1 /* 2 * Copyright 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef SYSTEM_KEYMASTER_KEM_H_ 18 #define SYSTEM_KEYMASTER_KEM_H_ 19 20 #include <keymaster/serializable.h> 21 22 #include "openssl_utils.h" 23 24 namespace keymaster { 25 26 // Kem is an abstract class that provides an interface to a key encapsulation 27 // mechansim primitive. A key encapsulation mechanism works just like a 28 // public-key encryption scheme, except that the encryption algorithm takes no 29 // input other than the recipient’s public key. Instead, the encryption algorithm 30 // generates a pair (K, C0), where K is a bit string of some specified length, 31 // and C0 is an encryption of K, that is, the decryption algorithm applied to C0 32 // yields K. 33 class Kem { 34 public: ~Kem()35 virtual ~Kem(){}; 36 37 // For a key encapsulation mechanism, the goal of encryption is to take the recipient's public 38 // key, and to generate a pair (K, C0), where K is a bit string of some specified length, 39 // and C0 is an encryption of K. 40 virtual bool Encrypt(const Buffer& peer_public_value, Buffer* output_clear_key, 41 Buffer* output_encrypted_key) = 0; 42 virtual bool Encrypt(const uint8_t* peer_public_value, size_t peer_public_value_len, 43 Buffer* output_clear_key, Buffer* output_encrypted_key) = 0; 44 45 // Decrypt takes an encrypted key, and outputs its clear text. 46 // Decrypt takes ownership of \p private_key. 47 virtual bool Decrypt(EC_KEY* private_key, const Buffer& encrypted_key, Buffer* output_key) = 0; 48 virtual bool Decrypt(EC_KEY* private_key, const uint8_t* encrypted_key, 49 size_t encrypted_key_len, Buffer* output_key) = 0; 50 }; 51 52 } // namespace keymaster 53 54 #endif // SYSTEM_KEYMASTER_KEM_H_ 55