caps/nsPrincipal.cpp
author Armen Zambrano Gasparnian <armenzg@mozilla.com>
Wed, 27 Jul 2016 10:51:38 -0400
changeset 307562 9f5fbb3066c91cdab754c2222299016ba6f2af21
parent 297027 fe2ea22e1edec1beee00931ea7b3af607fa69a0d
child 309071 2263d29df71686a2bea8255859867910fc66b220
permissions -rw-r--r--
Bug 1288742 - Increase expiration date of all gecko decision artifacts bar image context tar balls. r=dustin Until now Gecko decision task artifacts would expire after a week. Unfortunately, some of these artifacts are needed in order for Treeherder to determine which tasks it can schedule on a given push. In this change, we're changing the expiration of all artifacts except those that are related to docker image optimizations, which, are very large files and we only want to keep for a week. MozReview-Commit-ID: 96ahyWmoI7W

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et 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 "nsPrincipal.h"

#include "mozIThirdPartyUtil.h"
#include "nscore.h"
#include "nsScriptSecurityManager.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#include "pratom.h"
#include "nsIURI.h"
#include "nsIURL.h"
#include "nsIStandardURL.h"
#include "nsIURIWithPrincipal.h"
#include "nsJSPrincipals.h"
#include "nsIEffectiveTLDService.h"
#include "nsIClassInfoImpl.h"
#include "nsIProtocolHandler.h"
#include "nsError.h"
#include "nsIContentSecurityPolicy.h"
#include "nsNetCID.h"
#include "jswrapper.h"

#include "mozilla/dom/nsCSPContext.h"
#include "mozilla/dom/ScriptSettings.h"
#include "mozilla/Preferences.h"
#include "mozilla/HashFunctions.h"

#include "nsIAppsService.h"
#include "mozIApplication.h"

using namespace mozilla;

static bool gIsWhitelistingTestDomains = false;
static bool gCodeBasePrincipalSupport = false;

static bool URIIsImmutable(nsIURI* aURI)
{
  nsCOMPtr<nsIMutable> mutableObj(do_QueryInterface(aURI));
  bool isMutable;
  return
    mutableObj &&
    NS_SUCCEEDED(mutableObj->GetMutable(&isMutable)) &&
    !isMutable;
}

NS_IMPL_CLASSINFO(nsPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
                  NS_PRINCIPAL_CID)
NS_IMPL_QUERY_INTERFACE_CI(nsPrincipal,
                           nsIPrincipal,
                           nsISerializable)
NS_IMPL_CI_INTERFACE_GETTER(nsPrincipal,
                            nsIPrincipal,
                            nsISerializable)

// Called at startup:
/* static */ void
nsPrincipal::InitializeStatics()
{
  Preferences::AddBoolVarCache(
    &gIsWhitelistingTestDomains,
    "layout.css.unprefixing-service.include-test-domains");

  Preferences::AddBoolVarCache(&gCodeBasePrincipalSupport,
                               "signed.applets.codebase_principal_support",
                               false);
}

nsPrincipal::nsPrincipal()
  : mCodebaseImmutable(false)
  , mDomainImmutable(false)
  , mInitialized(false)
{ }

nsPrincipal::~nsPrincipal()
{ 
  // let's clear the principal within the csp to avoid a tangling pointer
  if (mCSP) {
    static_cast<nsCSPContext*>(mCSP.get())->clearLoadingPrincipal();
  }
}

nsresult
nsPrincipal::Init(nsIURI *aCodebase, const PrincipalOriginAttributes& aOriginAttributes)
{
  NS_ENSURE_STATE(!mInitialized);
  NS_ENSURE_ARG(aCodebase);

  mInitialized = true;

  mCodebase = NS_TryToMakeImmutable(aCodebase);
  mCodebaseImmutable = URIIsImmutable(mCodebase);
  mOriginAttributes = aOriginAttributes;

  return NS_OK;
}

void
nsPrincipal::GetScriptLocation(nsACString &aStr)
{
  mCodebase->GetSpec(aStr);
}

/* static */ nsresult
nsPrincipal::GetOriginForURI(nsIURI* aURI, nsACString& aOrigin)
{
  if (!aURI) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIURI> origin = NS_GetInnermostURI(aURI);
  if (!origin) {
    return NS_ERROR_FAILURE;
  }

  nsAutoCString hostPort;

  // chrome: URLs don't have a meaningful origin, so make
  // sure we just get the full spec for them.
  // XXX this should be removed in favor of the solution in
  // bug 160042.
  bool isChrome;
  nsresult rv = origin->SchemeIs("chrome", &isChrome);
  if (NS_SUCCEEDED(rv) && !isChrome) {
    rv = origin->GetAsciiHostPort(hostPort);
    // Some implementations return an empty string, treat it as no support
    // for asciiHost by that implementation.
    if (hostPort.IsEmpty()) {
      rv = NS_ERROR_FAILURE;
    }
  }

  // We want the invariant that prinA.origin == prinB.origin i.f.f.
  // prinA.equals(prinB). However, this requires that we impose certain constraints
  // on the behavior and origin semantics of principals, and in particular, forbid
  // creating origin strings for principals whose equality constraints are not
  // expressible as strings (i.e. object equality). Moreover, we want to forbid URIs
  // containing the magic "^" we use as a separating character for origin
  // attributes.
  //
  // These constraints can generally be achieved by restricting .origin to
  // nsIStandardURL-based URIs, but there are a few other URI schemes that we need
  // to handle.
  bool isBehaved;
  if ((NS_SUCCEEDED(origin->SchemeIs("about", &isBehaved)) && isBehaved) ||
      (NS_SUCCEEDED(origin->SchemeIs("moz-safe-about", &isBehaved)) && isBehaved) ||
      (NS_SUCCEEDED(origin->SchemeIs("indexeddb", &isBehaved)) && isBehaved)) {
    rv = origin->GetAsciiSpec(aOrigin);
    NS_ENSURE_SUCCESS(rv, rv);
    // These URIs could technically contain a '^', but they never should.
    if (NS_WARN_IF(aOrigin.FindChar('^', 0) != -1)) {
      aOrigin.Truncate();
      return NS_ERROR_FAILURE;
    }
    return NS_OK;
  }

  if (NS_SUCCEEDED(rv) && !isChrome) {
    rv = origin->GetScheme(aOrigin);
    NS_ENSURE_SUCCESS(rv, rv);
    aOrigin.AppendLiteral("://");
    aOrigin.Append(hostPort);
  }
  else {
    // If we reached this branch, we can only create an origin if we have a nsIStandardURL.
    // So, we query to a nsIStandardURL, and fail if we aren't an instance of an nsIStandardURL
    // nsIStandardURLs have the good property of escaping the '^' character in their specs,
    // which means that we can be sure that the caret character (which is reserved for delimiting
    // the end of the spec, and the beginning of the origin attributes) is not present in the
    // origin string
    nsCOMPtr<nsIStandardURL> standardURL = do_QueryInterface(origin);
    NS_ENSURE_TRUE(standardURL, NS_ERROR_FAILURE);
    rv = origin->GetAsciiSpec(aOrigin);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

nsresult
nsPrincipal::GetOriginInternal(nsACString& aOrigin)
{
  return GetOriginForURI(mCodebase, aOrigin);
}

bool
nsPrincipal::SubsumesInternal(nsIPrincipal* aOther,
                              BasePrincipal::DocumentDomainConsideration aConsideration)
{
  MOZ_ASSERT(aOther);

  // For nsPrincipal, Subsumes is equivalent to Equals.
  if (aOther == this) {
    return true;
  }

  if (OriginAttributesRef() != Cast(aOther)->OriginAttributesRef()) {
    return false;
  }

  // If either the subject or the object has changed its principal by
  // explicitly setting document.domain then the other must also have
  // done so in order to be considered the same origin. This prevents
  // DNS spoofing based on document.domain (154930)
  nsresult rv;
  if (aConsideration == ConsiderDocumentDomain) {
    // Get .domain on each principal.
    nsCOMPtr<nsIURI> thisDomain, otherDomain;
    GetDomain(getter_AddRefs(thisDomain));
    aOther->GetDomain(getter_AddRefs(otherDomain));

    // If either has .domain set, we have equality i.f.f. the domains match.
    // Otherwise, we fall through to the non-document-domain-considering case.
    if (thisDomain || otherDomain) {
      return nsScriptSecurityManager::SecurityCompareURIs(thisDomain, otherDomain);
    }
  }

    nsCOMPtr<nsIURI> otherURI;
    rv = aOther->GetURI(getter_AddRefs(otherURI));
    NS_ENSURE_SUCCESS(rv, false);

  // Compare codebases.
  return nsScriptSecurityManager::SecurityCompareURIs(mCodebase, otherURI);
}

NS_IMETHODIMP
nsPrincipal::GetURI(nsIURI** aURI)
{
  if (mCodebaseImmutable) {
    NS_ADDREF(*aURI = mCodebase);
    return NS_OK;
  }

  if (!mCodebase) {
    *aURI = nullptr;
    return NS_OK;
  }

  return NS_EnsureSafeToReturn(mCodebase, aURI);
}

bool
nsPrincipal::MayLoadInternal(nsIURI* aURI)
{
  // See if aURI is something like a Blob URI that is actually associated with
  // a principal.
  nsCOMPtr<nsIURIWithPrincipal> uriWithPrin = do_QueryInterface(aURI);
  nsCOMPtr<nsIPrincipal> uriPrin;
  if (uriWithPrin) {
    uriWithPrin->GetPrincipal(getter_AddRefs(uriPrin));
  }
  if (uriPrin) {
    return nsIPrincipal::Subsumes(uriPrin);
  }

  // If this principal is associated with an addon, check whether that addon
  // has been given permission to load from this domain.
  if (AddonAllowsLoad(aURI)) {
    return true;
  }

  if (nsScriptSecurityManager::SecurityCompareURIs(mCodebase, aURI)) {
    return true;
  }

  // If strict file origin policy is in effect, local files will always fail
  // SecurityCompareURIs unless they are identical. Explicitly check file origin
  // policy, in that case.
  if (nsScriptSecurityManager::GetStrictFileOriginPolicy() &&
      NS_URIIsLocalFile(aURI) &&
      NS_RelaxStrictFileOriginPolicy(aURI, mCodebase)) {
    return true;
  }

  return false;
}

void
nsPrincipal::SetURI(nsIURI* aURI)
{
  mCodebase = NS_TryToMakeImmutable(aURI);
  mCodebaseImmutable = URIIsImmutable(mCodebase);
}

NS_IMETHODIMP
nsPrincipal::GetHashValue(uint32_t* aValue)
{
  NS_PRECONDITION(mCodebase, "Need a codebase");

  *aValue = nsScriptSecurityManager::HashPrincipalByOrigin(this);
  return NS_OK;
}

NS_IMETHODIMP
nsPrincipal::GetDomain(nsIURI** aDomain)
{
  if (!mDomain) {
    *aDomain = nullptr;
    return NS_OK;
  }

  if (mDomainImmutable) {
    NS_ADDREF(*aDomain = mDomain);
    return NS_OK;
  }

  return NS_EnsureSafeToReturn(mDomain, aDomain);
}

NS_IMETHODIMP
nsPrincipal::SetDomain(nsIURI* aDomain)
{
  mDomain = NS_TryToMakeImmutable(aDomain);
  mDomainImmutable = URIIsImmutable(mDomain);

  // Recompute all wrappers between compartments using this principal and other
  // non-chrome compartments.
  AutoSafeJSContext cx;
  JSPrincipals *principals = nsJSPrincipals::get(static_cast<nsIPrincipal*>(this));
  bool success = js::RecomputeWrappers(cx, js::ContentCompartmentsOnly(),
                                       js::CompartmentsWithPrincipals(principals));
  NS_ENSURE_TRUE(success, NS_ERROR_FAILURE);
  success = js::RecomputeWrappers(cx, js::CompartmentsWithPrincipals(principals),
                                  js::ContentCompartmentsOnly());
  NS_ENSURE_TRUE(success, NS_ERROR_FAILURE);

  return NS_OK;
}

NS_IMETHODIMP
nsPrincipal::GetBaseDomain(nsACString& aBaseDomain)
{
  // For a file URI, we return the file path.
  if (NS_URIIsLocalFile(mCodebase)) {
    nsCOMPtr<nsIURL> url = do_QueryInterface(mCodebase);

    if (url) {
      return url->GetFilePath(aBaseDomain);
    }
  }

  bool hasNoRelativeFlag;
  nsresult rv = NS_URIChainHasFlags(mCodebase,
                                    nsIProtocolHandler::URI_NORELATIVE,
                                    &hasNoRelativeFlag);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (hasNoRelativeFlag) {
    return mCodebase->GetSpec(aBaseDomain);
  }

  // For everything else, we ask the TLD service via
  // the ThirdPartyUtil.
  nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
    do_GetService(THIRDPARTYUTIL_CONTRACTID);
  if (thirdPartyUtil) {
    return thirdPartyUtil->GetBaseDomain(mCodebase, aBaseDomain);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsPrincipal::Read(nsIObjectInputStream* aStream)
{
  nsCOMPtr<nsISupports> supports;
  nsCOMPtr<nsIURI> codebase;
  nsresult rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
  if (NS_FAILED(rv)) {
    return rv;
  }

  codebase = do_QueryInterface(supports);

  nsCOMPtr<nsIURI> domain;
  rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
  if (NS_FAILED(rv)) {
    return rv;
  }

  domain = do_QueryInterface(supports);

  nsAutoCString suffix;
  rv = aStream->ReadCString(suffix);
  NS_ENSURE_SUCCESS(rv, rv);

  PrincipalOriginAttributes attrs;
  bool ok = attrs.PopulateFromSuffix(suffix);
  NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);

  rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = Init(codebase, attrs);
  NS_ENSURE_SUCCESS(rv, rv);

  mCSP = do_QueryInterface(supports, &rv);
  // make sure setRequestContext is called after Init(),
  // to make sure  the principals URI been initalized.
  if (mCSP) {
    mCSP->SetRequestContext(nullptr, this);
  }

  SetDomain(domain);

  return NS_OK;
}

NS_IMETHODIMP
nsPrincipal::Write(nsIObjectOutputStream* aStream)
{
  NS_ENSURE_STATE(mCodebase);
  nsresult rv = NS_WriteOptionalCompoundObject(aStream, mCodebase, NS_GET_IID(nsIURI),
                                               true);
  if (NS_FAILED(rv)) {
    return rv;
  }

  rv = NS_WriteOptionalCompoundObject(aStream, mDomain, NS_GET_IID(nsIURI),
                                      true);
  if (NS_FAILED(rv)) {
    return rv;
  }

  nsAutoCString suffix;
  OriginAttributesRef().CreateSuffix(suffix);

  rv = aStream->WriteStringZ(suffix.get());
  NS_ENSURE_SUCCESS(rv, rv);

  rv = NS_WriteOptionalCompoundObject(aStream, mCSP,
                                      NS_GET_IID(nsIContentSecurityPolicy),
                                      true);
  if (NS_FAILED(rv)) {
    return rv;
  }

  // mCodebaseImmutable and mDomainImmutable will be recomputed based
  // on the deserialized URIs in Read().

  return NS_OK;
}

// Helper-function to indicate whether the CSS Unprefixing Service
// whitelist should include dummy domains that are only intended for
// use in testing. (Controlled by a pref.)
static inline bool
IsWhitelistingTestDomains()
{
  return gIsWhitelistingTestDomains;
}

// Checks if the given URI's host is on our "full domain" whitelist
// (i.e. if it's an exact match against a domain that needs unprefixing)
static bool
IsOnFullDomainWhitelist(nsIURI* aURI)
{
  nsAutoCString hostStr;
  nsresult rv = aURI->GetHost(hostStr);
  NS_ENSURE_SUCCESS(rv, false);

  // NOTE: This static whitelist is expected to be short. If that changes,
  // we should consider a different representation; e.g. hash-set, prefix tree.
  static const nsLiteralCString sFullDomainsOnWhitelist[] = {
    // 0th entry only active when testing:
    NS_LITERAL_CSTRING("test1.example.org"),
    NS_LITERAL_CSTRING("map.baidu.com"),
    NS_LITERAL_CSTRING("3g.163.com"),
    NS_LITERAL_CSTRING("3glogo.gtimg.com"), // for 3g.163.com
    NS_LITERAL_CSTRING("info.3g.qq.com"), // for 3g.qq.com
    NS_LITERAL_CSTRING("3gimg.qq.com"), // for 3g.qq.com
    NS_LITERAL_CSTRING("img.m.baidu.com"), // for [shucheng|ks].baidu.com
    NS_LITERAL_CSTRING("m.mogujie.com"),
    NS_LITERAL_CSTRING("touch.qunar.com"),
    NS_LITERAL_CSTRING("mjs.sinaimg.cn"), // for sina.cn
    NS_LITERAL_CSTRING("static.qiyi.com"), // for m.iqiyi.com
    NS_LITERAL_CSTRING("cdn.kuaidi100.com"), // for m.kuaidi100.com
    NS_LITERAL_CSTRING("m.pc6.com"),
    NS_LITERAL_CSTRING("m.haosou.com"),
    NS_LITERAL_CSTRING("m.mi.com"),
    NS_LITERAL_CSTRING("wappass.baidu.com"),
    NS_LITERAL_CSTRING("m.video.baidu.com"),
    NS_LITERAL_CSTRING("m.video.baidu.com"),
    NS_LITERAL_CSTRING("imgcache.gtimg.cn"), // for m.v.qq.com
    NS_LITERAL_CSTRING("s.tabelog.jp"),
    NS_LITERAL_CSTRING("s.yimg.jp"), // for s.tabelog.jp
    NS_LITERAL_CSTRING("i.yimg.jp"), // for *.yahoo.co.jp
    NS_LITERAL_CSTRING("ai.yimg.jp"), // for *.yahoo.co.jp
    NS_LITERAL_CSTRING("m.finance.yahoo.co.jp"),
    NS_LITERAL_CSTRING("daily.c.yimg.jp"), // for sp.daily.co.jp
    NS_LITERAL_CSTRING("stat100.ameba.jp"), // for ameblo.jp
    NS_LITERAL_CSTRING("user.ameba.jp"), // for ameblo.jp
    NS_LITERAL_CSTRING("www.goo.ne.jp"),
    NS_LITERAL_CSTRING("x.gnst.jp"), // for mobile.gnavi.co.jp
    NS_LITERAL_CSTRING("c.x.gnst.jp"), // for mobile.gnavi.co.jp
    NS_LITERAL_CSTRING("www.smbc-card.com"),
    NS_LITERAL_CSTRING("static.card.jp.rakuten-static.com"), // for rakuten-card.co.jp
    NS_LITERAL_CSTRING("img.travel.rakuten.co.jp"), // for travel.rakuten.co.jp
    NS_LITERAL_CSTRING("img.mixi.net"), // for mixi.jp
    NS_LITERAL_CSTRING("girlschannel.net"),
    NS_LITERAL_CSTRING("www.fancl.co.jp"),
    NS_LITERAL_CSTRING("s.cosme.net"),
    NS_LITERAL_CSTRING("www.sapporobeer.jp"),
    NS_LITERAL_CSTRING("www.mapion.co.jp"),
    NS_LITERAL_CSTRING("touch.navitime.co.jp"),
    NS_LITERAL_CSTRING("sp.mbga.jp"),
    NS_LITERAL_CSTRING("ava-a.sp.mbga.jp"), // for sp.mbga.jp
    NS_LITERAL_CSTRING("www.ntv.co.jp"),
    NS_LITERAL_CSTRING("mobile.suntory.co.jp"), // for suntory.jp
    NS_LITERAL_CSTRING("www.aeonsquare.net"),
    NS_LITERAL_CSTRING("mw.nikkei.com"),
    NS_LITERAL_CSTRING("www.nhk.or.jp"),
    NS_LITERAL_CSTRING("www.tokyo-sports.co.jp"),
    NS_LITERAL_CSTRING("www.bellemaison.jp"),
    NS_LITERAL_CSTRING("www.kuronekoyamato.co.jp"),
    NS_LITERAL_CSTRING("formassist.jp"), // for orico.jp
    NS_LITERAL_CSTRING("sp.m.reuters.co.jp"),
    NS_LITERAL_CSTRING("www.atre.co.jp"),
    NS_LITERAL_CSTRING("www.jtb.co.jp"),
    NS_LITERAL_CSTRING("www.sharp.co.jp"),
    NS_LITERAL_CSTRING("www.biccamera.com"),
    NS_LITERAL_CSTRING("weathernews.jp"),
    NS_LITERAL_CSTRING("cache.ymail.jp"), // for www.yamada-denkiweb.com
  };
  static const size_t sNumFullDomainsOnWhitelist =
    MOZ_ARRAY_LENGTH(sFullDomainsOnWhitelist);

  // Skip 0th (dummy) entry in whitelist, unless a pref is enabled.
  const size_t firstWhitelistIdx = IsWhitelistingTestDomains() ? 0 : 1;

  for (size_t i = firstWhitelistIdx; i < sNumFullDomainsOnWhitelist; ++i) {
    if (hostStr == sFullDomainsOnWhitelist[i]) {
      return true;
    }
  }
  return false;
}

// Checks if the given URI's host is on our "base domain" whitelist
// (i.e. if it's a subdomain of some host that we've whitelisted as needing
// unprefixing for all its subdomains)
static bool
IsOnBaseDomainWhitelist(nsIURI* aURI)
{
  static const nsLiteralCString sBaseDomainsOnWhitelist[] = {
    // 0th entry only active when testing:
    NS_LITERAL_CSTRING("test2.example.org"),
    NS_LITERAL_CSTRING("tbcdn.cn"), // for m.taobao.com
    NS_LITERAL_CSTRING("alicdn.com"), // for m.taobao.com
    NS_LITERAL_CSTRING("dpfile.com"), // for m.dianping.com
    NS_LITERAL_CSTRING("hao123img.com"), // for hao123.com
    NS_LITERAL_CSTRING("tabelog.k-img.com"), // for s.tabelog.com
    NS_LITERAL_CSTRING("tsite.jp"), // for *.tsite.jp
  };
  static const size_t sNumBaseDomainsOnWhitelist =
    MOZ_ARRAY_LENGTH(sBaseDomainsOnWhitelist);

  nsCOMPtr<nsIEffectiveTLDService> tldService =
    do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);

  if (tldService) {
    // Skip 0th test-entry in whitelist, unless the testing pref is enabled.
    const size_t firstWhitelistIdx = IsWhitelistingTestDomains() ? 0 : 1;

    // Right now, the test base-domain "test2.example.org" is the only entry in
    // its whitelist with a nonzero "depth". So we'll only bother going beyond
    // 0 depth (to 1) if that entry is enabled. (No point in slowing down the
    // normal codepath, for the benefit of a disabled test domain.)  If we add a
    // "real" base-domain with a depth of >= 1 to our whitelist, we can get rid
    // of this conditional & just make this a static variable.
    const uint32_t maxSubdomainDepth = IsWhitelistingTestDomains() ? 1 : 0;

    for (uint32_t subdomainDepth = 0;
         subdomainDepth <= maxSubdomainDepth; ++subdomainDepth) {

      // Get the base domain (to depth |subdomainDepth|) from passed-in URI:
      nsAutoCString baseDomainStr;
      nsresult rv = tldService->GetBaseDomain(aURI, subdomainDepth,
                                              baseDomainStr);
      if (NS_FAILED(rv)) {
        // aURI doesn't have |subdomainDepth| levels of subdomains. If we got
        // here without a match yet, then aURI is not on our whitelist.
        return false;
      }

      // Compare the base domain against each entry in our whitelist:
      for (size_t i = firstWhitelistIdx; i < sNumBaseDomainsOnWhitelist; ++i) {
        if (baseDomainStr == sBaseDomainsOnWhitelist[i]) {
          return true;
        }
      }
    }
  }

  return false;
}

// The actual (non-cached) implementation of IsOnCSSUnprefixingWhitelist():
static bool
IsOnCSSUnprefixingWhitelistImpl(nsIURI* aURI)
{
  // Check scheme, so we can drop any non-HTTP/HTTPS URIs right away
  nsAutoCString schemeStr;
  nsresult rv = aURI->GetScheme(schemeStr);
  NS_ENSURE_SUCCESS(rv, false);

  // Only proceed if scheme is "http" or "https"
  if (!(StringBeginsWith(schemeStr, NS_LITERAL_CSTRING("http")) &&
        (schemeStr.Length() == 4 ||
         (schemeStr.Length() == 5 && schemeStr[4] == 's')))) {
    return false;
  }

  return (IsOnFullDomainWhitelist(aURI) ||
          IsOnBaseDomainWhitelist(aURI));
}


bool
nsPrincipal::IsOnCSSUnprefixingWhitelist()
{
  if (mIsOnCSSUnprefixingWhitelist.isNothing()) {
    // Value not cached -- perform our lazy whitelist-check.
    // (NOTE: If our URI is mutable, we just assume it's not on the whitelist,
    // since our caching strategy won't work. This isn't expected to be common.)
    mIsOnCSSUnprefixingWhitelist.emplace(
      mCodebaseImmutable &&
      IsOnCSSUnprefixingWhitelistImpl(mCodebase));
  }

  return *mIsOnCSSUnprefixingWhitelist;
}

/************************************************************************************************************************/

NS_IMPL_CLASSINFO(nsExpandedPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
                  NS_EXPANDEDPRINCIPAL_CID)
NS_IMPL_QUERY_INTERFACE_CI(nsExpandedPrincipal,
                           nsIPrincipal,
                           nsIExpandedPrincipal)
NS_IMPL_CI_INTERFACE_GETTER(nsExpandedPrincipal,
                             nsIPrincipal,
                             nsIExpandedPrincipal)

struct OriginComparator
{
  bool LessThan(nsIPrincipal* a, nsIPrincipal* b) const
  {
    nsAutoCString originA;
    nsresult rv = a->GetOrigin(originA);
    NS_ENSURE_SUCCESS(rv, false);
    nsAutoCString originB;
    rv = b->GetOrigin(originB);
    NS_ENSURE_SUCCESS(rv, false);
    return originA < originB;
  }

  bool Equals(nsIPrincipal* a, nsIPrincipal* b) const
  {
    nsAutoCString originA;
    nsresult rv = a->GetOrigin(originA);
    NS_ENSURE_SUCCESS(rv, false);
    nsAutoCString originB;
    rv = b->GetOrigin(originB);
    NS_ENSURE_SUCCESS(rv, false);
    return a == b;
  }
};

nsExpandedPrincipal::nsExpandedPrincipal(nsTArray<nsCOMPtr <nsIPrincipal> > &aWhiteList)
{
  // We force the principals to be sorted by origin so that nsExpandedPrincipal
  // origins can have a canonical form.
  OriginComparator c;
  for (size_t i = 0; i < aWhiteList.Length(); ++i) {
    mPrincipals.InsertElementSorted(aWhiteList[i], c);
  }
}

nsExpandedPrincipal::~nsExpandedPrincipal()
{ }

NS_IMETHODIMP
nsExpandedPrincipal::GetDomain(nsIURI** aDomain)
{
  *aDomain = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
nsExpandedPrincipal::SetDomain(nsIURI* aDomain)
{
  return NS_OK;
}

nsresult
nsExpandedPrincipal::GetOriginInternal(nsACString& aOrigin)
{
  aOrigin.AssignLiteral("[Expanded Principal [");
  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
    if (i != 0) {
      aOrigin.AppendLiteral(", ");
    }

    nsAutoCString subOrigin;
    nsresult rv = mPrincipals.ElementAt(i)->GetOrigin(subOrigin);
    NS_ENSURE_SUCCESS(rv, rv);
    aOrigin.Append(subOrigin);
  }

  aOrigin.Append("]]");
  return NS_OK;
}

bool
nsExpandedPrincipal::SubsumesInternal(nsIPrincipal* aOther,
                                      BasePrincipal::DocumentDomainConsideration aConsideration)
{
  // If aOther is an ExpandedPrincipal too, we break it down into its component
  // nsIPrincipals, and check subsumes on each one.
  nsCOMPtr<nsIExpandedPrincipal> expanded = do_QueryInterface(aOther);
  if (expanded) {
    nsTArray< nsCOMPtr<nsIPrincipal> >* otherList;
    expanded->GetWhiteList(&otherList);
    for (uint32_t i = 0; i < otherList->Length(); ++i){
      if (!SubsumesInternal((*otherList)[i], aConsideration)) {
        return false;
      }
    }
    return true;
  }

  // We're dealing with a regular principal. One of our principals must subsume
  // it.
  for (uint32_t i = 0; i < mPrincipals.Length(); ++i) {
    if (Cast(mPrincipals[i])->Subsumes(aOther, aConsideration)) {
      return true;
    }
  }

  return false;
}

bool
nsExpandedPrincipal::MayLoadInternal(nsIURI* uri)
{
  for (uint32_t i = 0; i < mPrincipals.Length(); ++i){
    if (BasePrincipal::Cast(mPrincipals[i])->MayLoadInternal(uri)) {
      return true;
    }
  }

  return false;
}

NS_IMETHODIMP
nsExpandedPrincipal::GetHashValue(uint32_t* result)
{
  MOZ_CRASH("extended principal should never be used as key in a hash map");
}

NS_IMETHODIMP
nsExpandedPrincipal::GetURI(nsIURI** aURI)
{
  *aURI = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
nsExpandedPrincipal::GetWhiteList(nsTArray<nsCOMPtr<nsIPrincipal> >** aWhiteList)
{
  *aWhiteList = &mPrincipals;
  return NS_OK;
}

NS_IMETHODIMP
nsExpandedPrincipal::GetBaseDomain(nsACString& aBaseDomain)
{
  return NS_ERROR_NOT_AVAILABLE;
}

bool
nsExpandedPrincipal::IsOnCSSUnprefixingWhitelist()
{
  // CSS Unprefixing Whitelist is a per-origin thing; doesn't really make sense
  // for an expanded principal. (And probably shouldn't be needed.)
  return false;
}


void
nsExpandedPrincipal::GetScriptLocation(nsACString& aStr)
{
  aStr.Assign("[Expanded Principal [");
  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
    if (i != 0) {
      aStr.AppendLiteral(", ");
    }

    nsAutoCString spec;
    nsJSPrincipals::get(mPrincipals.ElementAt(i))->GetScriptLocation(spec);

    aStr.Append(spec);

  }
  aStr.Append("]]");
}

//////////////////////////////////////////
// Methods implementing nsISerializable //
//////////////////////////////////////////

NS_IMETHODIMP
nsExpandedPrincipal::Read(nsIObjectInputStream* aStream)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsExpandedPrincipal::Write(nsIObjectOutputStream* aStream)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}