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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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
#include "mozilla/dom/RTCCertificate.h"
#include <cstdio>
#include <cstring>
#include <memory>
#include <new>
#include <utility>
#include "ErrorList.h"
#include "MainThreadUtils.h"
#include "cert.h"
#include "cryptohi.h"
#include "js/StructuredClone.h"
#include "js/TypeDecls.h"
#include "js/Value.h"
#include "keyhi.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/MacroForEach.h"
#include "mozilla/OwningNonNull.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/CryptoBuffer.h"
#include "mozilla/dom/CryptoKey.h"
#include "mozilla/dom/KeyAlgorithmBinding.h"
#include "mozilla/dom/KeyAlgorithmProxy.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/RTCCertificateBinding.h"
#include "mozilla/dom/StructuredCloneHolder.h"
#include "mozilla/dom/SubtleCryptoBinding.h"
#include "mozilla/dom/UnionTypes.h"
#include "mozilla/dom/WebCryptoCommon.h"
#include "mozilla/dom/WebCryptoTask.h"
#include "mozilla/fallible.h"
#include "nsDebug.h"
#include "nsError.h"
#include "nsLiteralString.h"
#include "nsStringFlags.h"
#include "nsStringFwd.h"
#include "nsTLiteralString.h"
#include "pk11pub.h"
#include "plarena.h"
#include "secasn1.h"
#include "secasn1t.h"
#include "seccomon.h"
#include "secmodt.h"
#include "secoid.h"
#include "secoidt.h"
#include "transport/dtlsidentity.h"
#include "xpcpublic.h"
namespace mozilla::dom {
#define RTCCERTIFICATE_SC_VERSION 0x00000001
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(RTCCertificate, mGlobal)
NS_IMPL_CYCLE_COLLECTING_ADDREF(RTCCertificate)
NS_IMPL_CYCLE_COLLECTING_RELEASE(RTCCertificate)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(RTCCertificate)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
// Note: explicit casts necessary to avoid
// warning C4307: '*' : integral constant overflow
#define ONE_DAY \
PRTime(PR_USEC_PER_SEC) * PRTime(60) /*sec*/ \
* PRTime(60) /*min*/ * PRTime(24) /*hours*/
#define EXPIRATION_DEFAULT ONE_DAY* PRTime(30)
#define EXPIRATION_SLACK ONE_DAY
#define EXPIRATION_MAX ONE_DAY* PRTime(365) /*year*/
const size_t RTCCertificateCommonNameLength = 16;
const size_t RTCCertificateMinRsaSize = 1024;
class GenerateRTCCertificateTask : public GenerateAsymmetricKeyTask {
public:
GenerateRTCCertificateTask(nsIGlobalObject* aGlobal, JSContext* aCx,
const ObjectOrString& aAlgorithm,
const Sequence<nsString>& aKeyUsages,
PRTime aExpires)
: GenerateAsymmetricKeyTask(aGlobal, aCx, aAlgorithm, true, aKeyUsages),
mExpires(aExpires),
mAuthType(ssl_kea_null),
mCertificate(nullptr),
mSignatureAlg(SEC_OID_UNKNOWN) {
if (NS_FAILED(mEarlyRv)) {
// webrtc-pc says to throw NotSupportedError if we have passed "an
// algorithm that the user agent cannot or will not use to generate a
// certificate". This catches these cases.
mEarlyRv = NS_ERROR_DOM_NOT_SUPPORTED_ERR;
}
}
private:
PRTime mExpires;
SSLKEAType mAuthType;
UniqueCERTCertificate mCertificate;
SECOidTag mSignatureAlg;
static CERTName* GenerateRandomName(PK11SlotInfo* aSlot) {
uint8_t randomName[RTCCertificateCommonNameLength];
SECStatus rv =
PK11_GenerateRandomOnSlot(aSlot, randomName, sizeof(randomName));
if (rv != SECSuccess) {
return nullptr;
}
char buf[sizeof(randomName) * 2 + 4];
strncpy(buf, "CN=", 4);
for (size_t i = 0; i < sizeof(randomName); ++i) {
snprintf(&buf[i * 2 + 3], 3, "%.2x", randomName[i]);
}
buf[sizeof(buf) - 1] = '\0';
return CERT_AsciiToName(buf);
}
nsresult GenerateCertificate() {
UniquePK11SlotInfo slot(PK11_GetInternalSlot());
MOZ_ASSERT(slot.get());
UniqueCERTName subjectName(GenerateRandomName(slot.get()));
if (!subjectName) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
UniqueSECKEYPublicKey publicKey(mKeyPair->mPublicKey->GetPublicKey());
UniqueCERTSubjectPublicKeyInfo spki(
SECKEY_CreateSubjectPublicKeyInfo(publicKey.get()));
if (!spki) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
UniqueCERTCertificateRequest certreq(
CERT_CreateCertificateRequest(subjectName.get(), spki.get(), nullptr));
if (!certreq) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
PRTime now = PR_Now();
PRTime notBefore = now - EXPIRATION_SLACK;
mExpires += now;
UniqueCERTValidity validity(CERT_CreateValidity(notBefore, mExpires));
if (!validity) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
unsigned long serial;
// Note: This serial in principle could collide, but it's unlikely, and we
// don't expect anyone to be validating certificates anyway.
SECStatus rv = PK11_GenerateRandomOnSlot(
slot.get(), reinterpret_cast<unsigned char*>(&serial), sizeof(serial));
if (rv != SECSuccess) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
// NB: CERTCertificates created with CERT_CreateCertificate are not safe to
// use with other NSS functions like CERT_DupCertificate. The strategy
// here is to create a tbsCertificate ("to-be-signed certificate"), encode
// it, and sign it, resulting in a signed DER certificate that can be
// decoded into a CERTCertificate.
UniqueCERTCertificate tbsCertificate(CERT_CreateCertificate(
serial, subjectName.get(), validity.get(), certreq.get()));
if (!tbsCertificate) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
MOZ_ASSERT(mSignatureAlg != SEC_OID_UNKNOWN);
PLArenaPool* arena = tbsCertificate->arena;
rv = SECOID_SetAlgorithmID(arena, &tbsCertificate->signature, mSignatureAlg,
nullptr);
if (rv != SECSuccess) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
// Set version to X509v3.
*(tbsCertificate->version.data) = SEC_CERTIFICATE_VERSION_3;
tbsCertificate->version.len = 1;
SECItem innerDER = {siBuffer, nullptr, 0};
if (!SEC_ASN1EncodeItem(arena, &innerDER, tbsCertificate.get(),
SEC_ASN1_GET(CERT_CertificateTemplate))) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
SECItem* certDer = PORT_ArenaZNew(arena, SECItem);
if (!certDer) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
UniqueSECKEYPrivateKey privateKey(mKeyPair->mPrivateKey->GetPrivateKey());
rv = SEC_DerSignData(arena, certDer, innerDER.data, innerDER.len,
privateKey.get(), mSignatureAlg);
if (rv != SECSuccess) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
mCertificate.reset(CERT_NewTempCertificate(CERT_GetDefaultCertDB(), certDer,
nullptr, false, true));
if (!mCertificate) {
return NS_ERROR_DOM_UNKNOWN_ERR;
}
return NS_OK;
}
nsresult BeforeCrypto() override {
if (mAlgName.EqualsLiteral(WEBCRYPTO_ALG_RSASSA_PKCS1)) {
// Double check that size is OK.
auto sz = static_cast<size_t>(mRsaParams.keySizeInBits);
if (sz < RTCCertificateMinRsaSize) {
return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
}
KeyAlgorithmProxy& alg = mKeyPair->mPublicKey->Algorithm();
if (alg.mType != KeyAlgorithmProxy::RSA ||
!alg.mRsa.mHash.mName.EqualsLiteral(WEBCRYPTO_ALG_SHA256)) {
return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
}
mSignatureAlg = SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION;
mAuthType = ssl_kea_rsa;
} else if (mAlgName.EqualsLiteral(WEBCRYPTO_ALG_ECDSA)) {
// We only support good curves in WebCrypto.
// If that ever changes, check that a good one was chosen.
mSignatureAlg = SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE;
mAuthType = ssl_kea_ecdh;
} else {
return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
}
return NS_OK;
}
nsresult DoCrypto() override {
nsresult rv = GenerateAsymmetricKeyTask::DoCrypto();
NS_ENSURE_SUCCESS(rv, rv);
rv = GenerateCertificate();
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
virtual void Resolve() override {
// Make copies of the private key and certificate, otherwise, when this
// object is deleted, the structures they reference will be deleted too.
UniqueSECKEYPrivateKey key = mKeyPair->mPrivateKey->GetPrivateKey();
CERTCertificate* cert = CERT_DupCertificate(mCertificate.get());
RefPtr<RTCCertificate> result =
new RTCCertificate(mResultPromise->GetParentObject(), key.release(),
cert, mAuthType, mExpires);
mResultPromise->MaybeResolve(result);
}
};
static PRTime ReadExpires(JSContext* aCx, const ObjectOrString& aOptions,
ErrorResult& aRv) {
// This conversion might fail, but we don't really care; use the default.
// If this isn't an object, or it doesn't coerce into the right type,
// then we won't get the |expires| value. Either will be caught later.
RTCCertificateExpiration expiration;
if (!aOptions.IsObject()) {
return EXPIRATION_DEFAULT;
}
JS::Rooted<JS::Value> value(aCx, JS::ObjectValue(*aOptions.GetAsObject()));
if (!expiration.Init(aCx, value)) {
aRv.NoteJSContextException(aCx);
return 0;
}
if (!expiration.mExpires.WasPassed()) {
return EXPIRATION_DEFAULT;
}
static const uint64_t max =
static_cast<uint64_t>(EXPIRATION_MAX / PR_USEC_PER_MSEC);
if (expiration.mExpires.Value() > max) {
return EXPIRATION_MAX;
}
return static_cast<PRTime>(expiration.mExpires.Value() * PR_USEC_PER_MSEC);
}
already_AddRefed<Promise> RTCCertificate::GenerateCertificate(
const GlobalObject& aGlobal, const ObjectOrString& aOptions,
ErrorResult& aRv, JS::Compartment* aCompartment) {
nsIGlobalObject* global = xpc::NativeGlobal(aGlobal.Get());
RefPtr<Promise> p = Promise::Create(global, aRv);
if (aRv.Failed()) {
return nullptr;
}
Sequence<nsString> usages;
if (!usages.AppendElement(u"sign"_ns, fallible)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
PRTime expires = ReadExpires(aGlobal.Context(), aOptions, aRv);
if (aRv.Failed()) {
return nullptr;
}
RefPtr<WebCryptoTask> task = new GenerateRTCCertificateTask(
global, aGlobal.Context(), aOptions, usages, expires);
task->DispatchWithPromise(p);
return p.forget();
}
RTCCertificate::RTCCertificate(nsIGlobalObject* aGlobal)
: mGlobal(aGlobal),
mPrivateKey(nullptr),
mCertificate(nullptr),
mAuthType(ssl_kea_null),
mExpires(0) {}
RTCCertificate::RTCCertificate(nsIGlobalObject* aGlobal,
SECKEYPrivateKey* aPrivateKey,
CERTCertificate* aCertificate,
SSLKEAType aAuthType, PRTime aExpires)
: mGlobal(aGlobal),
mPrivateKey(aPrivateKey),
mCertificate(aCertificate),
mAuthType(aAuthType),
mExpires(aExpires) {}
RefPtr<DtlsIdentity> RTCCertificate::CreateDtlsIdentity() const {
if (!mPrivateKey || !mCertificate) {
return nullptr;
}
UniqueSECKEYPrivateKey key(SECKEY_CopyPrivateKey(mPrivateKey.get()));
UniqueCERTCertificate cert(CERT_DupCertificate(mCertificate.get()));
RefPtr<DtlsIdentity> id =
new DtlsIdentity(std::move(key), std::move(cert), mAuthType);
return id;
}
JSObject* RTCCertificate::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return RTCCertificate_Binding::Wrap(aCx, this, aGivenProto);
}
bool RTCCertificate::WritePrivateKey(JSStructuredCloneWriter* aWriter) const {
JsonWebKey jwk;
nsresult rv = CryptoKey::PrivateKeyToJwk(mPrivateKey.get(), jwk);
if (NS_FAILED(rv)) {
return false;
}
nsString json;
if (!jwk.ToJSON(json)) {
return false;
}
return StructuredCloneHolder::WriteString(aWriter, json);
}
bool RTCCertificate::WriteCertificate(JSStructuredCloneWriter* aWriter) const {
UniqueCERTCertificateList certs(CERT_CertListFromCert(mCertificate.get()));
if (!certs || certs->len <= 0) {
return false;
}
if (!JS_WriteUint32Pair(aWriter, certs->certs[0].len, 0)) {
return false;
}
return JS_WriteBytes(aWriter, certs->certs[0].data, certs->certs[0].len);
}
bool RTCCertificate::WriteStructuredClone(
JSContext* aCx, JSStructuredCloneWriter* aWriter) const {
if (!mPrivateKey || !mCertificate) {
return false;
}
return JS_WriteUint32Pair(aWriter, RTCCERTIFICATE_SC_VERSION, mAuthType) &&
JS_WriteUint32Pair(aWriter, (mExpires >> 32) & 0xffffffff,
mExpires & 0xffffffff) &&
WritePrivateKey(aWriter) && WriteCertificate(aWriter);
}
bool RTCCertificate::ReadPrivateKey(JSStructuredCloneReader* aReader) {
nsString json;
if (!StructuredCloneHolder::ReadString(aReader, json)) {
return false;
}
JsonWebKey jwk;
if (!jwk.Init(json)) {
return false;
}
mPrivateKey = CryptoKey::PrivateKeyFromJwk(jwk);
return !!mPrivateKey;
}
bool RTCCertificate::ReadCertificate(JSStructuredCloneReader* aReader) {
CryptoBuffer cert;
if (!ReadBuffer(aReader, cert) || cert.Length() == 0) {
return false;
}
SECItem der = {siBuffer, cert.Elements(),
static_cast<unsigned int>(cert.Length())};
mCertificate.reset(CERT_NewTempCertificate(CERT_GetDefaultCertDB(), &der,
nullptr, true, true));
return !!mCertificate;
}
// static
already_AddRefed<RTCCertificate> RTCCertificate::ReadStructuredClone(
JSContext* aCx, nsIGlobalObject* aGlobal,
JSStructuredCloneReader* aReader) {
if (!NS_IsMainThread()) {
// These objects are mainthread-only.
return nullptr;
}
uint32_t version, authType;
if (!JS_ReadUint32Pair(aReader, &version, &authType) ||
version != RTCCERTIFICATE_SC_VERSION) {
return nullptr;
}
RefPtr<RTCCertificate> cert = new RTCCertificate(aGlobal);
cert->mAuthType = static_cast<SSLKEAType>(authType);
uint32_t high, low;
if (!JS_ReadUint32Pair(aReader, &high, &low)) {
return nullptr;
}
cert->mExpires = static_cast<PRTime>(high) << 32 | low;
if (!cert->ReadPrivateKey(aReader) || !cert->ReadCertificate(aReader)) {
return nullptr;
}
return cert.forget();
}
} // namespace mozilla::dom