1 files changed, 154 insertions, 0 deletions
diff --git a/dom/quota/NSSCipherStrategy.cpp b/dom/quota/NSSCipherStrategy.cpp
new file mode 100644
index 0000000000..9d1da39ad8
--- /dev/null
+++ b/dom/quota/NSSCipherStrategy.cpp
@@ -0,0 +1,154 @@
+/* -*- 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 file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "NSSCipherStrategy.h"
+
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+#include <memory>
+#include <type_traits>
+#include <utility>
+#include "mozilla/Assertions.h"
+#include "mozilla/ResultExtensions.h"
+
+// NSS includes
+#include "blapit.h"
+#include "pk11pub.h"
+#include "pkcs11t.h"
+#include "seccomon.h"
+#include "secmodt.h"
+
+namespace mozilla::dom::quota {
+
+static_assert(sizeof(NSSCipherStrategy::KeyType) == 32);
+static_assert(NSSCipherStrategy::BlockPrefixLength == 32);
+static_assert(NSSCipherStrategy::BasicBlockSize == 16);
+
+Result<NSSCipherStrategy::KeyType, nsresult> NSSCipherStrategy::GenerateKey() {
+  const auto slot = UniquePK11SlotInfo{PK11_GetInternalSlot()};
+  if (slot == nullptr) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  const auto symKey = UniquePK11SymKey{PK11_KeyGen(
+      slot.get(), CKM_CHACHA20_KEY_GEN, nullptr, sizeof(KeyType), nullptr)};
+  if (symKey == nullptr) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  if (PK11_ExtractKeyValue(symKey.get()) != SECSuccess) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  // No need to free keyData as it is a buffer managed by symKey.
+  SECItem* keyData = PK11_GetKeyData(symKey.get());
+  if (keyData == nullptr) {
+    return Err(NS_ERROR_FAILURE);
+  }
+  KeyType key;
+  MOZ_RELEASE_ASSERT(keyData->len == key.size());
+  std::copy(keyData->data, keyData->data + key.size(), key.data());
+  return key;
+}
+
+nsresult NSSCipherStrategy::Init(const CipherMode aMode,
+                                 const Span<const uint8_t> aKey,
+                                 const Span<const uint8_t> aInitialIv) {
+  MOZ_ASSERT_IF(CipherMode::Encrypt == aMode, aInitialIv.Length() == 32);
+
+  mMode.init(aMode);
+
+  mIv.AppendElements(aInitialIv);
+
+  const auto slot = UniquePK11SlotInfo{PK11_GetInternalSlot()};
+  if (slot == nullptr) {
+    return NS_ERROR_FAILURE;
+  }
+
+  SECItem keyItem;
+  keyItem.data = const_cast<uint8_t*>(aKey.Elements());
+  keyItem.len = aKey.Length();
+  const auto symKey = UniquePK11SymKey{
+      PK11_ImportSymKey(slot.get(), CKM_CHACHA20_POLY1305, PK11_OriginUnwrap,
+                        CKA_ENCRYPT, &keyItem, nullptr)};
+  if (symKey == nullptr) {
+    return NS_ERROR_FAILURE;
+  }
+
+  SECItem empty = {siBuffer, nullptr, 0};
+  auto pk11Context = UniquePK11Context{PK11_CreateContextBySymKey(
+      CKM_CHACHA20_POLY1305,
+      CKA_NSS_MESSAGE |
+          (CipherMode::Encrypt == aMode ? CKA_ENCRYPT : CKA_DECRYPT),
+      symKey.get(), &empty)};
+  if (pk11Context == nullptr) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mPK11Context.init(std::move(pk11Context));
+  return NS_OK;
+}
+
+nsresult NSSCipherStrategy::Cipher(const Span<uint8_t> aIv,
+                                   const Span<const uint8_t> aIn,
+                                   const Span<uint8_t> aOut) {
+  if (CipherMode::Encrypt == *mMode) {
+    MOZ_RELEASE_ASSERT(aIv.Length() == mIv.Length());
+    memcpy(aIv.Elements(), mIv.Elements(), aIv.Length());
+  }
+
+  // XXX make tag a separate parameter
+  constexpr size_t tagLen = 16;
+  const auto tag = aIv.Last(tagLen);
+  // tag is const on decrypt, but returned on encrypt
+
+  const auto iv = aIv.First(12);
+  MOZ_ASSERT(tag.Length() + iv.Length() <= aIv.Length());
+
+  int outLen;
+  // aIn and aOut may not overlap resp. be the same, so we can't do this
+  // in-place.
+  const SECStatus rv = PK11_AEADOp(
+      mPK11Context->get(), CKG_GENERATE_COUNTER, 0, iv.Elements(), iv.Length(),
+      nullptr, 0, aOut.Elements(), &outLen, aOut.Length(), tag.Elements(),
+      tag.Length(), aIn.Elements(), aIn.Length());
+
+  if (CipherMode::Encrypt == *mMode) {
+    memcpy(mIv.Elements(), aIv.Elements(), aIv.Length());
+  }
+
+  return MapSECStatus(rv);
+}
+
+template <size_t N>
+static std::array<uint8_t, N> MakeRandomData() {
+  std::array<uint8_t, N> res;
+
+  const auto rv = PK11_GenerateRandom(res.data(), res.size());
+  /// XXX Allow return of error code to handle this gracefully.
+  MOZ_RELEASE_ASSERT(rv == SECSuccess);
+
+  return res;
+}
+
+std::array<uint8_t, NSSCipherStrategy::BlockPrefixLength>
+NSSCipherStrategy::MakeBlockPrefix() {
+  return MakeRandomData<BlockPrefixLength>();
+}
+
+Span<const uint8_t> NSSCipherStrategy::SerializeKey(const KeyType& aKey) {
+  return Span(aKey);
+}
+
+Maybe<NSSCipherStrategy::KeyType> NSSCipherStrategy::DeserializeKey(
+    const Span<const uint8_t>& aSerializedKey) {
+  KeyType res;
+  if (res.size() != aSerializedKey.size()) {
+    return Nothing();
+  }
+  std::copy(aSerializedKey.cbegin(), aSerializedKey.cend(), res.begin());
+  return Some(res);
+}
+
+}  // namespace mozilla::dom::quota