chromecast/crypto/signature_cache.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROMECAST_CRYPTO_SIGNATURE_CACHE_H_
   6 #define CHROMECAST_CRYPTO_SIGNATURE_CACHE_H_
   7
   8 #include <string>
   9
  10 #include "base/containers/mru_cache.h"
  11 #include "base/macros.h"
  12 #include "base/synchronization/lock.h"
  13
  14 namespace chromecast {
  15
  16 // Cache the signatures of hashes corresponding to a particular private key
  17 // (only the most recent one for which a signature was cached). We expect that
  18 // normally the same private key will be used always, however we also
  19 // accommodate the case where the key is changed and a new key becomes current.
  20 // In this case we flush the cache and start over with the new key.
  21 class SignatureCache {
  22  public:
  23   SignatureCache();
  24   ~SignatureCache();
  25
  26   std::string Get(const std::string& wrapped_private_key,
  27                   const std::string& hash);
  28
  29   void Put(const std::string& wrapped_private_key,
  30            const std::string& hash,
  31            const std::string& signature);
  32
  33  private:
  34   std::string key_;
  35   base::Lock lock_;
  36   base::HashingMRUCache<std::string, std::string> contents_;
  37
  38   DISALLOW_COPY_AND_ASSIGN(SignatureCache);
  39 };
  40
  41 }  // namespace chromecast
  42
  43 #endif  // CHROMECAST_CRYPTO_SIGNATURE_CACHE_H_