gecko-dev/security/manager/ssl/OSKeyStore.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 "OSKeyStore.h"

#include "mozilla/Base64.h"
#include "mozilla/dom/Promise.h"
#include "nsIRandomGenerator.h"
#include "nsXPCOM.h"
#include "pk11pub.h"

#ifdef MOZ_LIB_SECRET
#include "LibSecret.h"
#elif defined(XP_MACOSX)
#include "KeychainSecret.h"
#elif defined(XP_WIN)
#include "CredentialManagerSecret.h"
#else
#include "NSSKeyStore.h"
#endif

NS_IMPL_ISUPPORTS(OSKeyStore, nsIOSKeyStore)

using namespace mozilla;
using dom::Promise;

mozilla::LazyLogModule gOSKeyStoreLog("oskeystore");

OSKeyStore::OSKeyStore()
 : mKs(nullptr)
 , mKsThread(nullptr)
 , mKsIsNSSKeyStore(false)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (NS_WARN_IF(!NS_IsMainThread())) {
    return;
  }

#ifdef MOZ_LIB_SECRET
  mKs.reset(new LibSecret());
#elif defined(XP_MACOSX)
  mKs.reset(new KeychainSecret());
#elif defined(XP_WIN)
  mKs.reset(new CredentialManagerSecret());
#else
  mKs.reset(new NSSKeyStore());
  mKsIsNSSKeyStore = true;
#endif

  nsCOMPtr<nsIThread> thread;
  nsresult rv = NS_NewNamedThread("OSKeyStore", getter_AddRefs(thread));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    mKs = nullptr;
    return;
  }
  mKsThread = thread;

  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
  if (NS_WARN_IF(!obs)) {
    mKsThread = nullptr;
    mKs = nullptr;
    return;
  }
  rv = obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    mKsThread = nullptr;
    mKs = nullptr;
  }
}

NS_IMETHODIMP
OSKeyStore::Observe(nsISupports*, const char* aTopic, const char16_t*)
{
  MOZ_ASSERT(!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID));
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  if (mKsThread) {
    mKsThread->Shutdown();
    mKsThread = nullptr;
    mKs = nullptr;
  }

  return NS_OK;
}

static nsresult
GenerateRandom(std::vector<uint8_t>& r)
{
  if (r.size() < 1) {
    return NS_ERROR_INVALID_ARG;
  }
  UniquePK11SlotInfo slot(PK11_GetInternalSlot());
  if (!slot) {
    return NS_ERROR_FAILURE;
  }

  SECStatus srv = PK11_GenerateRandomOnSlot(slot.get(), r.data(), r.size());
  if (srv != SECSuccess) {
    r.clear();
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult
OSKeyStore::SecretAvailable(const nsACString& aLabel,
                            /* out */ bool* aAvailable)
{
  NS_ENSURE_STATE(mKs);
  nsAutoCString label = mLabelPrefix + aLabel;
  *aAvailable = mKs->SecretAvailable(label);
  return NS_OK;
}

nsresult
OSKeyStore::GenerateSecret(const nsACString& aLabel,
                           /* out */ nsACString& aRecoveryPhrase)
{
  NS_ENSURE_STATE(mKs);
  size_t keyByteLength = mKs->GetKeyByteLength();
  std::vector<uint8_t> secret(keyByteLength);
  nsresult rv = GenerateRandom(secret);
  if (NS_FAILED(rv) || secret.size() != keyByteLength) {
    return NS_ERROR_FAILURE;
  }
  nsAutoCString secretString;
  secretString.Assign(BitwiseCast<char*, uint8_t*>(secret.data()),
                      secret.size());

  nsAutoCString base64;
  rv = Base64Encode(secretString, base64);
  if (NS_FAILED(rv)) {
    return rv;
  }

  nsAutoCString label = mLabelPrefix + aLabel;
  rv = mKs->StoreSecret(secretString, label);
  if (NS_FAILED(rv)) {
    return rv;
  }

  aRecoveryPhrase = base64;
  return NS_OK;
}

nsresult
OSKeyStore::RecoverSecret(const nsACString& aLabel,
                          const nsACString& aRecoveryPhrase)
{
  NS_ENSURE_STATE(mKs);
  nsAutoCString secret;
  nsresult rv = Base64Decode(aRecoveryPhrase, secret);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsAutoCString label = mLabelPrefix + aLabel;
  rv = mKs->StoreSecret(secret, label);
  if (NS_FAILED(rv)) {
    return rv;
  }

  return NS_OK;
}

nsresult
OSKeyStore::DeleteSecret(const nsACString& aLabel)
{
  NS_ENSURE_STATE(mKs);
  nsAutoCString label = mLabelPrefix + aLabel;
  return mKs->DeleteSecret(label);
}

enum Cipher
{
  Encrypt = true,
  Decrypt = false
};

nsresult
OSKeyStore::EncryptBytes(const nsACString& aLabel,
                         uint32_t inLen,
                         uint8_t* inBytes,
                         /*out*/ nsACString& aEncryptedBase64Text)
{
  NS_ENSURE_STATE(mKs);
  NS_ENSURE_ARG_POINTER(inBytes);

  nsAutoCString label = mLabelPrefix + aLabel;
  aEncryptedBase64Text.Truncate();
  const std::vector<uint8_t> in(inBytes, inBytes + inLen);
  std::vector<uint8_t> outBytes;
  nsresult rv = mKs->EncryptDecrypt(label, in, outBytes, Cipher::Encrypt);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsAutoCString ciphertext;
  ciphertext.Assign(BitwiseCast<char*, uint8_t*>(outBytes.data()),
                    outBytes.size());

  nsAutoCString base64ciphertext;
  rv = Base64Encode(ciphertext, base64ciphertext);
  if (NS_FAILED(rv)) {
    return rv;
  }
  aEncryptedBase64Text.Assign(base64ciphertext);
  return NS_OK;
}

nsresult
OSKeyStore::DecryptBytes(const nsACString& aLabel,
                         const nsACString& aEncryptedBase64Text,
                         /*out*/ uint32_t* outLen,
                         /*out*/ uint8_t** outBytes)
{
  NS_ENSURE_STATE(mKs);
  NS_ENSURE_ARG_POINTER(outLen);
  NS_ENSURE_ARG_POINTER(outBytes);
  *outLen = 0;
  *outBytes = nullptr;

  nsAutoCString ciphertext;
  nsresult rv = Base64Decode(aEncryptedBase64Text, ciphertext);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsAutoCString label = mLabelPrefix + aLabel;
  uint8_t* tmp = BitwiseCast<uint8_t*, const char*>(ciphertext.BeginReading());
  const std::vector<uint8_t> ciphertextBytes(tmp, tmp + ciphertext.Length());
  std::vector<uint8_t> plaintextBytes;
  rv = mKs->EncryptDecrypt(
    label, ciphertextBytes, plaintextBytes, Cipher::Decrypt);
  if (NS_FAILED(rv)) {
    return rv;
  }

  *outBytes = (uint8_t*)moz_xmalloc(plaintextBytes.size());
  memcpy(*outBytes, plaintextBytes.data(), plaintextBytes.size());
  *outLen = plaintextBytes.size();
  return NS_OK;
}

nsresult
OSKeyStore::Lock()
{
  NS_ENSURE_STATE(mKs);
  return mKs->Lock();
}

nsresult
OSKeyStore::Unlock()
{
  NS_ENSURE_STATE(mKs);
  return mKs->Unlock();
}

NS_IMETHODIMP
OSKeyStore::GetIsNSSKeyStore(bool* aNSSKeyStore)
{
  NS_ENSURE_ARG_POINTER(aNSSKeyStore);
  *aNSSKeyStore = mKsIsNSSKeyStore;
  return NS_OK;
}

// Async interfaces that return promises because the key store implementation
// might block, e.g. asking for a password.

nsresult
GetPromise(JSContext* aCx, /* out */ RefPtr<Promise>& aPromise)
{
  nsIGlobalObject* globalObject = xpc::CurrentNativeGlobal(aCx);
  if (NS_WARN_IF(!globalObject)) {
    return NS_ERROR_UNEXPECTED;
  }
  ErrorResult result;
  aPromise = Promise::Create(globalObject, result);
  if (NS_WARN_IF(result.Failed())) {
    return result.StealNSResult();
  }
  return NS_OK;
}

void
BackgroundUnlock(RefPtr<Promise>& aPromise, RefPtr<OSKeyStore> self)
{
  nsAutoCString recovery;
  nsresult rv = self->Unlock();
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundUnlockOSKSResolve", [rv, aPromise = std::move(aPromise)]() {
      if (NS_FAILED(rv)) {
        aPromise->MaybeReject(rv);
      } else {
        aPromise->MaybeResolveWithUndefined();
      }
    }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncUnlock(JSContext* aCx, Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(
    NS_NewRunnableFunction("BackgroundUnlock", [self, promiseHandle]() mutable {
      BackgroundUnlock(promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundLock(RefPtr<Promise>& aPromise, RefPtr<OSKeyStore> self)
{
  nsresult rv = self->Lock();
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundLockOSKSResolve", [rv, aPromise = std::move(aPromise)]() {
      if (NS_FAILED(rv)) {
        aPromise->MaybeReject(rv);
      } else {
        aPromise->MaybeResolveWithUndefined();
      }
    }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncLock(JSContext* aCx, Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(
    NS_NewRunnableFunction("BackgroundLock", [self, promiseHandle]() mutable {
      BackgroundLock(promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundGenerateSecret(const nsACString& aLabel,
                         RefPtr<Promise>& aPromise,
                         RefPtr<OSKeyStore> self)
{
  nsAutoCString recovery;
  nsresult rv = self->GenerateSecret(aLabel, recovery);
  nsAutoString recoveryString;
  if (NS_SUCCEEDED(rv)){
    CopyUTF8toUTF16(recovery, recoveryString);
  }
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundGenerateSecreteOSKSResolve",
    [rv, aPromise = std::move(aPromise), recoveryString]() {
      if (NS_FAILED(rv)) {
        aPromise->MaybeReject(rv);
      } else {
        aPromise->MaybeResolve(recoveryString);
      }
    }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncGenerateSecret(const nsACString& aLabel,
                                JSContext* aCx,
                                Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundGenerateSecret",
    [self, promiseHandle, aLabel = nsAutoCString(aLabel)]() mutable {
      BackgroundGenerateSecret(aLabel, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundSecretAvailable(const nsACString& aLabel,
                          RefPtr<Promise>& aPromise,
                          RefPtr<OSKeyStore> self)
{
  bool available = false;
  nsresult rv = self->SecretAvailable(aLabel, &available);
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundSecreteAvailableOSKSResolve",
    [rv, aPromise = std::move(aPromise), available = available]() {
      if (NS_FAILED(rv)) {
        aPromise->MaybeReject(rv);
      } else {
        aPromise->MaybeResolve(available);
      }
    }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncSecretAvailable(const nsACString& aLabel,
                                 JSContext* aCx,
                                 Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundSecretAvailable",
    [self, promiseHandle, aLabel = nsAutoCString(aLabel)]() mutable {
      BackgroundSecretAvailable(aLabel, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundRecoverSecret(const nsACString& aLabel,
                        const nsACString& aRecoveryPhrase,
                        RefPtr<Promise>& aPromise,
                        RefPtr<OSKeyStore> self)
{
  nsresult rv = self->RecoverSecret(aLabel, aRecoveryPhrase);
  nsCOMPtr<nsIRunnable> runnable(
    NS_NewRunnableFunction("BackgroundRecoverSecreteOSKSResolve",
                           [rv, aPromise = std::move(aPromise)]() {
                             if (NS_FAILED(rv)) {
                               aPromise->MaybeReject(rv);
                             } else {
                               aPromise->MaybeResolveWithUndefined();
                             }
                           }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncRecoverSecret(const nsACString& aLabel,
                               const nsACString& aRecoveryPhrase,
                               JSContext* aCx,
                               Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundRecoverSecret",
    [self,
     promiseHandle,
     aLabel = nsAutoCString(aLabel),
     aRecoveryPhrase = nsAutoCString(aRecoveryPhrase)]() mutable {
      BackgroundRecoverSecret(aLabel, aRecoveryPhrase, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundDeleteSecret(const nsACString& aLabel,
                       RefPtr<Promise>& aPromise,
                       RefPtr<OSKeyStore> self)
{
  nsresult rv = self->DeleteSecret(aLabel);
  nsCOMPtr<nsIRunnable> runnable(
    NS_NewRunnableFunction("BackgroundDeleteSecreteOSKSResolve",
                           [rv, aPromise = std::move(aPromise)]() {
                             if (NS_FAILED(rv)) {
                               aPromise->MaybeReject(rv);
                             } else {
                               aPromise->MaybeResolveWithUndefined();
                             }
                           }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncDeleteSecret(const nsACString& aLabel,
                              JSContext* aCx,
                              Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundDeleteSecret",
    [self, promiseHandle, aLabel = nsAutoCString(aLabel)]() mutable {
      BackgroundDeleteSecret(aLabel, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundEncryptBytes(const nsACString& aLabel,
                       std::vector<uint8_t> inBytes,
                       RefPtr<Promise>& aPromise,
                       RefPtr<OSKeyStore> self)
{
  nsAutoCString ciphertext;
  nsresult rv =
    self->EncryptBytes(aLabel, inBytes.size(), inBytes.data(), ciphertext);
  nsAutoString ctext;
  CopyUTF8toUTF16(ciphertext, ctext);

  nsCOMPtr<nsIRunnable> runnable(
    NS_NewRunnableFunction("BackgroundEncryptOSKSResolve",
                           [rv, aPromise = std::move(aPromise), ctext]() {
                             if (NS_FAILED(rv)) {
                               aPromise->MaybeReject(rv);
                             } else {
                               aPromise->MaybeResolve(ctext);
                             }
                           }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncEncryptBytes(const nsACString& aLabel,
                              uint32_t inLen,
                              uint8_t* inBytes,
                              JSContext* aCx,
                              Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_ARG_POINTER(inBytes);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundEncryptBytes",
    [promiseHandle,
     inBytes = std::vector<uint8_t>(inBytes, inBytes + inLen),
     aLabel = nsAutoCString(aLabel),
     self]() mutable {
      BackgroundEncryptBytes(aLabel, inBytes, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

void
BackgroundDecryptBytes(const nsACString& aLabel,
                       const nsACString& aEncryptedBase64Text,
                       RefPtr<Promise>& aPromise,
                       RefPtr<OSKeyStore> self)
{
  uint8_t* plaintext = nullptr;
  uint32_t plaintextLen = 0;
  nsresult rv =
    self->DecryptBytes(aLabel, aEncryptedBase64Text, &plaintextLen, &plaintext);
  nsTArray<uint8_t> plain;
  if (plaintext) {
    MOZ_ASSERT(plaintextLen > 0);
    plain.AppendElements(plaintext, plaintextLen);
    free(plaintext);
  }

  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundDecryptOSKSResolve",
    [rv, aPromise = std::move(aPromise), plain = std::move(plain)]() {
      if (NS_FAILED(rv)) {
        aPromise->MaybeReject(rv);
      } else {
        aPromise->MaybeResolve(plain);
      }
    }));
  NS_DispatchToMainThread(runnable.forget());
}

NS_IMETHODIMP
OSKeyStore::AsyncDecryptBytes(const nsACString& aLabel,
                              const nsACString& aEncryptedBase64Text,
                              JSContext* aCx,
                              Promise** promiseOut)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!NS_IsMainThread()) {
    return NS_ERROR_NOT_SAME_THREAD;
  }

  NS_ENSURE_ARG_POINTER(aCx);
  NS_ENSURE_STATE(mKsThread);

  RefPtr<Promise> promiseHandle;
  nsresult rv = GetPromise(aCx, promiseHandle);
  if (NS_FAILED(rv)) {
    return rv;
  }

  RefPtr<OSKeyStore> self = this;
  nsCOMPtr<nsIRunnable> runnable(NS_NewRunnableFunction(
    "BackgroundDecryptBytes",
    [promiseHandle,
     self,
     aEncryptedBase64Text = nsAutoCString(aEncryptedBase64Text),
     aLabel = nsAutoCString(aLabel)]() mutable {
      BackgroundDecryptBytes(aLabel, aEncryptedBase64Text, promiseHandle, self);
    }));

  promiseHandle.forget(promiseOut);
  return mKsThread->Dispatch(runnable.forget());
}

// Generic AES-GCM cipher wrapper for NSS functions.

nsresult
AbstractOSKeyStore::BuildAesGcmKey(std::vector<uint8_t> aKeyBytes,
                                   /* out */ UniquePK11SymKey& aKey)
{
  if (aKeyBytes.size() != mKeyByteLength) {
    return NS_ERROR_INVALID_ARG;
  }

  UniquePK11SlotInfo slot(PK11_GetInternalSlot());
  if (!slot) {
    return NS_ERROR_FAILURE;
  }

  UniqueSECItem key =
    UniqueSECItem(SECITEM_AllocItem(nullptr, nullptr, mKeyByteLength));
  if (!key) {
    return NS_ERROR_FAILURE;
  }
  key->type = siBuffer;
  memcpy(key->data, aKeyBytes.data(), mKeyByteLength);
  key->len = mKeyByteLength;

  UniquePK11SymKey symKey(PK11_ImportSymKey(slot.get(),
                                            CKM_AES_GCM,
                                            PK11_OriginUnwrap,
                                            CKA_DECRYPT | CKA_ENCRYPT,
                                            key.get(),
                                            nullptr));

  if (!symKey) {
    return NS_ERROR_FAILURE;
  }
  aKey.swap(symKey);

  return NS_OK;
}

nsresult
AbstractOSKeyStore::DoCipher(const UniquePK11SymKey& aSymKey,
                             const std::vector<uint8_t>& inBytes,
                             std::vector<uint8_t>& outBytes,
                             bool encrypt)
{
  NS_ENSURE_ARG_POINTER(aSymKey);
  outBytes.clear();

  // Build params.
  // We need to get the IV from inBytes if we decrypt.
  if (!encrypt && (inBytes.size() < mIVLength || inBytes.size() == 0)) {
    return NS_ERROR_INVALID_ARG;
  }

  const uint8_t* ivp = nullptr;
  std::vector<uint8_t> ivBuf;
  if (encrypt) {
    // Generate a new IV.
    ivBuf.resize(mIVLength);
    nsresult rv = GenerateRandom(ivBuf);
    if (NS_FAILED(rv) || ivBuf.size() != mIVLength) {
      return NS_ERROR_FAILURE;
    }
    ivp = ivBuf.data();
  } else {
    // An IV was passed in. Use the first mIVLength bytes from inBytes as IV.
    ivp = inBytes.data();
  }

  CK_GCM_PARAMS gcm_params;
  gcm_params.pIv = const_cast<unsigned char*>(ivp);
  gcm_params.ulIvLen = mIVLength;
  gcm_params.ulTagBits = 128;
  gcm_params.pAAD = nullptr;
  gcm_params.ulAADLen = 0;

  SECItem paramsItem = { siBuffer,
                         reinterpret_cast<unsigned char*>(&gcm_params),
                         sizeof(CK_GCM_PARAMS) };

  size_t blockLength = 16;
  outBytes.resize(inBytes.size() + blockLength);
  unsigned int outLen = 0;
  SECStatus srv = SECFailure;
  if (encrypt) {
    srv = PK11_Encrypt(aSymKey.get(),
                       CKM_AES_GCM,
                       &paramsItem,
                       outBytes.data(),
                       &outLen,
                       inBytes.size() + blockLength,
                       inBytes.data(),
                       inBytes.size());
    // Prepend the used IV to the ciphertext.
    Unused << outBytes.insert(outBytes.begin(), ivp, ivp + mIVLength);
    outLen += mIVLength;
  } else {
    // Remove the IV from the input.
    std::vector<uint8_t> input(inBytes);
    input.erase(input.begin(), input.begin() + mIVLength);
    srv = PK11_Decrypt(aSymKey.get(),
                       CKM_AES_GCM,
                       &paramsItem,
                       outBytes.data(),
                       &outLen,
                       input.size() + blockLength,
                       input.data(),
                       input.size());
  }
  if (srv != SECSuccess || outLen > outBytes.size()) {
    outBytes.clear();
    return NS_ERROR_FAILURE;
  }
  if (outLen < outBytes.size()) {
    outBytes.resize(outLen);
  }

  return NS_OK;
}

bool
AbstractOSKeyStore::SecretAvailable(const nsACString& aLabel)
{
  nsAutoCString secret;
  nsresult rv = RetrieveSecret(aLabel, secret);
  if (NS_FAILED(rv) || secret.Length() == 0) {
    return false;
  }
  return true;
}

nsresult
AbstractOSKeyStore::EncryptDecrypt(const nsACString& aLabel,
                                   const std::vector<uint8_t>& inBytes,
                                   std::vector<uint8_t>& outBytes,
                                   bool encrypt)
{
  nsAutoCString secret;
  nsresult rv = RetrieveSecret(aLabel, secret);
  if (NS_FAILED(rv) || secret.Length() == 0) {
    return NS_ERROR_FAILURE;
  }

  uint8_t* p = BitwiseCast<uint8_t*, const char*>(secret.BeginReading());
  std::vector<uint8_t> buf(p, p + secret.Length());
  UniquePK11SymKey symKey;
  rv = BuildAesGcmKey(buf, symKey);
  if (NS_FAILED(rv)) {
    return NS_ERROR_FAILURE;
  }
  return DoCipher(symKey, inBytes, outBytes, encrypt);
}