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 #include <hardware/hw_auth_token.h>
18 #include <keymasterV4_0/keymaster_utils.h>
19
20 namespace android {
21 namespace hardware {
22
operator <(const hidl_vec<uint8_t> & a,const hidl_vec<uint8_t> & b)23 inline static bool operator<(const hidl_vec<uint8_t>& a, const hidl_vec<uint8_t>& b) {
24 return memcmp(a.data(), b.data(), std::min(a.size(), b.size())) == -1;
25 }
26
27 template <size_t SIZE>
operator <(const hidl_array<uint8_t,SIZE> & a,const hidl_array<uint8_t,SIZE> & b)28 inline static bool operator<(const hidl_array<uint8_t, SIZE>& a,
29 const hidl_array<uint8_t, SIZE>& b) {
30 return memcmp(a.data(), b.data(), SIZE) == -1;
31 }
32
33 namespace keymaster {
34 namespace V4_0 {
35
operator <(const HmacSharingParameters & a,const HmacSharingParameters & b)36 bool operator<(const HmacSharingParameters& a, const HmacSharingParameters& b) {
37 return std::tie(a.seed, a.nonce) < std::tie(b.seed, b.nonce);
38 }
39
40 namespace support {
41
42 template <typename T, typename InIter>
copy_bytes_from_iterator(T * value,InIter src)43 inline static InIter copy_bytes_from_iterator(T* value, InIter src) {
44 uint8_t* value_ptr = reinterpret_cast<uint8_t*>(value);
45 std::copy(src, src + sizeof(T), value_ptr);
46 return src + sizeof(T);
47 }
48
49 template <typename T, typename OutIter>
copy_bytes_to_iterator(const T & value,OutIter dest)50 inline static OutIter copy_bytes_to_iterator(const T& value, OutIter dest) {
51 const uint8_t* value_ptr = reinterpret_cast<const uint8_t*>(&value);
52 return std::copy(value_ptr, value_ptr + sizeof(value), dest);
53 }
54
55 constexpr size_t kHmacSize = 32;
56
authToken2HidlVec(const HardwareAuthToken & token)57 hidl_vec<uint8_t> authToken2HidlVec(const HardwareAuthToken& token) {
58 static_assert(1 /* version size */ + sizeof(token.challenge) + sizeof(token.userId) +
59 sizeof(token.authenticatorId) + sizeof(token.authenticatorType) +
60 sizeof(token.timestamp) + kHmacSize ==
61 sizeof(hw_auth_token_t),
62 "HardwareAuthToken content size does not match hw_auth_token_t size");
63
64 hidl_vec<uint8_t> result;
65 result.resize(sizeof(hw_auth_token_t));
66 auto pos = result.begin();
67 *pos++ = 0; // Version byte
68 pos = copy_bytes_to_iterator(token.challenge, pos);
69 pos = copy_bytes_to_iterator(token.userId, pos);
70 pos = copy_bytes_to_iterator(token.authenticatorId, pos);
71 auto auth_type = htonl(static_cast<uint32_t>(token.authenticatorType));
72 pos = copy_bytes_to_iterator(auth_type, pos);
73 auto timestamp = htonq(token.timestamp);
74 pos = copy_bytes_to_iterator(timestamp, pos);
75 if (token.mac.size() != kHmacSize) {
76 std::fill(pos, pos + kHmacSize, 0);
77 } else {
78 std::copy(token.mac.begin(), token.mac.end(), pos);
79 }
80
81 return result;
82 }
83
hidlVec2AuthToken(const hidl_vec<uint8_t> & buffer)84 HardwareAuthToken hidlVec2AuthToken(const hidl_vec<uint8_t>& buffer) {
85 HardwareAuthToken token;
86 static_assert(1 /* version size */ + sizeof(token.challenge) + sizeof(token.userId) +
87 sizeof(token.authenticatorId) + sizeof(token.authenticatorType) +
88 sizeof(token.timestamp) + kHmacSize ==
89 sizeof(hw_auth_token_t),
90 "HardwareAuthToken content size does not match hw_auth_token_t size");
91
92 if (buffer.size() != sizeof(hw_auth_token_t)) return {};
93
94 auto pos = buffer.begin();
95 ++pos; // skip first byte
96 pos = copy_bytes_from_iterator(&token.challenge, pos);
97 pos = copy_bytes_from_iterator(&token.userId, pos);
98 pos = copy_bytes_from_iterator(&token.authenticatorId, pos);
99 pos = copy_bytes_from_iterator(&token.authenticatorType, pos);
100 token.authenticatorType = static_cast<HardwareAuthenticatorType>(
101 ntohl(static_cast<uint32_t>(token.authenticatorType)));
102 pos = copy_bytes_from_iterator(&token.timestamp, pos);
103 token.timestamp = ntohq(token.timestamp);
104 token.mac.resize(kHmacSize);
105 std::copy(pos, pos + kHmacSize, token.mac.data());
106
107 return token;
108 }
109
110 } // namespace support
111 } // namespace V4_0
112 } // namespace keymaster
113 } // namespace hardware
114 } // namespace android
115