gecko-dev/dom/u2f/U2F.cpp
Nicholas Nethercote 34dcc7b852 Bug 1299384 - Use MOZ_MUST_USE with NS_warn_if_impl(). r=erahm.
This change avoids lots of false positives for Coverity's CHECKED_RETURN
warning, caused by NS_WARN_IF's current use in both statement-style and
expression-style.

In the case where the code within the NS_WARN_IF has side-effects, I made the
following change.

> NS_WARN_IF(NS_FAILED(FunctionWithSideEffects()));
> -->
> Unused << NS_WARN_IF(NS_FAILED(FunctionWithSideEffects()));

In the case where the code within the NS_WARN_IF lacks side-effects, I made the
following change.

> NS_WARN_IF(!condWithoutSideEffects);
> -->
> NS_WARNING_ASSERTION(condWithoutSideEffects, "msg");

This has two improvements.
- The condition is not evaluated in non-debug builds.
- The sense of the condition is inverted to the familiar "this condition should
  be true" sense used in assertions.

A common variation on the side-effect-free case is the following.

> nsresult rv = Fn();
> NS_WARN_IF_(NS_FAILED(rv));
> -->
> DebugOnly<nsresult rv> = Fn();
> NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Fn failed");

--HG--
extra : rebase_source : 58788245021096efa8372a9dc1d597a611d45611
2016-09-02 17:12:24 +10:00

660 lines
20 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 "hasht.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/CryptoBuffer.h"
#include "mozilla/dom/NSSU2FTokenRemote.h"
#include "mozilla/dom/U2F.h"
#include "mozilla/dom/U2FBinding.h"
#include "mozilla/Preferences.h"
#include "nsContentUtils.h"
#include "nsINSSU2FToken.h"
#include "nsNetCID.h"
#include "nsNSSComponent.h"
#include "nsURLParsers.h"
#include "pk11pub.h"
using mozilla::dom::ContentChild;
namespace mozilla {
namespace dom {
#define PREF_U2F_SOFTTOKEN_ENABLED "security.webauth.u2f_enable_softtoken"
#define PREF_U2F_USBTOKEN_ENABLED "security.webauth.u2f_enable_usbtoken"
NS_NAMED_LITERAL_STRING(kFinishEnrollment, "navigator.id.finishEnrollment");
NS_NAMED_LITERAL_STRING(kGetAssertion, "navigator.id.getAssertion");
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(U2F)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(U2F)
NS_IMPL_CYCLE_COLLECTING_RELEASE(U2F)
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(U2F, mParent)
static mozilla::LazyLogModule gWebauthLog("webauth_u2f");
template <class CB, class Rsp>
void
SendError(CB* aCallback, ErrorCode aErrorCode)
{
Rsp response;
response.mErrorCode.Construct(static_cast<uint32_t>(aErrorCode));
ErrorResult rv;
aCallback->Call(response, rv);
NS_WARNING_ASSERTION(!rv.Failed(), "callback failed");
// Useful exceptions already got reported.
rv.SuppressException();
}
static nsresult
AssembleClientData(const nsAString& aOrigin, const nsAString& aTyp,
const nsAString& aChallenge, CryptoBuffer& aClientData)
{
ClientData clientDataObject;
clientDataObject.mTyp.Construct(aTyp); // "Typ" from the U2F specification
clientDataObject.mChallenge.Construct(aChallenge);
clientDataObject.mOrigin.Construct(aOrigin);
nsAutoString json;
if (NS_WARN_IF(!clientDataObject.ToJSON(json))) {
return NS_ERROR_FAILURE;
}
if (NS_WARN_IF(!aClientData.Assign(NS_ConvertUTF16toUTF8(json)))) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
U2FTask::U2FTask(const nsAString& aOrigin, const nsAString& aAppId)
: mOrigin(aOrigin)
, mAppId(aAppId)
{}
U2FTask::~U2FTask()
{}
U2FRegisterTask::U2FRegisterTask(const nsAString& aOrigin,
const nsAString& aAppId,
const Sequence<RegisterRequest>& aRegisterRequests,
const Sequence<RegisteredKey>& aRegisteredKeys,
U2FRegisterCallback* aCallback,
const Sequence<Authenticator>& aAuthenticators)
: U2FTask(aOrigin, aAppId)
, mRegisterRequests(aRegisterRequests)
, mRegisteredKeys(aRegisteredKeys)
, mCallback(aCallback)
, mAuthenticators(aAuthenticators)
{}
U2FRegisterTask::~U2FRegisterTask()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
return;
}
shutdown(ShutdownCalledFrom::Object);
}
void
U2FRegisterTask::ReturnError(ErrorCode aCode)
{
SendError<U2FRegisterCallback, RegisterResponse>(mCallback.get(), aCode);
}
NS_IMETHODIMP
U2FRegisterTask::Run()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
for (size_t i = 0; i < mRegisteredKeys.Length(); ++i) {
RegisteredKey request(mRegisteredKeys[i]);
// Check for required attributes
if (!(request.mKeyHandle.WasPassed() &&
request.mVersion.WasPassed())) {
continue;
}
// Do not permit an individual RegisteredKey to assert a different AppID
if (request.mAppId.WasPassed() && mAppId != request.mAppId.Value()) {
continue;
}
// Decode the key handle
CryptoBuffer keyHandle;
nsresult rv = keyHandle.FromJwkBase64(request.mKeyHandle.Value());
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::BAD_REQUEST);
return NS_ERROR_FAILURE;
}
// We ignore mTransports, as it is intended to be used for sorting the
// available devices by preference, but is not an exclusion factor.
bool isCompatible = false;
bool isRegistered = false;
// Determine if the provided keyHandle is registered at any device. If so,
// then we'll return DEVICE_INELIGIBLE to signify we're already registered.
for (auto token : mAuthenticators) {
rv = token->IsCompatibleVersion(request.mVersion.Value(), &isCompatible);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (!isCompatible) {
continue;
}
rv = token->IsRegistered(keyHandle.Elements(), keyHandle.Length(),
&isRegistered);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (isCompatible && isRegistered) {
ReturnError(ErrorCode::DEVICE_INELIGIBLE);
return NS_OK;
}
}
}
// Search the requests in order for the first some token can fulfill
for (size_t i = 0; i < mRegisterRequests.Length(); ++i) {
RegisterRequest request(mRegisterRequests[i]);
// Check for equired attributes
if (!(request.mVersion.WasPassed() &&
request.mChallenge.WasPassed())) {
continue;
}
CryptoBuffer clientData;
nsresult rv = AssembleClientData(mOrigin, kFinishEnrollment,
request.mChallenge.Value(),
clientData);
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Hash the AppID and the ClientData into the AppParam and ChallengeParam
SECStatus srv;
nsCString cAppId = NS_ConvertUTF16toUTF8(mAppId);
CryptoBuffer appParam;
CryptoBuffer challengeParam;
if (!appParam.SetLength(SHA256_LENGTH, fallible) ||
!challengeParam.SetLength(SHA256_LENGTH, fallible)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, appParam.Elements(),
reinterpret_cast<const uint8_t*>(cAppId.BeginReading()),
cAppId.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, challengeParam.Elements(),
clientData.Elements(), clientData.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Get the registration data from the token
CryptoBuffer regData;
bool registerSuccess = false;
bool isCompatible = false;
for (auto token : mAuthenticators) {
rv = token->IsCompatibleVersion(request.mVersion.Value(), &isCompatible);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (isCompatible) {
uint8_t* buffer;
uint32_t bufferlen;
nsresult rv;
rv = token->Register(appParam.Elements(), appParam.Length(),
challengeParam.Elements(), challengeParam.Length(),
&buffer, &bufferlen);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
MOZ_ASSERT(buffer);
regData.Assign(buffer, bufferlen);
free(buffer);
registerSuccess = true;
break;
}
}
if (!registerSuccess) {
// Try another request
continue;
}
// Assemble a response object to return
nsString clientDataBase64, registrationDataBase64;
nsresult rvClientData =
clientData.ToJwkBase64(clientDataBase64);
nsresult rvRegistrationData =
regData.ToJwkBase64(registrationDataBase64);
if (NS_WARN_IF(NS_FAILED(rvClientData)) ||
NS_WARN_IF(NS_FAILED(rvRegistrationData))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
RegisterResponse response;
response.mClientData.Construct(clientDataBase64);
response.mRegistrationData.Construct(registrationDataBase64);
response.mErrorCode.Construct(static_cast<uint32_t>(ErrorCode::OK));
ErrorResult result;
mCallback->Call(response, result);
NS_WARNING_ASSERTION(!result.Failed(), "callback failed");
// Useful exceptions already got reported.
result.SuppressException();
return NS_OK;
}
// Nothing could satisfy
ReturnError(ErrorCode::BAD_REQUEST);
return NS_ERROR_FAILURE;
}
U2FSignTask::U2FSignTask(const nsAString& aOrigin,
const nsAString& aAppId,
const nsAString& aChallenge,
const Sequence<RegisteredKey>& aRegisteredKeys,
U2FSignCallback* aCallback,
const Sequence<Authenticator>& aAuthenticators)
: U2FTask(aOrigin, aAppId)
, mChallenge(aChallenge)
, mRegisteredKeys(aRegisteredKeys)
, mCallback(aCallback)
, mAuthenticators(aAuthenticators)
{}
U2FSignTask::~U2FSignTask()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
return;
}
shutdown(ShutdownCalledFrom::Object);
}
void
U2FSignTask::ReturnError(ErrorCode aCode)
{
SendError<U2FSignCallback, SignResponse>(mCallback.get(), aCode);
}
NS_IMETHODIMP
U2FSignTask::Run()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Search the requests for one a token can fulfill
for (size_t i = 0; i < mRegisteredKeys.Length(); i += 1) {
RegisteredKey request(mRegisteredKeys[i]);
// Check for required attributes
if (!(request.mVersion.WasPassed() &&
request.mKeyHandle.WasPassed())) {
continue;
}
// Do not permit an individual RegisteredKey to assert a different AppID
if (request.mAppId.WasPassed() && mAppId != request.mAppId.Value()) {
continue;
}
// Assemble a clientData object
CryptoBuffer clientData;
nsresult rv = AssembleClientData(mOrigin, kGetAssertion, mChallenge,
clientData);
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Hash the AppID and the ClientData into the AppParam and ChallengeParam
SECStatus srv;
nsCString cAppId = NS_ConvertUTF16toUTF8(mAppId);
CryptoBuffer appParam;
CryptoBuffer challengeParam;
if (!appParam.SetLength(SHA256_LENGTH, fallible) ||
!challengeParam.SetLength(SHA256_LENGTH, fallible)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, appParam.Elements(),
reinterpret_cast<const uint8_t*>(cAppId.BeginReading()),
cAppId.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
srv = PK11_HashBuf(SEC_OID_SHA256, challengeParam.Elements(),
clientData.Elements(), clientData.Length());
if (srv != SECSuccess) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Decode the key handle
CryptoBuffer keyHandle;
rv = keyHandle.FromJwkBase64(request.mKeyHandle.Value());
if (NS_WARN_IF(NS_FAILED(rv))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
// Get the signature from the token
CryptoBuffer signatureData;
bool signSuccess = false;
// We ignore mTransports, as it is intended to be used for sorting the
// available devices by preference, but is not an exclusion factor.
for (size_t a = 0; a < mAuthenticators.Length() && !signSuccess; ++a) {
Authenticator token(mAuthenticators[a]);
bool isCompatible = false;
bool isRegistered = false;
rv = token->IsCompatibleVersion(request.mVersion.Value(), &isCompatible);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (!isCompatible) {
continue;
}
rv = token->IsRegistered(keyHandle.Elements(), keyHandle.Length(),
&isRegistered);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
if (isCompatible && isRegistered) {
uint8_t* buffer;
uint32_t bufferlen;
nsresult rv = token->Sign(appParam.Elements(), appParam.Length(),
challengeParam.Elements(), challengeParam.Length(),
keyHandle.Elements(), keyHandle.Length(),
&buffer, &bufferlen);
if (NS_FAILED(rv)) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
MOZ_ASSERT(buffer);
signatureData.Assign(buffer, bufferlen);
free(buffer);
signSuccess = true;
}
}
if (!signSuccess) {
// Try another request
continue;
}
// Assemble a response object to return
nsString clientDataBase64, signatureDataBase64;
nsresult rvClientData =
clientData.ToJwkBase64(clientDataBase64);
nsresult rvSignatureData =
signatureData.ToJwkBase64(signatureDataBase64);
if (NS_WARN_IF(NS_FAILED(rvClientData)) ||
NS_WARN_IF(NS_FAILED(rvSignatureData))) {
ReturnError(ErrorCode::OTHER_ERROR);
return NS_ERROR_FAILURE;
}
SignResponse response;
response.mKeyHandle.Construct(request.mKeyHandle.Value());
response.mClientData.Construct(clientDataBase64);
response.mSignatureData.Construct(signatureDataBase64);
response.mErrorCode.Construct(static_cast<uint32_t>(ErrorCode::OK));
ErrorResult result;
mCallback->Call(response, result);
NS_WARNING_ASSERTION(!result.Failed(), "callback failed");
// Useful exceptions already got reported.
result.SuppressException();
return NS_OK;
}
// Nothing could satisfy
ReturnError(ErrorCode::DEVICE_INELIGIBLE);
return NS_ERROR_FAILURE;
}
// EvaluateAppIDAndRunTask determines whether the supplied FIDO AppID is valid for
// the current FacetID, e.g., the current origin.
// See https://fidoalliance.org/specs/fido-u2f-v1.0-nfc-bt-amendment-20150514/fido-appid-and-facets.html
// for a description of the algorithm.
static void
EvaluateAppIDAndRunTask(U2FTask* aTask)
{
MOZ_ASSERT(aTask);
nsCOMPtr<nsIURLParser> urlParser =
do_GetService(NS_STDURLPARSER_CONTRACTID);
MOZ_ASSERT(urlParser);
uint32_t facetSchemePos;
int32_t facetSchemeLen;
uint32_t facetAuthPos;
int32_t facetAuthLen;
// Facet is the specification's way of referring to the web origin.
nsAutoCString facetUrl = NS_ConvertUTF16toUTF8(aTask->mOrigin);
nsresult rv = urlParser->ParseURL(facetUrl.get(), aTask->mOrigin.Length(),
&facetSchemePos, &facetSchemeLen,
&facetAuthPos, &facetAuthLen,
nullptr, nullptr); // ignore path
if (NS_WARN_IF(NS_FAILED(rv))) {
aTask->ReturnError(ErrorCode::BAD_REQUEST);
return;
}
nsAutoCString facetScheme(Substring(facetUrl, facetSchemePos, facetSchemeLen));
nsAutoCString facetAuth(Substring(facetUrl, facetAuthPos, facetAuthLen));
uint32_t appIdSchemePos;
int32_t appIdSchemeLen;
uint32_t appIdAuthPos;
int32_t appIdAuthLen;
// AppID is user-supplied. It's quite possible for this parse to fail.
nsAutoCString appIdUrl = NS_ConvertUTF16toUTF8(aTask->mAppId);
rv = urlParser->ParseURL(appIdUrl.get(), aTask->mAppId.Length(),
&appIdSchemePos, &appIdSchemeLen,
&appIdAuthPos, &appIdAuthLen,
nullptr, nullptr); // ignore path
if (NS_FAILED(rv)) {
aTask->ReturnError(ErrorCode::BAD_REQUEST);
return;
}
nsAutoCString appIdScheme(Substring(appIdUrl, appIdSchemePos, appIdSchemeLen));
nsAutoCString appIdAuth(Substring(appIdUrl, appIdAuthPos, appIdAuthLen));
// If the facetId (origin) is not HTTPS, reject
if (!facetScheme.LowerCaseEqualsLiteral("https")) {
aTask->ReturnError(ErrorCode::BAD_REQUEST);
return;
}
// If the appId is empty or null, overwrite it with the facetId and accept
if (aTask->mAppId.IsEmpty() || aTask->mAppId.EqualsLiteral("null")) {
aTask->mAppId.Assign(aTask->mOrigin);
aTask->Run();
return;
}
// if the appId URL is not HTTPS, reject.
if (!appIdScheme.LowerCaseEqualsLiteral("https")) {
aTask->ReturnError(ErrorCode::BAD_REQUEST);
return;
}
// If the facetId and the appId auths match, accept
if (facetAuth == appIdAuth) {
aTask->Run();
return;
}
// TODO(Bug 1244959) Implement the remaining algorithm.
aTask->ReturnError(ErrorCode::BAD_REQUEST);
return;
}
U2F::U2F()
{}
U2F::~U2F()
{
nsNSSShutDownPreventionLock locker;
if (isAlreadyShutDown()) {
return;
}
shutdown(ShutdownCalledFrom::Object);
}
/* virtual */ JSObject*
U2F::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return U2FBinding::Wrap(aCx, this, aGivenProto);
}
void
U2F::Init(nsPIDOMWindowInner* aParent, ErrorResult& aRv)
{
MOZ_ASSERT(!mParent);
mParent = do_QueryInterface(aParent);
MOZ_ASSERT(mParent);
nsCOMPtr<nsIDocument> doc = mParent->GetDoc();
MOZ_ASSERT(doc);
nsIPrincipal* principal = doc->NodePrincipal();
aRv = nsContentUtils::GetUTFOrigin(principal, mOrigin);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
if (NS_WARN_IF(mOrigin.IsEmpty())) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
if (!EnsureNSSInitializedChromeOrContent()) {
MOZ_LOG(gWebauthLog, LogLevel::Debug, ("Failed to get NSS context for U2F"));
aRv.Throw(NS_ERROR_FAILURE);
return;
}
// Monolithically insert compatible nsIU2FToken objects into mAuthenticators.
// In future functionality expansions, this is where we could add a dynamic
// add/remove interface.
if (Preferences::GetBool(PREF_U2F_SOFTTOKEN_ENABLED)) {
if (!XRE_IsParentProcess()) {
MOZ_LOG(gWebauthLog, LogLevel::Debug,
("Is e10s Process, getting remote U2F soft token"));
if (!mAuthenticators.AppendElement(new NSSU2FTokenRemote(),
mozilla::fallible)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
} else {
MOZ_LOG(gWebauthLog, LogLevel::Debug,
("Is non-e10s Process, getting direct U2F soft token"));
nsCOMPtr<nsINSSU2FToken> softToken =
do_GetService(NS_NSSU2FTOKEN_CONTRACTID);
if (NS_WARN_IF(!softToken)) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
if (!mAuthenticators.AppendElement(softToken, mozilla::fallible)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
}
}
}
void
U2F::Register(const nsAString& aAppId,
const Sequence<RegisterRequest>& aRegisterRequests,
const Sequence<RegisteredKey>& aRegisteredKeys,
U2FRegisterCallback& aCallback,
const Optional<Nullable<int32_t>>& opt_aTimeoutSeconds,
ErrorResult& aRv)
{
RefPtr<U2FRegisterTask> registerTask = new U2FRegisterTask(mOrigin, aAppId,
aRegisterRequests,
aRegisteredKeys,
&aCallback,
mAuthenticators);
EvaluateAppIDAndRunTask(registerTask);
}
void
U2F::Sign(const nsAString& aAppId,
const nsAString& aChallenge,
const Sequence<RegisteredKey>& aRegisteredKeys,
U2FSignCallback& aCallback,
const Optional<Nullable<int32_t>>& opt_aTimeoutSeconds,
ErrorResult& aRv)
{
RefPtr<U2FSignTask> signTask = new U2FSignTask(mOrigin, aAppId, aChallenge,
aRegisteredKeys, &aCallback,
mAuthenticators);
EvaluateAppIDAndRunTask(signTask);
}
} // namespace dom
} // namespace mozilla