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 <array>
20
21 namespace bluetooth {
22 namespace crypto_toolbox {
23
24 constexpr int OCTET16_LEN = 16;
25 using Octet16 = std::array<uint8_t, OCTET16_LEN>;
26
27 Octet16 c1(const Octet16& k, const Octet16& r, const uint8_t* pres, const uint8_t* preq, const uint8_t iat,
28 const uint8_t* ia, const uint8_t rat, const uint8_t* ra);
29 Octet16 s1(const Octet16& k, const Octet16& r1, const Octet16& r2);
30
31 extern Octet16 aes_128(const Octet16& key, const Octet16& message);
32 extern Octet16 aes_cmac(const Octet16& key, const uint8_t* message, uint16_t length);
33 extern Octet16 f4(uint8_t* u, uint8_t* v, const Octet16& x, uint8_t z);
34 extern void f5(uint8_t* w, const Octet16& n1, const Octet16& n2, uint8_t* a1, uint8_t* a2, Octet16* mac_key,
35 Octet16* ltk);
36 extern Octet16 f6(const Octet16& w, const Octet16& n1, const Octet16& n2, const Octet16& r, uint8_t* iocap, uint8_t* a1,
37 uint8_t* a2);
38 extern Octet16 h6(const Octet16& w, std::array<uint8_t, 4> keyid);
39 extern Octet16 h7(const Octet16& salt, const Octet16& w);
40 extern uint32_t g2(uint8_t* u, uint8_t* v, const Octet16& x, const Octet16& y);
41 extern Octet16 ltk_to_link_key(const Octet16& ltk, bool use_h7);
42 extern Octet16 link_key_to_ltk(const Octet16& link_key, bool use_h7);
43
44 /* This function computes AES_128(key, message). |key| must be 128bit.
45 * |message| can be at most 16 bytes long, it's length in bytes is given in
46 * |length| */
aes_128(const Octet16 & key,const uint8_t * message,const uint8_t length)47 inline Octet16 aes_128(const Octet16& key, const uint8_t* message, const uint8_t length) {
48 // CHECK(length <= OCTET16_LEN) << "you tried aes_128 more than 16 bytes!";
49 Octet16 msg{0};
50 std::copy(message, message + length, msg.begin());
51 return aes_128(key, msg);
52 }
53
54 // |tlen| - lenth of mac desired
55 // |p_signature| - data pointer to where signed data to be stored, tlen long.
aes_cmac(const Octet16 & key,const uint8_t * message,uint16_t length,uint16_t tlen,uint8_t * p_signature)56 inline void aes_cmac(const Octet16& key, const uint8_t* message, uint16_t length, uint16_t tlen, uint8_t* p_signature) {
57 Octet16 signature = aes_cmac(key, message, length);
58
59 uint8_t* p_mac = signature.data() + (OCTET16_LEN - tlen);
60 memcpy(p_signature, p_mac, tlen);
61 }
62
aes_cmac(const Octet16 & key,const Octet16 & message)63 inline Octet16 aes_cmac(const Octet16& key, const Octet16& message) {
64 return aes_cmac(key, message.data(), message.size());
65 }
66
67 } // namespace crypto_toolbox
68 } // namespace bluetooth