1 /*
2  **
3  ** Copyright 2016, The Android Open Source Project
4  **
5  ** Licensed under the Apache License, Version 2.0 (the "License");
6  ** you may not use this file except in compliance with the License.
7  ** You may obtain a copy of the License at
8  **
9  **     http://www.apache.org/licenses/LICENSE-2.0
10  **
11  ** Unless required by applicable law or agreed to in writing, software
12  ** distributed under the License is distributed on an "AS IS" BASIS,
13  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  ** See the License for the specific language governing permissions and
15  ** limitations under the License.
16  */
17 
18 #ifndef KEYSTORE_KEYSTORE_HIDL_SUPPORT_H_
19 #define KEYSTORE_KEYSTORE_HIDL_SUPPORT_H_
20 
21 #include <android/hardware/keymaster/3.0/IKeymasterDevice.h>
22 #include <hidl/Status.h>
23 #include <keystore/keymaster_tags.h>
24 #include <ostream>
25 #include <sstream>
26 #include <string>
27 
28 namespace keystore {
29 
formatArgs(std::ostream & out)30 inline static std::ostream& formatArgs(std::ostream& out) {
31     return out;
32 }
33 
34 template <typename First, typename... Args>
formatArgs(std::ostream & out,First && first,Args &&...args)35 inline static std::ostream& formatArgs(std::ostream& out, First&& first, Args&&... args) {
36     out << first;
37     return formatArgs(out, args...);
38 }
39 
argsToString(Args &&...args)40 template <typename... Args> inline static std::string argsToString(Args&&... args) {
41     std::stringstream s;
42     formatArgs(s, args...);
43     return s.str();
44 }
45 
46 template <typename... Msgs>
ksHandleHidlError(const Return<ErrorCode> & error,Msgs &&...msgs)47 inline static ErrorCode ksHandleHidlError(const Return<ErrorCode>& error, Msgs&&... msgs) {
48     if (!error.isOk()) {
49         ALOGE("HIDL call failed with %s @ %s", error.description().c_str(),
50               argsToString(msgs...).c_str());
51         return ErrorCode::UNKNOWN_ERROR;
52     }
53     return ErrorCode(error);
54 }
55 template <typename... Msgs>
ksHandleHidlError(const Return<void> & error,Msgs &&...msgs)56 inline static ErrorCode ksHandleHidlError(const Return<void>& error, Msgs&&... msgs) {
57     if (!error.isOk()) {
58         ALOGE("HIDL call failed with %s @ %s", error.description().c_str(),
59               argsToString(msgs...).c_str());
60         return ErrorCode::UNKNOWN_ERROR;
61     }
62     return ErrorCode::OK;
63 }
64 
65 #define KS_HANDLE_HIDL_ERROR(rc)                                                                   \
66     ::keystore::ksHandleHidlError(rc, __FILE__, ":", __LINE__, ":", __PRETTY_FUNCTION__)
67 
68 inline static hidl_vec<uint8_t> blob2hidlVec(const uint8_t* data, const size_t length,
69                                              bool inPlace = true) {
70     hidl_vec<uint8_t> result;
71     if (inPlace)
72         result.setToExternal(const_cast<unsigned char*>(data), length);
73     else {
74         result.resize(length);
75         memcpy(&result[0], data, length);
76     }
77     return result;
78 }
79 
blob2hidlVec(const std::string & value)80 inline static hidl_vec<uint8_t> blob2hidlVec(const std::string& value) {
81     hidl_vec<uint8_t> result;
82     result.setToExternal(
83         reinterpret_cast<uint8_t*>(const_cast<std::string::value_type*>(value.data())),
84         static_cast<size_t>(value.size()));
85     return result;
86 }
87 
blob2hidlVec(const std::vector<uint8_t> & blob)88 inline static hidl_vec<uint8_t> blob2hidlVec(const std::vector<uint8_t>& blob) {
89     hidl_vec<uint8_t> result;
90     result.setToExternal(const_cast<uint8_t*>(blob.data()), static_cast<size_t>(blob.size()));
91     return result;
92 }
93 
94 template <typename T, typename OutIter>
copy_bytes_to_iterator(const T & value,OutIter dest)95 inline static OutIter copy_bytes_to_iterator(const T& value, OutIter dest) {
96     const uint8_t* value_ptr = reinterpret_cast<const uint8_t*>(&value);
97     return std::copy(value_ptr, value_ptr + sizeof(value), dest);
98 }
99 
authToken2HidlVec(const HardwareAuthToken & token)100 inline static hidl_vec<uint8_t> authToken2HidlVec(const HardwareAuthToken& token) {
101     static_assert(
102         std::is_same<decltype(token.hmac), ::android::hardware::hidl_array<uint8_t, 32>>::value,
103         "This function assumes token HMAC is 32 bytes, but it might not be.");
104     static_assert(1 /* version size */ + sizeof(token.challenge) + sizeof(token.userId) +
105                           sizeof(token.authenticatorId) + sizeof(token.authenticatorType) +
106                           sizeof(token.timestamp) + 32 /* HMAC size */
107                       == sizeof(hw_auth_token_t),
108                   "HardwareAuthToken content size does not match hw_auth_token_t size");
109 
110     hidl_vec<uint8_t> result;
111     result.resize(sizeof(hw_auth_token_t));
112     auto pos = result.begin();
113     *pos++ = 0;  // Version byte
114     pos = copy_bytes_to_iterator(token.challenge, pos);
115     pos = copy_bytes_to_iterator(token.userId, pos);
116     pos = copy_bytes_to_iterator(token.authenticatorId, pos);
117     pos = copy_bytes_to_iterator(token.authenticatorType, pos);
118     pos = copy_bytes_to_iterator(token.timestamp, pos);
119     pos = std::copy(token.hmac.data(), token.hmac.data() + token.hmac.size(), pos);
120 
121     return result;
122 }
123 
hidlVec2String(const hidl_vec<uint8_t> & value)124 inline std::string hidlVec2String(const hidl_vec<uint8_t>& value) {
125     return std::string(reinterpret_cast<const std::string::value_type*>(&value[0]), value.size());
126 }
127 
128 }  // namespace keystore
129 
130 #endif  // KEYSTORE_KEYSTORE_HIDL_SUPPORT_H_
131