return NS_OK;
     }
     // If the schemes don't match, the policy is specified by the protocol
     // flags on the target URI.  Note that the order of policy checks here is
     // very important!  We start from most restrictive and work our way down.
     // Note that since we're working with the innermost URI, we can just use
     // the methods that work on chains of nested URIs and they will only look
     // at the flags for our one URI.
     // Check for system target URI
     rv = DenyAccessIfURIHasFlags(targetBaseURI,
                                  nsIProtocolHandler::URI_DANGEROUS_TO_LOAD);
     if (NS_FAILED(rv)) {
         // Deny access, since the origin principal is not system
         if (reportErrors) {
             ReportError(nullptr, errorTag, sourceURI, aTargetURI);
         }
         return rv;
     }
     // Check for chrome target URI
     rv = NS_URIChainHasFlags(targetBaseURI,
                              nsIProtocolHandler::URI_IS_UI_RESOURCE,
                              &hasFlags);
     NS_ENSURE_SUCCESS(rv, rv);
     if (hasFlags) {
         if (aFlags & nsIScriptSecurityManager::ALLOW_CHROME) {
             if (!targetScheme.EqualsLiteral("chrome")) {
                 // for now don't change behavior for resource: or moz-icon:
                 return NS_OK;
             }
             // allow load only if chrome package is whitelisted
             nsCOMPtr<nsIXULChromeRegistry> reg(do_GetService(
                                                  NS_CHROMEREGISTRY_CONTRACTID));
             if (reg) {
                 bool accessAllowed = false;
                 reg->AllowContentToAccess(targetBaseURI, &accessAllowed);
                 if (accessAllowed) {
                     return NS_OK;
                 }
             }
         }
         // resource: and chrome: are equivalent, securitywise
         // That's bogus!!  Fix this.  But watch out for
         // the view-source stylesheet?
         bool sourceIsChrome;
         rv = NS_URIChainHasFlags(sourceBaseURI,
                                  nsIProtocolHandler::URI_IS_UI_RESOURCE,
                                  &sourceIsChrome);
         NS_ENSURE_SUCCESS(rv, rv);
         if (sourceIsChrome) {
             return NS_OK;
         }
         if (reportErrors) {
             ReportError(nullptr, errorTag, sourceURI, aTargetURI);
         }
         return NS_ERROR_DOM_BAD_URI;
     }
     // Check for target URI pointing to a file
     rv = NS_URIChainHasFlags(targetBaseURI,
                              nsIProtocolHandler::URI_IS_LOCAL_FILE,
                              &hasFlags);
     NS_ENSURE_SUCCESS(rv, rv);
     if (hasFlags) {
         // Allow domains that were whitelisted in the prefs. In 99.9% of cases,
         // this array is empty.
         for (size_t i = 0; i < mFileURIWhitelist.Length(); ++i) {
             if (EqualOrSubdomain(sourceURI, mFileURIWhitelist[i])) {
                 return NS_OK;
             }
         }
         // resource: and chrome: are equivalent, securitywise
         // That's bogus!!  Fix this.  But watch out for
         // the view-source stylesheet?
         bool sourceIsChrome;
         rv = NS_URIChainHasFlags(sourceURI,
                                  nsIProtocolHandler::URI_IS_UI_RESOURCE,
                                  &sourceIsChrome);
         NS_ENSURE_SUCCESS(rv, rv);
         if (sourceIsChrome) {
             return NS_OK;
         }
         if (reportErrors) {
             ReportError(nullptr, errorTag, sourceURI, aTargetURI);
         }
         return NS_ERROR_DOM_BAD_URI;
     }
     // OK, everyone is allowed to load this, since unflagged handlers are
     // deprecated but treated as URI_LOADABLE_BY_ANYONE.  But check whether we
     // need to warn.  At some point we'll want to make this warning into an
     // error and treat unflagged handlers as URI_DANGEROUS_TO_LOAD.
     rv = NS_URIChainHasFlags(targetBaseURI,
                              nsIProtocolHandler::URI_LOADABLE_BY_ANYONE,
                              &hasFlags);
     NS_ENSURE_SUCCESS(rv, rv);
     if (!hasFlags) {
         nsXPIDLString message;
         NS_ConvertASCIItoUTF16 ucsTargetScheme(targetScheme);
         const char16_t* formatStrings[] = { ucsTargetScheme.get() };
         rv = sStrBundle->
             FormatStringFromName(MOZ_UTF16("ProtocolFlagError"),
                                  formatStrings,
                                  ArrayLength(formatStrings),
                                  getter_Copies(message));
         if (NS_SUCCEEDED(rv)) {
             nsCOMPtr<nsIConsoleService> console(
               do_GetService("@mozilla.org/consoleservice;1"));
             NS_ENSURE_TRUE(console, NS_ERROR_FAILURE);
             console->LogStringMessage(message.get());
         }
     }
     return NS_OK;
 }
 nsresult
 nsScriptSecurityManager::ReportError(JSContext* cx, const nsAString& messageTag,
                                      nsIURI* aSource, nsIURI* aTarget)
 {
     nsresult rv;
     NS_ENSURE_TRUE(aSource && aTarget, NS_ERROR_NULL_POINTER);
     // Get the source URL spec
     nsAutoCString sourceSpec;
     rv = aSource->GetAsciiSpec(sourceSpec);
     NS_ENSURE_SUCCESS(rv, rv);
     // Get the target URL spec
     nsAutoCString targetSpec;
     rv = aTarget->GetAsciiSpec(targetSpec);
     NS_ENSURE_SUCCESS(rv, rv);
     // Localize the error message
     nsXPIDLString message;
     NS_ConvertASCIItoUTF16 ucsSourceSpec(sourceSpec);
     NS_ConvertASCIItoUTF16 ucsTargetSpec(targetSpec);
     const char16_t *formatStrings[] = { ucsSourceSpec.get(), ucsTargetSpec.get() };
     rv = sStrBundle->FormatStringFromName(PromiseFlatString(messageTag).get(),
                                           formatStrings,
                                           ArrayLength(formatStrings),
                                           getter_Copies(message));
     NS_ENSURE_SUCCESS(rv, rv);
     // If a JS context was passed in, set a JS exception.
     // Otherwise, print the error message directly to the JS console
     // and to standard output
     if (cx)
     {
         SetPendingException(cx, message.get());
     }
     else // Print directly to the console
     {
         nsCOMPtr<nsIConsoleService> console(
             do_GetService("@mozilla.org/consoleservice;1"));
         NS_ENSURE_TRUE(console, NS_ERROR_FAILURE);
         console->LogStringMessage(message.get());
     }
     return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CheckLoadURIStrWithPrincipal(nsIPrincipal* aPrincipal,
                                                       const nsACString& aTargetURIStr,
                                                       uint32_t aFlags)
 {
     nsresult rv;
     nsCOMPtr<nsIURI> target;
     rv = NS_NewURI(getter_AddRefs(target), aTargetURIStr,
                    nullptr, nullptr, sIOService);
     NS_ENSURE_SUCCESS(rv, rv);
     rv = CheckLoadURIWithPrincipal(aPrincipal, target, aFlags);
     if (rv == NS_ERROR_DOM_BAD_URI) {
         // Don't warn because NS_ERROR_DOM_BAD_URI is one of the expected
         // return values.
         return rv;
     }
     NS_ENSURE_SUCCESS(rv, rv);
     // Now start testing fixup -- since aTargetURIStr is a string, not
     // an nsIURI, we may well end up fixing it up before loading.
     // Note: This needs to stay in sync with the nsIURIFixup api.
     nsCOMPtr<nsIURIFixup> fixup = do_GetService(NS_URIFIXUP_CONTRACTID);
     if (!fixup) {
         return rv;
     }
     uint32_t flags[] = {
         nsIURIFixup::FIXUP_FLAG_NONE,
         nsIURIFixup::FIXUP_FLAG_FIX_SCHEME_TYPOS,
         nsIURIFixup::FIXUP_FLAG_ALLOW_KEYWORD_LOOKUP,
         nsIURIFixup::FIXUP_FLAGS_MAKE_ALTERNATE_URI,
         nsIURIFixup::FIXUP_FLAG_ALLOW_KEYWORD_LOOKUP |
         nsIURIFixup::FIXUP_FLAGS_MAKE_ALTERNATE_URI
     };
     for (uint32_t i = 0; i < ArrayLength(flags); ++i) {
         rv = fixup->CreateFixupURI(aTargetURIStr, flags[i], nullptr,
                                    getter_AddRefs(target));
         NS_ENSURE_SUCCESS(rv, rv);
         rv = CheckLoadURIWithPrincipal(aPrincipal, target, aFlags);
         if (rv == NS_ERROR_DOM_BAD_URI) {
             // Don't warn because NS_ERROR_DOM_BAD_URI is one of the expected
             // return values.
             return rv;
         }
         NS_ENSURE_SUCCESS(rv, rv);
     }
     return rv;
 }
 bool
 nsScriptSecurityManager::ScriptAllowed(JSObject *aGlobal)
 {
     MOZ_ASSERT(aGlobal);
     MOZ_ASSERT(JS_IsGlobalObject(aGlobal) || js::IsOuterObject(aGlobal));
     AutoJSContext cx;
     JS::RootedObject global(cx, js::UncheckedUnwrap(aGlobal, /* stopAtOuter = */ false));
     // Check the bits on the compartment private.
     return xpc::Scriptability::Get(aGlobal).Allowed();
 }
 ///////////////// Principals ///////////////////////
 NS_IMETHODIMP
 nsScriptSecurityManager::GetSubjectPrincipal(nsIPrincipal **aSubjectPrincipal)
 {
     nsresult rv;
     *aSubjectPrincipal = doGetSubjectPrincipal(&rv);
     if (NS_SUCCEEDED(rv))
         NS_IF_ADDREF(*aSubjectPrincipal);
     return rv;
 }
 nsIPrincipal*
 nsScriptSecurityManager::doGetSubjectPrincipal(nsresult* rv)
 {
     NS_PRECONDITION(rv, "Null out param");
     JSContext *cx = GetCurrentJSContext();
     if (!cx)
     {
         *rv = NS_OK;
         return nullptr;
     }
     return GetSubjectPrincipal(cx, rv);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetSystemPrincipal(nsIPrincipal **result)
 {
     NS_ADDREF(*result = mSystemPrincipal);
     return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::SubjectPrincipalIsSystem(bool* aIsSystem)
 {
     NS_ENSURE_ARG_POINTER(aIsSystem);
     *aIsSystem = false;
     if (!mSystemPrincipal)
         return NS_OK;
     nsCOMPtr<nsIPrincipal> subject;
     nsresult rv = GetSubjectPrincipal(getter_AddRefs(subject));
     if (NS_FAILED(rv))
         return rv;
     if(!subject)
     {
         // No subject principal means no JS is running;
         // this is the equivalent of system principal code
         *aIsSystem = true;
         return NS_OK;
     }
     return mSystemPrincipal->Equals(subject, aIsSystem);
 }
 nsresult
 nsScriptSecurityManager::CreateCodebasePrincipal(nsIURI* aURI, uint32_t aAppId,
                                                  bool aInMozBrowser,
                                                  nsIPrincipal **result)
 {
     // I _think_ it's safe to not create null principals here based on aURI.
     // At least all the callers would do the right thing in those cases, as far
     // as I can tell.  --bz
     nsCOMPtr<nsIURIWithPrincipal> uriPrinc = do_QueryInterface(aURI);
     if (uriPrinc) {
         nsCOMPtr<nsIPrincipal> principal;
         uriPrinc->GetPrincipal(getter_AddRefs(principal));
         if (!principal || principal == mSystemPrincipal) {
             return CallCreateInstance(NS_NULLPRINCIPAL_CONTRACTID, result);
         }
         principal.forget(result);
         return NS_OK;
     }
     nsRefPtr<nsPrincipal> codebase = new nsPrincipal();
     if (!codebase)
         return NS_ERROR_OUT_OF_MEMORY;
     nsresult rv = codebase->Init(aURI, aAppId, aInMozBrowser);
     if (NS_FAILED(rv))
         return rv;
     NS_ADDREF(*result = codebase);
     return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetSimpleCodebasePrincipal(nsIURI* aURI,
                                                     nsIPrincipal** aPrincipal)
 {
   return GetCodebasePrincipalInternal(aURI,
                                       nsIScriptSecurityManager::UNKNOWN_APP_ID,
                                       false, aPrincipal);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetNoAppCodebasePrincipal(nsIURI* aURI,
                                                    nsIPrincipal** aPrincipal)
 {
   return GetCodebasePrincipalInternal(aURI,  nsIScriptSecurityManager::NO_APP_ID,
                                       false, aPrincipal);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetCodebasePrincipal(nsIURI* aURI,
                                               nsIPrincipal** aPrincipal)
 {
   return GetNoAppCodebasePrincipal(aURI, aPrincipal);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetAppCodebasePrincipal(nsIURI* aURI,
                                                  uint32_t aAppId,
                                                  bool aInMozBrowser,
                                                  nsIPrincipal** aPrincipal)
 {
   NS_ENSURE_TRUE(aAppId != nsIScriptSecurityManager::UNKNOWN_APP_ID,
                  NS_ERROR_INVALID_ARG);
   return GetCodebasePrincipalInternal(aURI, aAppId, aInMozBrowser, aPrincipal);
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetDocShellCodebasePrincipal(nsIURI* aURI,
                                                       nsIDocShell* aDocShell,
                                                       nsIPrincipal** aPrincipal)
 {
   return GetCodebasePrincipalInternal(aURI,
                                       aDocShell->GetAppId(),
                                       aDocShell->GetIsInBrowserElement(),
                                       aPrincipal);
 }
 nsresult
 nsScriptSecurityManager::GetCodebasePrincipalInternal(nsIURI *aURI,
                                                       uint32_t aAppId,
                                                       bool aInMozBrowser,
                                                       nsIPrincipal **result)
 {
     NS_ENSURE_ARG(aURI);
     bool inheritsPrincipal;
     nsresult rv =
         NS_URIChainHasFlags(aURI,
                             nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT,
                             &inheritsPrincipal);
     if (NS_FAILED(rv) || inheritsPrincipal) {
         return CallCreateInstance(NS_NULLPRINCIPAL_CONTRACTID, result);
     }
     nsCOMPtr<nsIPrincipal> principal;
     rv = CreateCodebasePrincipal(aURI, aAppId, aInMozBrowser,
                                  getter_AddRefs(principal));
     NS_ENSURE_SUCCESS(rv, rv);
     NS_IF_ADDREF(*result = principal);
     return NS_OK;
 }
 nsIPrincipal*
 nsScriptSecurityManager::GetSubjectPrincipal(JSContext *cx,
                                              nsresult* rv)
 {
     *rv = NS_OK;
     JSCompartment *compartment = js::GetContextCompartment(cx);
     // The context should always be in a compartment, either one it has entered
     // or the one associated with its global.
     MOZ_ASSERT(!!compartment);
     JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
     return nsJSPrincipals::get(principals);
 }
 // static
 nsIPrincipal*
 nsScriptSecurityManager::doGetObjectPrincipal(JSObject *aObj)
 {
     JSCompartment *compartment = js::GetObjectCompartment(aObj);
     JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
     return nsJSPrincipals::get(principals);
 }
 ////////////////////////////////////////////////
 // Methods implementing nsIXPCSecurityManager //
 ////////////////////////////////////////////////
 NS_IMETHODIMP
 nsScriptSecurityManager::CanCreateWrapper(JSContext *cx,
                                           const nsIID &aIID,
                                           nsISupports *aObj,
                                           nsIClassInfo *aClassInfo)
 {
 // XXX Special case for nsIXPCException ?
     ClassInfoData objClassInfo = ClassInfoData(aClassInfo, nullptr);
     if (objClassInfo.IsDOMClass())
     {
         return NS_OK;
     }
     // We give remote-XUL whitelisted domains a free pass here. See bug 932906.
     if (!xpc::AllowXBLScope(js::GetContextCompartment(cx)))
     {
         return NS_OK;
     }
     if (SubjectIsPrivileged())
     {
         return NS_OK;
     }
     //-- Access denied, report an error
     NS_ConvertUTF8toUTF16 strName("CreateWrapperDenied");
     nsAutoCString origin;
     nsresult rv2;
     nsIPrincipal* subjectPrincipal = doGetSubjectPrincipal(&rv2);
     if (NS_SUCCEEDED(rv2) && subjectPrincipal) {
         GetPrincipalDomainOrigin(subjectPrincipal, origin);
     }
     NS_ConvertUTF8toUTF16 originUnicode(origin);
     NS_ConvertUTF8toUTF16 classInfoName(objClassInfo.GetName());
     const char16_t* formatStrings[] = {
         classInfoName.get(),
         originUnicode.get()
     };
     uint32_t length = ArrayLength(formatStrings);
     if (originUnicode.IsEmpty()) {
         --length;
     } else {
         strName.AppendLiteral("ForOrigin");
     }
     nsXPIDLString errorMsg;
     // We need to keep our existing failure rv and not override it
     // with a likely success code from the following string bundle
     // call in order to throw the correct security exception later.
     rv2 = sStrBundle->FormatStringFromName(strName.get(),
                                            formatStrings,
                                            length,
                                            getter_Copies(errorMsg));
     NS_ENSURE_SUCCESS(rv2, rv2);
     SetPendingException(cx, errorMsg.get());
     return NS_ERROR_DOM_XPCONNECT_ACCESS_DENIED;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CanCreateInstance(JSContext *cx,
                                            const nsCID &aCID)
 {
     if (SubjectIsPrivileged()) {
         return NS_OK;
     }
     //-- Access denied, report an error
     nsAutoCString errorMsg("Permission denied to create instance of class. CID=");
     char cidStr[NSID_LENGTH];
     aCID.ToProvidedString(cidStr);
     errorMsg.Append(cidStr);
     SetPendingException(cx, errorMsg.get());
     return NS_ERROR_DOM_XPCONNECT_ACCESS_DENIED;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::CanGetService(JSContext *cx,
                                        const nsCID &aCID)
 {
     if (SubjectIsPrivileged()) {
         return NS_OK;
     }
     //-- Access denied, report an error
     nsAutoCString errorMsg("Permission denied to get service. CID=");
     char cidStr[NSID_LENGTH];
     aCID.ToProvidedString(cidStr);
     errorMsg.Append(cidStr);
     SetPendingException(cx, errorMsg.get());
     return NS_ERROR_DOM_XPCONNECT_ACCESS_DENIED;
 }
 /////////////////////////////////////////////
 // Method implementing nsIChannelEventSink //
 /////////////////////////////////////////////
 NS_IMETHODIMP
 nsScriptSecurityManager::AsyncOnChannelRedirect(nsIChannel* oldChannel,
                                                 nsIChannel* newChannel,
                                                 uint32_t redirFlags,
                                                 nsIAsyncVerifyRedirectCallback *cb)
 {
     nsCOMPtr<nsIPrincipal> oldPrincipal;
     GetChannelPrincipal(oldChannel, getter_AddRefs(oldPrincipal));
     nsCOMPtr<nsIURI> newURI;
     newChannel->GetURI(getter_AddRefs(newURI));
     nsCOMPtr<nsIURI> newOriginalURI;
     newChannel->GetOriginalURI(getter_AddRefs(newOriginalURI));
     NS_ENSURE_STATE(oldPrincipal && newURI && newOriginalURI);
     const uint32_t flags =
         nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT |
         nsIScriptSecurityManager::DISALLOW_SCRIPT;
     nsresult rv = CheckLoadURIWithPrincipal(oldPrincipal, newURI, flags);
     if (NS_SUCCEEDED(rv) && newOriginalURI != newURI) {
         rv = CheckLoadURIWithPrincipal(oldPrincipal, newOriginalURI, flags);
     }
     if (NS_FAILED(rv))
         return rv;
     cb->OnRedirectVerifyCallback(NS_OK);
     return NS_OK;
 }
 /////////////////////////////////////
 // Method implementing nsIObserver //
 /////////////////////////////////////
 const char sJSEnabledPrefName[] = "javascript.enabled";
 const char sFileOriginPolicyPrefName[] =
     "security.fileuri.strict_origin_policy";
 static const char* kObservedPrefs[] = {
   sJSEnabledPrefName,
   sFileOriginPolicyPrefName,
   "capability.policy.",
   nullptr
 };
 NS_IMETHODIMP
 nsScriptSecurityManager::Observe(nsISupports* aObject, const char* aTopic,
                                  const char16_t* aMessage)
 {
     ScriptSecurityPrefChanged();
     return NS_OK;
 }
 /////////////////////////////////////////////
 // Constructor, Destructor, Initialization //
 /////////////////////////////////////////////
 nsScriptSecurityManager::nsScriptSecurityManager(void)
     : mPrefInitialized(false)
     , mIsJavaScriptEnabled(false)
 {
     static_assert(sizeof(intptr_t) == sizeof(void*),
                   "intptr_t and void* have different lengths on this platform. "
                   "This may cause a security failure with the SecurityLevel union.");
 }
 nsresult nsScriptSecurityManager::Init()
 {
     nsresult rv = CallGetService(NS_IOSERVICE_CONTRACTID, &sIOService);
     NS_ENSURE_SUCCESS(rv, rv);
     InitPrefs();
     nsCOMPtr<nsIStringBundleService> bundleService =
         mozilla::services::GetStringBundleService();
     if (!bundleService)
         return NS_ERROR_FAILURE;
     rv = bundleService->CreateBundle("chrome://global/locale/security/caps.properties", &sStrBundle);
     NS_ENSURE_SUCCESS(rv, rv);
     // Create our system principal singleton
     nsRefPtr<nsSystemPrincipal> system = new nsSystemPrincipal();
     NS_ENSURE_TRUE(system, NS_ERROR_OUT_OF_MEMORY);
     mSystemPrincipal = system;
     //-- Register security check callback in the JS engine
     //   Currently this is used to control access to function.caller
     rv = nsXPConnect::XPConnect()->GetRuntime(&sRuntime);
     NS_ENSURE_SUCCESS(rv, rv);
     static const JSSecurityCallbacks securityCallbacks = {
         ContentSecurityPolicyPermitsJSAction,
         JSPrincipalsSubsume,
     };
     MOZ_ASSERT(!JS_GetSecurityCallbacks(sRuntime));
     JS_SetSecurityCallbacks(sRuntime, &securityCallbacks);
     JS_InitDestroyPrincipalsCallback(sRuntime, nsJSPrincipals::Destroy);
     JS_SetTrustedPrincipals(sRuntime, system);
     return NS_OK;
 }
 static StaticRefPtr<nsScriptSecurityManager> gScriptSecMan;
 nsScriptSecurityManager::~nsScriptSecurityManager(void)
 {
     Preferences::RemoveObservers(this, kObservedPrefs);
     if (mDomainPolicy)
         mDomainPolicy->Deactivate();
     MOZ_ASSERT(!mDomainPolicy);
 }
 void
 nsScriptSecurityManager::Shutdown()
 {
     if (sRuntime) {
         JS_SetSecurityCallbacks(sRuntime, nullptr);
         JS_SetTrustedPrincipals(sRuntime, nullptr);
         sRuntime = nullptr;
     }
     NS_IF_RELEASE(sIOService);
     NS_IF_RELEASE(sStrBundle);
 }
 nsScriptSecurityManager *
 nsScriptSecurityManager::GetScriptSecurityManager()
 {
     if (!gScriptSecMan && nsXPConnect::XPConnect())
     {
         nsRefPtr<nsScriptSecurityManager> ssManager = new nsScriptSecurityManager();
         nsresult rv;
         rv = ssManager->Init();
         if (NS_FAILED(rv)) {
             return nullptr;
         }
         rv = nsXPConnect::XPConnect()->
             SetDefaultSecurityManager(ssManager);
         if (NS_FAILED(rv)) {
             NS_WARNING("Failed to install xpconnect security manager!");
             return nullptr;
         }
         ClearOnShutdown(&gScriptSecMan);
         gScriptSecMan = ssManager;
     }
     return gScriptSecMan;
 }
 // Currently this nsGenericFactory constructor is used only from FastLoad
 // (XPCOM object deserialization) code, when "creating" the system principal
 // singleton.
 nsSystemPrincipal *
 nsScriptSecurityManager::SystemPrincipalSingletonConstructor()
 {
     nsIPrincipal *sysprin = nullptr;
     if (gScriptSecMan)
         NS_ADDREF(sysprin = gScriptSecMan->mSystemPrincipal);
     return static_cast<nsSystemPrincipal*>(sysprin);
 }
 struct IsWhitespace {
     static bool Test(char aChar) { return NS_IsAsciiWhitespace(aChar); };
 };
 struct IsWhitespaceOrComma {
     static bool Test(char aChar) { return aChar == ',' || NS_IsAsciiWhitespace(aChar); };
 };
 template <typename Predicate>
 uint32_t SkipPast(const nsCString& str, uint32_t base)
 {
     while (base < str.Length() && Predicate::Test(str[base])) {
         ++base;
     }
     return base;
 }
 template <typename Predicate>
 uint32_t SkipUntil(const nsCString& str, uint32_t base)
 {
     while (base < str.Length() && !Predicate::Test(str[base])) {
         ++base;
     }
     return base;
 }
 inline void
 nsScriptSecurityManager::ScriptSecurityPrefChanged()
 {
     MOZ_ASSERT(mPrefInitialized);
     mIsJavaScriptEnabled =
         Preferences::GetBool(sJSEnabledPrefName, mIsJavaScriptEnabled);
     sStrictFileOriginPolicy =
         Preferences::GetBool(sFileOriginPolicyPrefName, false);
     //
     // Rebuild the set of principals for which we allow file:// URI loads. This
     // implements a small subset of an old pref-based CAPS people that people
     // have come to depend on. See bug 995943.
     //
     mFileURIWhitelist.Clear();
     auto policies = mozilla::Preferences::GetCString("capability.policy.policynames");
     for (uint32_t base = SkipPast<IsWhitespaceOrComma>(policies, 0), bound = 0;
          base < policies.Length();
          base = SkipPast<IsWhitespaceOrComma>(policies, bound))
     {
         // Grab the current policy name.
         bound = SkipUntil<IsWhitespaceOrComma>(policies, base);
         auto policyName = Substring(policies, base, bound - base);
         // Figure out if this policy allows loading file:// URIs. If not, we can skip it.
         nsCString checkLoadURIPrefName = NS_LITERAL_CSTRING("capability.policy.") +
                                          policyName +
                                          NS_LITERAL_CSTRING(".checkloaduri.enabled");
         if (!Preferences::GetString(checkLoadURIPrefName.get()).LowerCaseEqualsLiteral("allaccess")) {
             continue;
         }
         // Grab the list of domains associated with this policy.
         nsCString domainPrefName = NS_LITERAL_CSTRING("capability.policy.") +
                                    policyName +
                                    NS_LITERAL_CSTRING(".sites");
         auto siteList = Preferences::GetCString(domainPrefName.get());
         AddSitesToFileURIWhitelist(siteList);
     }
 }
 void
 nsScriptSecurityManager::AddSitesToFileURIWhitelist(const nsCString& aSiteList)
 {
     for (uint32_t base = SkipPast<IsWhitespace>(aSiteList, 0), bound = 0;
          base < aSiteList.Length();
          base = SkipPast<IsWhitespace>(aSiteList, bound))
     {
         // Grab the current site.
         bound = SkipUntil<IsWhitespace>(aSiteList, base);
         nsAutoCString site(Substring(aSiteList, base, bound - base));
         // Check if the URI is schemeless. If so, add both http and https.
         nsAutoCString unused;
         if (NS_FAILED(sIOService->ExtractScheme(site, unused))) {
             AddSitesToFileURIWhitelist(NS_LITERAL_CSTRING("http://") + site);
             AddSitesToFileURIWhitelist(NS_LITERAL_CSTRING("https://") + site);
             continue;
         }
         // Convert it to a URI and add it to our list.
         nsCOMPtr<nsIURI> uri;
         nsresult rv = NS_NewURI(getter_AddRefs(uri), site, nullptr, nullptr, sIOService);
         if (NS_SUCCEEDED(rv)) {
             mFileURIWhitelist.AppendElement(uri);
         } else {
             nsCOMPtr<nsIConsoleService> console(do_GetService("@mozilla.org/consoleservice;1"));
             if (console) {
                 nsAutoString msg = NS_LITERAL_STRING("Unable to to add site to file:// URI whitelist: ") +
                                    NS_ConvertASCIItoUTF16(site);
                 console->LogStringMessage(msg.get());
             }
         }
     }
 }
 nsresult
 nsScriptSecurityManager::InitPrefs()
 {
     nsIPrefBranch* branch = Preferences::GetRootBranch();
     NS_ENSURE_TRUE(branch, NS_ERROR_FAILURE);
     mPrefInitialized = true;
     // Set the initial value of the "javascript.enabled" prefs
     ScriptSecurityPrefChanged();
     // set observer callbacks in case the value of the prefs change
     Preferences::AddStrongObservers(this, kObservedPrefs);
     return NS_OK;
 }
 namespace mozilla {
 void
 GetJarPrefix(uint32_t aAppId, bool aInMozBrowser, nsACString& aJarPrefix)
 {
   MOZ_ASSERT(aAppId != nsIScriptSecurityManager::UNKNOWN_APP_ID);
   if (aAppId == nsIScriptSecurityManager::UNKNOWN_APP_ID) {
     aAppId = nsIScriptSecurityManager::NO_APP_ID;
   }
   aJarPrefix.Truncate();
   // Fallback.
   if (aAppId == nsIScriptSecurityManager::NO_APP_ID && !aInMozBrowser) {
     return;
   }
   // aJarPrefix = appId + "+" + { 't', 'f' } + "+";
   aJarPrefix.AppendInt(aAppId);
   aJarPrefix.Append('+');
   aJarPrefix.Append(aInMozBrowser ? 't' : 'f');
   aJarPrefix.Append('+');
   return;
 }
 } // namespace mozilla
 NS_IMETHODIMP
 nsScriptSecurityManager::GetJarPrefix(uint32_t aAppId,
                                       bool aInMozBrowser,
                                       nsACString& aJarPrefix)
 {
   MOZ_ASSERT(aAppId != nsIScriptSecurityManager::UNKNOWN_APP_ID);
   mozilla::GetJarPrefix(aAppId, aInMozBrowser, aJarPrefix);
   return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::GetDomainPolicyActive(bool *aRv)
 {
     *aRv = !!mDomainPolicy;
     return NS_OK;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::ActivateDomainPolicy(nsIDomainPolicy** aRv)
 {
     // We only allow one domain policy at a time. The holder of the previous
     // policy must explicitly deactivate it first.
     if (mDomainPolicy) {
         return NS_ERROR_SERVICE_NOT_AVAILABLE;
     }
     mDomainPolicy = new DomainPolicy();
     nsCOMPtr<nsIDomainPolicy> ptr = mDomainPolicy;
     ptr.forget(aRv);
     return NS_OK;
 }
 // Intentionally non-scriptable. Script must have a reference to the
 // nsIDomainPolicy to deactivate it.
 void
 nsScriptSecurityManager::DeactivateDomainPolicy()
 {
     mDomainPolicy = nullptr;
 }
 NS_IMETHODIMP
 nsScriptSecurityManager::PolicyAllowsScript(nsIURI* aURI, bool *aRv)
 {
     nsresult rv;
     // Compute our rule. If we don't have any domain policy set up that might
     // provide exceptions to this rule, we're done.
     *aRv = mIsJavaScriptEnabled;
     if (!mDomainPolicy) {
         return NS_OK;
     }
     // We have a domain policy. Grab the appropriate set of exceptions to the
     // rule (either the blacklist or the whitelist, depending on whether script
     // is enabled or disabled by default).
     nsCOMPtr<nsIDomainSet> exceptions;
     nsCOMPtr<nsIDomainSet> superExceptions;
     if (*aRv) {
         mDomainPolicy->GetBlacklist(getter_AddRefs(exceptions));
         mDomainPolicy->GetSuperBlacklist(getter_AddRefs(superExceptions));
     } else {
         mDomainPolicy->GetWhitelist(getter_AddRefs(exceptions));
         mDomainPolicy->GetSuperWhitelist(getter_AddRefs(superExceptions));
     }
     bool contains;
     rv = exceptions->Contains(aURI, &contains);
     NS_ENSURE_SUCCESS(rv, rv);
     if (contains) {
         *aRv = !*aRv;
         return NS_OK;
     }
     rv = superExceptions->ContainsSuperDomain(aURI, &contains);
     NS_ENSURE_SUCCESS(rv, rv);
     if (contains) {
         *aRv = !*aRv;
     }
     return NS_OK;
 }

The Tor Browser / annotate

caps/src/nsScriptSecurityManager.cpp@97036ab72558 (annotated)

caps/src/nsScriptSecurityManager.cpp