1 // Copyright 2023 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 //////////////////////////////////////////////////////////////////////////////// 16 17 #ifndef TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 18 #define TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 19 20 #include "absl/strings/string_view.h" 21 #include "tink/hybrid/hybrid_parameters.h" 22 #include "tink/key.h" 23 24 namespace crypto { 25 namespace tink { 26 27 // Represents the encryption function for a hybrid encryption primitive. 28 class HybridPublicKey : public Key { 29 public: 30 // Returns the bytes prefixed to every ciphertext generated by this key. 31 // 32 // In order to make key rotation more efficient, Tink allows every hybrid 33 // public key to have an associated ciphertext output prefix. When decrypting 34 // a ciphertext, only keys with a matching prefix have to be tried. 35 // 36 // See https://developers.google.com/tink/wire-format#tink_output_prefix for 37 // more background information on Tink output prefixes. 38 virtual absl::string_view GetOutputPrefix() const = 0; 39 40 const HybridParameters& GetParameters() const override = 0; 41 42 bool operator==(const Key& other) const override = 0; 43 }; 44 45 } // namespace tink 46 } // namespace crypto 47 48 #endif // TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 49