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_SIGNATURE_SIGNATURE_PUBLIC_KEY_H_ 18 #define TINK_SIGNATURE_SIGNATURE_PUBLIC_KEY_H_ 19 20 #include "absl/strings/string_view.h" 21 #include "tink/key.h" 22 #include "tink/signature/signature_parameters.h" 23 24 namespace crypto { 25 namespace tink { 26 27 // Represents a function to verify digital signatures. 28 class SignaturePublicKey : public Key { 29 public: 30 // Returns the bytes prefixed to every signature generated by the 31 // corresponding private key. 32 // 33 // In order to make key rotation more efficient, Tink allows every signature 34 // public key to have an associated signature output prefix. When verifying a 35 // digital signature, only keys with a matching prefix have to be tried. 36 // 37 // See https://developers.google.com/tink/wire-format#tink_output_prefix for 38 // more background information on Tink output prefixes. 39 virtual absl::string_view GetOutputPrefix() const = 0; 40 41 const SignatureParameters& GetParameters() const override = 0; 42 43 bool operator==(const Key& other) const override = 0; 44 }; 45 46 } // namespace tink 47 } // namespace crypto 48 49 #endif // TINK_SIGNATURE_SIGNATURE_PUBLIC_KEY_H_ 50