gecko-dev/caps/ExpandedPrincipal.cpp
Luca Greco 635e7a7358 Bug 1741600 - Fix ExpandedPrincipal and nsCSPContext leaks triggered by ApplyAddonContentScriptCSP. r=ckerschb,robwu
This patch is meant to be a proposed short run fix to prevent ApplyAddonContentScriptCSP
from leaking the ExpandedPrincipal and nsCSPContext instance because they keep a reference
to each other.
This patch prevent that leak by creating a clone of the ExpandedPrincipal and then use
that cloned instance in the call to nsCSPContext::SetRequestContextWithPrincipal.

Once Bug 1548468 will move the CSP off the ExpandedPrincipal class, cloning the expanded
principal to prevent that leak should not be necessary anymore.

Differential Revision: https://phabricator.services.mozilla.com/D132144
2021-11-26 15:51:13 +00:00

383 lines
12 KiB
C++

/* -*- 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 "ExpandedPrincipal.h"
#include "nsIClassInfoImpl.h"
#include "nsIObjectInputStream.h"
#include "nsReadableUtils.h"
#include "mozilla/Base64.h"
#include "json/json.h"
using namespace mozilla;
NS_IMPL_CLASSINFO(ExpandedPrincipal, nullptr, nsIClassInfo::MAIN_THREAD_ONLY,
NS_EXPANDEDPRINCIPAL_CID)
NS_IMPL_QUERY_INTERFACE_CI(ExpandedPrincipal, nsIPrincipal,
nsIExpandedPrincipal)
NS_IMPL_CI_INTERFACE_GETTER(ExpandedPrincipal, nsIPrincipal,
nsIExpandedPrincipal)
struct OriginComparator {
bool LessThan(nsIPrincipal* a, nsIPrincipal* b) const {
nsAutoCString originA;
DebugOnly<nsresult> rv = a->GetOrigin(originA);
MOZ_ASSERT(NS_SUCCEEDED(rv));
nsAutoCString originB;
rv = b->GetOrigin(originB);
MOZ_ASSERT(NS_SUCCEEDED(rv));
return originA < originB;
}
bool Equals(nsIPrincipal* a, nsIPrincipal* b) const {
nsAutoCString originA;
DebugOnly<nsresult> rv = a->GetOrigin(originA);
MOZ_ASSERT(NS_SUCCEEDED(rv));
nsAutoCString originB;
rv = b->GetOrigin(originB);
MOZ_ASSERT(NS_SUCCEEDED(rv));
return a == b;
}
};
ExpandedPrincipal::ExpandedPrincipal(
nsTArray<nsCOMPtr<nsIPrincipal>>&& aPrincipals,
const nsACString& aOriginNoSuffix, const OriginAttributes& aAttrs)
: BasePrincipal(eExpandedPrincipal, aOriginNoSuffix, aAttrs),
mPrincipals(std::move(aPrincipals)) {}
ExpandedPrincipal::~ExpandedPrincipal() = default;
already_AddRefed<ExpandedPrincipal> ExpandedPrincipal::Create(
const nsTArray<nsCOMPtr<nsIPrincipal>>& aAllowList,
const OriginAttributes& aAttrs) {
// We force the principals to be sorted by origin so that ExpandedPrincipal
// origins can have a canonical form.
nsTArray<nsCOMPtr<nsIPrincipal>> principals;
OriginComparator c;
for (size_t i = 0; i < aAllowList.Length(); ++i) {
principals.InsertElementSorted(aAllowList[i], c);
}
nsAutoCString origin;
origin.AssignLiteral("[Expanded Principal [");
StringJoinAppend(
origin, ", "_ns, principals,
[](nsACString& dest, const nsCOMPtr<nsIPrincipal>& principal) {
nsAutoCString subOrigin;
DebugOnly<nsresult> rv = principal->GetOrigin(subOrigin);
MOZ_ASSERT(NS_SUCCEEDED(rv));
dest.Append(subOrigin);
});
origin.AppendLiteral("]]");
RefPtr<ExpandedPrincipal> ep =
new ExpandedPrincipal(std::move(principals), origin, aAttrs);
return ep.forget();
}
NS_IMETHODIMP
ExpandedPrincipal::GetDomain(nsIURI** aDomain) {
*aDomain = nullptr;
return NS_OK;
}
NS_IMETHODIMP
ExpandedPrincipal::SetDomain(nsIURI* aDomain) { return NS_OK; }
bool ExpandedPrincipal::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.
if (Cast(aOther)->Is<ExpandedPrincipal>()) {
auto* expanded = Cast(aOther)->As<ExpandedPrincipal>();
for (auto& other : expanded->AllowList()) {
// Use SubsumesInternal rather than Subsumes here, since OriginAttribute
// checks are only done between non-expanded sub-principals, and we don't
// need to incur the extra virtual call overhead.
if (!SubsumesInternal(other, 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 ExpandedPrincipal::MayLoadInternal(nsIURI* uri) {
for (uint32_t i = 0; i < mPrincipals.Length(); ++i) {
if (BasePrincipal::Cast(mPrincipals[i])->MayLoadInternal(uri)) {
return true;
}
}
return false;
}
uint32_t ExpandedPrincipal::GetHashValue() {
MOZ_CRASH("extended principal should never be used as key in a hash map");
}
NS_IMETHODIMP
ExpandedPrincipal::GetURI(nsIURI** aURI) {
*aURI = nullptr;
return NS_OK;
}
const nsTArray<nsCOMPtr<nsIPrincipal>>& ExpandedPrincipal::AllowList() {
return mPrincipals;
}
NS_IMETHODIMP
ExpandedPrincipal::GetBaseDomain(nsACString& aBaseDomain) {
return NS_ERROR_NOT_AVAILABLE;
}
NS_IMETHODIMP
ExpandedPrincipal::GetAddonId(nsAString& aAddonId) {
aAddonId.Truncate();
return NS_OK;
};
bool ExpandedPrincipal::AddonHasPermission(const nsAtom* aPerm) {
for (size_t i = 0; i < mPrincipals.Length(); ++i) {
if (BasePrincipal::Cast(mPrincipals[i])->AddonHasPermission(aPerm)) {
return true;
}
}
return false;
}
bool ExpandedPrincipal::AddonAllowsLoad(nsIURI* aURI,
bool aExplicit /* = false */) {
for (const auto& principal : mPrincipals) {
if (Cast(principal)->AddonAllowsLoad(aURI, aExplicit)) {
return true;
}
}
return false;
}
void ExpandedPrincipal::SetCsp(nsIContentSecurityPolicy* aCSP) { mCSP = aCSP; }
NS_IMETHODIMP
ExpandedPrincipal::GetCsp(nsIContentSecurityPolicy** aCsp) {
NS_IF_ADDREF(*aCsp = mCSP);
return NS_OK;
}
nsIPrincipal* ExpandedPrincipal::PrincipalToInherit(nsIURI* aRequestedURI) {
if (aRequestedURI) {
// If a given sub-principal subsumes the given URI, use that principal for
// inheritance. In general, this only happens with certain CORS modes, loads
// with forced principal inheritance, and creation of XML documents from
// XMLHttpRequests or fetch requests. For URIs that normally inherit a
// principal (such as data: URIs), we fall back to the last principal in the
// allowlist.
for (const auto& principal : mPrincipals) {
if (Cast(principal)->MayLoadInternal(aRequestedURI)) {
return principal;
}
}
}
return mPrincipals.LastElement();
}
nsresult ExpandedPrincipal::GetScriptLocation(nsACString& aStr) {
aStr.AssignLiteral("[Expanded Principal [");
for (size_t i = 0; i < mPrincipals.Length(); ++i) {
if (i != 0) {
aStr.AppendLiteral(", ");
}
nsAutoCString spec;
nsresult rv =
nsJSPrincipals::get(mPrincipals.ElementAt(i))->GetScriptLocation(spec);
NS_ENSURE_SUCCESS(rv, rv);
aStr.Append(spec);
}
aStr.AppendLiteral("]]");
return NS_OK;
}
//////////////////////////////////////////
// Methods implementing nsISerializable //
//////////////////////////////////////////
// We've had way too many issues with unversioned serializations, so
// explicitly version this one.
static const uint32_t kSerializationVersion = 1;
NS_IMETHODIMP
ExpandedPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
uint32_t version;
nsresult rv = aStream->Read32(&version);
if (version != kSerializationVersion) {
MOZ_ASSERT(false,
"We really need to add handling of the old(?) version here");
return NS_ERROR_UNEXPECTED;
}
uint32_t count;
rv = aStream->Read32(&count);
if (NS_FAILED(rv)) {
return rv;
}
nsTArray<nsCOMPtr<nsIPrincipal>> principals;
if (!principals.SetCapacity(count, fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
OriginComparator c;
for (uint32_t i = 0; i < count; ++i) {
nsCOMPtr<nsISupports> read;
rv = aStream->ReadObject(true, getter_AddRefs(read));
if (NS_FAILED(rv)) {
return rv;
}
nsCOMPtr<nsIPrincipal> principal = do_QueryInterface(read);
if (!principal) {
return NS_ERROR_UNEXPECTED;
}
// Play it safe and InsertElementSorted, in case the sort order
// changed for some bizarre reason.
principals.InsertElementSorted(std::move(principal), c);
}
mPrincipal = ExpandedPrincipal::Create(principals, OriginAttributes());
return NS_OK;
}
nsresult ExpandedPrincipal::GetSiteIdentifier(SiteIdentifier& aSite) {
// Call GetSiteIdentifier on each of our principals and return a new
// ExpandedPrincipal.
nsTArray<nsCOMPtr<nsIPrincipal>> allowlist;
for (const auto& principal : mPrincipals) {
SiteIdentifier site;
nsresult rv = Cast(principal)->GetSiteIdentifier(site);
NS_ENSURE_SUCCESS(rv, rv);
allowlist.AppendElement(site.GetPrincipal());
}
RefPtr<ExpandedPrincipal> expandedPrincipal =
ExpandedPrincipal::Create(allowlist, OriginAttributesRef());
MOZ_ASSERT(expandedPrincipal, "ExpandedPrincipal::Create returned nullptr?");
aSite.Init(expandedPrincipal);
return NS_OK;
}
nsresult ExpandedPrincipal::PopulateJSONObject(Json::Value& aObject) {
nsAutoCString principalList;
// First item through we have a blank separator and append the next result
nsAutoCString sep;
for (auto& principal : mPrincipals) {
nsAutoCString JSON;
BasePrincipal::Cast(principal)->ToJSON(JSON);
// This is blank for the first run through so the last in the list doesn't
// add a separator
principalList.Append(sep);
sep = ',';
// Values currently only copes with strings so encode into base64 to allow a
// CSV safely.
nsresult rv;
rv = Base64EncodeAppend(JSON, principalList);
NS_ENSURE_SUCCESS(rv, rv);
}
aObject[std::to_string(eSpecs)] = principalList.get();
nsAutoCString suffix;
OriginAttributesRef().CreateSuffix(suffix);
if (suffix.Length() > 0) {
aObject[std::to_string(eSuffix)] = suffix.get();
}
return NS_OK;
}
already_AddRefed<BasePrincipal> ExpandedPrincipal::FromProperties(
nsTArray<ExpandedPrincipal::KeyVal>& aFields) {
MOZ_ASSERT(aFields.Length() == eMax + 1, "Must have all the keys");
nsTArray<nsCOMPtr<nsIPrincipal>> allowList;
OriginAttributes attrs;
// The odd structure here is to make the code to not compile
// if all the switch enum cases haven't been codified
for (const auto& field : aFields) {
switch (field.key) {
case ExpandedPrincipal::eSpecs:
if (!field.valueWasSerialized) {
MOZ_ASSERT(false,
"Expanded principals require specs in serialized JSON");
return nullptr;
}
for (const nsACString& each : field.value.Split(',')) {
nsAutoCString result;
nsresult rv;
rv = Base64Decode(each, result);
MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to decode");
NS_ENSURE_SUCCESS(rv, nullptr);
nsCOMPtr<nsIPrincipal> principal = BasePrincipal::FromJSON(result);
allowList.AppendElement(principal);
}
break;
case ExpandedPrincipal::eSuffix:
if (field.valueWasSerialized) {
bool ok = attrs.PopulateFromSuffix(field.value);
if (!ok) {
return nullptr;
}
}
break;
}
}
if (allowList.Length() == 0) {
return nullptr;
}
RefPtr<ExpandedPrincipal> expandedPrincipal =
ExpandedPrincipal::Create(allowList, attrs);
return expandedPrincipal.forget();
}
NS_IMETHODIMP
ExpandedPrincipal::IsThirdPartyURI(nsIURI* aURI, bool* aRes) {
// ExpandedPrincipal for extension content scripts consist of two principals,
// the document's principal and the extension's principal.
// To make sure that the third-party check behaves like the web page on which
// the content script is running, ignore the extension's principal.
for (const auto& principal : mPrincipals) {
if (!Cast(principal)->AddonPolicy()) {
return Cast(principal)->IsThirdPartyURI(aURI, aRes);
}
}
if (mPrincipals.IsEmpty()) {
*aRes = true;
return NS_OK;
}
return Cast(mPrincipals[0])->IsThirdPartyURI(aURI, aRes);
}