/* -*- 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/. */

// Generic key store implementation for platforms that we don't support with OS

// specific implementations.

#ifndef OSKeyStore_h

#define OSKeyStore_h

#include "nsIOSKeyStore.h"

#include "nsString.h"

#include <memory>

class AbstractOSKeyStore

{

public:

  // Retrieve a secret with the given label.

  virtual nsresult RetrieveSecret(const nsACString& aLabel,

                        /* out */ nsACString& aSecret) = 0;

  // Store a new secret with the given label.

  virtual nsresult StoreSecret(const nsACString& secret,

                               const nsACString& label) = 0;

  // Delete the secret with the given label.

  virtual nsresult DeleteSecret(const nsACString& label) = 0;

  // Lock the key store.

  virtual nsresult Lock() = 0;

  // Unlock the key store.

  virtual nsresult Unlock() = 0;

  // Identify the fallback NSS key store.

  virtual bool IsNSSKeyStore();

  virtual ~AbstractOSKeyStore() {}

  // Returns true if the secret with the given label is available in the key

  // store, false otherwise.

  virtual bool SecretAvailable(const nsACString& label);

  // Perform encryption or decryption operation with the given secret and input

  // bytes. The output is written in outBytes. This function can make use of the

  // AesGcm class to use NSS for encryption and decryption.

  virtual nsresult EncryptDecrypt(const nsACString& label,

                                  const std::vector<uint8_t>& inBytes,

                                  std::vector<uint8_t>& outBytes,

                                  bool encrypt);

  size_t GetKeyByteLength() { return mKeyByteLength; }

protected:

  /* These helper functions are implemented in OSKeyStore.cpp and implement

   * common functionality of the abstract key store to encrypt and decrypt.

   */

  nsresult DoCipher(const UniquePK11SymKey& aSymKey,

                    const std::vector<uint8_t>& inBytes,

                    std::vector<uint8_t>& outBytes,

                    bool aEncrypt);

  nsresult BuildAesGcmKey(std::vector<uint8_t> keyBytes,

                          /* out */ UniquePK11SymKey& aKey);

private:

  const size_t mKeyByteLength = 16;

  const size_t mIVLength = 12;

};

#define NS_OSKEYSTORE_CONTRACTID "@mozilla.org/security/oskeystore;1"

#define NS_OSKEYSTORE_CID \

  { 0x57972956, 0x5718, 0x42d2, { 0x80, 0x70, 0xb3, 0xfc, 0x72, 0x21, 0x2e, 0xaf } }

class OSKeyStore : public nsIOSKeyStore

{

public:

  NS_DECL_THREADSAFE_ISUPPORTS

  NS_DECL_NSIOSKEYSTORE

  OSKeyStore();

  nsresult GenerateSecret(const nsACString& aLabel,

                          /* out */ nsACString& aRecoveryPhrase);

  nsresult SecretAvailable(const nsACString& aLabel,

                           /* out */ bool* aAvailable);

  nsresult RecoverSecret(const nsACString& aLabel,

                         const nsACString& aRecoveryPhrase);

  nsresult DeleteSecret(const nsACString& aLabel);

  nsresult EncryptBytes(const nsACString& aLabel,

                        uint32_t inLen,

                        uint8_t* inBytes,

                        /*out*/ nsACString& aEncryptedBase64Text);

  nsresult DecryptBytes(const nsACString& aLabel,

                        const nsACString& aEncryptedBase64Text,

                        /*out*/ uint32_t* outLen,

                        /*out*/ uint8_t** outBytes);

  nsresult Lock();

  nsresult Unlock();

protected:

  virtual ~OSKeyStore();

private:

  nsresult FinishAsync(RefPtr<mozilla::dom::Promise>& aPromise,

                       /* out*/ mozilla::dom::Promise** anotherPromise,

                       const nsACString& aName,

                       nsCOMPtr<nsIRunnable> aRunnable);

  std::unique_ptr<AbstractOSKeyStore> mKs = nullptr;

  Mutex mMutex;

  const nsCString mLabelPrefix =

    NS_LITERAL_CSTRING("org.mozilla.nss.keystore.");

};

#endif // OSKeyStore_h