1 // Copyright 2017 Google Inc. 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_SUBTLE_IND_CPA_CIPHER_H_ 18 #define TINK_SUBTLE_IND_CPA_CIPHER_H_ 19 20 #include <string> 21 22 #include "absl/strings/string_view.h" 23 #include "tink/util/statusor.h" 24 25 namespace crypto { 26 namespace tink { 27 namespace subtle { 28 29 /////////////////////////////////////////////////////////////////////////////// 30 // This interface for symmetric key ciphers that are indistinguishable against 31 // chosen-plaintext attacks. Said primitives do not provide authentication, 32 // thus should not be used directly, but only to construct safer primitives 33 // such as Aead. 34 class IndCpaCipher { 35 public: 36 // Encrypts 'plaintext'. The resulting ciphertext is indistinguishable under 37 // chosen-plaintext attack. However, it does not have integrity protection. 38 virtual crypto::tink::util::StatusOr<std::string> Encrypt( 39 absl::string_view plaintext) const = 0; 40 41 // Decrypts 'ciphertext' and returns the resulting plaintext. 42 virtual crypto::tink::util::StatusOr<std::string> Decrypt( 43 absl::string_view ciphertext) const = 0; 44 45 virtual ~IndCpaCipher() = default; 46 }; 47 48 } // namespace subtle 49 } // namespace tink 50 } // namespace crypto 51 52 #endif // TINK_SUBTLE_IND_CPA_CIPHER_H_ 53