dom/base/Crypto.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "Crypto.h"
   8 #include "js/ScalarType.h"
   9 #include "js/experimental/TypedData.h"  // JS_GetArrayBufferViewType
  10 #include "nsCOMPtr.h"
  11 #include "nsIRandomGenerator.h"
  12 #include "nsReadableUtils.h"
  13
  14 #include "mozilla/dom/CryptoBinding.h"
  15 #include "mozilla/dom/SubtleCrypto.h"
  16 #include "nsServiceManagerUtils.h"
  17
  18 namespace mozilla::dom {
  19
  20 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Crypto)
  21   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  22   NS_INTERFACE_MAP_ENTRY(nsISupports)
  23 NS_INTERFACE_MAP_END
  24
  25 NS_IMPL_CYCLE_COLLECTING_ADDREF(Crypto)
  26 NS_IMPL_CYCLE_COLLECTING_RELEASE(Crypto)
  27
  28 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Crypto, mParent, mSubtle)
  29
  30 Crypto::Crypto(nsIGlobalObject* aParent) : mParent(aParent) {}
  31
  32 Crypto::~Crypto() = default;
  33
  34 /* virtual */
  35 JSObject* Crypto::WrapObject(JSContext* aCx,
  36                              JS::Handle<JSObject*> aGivenProto) {
  37   return Crypto_Binding::Wrap(aCx, this, aGivenProto);
  38 }
  39
  40 void Crypto::GetRandomValues(JSContext* aCx, const ArrayBufferView& aArray,
  41                              JS::MutableHandle<JSObject*> aRetval,
  42                              ErrorResult& aRv) {
  43   // Throw if the wrong type of ArrayBufferView is passed in
  44   // (Part of the Web Crypto API spec)
  45   switch (aArray.Type()) {
  46     case js::Scalar::Int8:
  47     case js::Scalar::Uint8:
  48     case js::Scalar::Uint8Clamped:
  49     case js::Scalar::Int16:
  50     case js::Scalar::Uint16:
  51     case js::Scalar::Int32:
  52     case js::Scalar::Uint32:
  53     case js::Scalar::BigInt64:
  54     case js::Scalar::BigUint64:
  55       break;
  56     default:
  57       aRv.Throw(NS_ERROR_DOM_TYPE_MISMATCH_ERR);
  58       return;
  59   }
  60
  61   nsCOMPtr<nsIRandomGenerator> randomGenerator =
  62       do_GetService("@mozilla.org/security/random-generator;1");
  63   if (!randomGenerator) {
  64     aRv.Throw(NS_ERROR_DOM_OPERATION_ERR);
  65     return;
  66   }
  67
  68   aArray.ProcessFixedData([&](const Span<uint8_t>& aData) {
  69     if (aData.Length() == 0) {
  70       NS_WARNING("ArrayBufferView length is 0, cannot continue");
  71       aRetval.set(aArray.Obj());
  72       return;
  73     }
  74
  75     if (aData.Length() > 65536) {
  76       aRv.ThrowQuotaExceededError(
  77           "getRandomValues can only generate maximum 65536 bytes");
  78       return;
  79     }
  80
  81     nsresult rv = randomGenerator->GenerateRandomBytesInto(aData.Elements(),
  82                                                            aData.Length());
  83     if (NS_FAILED(rv)) {
  84       aRv.Throw(NS_ERROR_DOM_OPERATION_ERR);
  85       return;
  86     }
  87
  88     aRetval.set(aArray.Obj());
  89   });
  90 }
  91
  92 void Crypto::RandomUUID(nsACString& aRetVal) {
  93   // NSID_LENGTH == 39 == 36 UUID chars + 2 curly braces + 1 NUL byte
  94   static_assert(NSID_LENGTH == 39);
  95
  96   nsIDToCString uuidString(nsID::GenerateUUID());
  97   MOZ_ASSERT(strlen(uuidString.get()) == NSID_LENGTH - 1);
  98
  99   // Omit the curly braces and NUL.
 100   aRetVal = Substring(uuidString.get() + 1, NSID_LENGTH - 3);
 101   MOZ_ASSERT(aRetVal.Length() == NSID_LENGTH - 3);
 102 }
 103
 104 SubtleCrypto* Crypto::Subtle() {
 105   if (!mSubtle) {
 106     mSubtle = new SubtleCrypto(GetParentObject());
 107   }
 108   return mSubtle;
 109 }
 110
 111 }  // namespace mozilla::dom