1*e7b1675dSTing-Kang Chang // Copyright 2023 Google LLC 2*e7b1675dSTing-Kang Chang // 3*e7b1675dSTing-Kang Chang // Licensed under the Apache License, Version 2.0 (the "License"); 4*e7b1675dSTing-Kang Chang // you may not use this file except in compliance with the License. 5*e7b1675dSTing-Kang Chang // You may obtain a copy of the License at 6*e7b1675dSTing-Kang Chang // 7*e7b1675dSTing-Kang Chang // http://www.apache.org/licenses/LICENSE-2.0 8*e7b1675dSTing-Kang Chang // 9*e7b1675dSTing-Kang Chang // Unless required by applicable law or agreed to in writing, software 10*e7b1675dSTing-Kang Chang // distributed under the License is distributed on an "AS IS" BASIS, 11*e7b1675dSTing-Kang Chang // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12*e7b1675dSTing-Kang Chang // See the License for the specific language governing permissions and 13*e7b1675dSTing-Kang Chang // limitations under the License. 14*e7b1675dSTing-Kang Chang // 15*e7b1675dSTing-Kang Chang //////////////////////////////////////////////////////////////////////////////// 16*e7b1675dSTing-Kang Chang 17*e7b1675dSTing-Kang Chang #ifndef TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 18*e7b1675dSTing-Kang Chang #define TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 19*e7b1675dSTing-Kang Chang 20*e7b1675dSTing-Kang Chang #include "absl/strings/string_view.h" 21*e7b1675dSTing-Kang Chang #include "tink/hybrid/hybrid_parameters.h" 22*e7b1675dSTing-Kang Chang #include "tink/key.h" 23*e7b1675dSTing-Kang Chang 24*e7b1675dSTing-Kang Chang namespace crypto { 25*e7b1675dSTing-Kang Chang namespace tink { 26*e7b1675dSTing-Kang Chang 27*e7b1675dSTing-Kang Chang // Represents the encryption function for a hybrid encryption primitive. 28*e7b1675dSTing-Kang Chang class HybridPublicKey : public Key { 29*e7b1675dSTing-Kang Chang public: 30*e7b1675dSTing-Kang Chang // Returns the bytes prefixed to every ciphertext generated by this key. 31*e7b1675dSTing-Kang Chang // 32*e7b1675dSTing-Kang Chang // In order to make key rotation more efficient, Tink allows every hybrid 33*e7b1675dSTing-Kang Chang // public key to have an associated ciphertext output prefix. When decrypting 34*e7b1675dSTing-Kang Chang // a ciphertext, only keys with a matching prefix have to be tried. 35*e7b1675dSTing-Kang Chang // 36*e7b1675dSTing-Kang Chang // See https://developers.google.com/tink/wire-format#tink_output_prefix for 37*e7b1675dSTing-Kang Chang // more background information on Tink output prefixes. 38*e7b1675dSTing-Kang Chang virtual absl::string_view GetOutputPrefix() const = 0; 39*e7b1675dSTing-Kang Chang 40*e7b1675dSTing-Kang Chang const HybridParameters& GetParameters() const override = 0; 41*e7b1675dSTing-Kang Chang 42*e7b1675dSTing-Kang Chang bool operator==(const Key& other) const override = 0; 43*e7b1675dSTing-Kang Chang }; 44*e7b1675dSTing-Kang Chang 45*e7b1675dSTing-Kang Chang } // namespace tink 46*e7b1675dSTing-Kang Chang } // namespace crypto 47*e7b1675dSTing-Kang Chang 48*e7b1675dSTing-Kang Chang #endif // TINK_HYBRID_HYBRID_PUBLIC_KEY_H_ 49