1 /*
2  * Copyright (C) 2018 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 #pragma once
18 
19 #include <algorithm>
20 #include <array>
21 #include <cstdint>
22 
23 namespace rootcanal::crypto {
24 
25 constexpr int kOctet16Length = 16;
26 using Octet16 = std::array<uint8_t, kOctet16Length>;
27 
28 Octet16 aes_128(const Octet16& key, const Octet16& message);
29 
30 /* This function computes AES_128(key, message). |key| must be 128bit.
31  * |message| can be at most 16 bytes long, its length in bytes is given in
32  * |length| */
aes_128(const Octet16 & key,const uint8_t * message,const uint8_t length)33 inline Octet16 aes_128(const Octet16& key, const uint8_t* message,
34                        const uint8_t length) {
35   Octet16 padded_message{0};
36   std::copy(message, message + length, padded_message.begin());
37   return aes_128(key, padded_message);
38 }
39 
40 }  // namespace rootcanal::crypto
41