| // Copyright 2017 Google Inc. |
| // |
| // 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. |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifndef TINK_SUBTLE_AES_CMAC_BORINGSSL_H_ |
| #define TINK_SUBTLE_AES_CMAC_BORINGSSL_H_ |
| |
| #include <memory> |
| |
| #include "absl/strings/string_view.h" |
| #include "tink/mac.h" |
| #include "tink/subtle/common_enums.h" |
| #include "tink/util/status.h" |
| #include "tink/util/statusor.h" |
| |
| namespace crypto { |
| namespace tink { |
| namespace subtle { |
| |
| class AesCmacBoringSsl : public Mac { |
| public: |
| static crypto::tink::util::StatusOr<std::unique_ptr<Mac>> New( |
| const std::string& key_value, uint32_t tag_size); |
| |
| // Computes and returns the CMAC for 'data'. |
| crypto::tink::util::StatusOr<std::string> ComputeMac( |
| absl::string_view data) const override; |
| |
| // Verifies if 'mac' is a correct CMAC for 'data'. |
| // Returns Status::OK if 'mac' is correct, and a non-OK-Status otherwise. |
| crypto::tink::util::Status VerifyMac(absl::string_view mac, |
| absl::string_view data) const override; |
| |
| ~AesCmacBoringSsl() override {} |
| |
| private: |
| // CMAC key sizes in bytes. |
| // The small key size is used only to check RFC 4493's test vectors due to |
| // the attack described in |
| // https://www.math.uwaterloo.ca/~ajmeneze/publications/tightness.pdf. We |
| // check this restriction in AesCmacManager. |
| static const size_t kSmallKeySize = 16; |
| static const size_t kBigKeySize = 32; |
| static const size_t kMaxTagSize = 16; |
| |
| AesCmacBoringSsl(const std::string& key_value, uint32_t tag_size); |
| |
| const std::string key_value_; |
| const uint32_t tag_size_; |
| }; |
| |
| } // namespace subtle |
| } // namespace tink |
| } // namespace crypto |
| |
| #endif // TINK_SUBTLE_AES_CMAC_BORINGSSL_H_ |