| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| // Author: jmaessen@google.com (Jan-Willem Maessen) |
| |
| #ifndef PAGESPEED_KERNEL_UTIL_NONCE_GENERATOR_H_ |
| #define PAGESPEED_KERNEL_UTIL_NONCE_GENERATOR_H_ |
| |
| #include "pagespeed/kernel/base/abstract_mutex.h" |
| #include "pagespeed/kernel/base/basictypes.h" |
| #include "pagespeed/kernel/base/scoped_ptr.h" |
| |
| namespace net_instaweb { |
| |
| // Abstract base class for a generator of cryptographic nonce values (ie a |
| // cryptographic random number generator). |
| class NonceGenerator { |
| public: |
| virtual ~NonceGenerator(); |
| // Generate a fresh, ideally cryptographic, nonce. Thread-safe. |
| uint64 NewNonce(); |
| |
| protected: |
| // Takes ownership of mutex. |
| explicit NonceGenerator(AbstractMutex* mutex) : mutex_(mutex) { } |
| |
| // Subclasses must implement this method. Locking is already handled. |
| virtual uint64 NewNonceImpl() = 0; |
| |
| private: |
| scoped_ptr<AbstractMutex> mutex_; |
| |
| DISALLOW_COPY_AND_ASSIGN(NonceGenerator); |
| }; |
| |
| } // namespace net_instaweb |
| |
| #endif // PAGESPEED_KERNEL_UTIL_NONCE_GENERATOR_H_ |