1 /*
2 * Copyright (C) 2016 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 <keymaster/keymaster_configuration.h>
18
19 #include <regex>
20 #include <string>
21
22 #include <regex.h>
23
24 #define LOG_TAG "keymaster"
25
26 #include <android-base/properties.h>
27 #include <log/log.h>
28
29 #include <keymaster/authorization_set.h>
30
31 namespace keymaster {
32
33 namespace {
34
35 constexpr char kPlatformVersionProp[] = "ro.build.version.release";
36 constexpr char kPlatformVersionRegex[] = "^([0-9]{1,2})(\\.([0-9]{1,2}))?(\\.([0-9]{1,2}))?";
37 constexpr size_t kMajorVersionMatch = 1;
38 constexpr size_t kMinorVersionMatch = 3;
39 constexpr size_t kSubminorVersionMatch = 5;
40 constexpr size_t kPlatformVersionMatchCount = kSubminorVersionMatch + 1;
41
42 constexpr char kPlatformPatchlevelProp[] = "ro.build.version.security_patch";
43 constexpr char kPlatformPatchlevelRegex[] = "^([0-9]{4})-([0-9]{2})-[0-9]{2}$";
44 constexpr size_t kYearMatch = 1;
45 constexpr size_t kMonthMatch = 2;
46 constexpr size_t kPlatformPatchlevelMatchCount = kMonthMatch + 1;
47
match_to_uint32(const char * expression,const regmatch_t & match)48 uint32_t match_to_uint32(const char* expression, const regmatch_t& match) {
49 if (match.rm_so == -1)
50 return 0;
51
52 size_t len = match.rm_eo - match.rm_so;
53 std::string s(expression + match.rm_so, len);
54 return std::stoul(s);
55 }
56
wait_and_get_property(const char * prop)57 std::string wait_and_get_property(const char* prop) {
58 std::string prop_value;
59 #ifndef KEYMASTER_UNIT_TEST_BUILD
60 while (!android::base::WaitForPropertyCreation(prop)) {
61 SLOGE("waited 15s for %s, still waiting...", prop);
62 }
63 prop_value = android::base::GetProperty(prop, "" /* default */);
64 #endif
65 return prop_value;
66 }
67
68 } // anonymous namespace
69
ConfigureDevice(keymaster2_device_t * dev,uint32_t os_version,uint32_t os_patchlevel)70 keymaster_error_t ConfigureDevice(keymaster2_device_t* dev, uint32_t os_version,
71 uint32_t os_patchlevel) {
72 AuthorizationSet config_params(AuthorizationSetBuilder()
73 .Authorization(keymaster::TAG_OS_VERSION, os_version)
74 .Authorization(keymaster::TAG_OS_PATCHLEVEL, os_patchlevel));
75 return dev->configure(dev, &config_params);
76 }
77
ConfigureDevice(keymaster2_device_t * dev)78 keymaster_error_t ConfigureDevice(keymaster2_device_t* dev) {
79 return ConfigureDevice(dev, GetOsVersion(), GetOsPatchlevel());
80 }
81
GetOsVersion(const char * version_str)82 uint32_t GetOsVersion(const char* version_str) {
83 regex_t regex;
84 if (regcomp(®ex, kPlatformVersionRegex, REG_EXTENDED)) {
85 ALOGE("Failed to compile version regex! (%s)", kPlatformVersionRegex);
86 return 0;
87 }
88
89 regmatch_t matches[kPlatformVersionMatchCount];
90 int not_match =
91 regexec(®ex, version_str, kPlatformVersionMatchCount, matches, 0 /* flags */);
92 regfree(®ex);
93 if (not_match) {
94 ALOGI("Platform version string does not match expected format. Using version 0.");
95 return 0;
96 }
97
98 uint32_t major = match_to_uint32(version_str, matches[kMajorVersionMatch]);
99 uint32_t minor = match_to_uint32(version_str, matches[kMinorVersionMatch]);
100 uint32_t subminor = match_to_uint32(version_str, matches[kSubminorVersionMatch]);
101
102 return (major * 100 + minor) * 100 + subminor;
103 }
104
GetOsVersion()105 uint32_t GetOsVersion() {
106 std::string version = wait_and_get_property(kPlatformVersionProp);
107 return GetOsVersion(version.c_str());
108 }
109
GetOsPatchlevel(const char * patchlevel_str)110 uint32_t GetOsPatchlevel(const char* patchlevel_str) {
111 regex_t regex;
112 if (regcomp(®ex, kPlatformPatchlevelRegex, REG_EXTENDED) != 0) {
113 ALOGE("Failed to compile platform patchlevel regex! (%s)", kPlatformPatchlevelRegex);
114 return 0;
115 }
116
117 regmatch_t matches[kPlatformPatchlevelMatchCount];
118 int not_match =
119 regexec(®ex, patchlevel_str, kPlatformPatchlevelMatchCount, matches, 0 /* flags */);
120 regfree(®ex);
121 if (not_match) {
122 ALOGI("Platform patchlevel string does not match expected format. Using patchlevel 0");
123 return 0;
124 }
125
126 uint32_t year = match_to_uint32(patchlevel_str, matches[kYearMatch]);
127 uint32_t month = match_to_uint32(patchlevel_str, matches[kMonthMatch]);
128
129 if (month < 1 || month > 12) {
130 ALOGE("Invalid patch month %d", month);
131 return 0;
132 }
133 return year * 100 + month;
134 }
135
GetOsPatchlevel()136 uint32_t GetOsPatchlevel() {
137 std::string patchlevel = wait_and_get_property(kPlatformPatchlevelProp);
138 return GetOsPatchlevel(patchlevel.c_str());
139 }
140
141 } // namespace keymaster
142