caps/ContentPrincipal.cpp
author Jim Chen <nchen@mozilla.com>
Wed, 20 Jun 2018 16:46:20 -0400
changeset 423113 2806729c61eaac199ad4670788c4008079a99f34
parent 418635 7cef5b202339fb6b687fa921ccd438f17714d07d
child 428158 b2a1cd818cf294a278570c4eeb1d03f7f5520976
permissions -rw-r--r--
Bug 1469683 - 1. Fix crash tests; r=esawin Specify individual sessions in crash tests (i.e. "mainSession.waitUntilCalled" instead of "sessionRule.waitUntilCalled"), so that the tests assert behavior on the correct session, and not inadvertently on the cached session. Also, under x86 debug builds, Gecko installs an "ah_crap_handler" for SIGSEGV that waits for a long time, which causes our crash tests to time out. Therefore, ignore crash tests under x86 debug. MozReview-Commit-ID: DdtmRBLmPGp

/* -*- 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 "ContentPrincipal.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 "nsIObjectInputStream.h"
#include "nsIObjectOutputStream.h"
#include "nsIProtocolHandler.h"
#include "nsError.h"
#include "nsIContentSecurityPolicy.h"
#include "nsNetCID.h"
#include "js/Wrapper.h"

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

using namespace mozilla;

static inline ExtensionPolicyService&
EPS()
{
  return ExtensionPolicyService::GetSingleton();
}

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

ContentPrincipal::ContentPrincipal()
  : BasePrincipal(eCodebasePrincipal)
{
}

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

nsresult
ContentPrincipal::Init(nsIURI *aCodebase,
                       const OriginAttributes& aOriginAttributes,
                       const nsACString& aOriginNoSuffix)
{
  NS_ENSURE_ARG(aCodebase);

  // Assert that the URI we get here isn't any of the schemes that we know we
  // should not get here.  These schemes always either inherit their principal
  // or fall back to a null principal.  These are schemes which return
  // URI_INHERITS_SECURITY_CONTEXT from their protocol handler's
  // GetProtocolFlags function.
  bool hasFlag;
  Unused << hasFlag; // silence possible compiler warnings.
  MOZ_DIAGNOSTIC_ASSERT(
      NS_SUCCEEDED(NS_URIChainHasFlags(aCodebase,
                                       nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT,
                                       &hasFlag)) &&
      !hasFlag);

  mCodebase = aCodebase;
  FinishInit(aOriginNoSuffix, aOriginAttributes);

  return NS_OK;
}

nsresult
ContentPrincipal::GetScriptLocation(nsACString &aStr)
{
  return mCodebase->GetSpec(aStr);
}

/* static */ nsresult
ContentPrincipal::GenerateOriginNoSuffixFromURI(nsIURI* aURI,
                                                nsACString& aOriginNoSuffix)
{
  if (!aURI) {
    return NS_ERROR_FAILURE;
  }

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

  MOZ_ASSERT(!NS_IsAboutBlank(origin),
             "The inner URI for about:blank must be moz-safe-about:blank");

  // Handle non-strict file:// uris.
  if (!nsScriptSecurityManager::GetStrictFileOriginPolicy() &&
      NS_URIIsLocalFile(origin)) {
    // If strict file origin policy is not in effect, all local files are
    // considered to be same-origin, so return a known dummy origin here.
    aOriginNoSuffix.AssignLiteral("file://UNIVERSAL_FILE_URI_ORIGIN");
    return NS_OK;
  }


  nsresult rv;
// NB: This is only compiled for Thunderbird/Suite.
#if IS_ORIGIN_IS_FULL_SPEC_DEFINED
  bool fullSpec = false;
  rv = NS_URIChainHasFlags(origin, nsIProtocolHandler::ORIGIN_IS_FULL_SPEC, &fullSpec);
  NS_ENSURE_SUCCESS(rv, rv);
  if (fullSpec) {
    return origin->GetAsciiSpec(aOriginNoSuffix);
  }
#endif

  // 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 &&
       // We generally consider two about:foo origins to be same-origin, but
       // about:blank is special since it can be generated from different sources.
       // We check for moz-safe-about:blank since origin is an innermost URI.
       !origin->GetSpecOrDefault().EqualsLiteral("moz-safe-about:blank")) ||
      (NS_SUCCEEDED(origin->SchemeIs("indexeddb", &isBehaved)) && isBehaved)) {
    rv = origin->GetAsciiSpec(aOriginNoSuffix);
    NS_ENSURE_SUCCESS(rv, rv);
    // These URIs could technically contain a '^', but they never should.
    if (NS_WARN_IF(aOriginNoSuffix.FindChar('^', 0) != -1)) {
      aOriginNoSuffix.Truncate();
      return NS_ERROR_FAILURE;
    }
    return NS_OK;
  }

  // This URL can be a blobURL. In this case, we should use the 'parent'
  // principal instead.
  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(origin);
  if (uriWithPrincipal) {
    nsCOMPtr<nsIPrincipal> uriPrincipal;
    rv = uriWithPrincipal->GetPrincipal(getter_AddRefs(uriPrincipal));
    NS_ENSURE_SUCCESS(rv, rv);

    if (uriPrincipal) {
      return uriPrincipal->GetOriginNoSuffix(aOriginNoSuffix);
    }
  }

  // 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);
  if (!standardURL) {
    return NS_ERROR_FAILURE;
  }

  // See whether we have a useful hostPort. If we do, use that.
  nsAutoCString hostPort;
  bool isChrome = false;
  rv = origin->SchemeIs("chrome", &isChrome);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!isChrome) {
    rv = origin->GetAsciiHostPort(hostPort);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  if (!hostPort.IsEmpty()) {
    rv = origin->GetScheme(aOriginNoSuffix);
    NS_ENSURE_SUCCESS(rv, rv);
    aOriginNoSuffix.AppendLiteral("://");
    aOriginNoSuffix.Append(hostPort);
    return NS_OK;
  }

  rv = aURI->GetAsciiSpec(aOriginNoSuffix);
  NS_ENSURE_SUCCESS(rv, rv);

  // The origin, when taken from the spec, should not contain the ref part of
  // the URL.

  int32_t pos = aOriginNoSuffix.FindChar('?');
  int32_t hashPos = aOriginNoSuffix.FindChar('#');

  if (hashPos != kNotFound && (pos == kNotFound || hashPos < pos)) {
    pos = hashPos;
  }

  if (pos != kNotFound) {
    aOriginNoSuffix.Truncate(pos);
  }

  return NS_OK;
}

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

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

  // 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
ContentPrincipal::GetURI(nsIURI** aURI)
{
  NS_ADDREF(*aURI = mCodebase);
  return NS_OK;
}

bool
ContentPrincipal::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;
}

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

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

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

  NS_ADDREF(*aDomain = mDomain);
  return NS_OK;
}

NS_IMETHODIMP
ContentPrincipal::SetDomain(nsIURI* aDomain)
{
  mDomain = aDomain;
  SetHasExplicitDomain();

  // 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
ContentPrincipal::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;
}

WebExtensionPolicy*
ContentPrincipal::AddonPolicy()
{
  if (!mAddon.isSome()) {
    NS_ENSURE_TRUE(mCodebase, nullptr);

    bool isMozExt;
    if (NS_SUCCEEDED(mCodebase->SchemeIs("moz-extension", &isMozExt)) && isMozExt) {
      mAddon.emplace(EPS().GetByURL(mCodebase.get()));
    } else {
      mAddon.emplace(nullptr);
    }
  }

  return mAddon.value();
}

NS_IMETHODIMP
ContentPrincipal::GetAddonId(nsAString& aAddonId)
{
  auto policy = AddonPolicy();
  if (policy) {
    policy->GetId(aAddonId);
  } else {
    aAddonId.Truncate();
  }
  return NS_OK;
}

NS_IMETHODIMP
ContentPrincipal::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);
  // Enforce re-parsing about: URIs so that if they change, we continue to use
  // their new principals correctly.
  bool isAbout = false;
  if (NS_SUCCEEDED(codebase->SchemeIs("about", &isAbout)) && isAbout) {
    nsAutoCString spec;
    codebase->GetSpec(spec);
    NS_ENSURE_SUCCESS(NS_NewURI(getter_AddRefs(codebase), spec), NS_ERROR_FAILURE);
  }

  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);

  OriginAttributes 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);

  nsAutoCString originNoSuffix;
  rv = GenerateOriginNoSuffixFromURI(codebase, originNoSuffix);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = Init(codebase, attrs, originNoSuffix);
  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
ContentPrincipal::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;
  }

  return NS_OK;
}