1 /*
2 * Copyright (C) 2020 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 <regex.h>
18
19 #include <android-base/properties.h>
20 #include <hardware/hw_auth_token.h>
21
22 namespace aidl::android::hardware::security::keymint {
23
24 namespace {
25
26 constexpr char kPlatformVersionProp[] = "ro.build.version.release";
27 constexpr char kPlatformVersionRegex[] = "^([0-9]{1,2})(\\.([0-9]{1,2}))?(\\.([0-9]{1,2}))?";
28 constexpr size_t kMajorVersionMatch = 1;
29 constexpr size_t kMinorVersionMatch = 3;
30 constexpr size_t kSubminorVersionMatch = 5;
31 constexpr size_t kPlatformVersionMatchCount = kSubminorVersionMatch + 1;
32
33 constexpr char kPlatformPatchlevelProp[] = "ro.build.version.security_patch";
34 constexpr char kVendorPatchlevelProp[] = "ro.vendor.build.security_patch";
35 constexpr char kPatchlevelRegex[] = "^([0-9]{4})-([0-9]{2})-([0-9]{2})$";
36 constexpr size_t kYearMatch = 1;
37 constexpr size_t kMonthMatch = 2;
38 constexpr size_t kDayMatch = 3;
39 constexpr size_t kPatchlevelMatchCount = kDayMatch + 1;
40
match_to_uint32(const char * expression,const regmatch_t & match)41 uint32_t match_to_uint32(const char* expression, const regmatch_t& match) {
42 if (match.rm_so == -1) return 0;
43
44 size_t len = match.rm_eo - match.rm_so;
45 std::string s(expression + match.rm_so, len);
46 return std::stoul(s);
47 }
48
wait_and_get_property(const char * prop)49 std::string wait_and_get_property(const char* prop) {
50 std::string prop_value;
51 while (!::android::base::WaitForPropertyCreation(prop))
52 ;
53 prop_value = ::android::base::GetProperty(prop, "" /* default */);
54 return prop_value;
55 }
56
getOsVersion(const char * version_str)57 uint32_t getOsVersion(const char* version_str) {
58 regex_t regex;
59 if (regcomp(®ex, kPlatformVersionRegex, REG_EXTENDED)) {
60 return 0;
61 }
62
63 regmatch_t matches[kPlatformVersionMatchCount];
64 int not_match =
65 regexec(®ex, version_str, kPlatformVersionMatchCount, matches, 0 /* flags */);
66 regfree(®ex);
67 if (not_match) {
68 return 0;
69 }
70
71 uint32_t major = match_to_uint32(version_str, matches[kMajorVersionMatch]);
72 uint32_t minor = match_to_uint32(version_str, matches[kMinorVersionMatch]);
73 uint32_t subminor = match_to_uint32(version_str, matches[kSubminorVersionMatch]);
74
75 return (major * 100 + minor) * 100 + subminor;
76 }
77
78 enum class PatchlevelOutput { kYearMonthDay, kYearMonth };
79
getPatchlevel(const char * patchlevel_str,PatchlevelOutput detail)80 uint32_t getPatchlevel(const char* patchlevel_str, PatchlevelOutput detail) {
81 regex_t regex;
82 if (regcomp(®ex, kPatchlevelRegex, REG_EXTENDED) != 0) {
83 return 0;
84 }
85
86 regmatch_t matches[kPatchlevelMatchCount];
87 int not_match = regexec(®ex, patchlevel_str, kPatchlevelMatchCount, matches, 0 /* flags */);
88 regfree(®ex);
89 if (not_match) {
90 return 0;
91 }
92
93 uint32_t year = match_to_uint32(patchlevel_str, matches[kYearMatch]);
94 uint32_t month = match_to_uint32(patchlevel_str, matches[kMonthMatch]);
95
96 if (month < 1 || month > 12) {
97 return 0;
98 }
99
100 switch (detail) {
101 case PatchlevelOutput::kYearMonthDay: {
102 uint32_t day = match_to_uint32(patchlevel_str, matches[kDayMatch]);
103 if (day < 1 || day > 31) {
104 return 0;
105 }
106 return year * 10000 + month * 100 + day;
107 }
108 case PatchlevelOutput::kYearMonth:
109 return year * 100 + month;
110 }
111 }
112
113 } // anonymous namespace
114
getOsVersion()115 uint32_t getOsVersion() {
116 std::string version = wait_and_get_property(kPlatformVersionProp);
117 return getOsVersion(version.c_str());
118 }
119
getOsPatchlevel()120 uint32_t getOsPatchlevel() {
121 std::string patchlevel = wait_and_get_property(kPlatformPatchlevelProp);
122 return getPatchlevel(patchlevel.c_str(), PatchlevelOutput::kYearMonth);
123 }
124
getVendorPatchlevel()125 uint32_t getVendorPatchlevel() {
126 std::string patchlevel = wait_and_get_property(kVendorPatchlevelProp);
127 return getPatchlevel(patchlevel.c_str(), PatchlevelOutput::kYearMonthDay);
128 }
129
130 } // namespace aidl::android::hardware::security::keymint
131