1 files changed, 114 insertions, 0 deletions
diff --git a/security/keymint/support/keymint_utils.cpp b/security/keymint/support/keymint_utils.cpp
new file mode 100644
index 0000000000..cd4cca222a
--- /dev/null
+++ b/security/keymint/support/keymint_utils.cpp
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <regex.h>
+
+#include <android-base/properties.h>
+#include <hardware/hw_auth_token.h>
+#include <keymint_support/keymint_utils.h>
+
+#include <arpa/inet.h>
+
+namespace android::hardware::security::keymint {
+
+namespace {
+
+constexpr char kPlatformVersionProp[] = "ro.build.version.release";
+constexpr char kPlatformVersionRegex[] = "^([0-9]{1,2})(\\.([0-9]{1,2}))?(\\.([0-9]{1,2}))?";
+constexpr size_t kMajorVersionMatch = 1;
+constexpr size_t kMinorVersionMatch = 3;
+constexpr size_t kSubminorVersionMatch = 5;
+constexpr size_t kPlatformVersionMatchCount = kSubminorVersionMatch + 1;
+
+constexpr char kPlatformPatchlevelProp[] = "ro.build.version.security_patch";
+constexpr char kPlatformPatchlevelRegex[] = "^([0-9]{4})-([0-9]{2})-[0-9]{2}$";
+constexpr size_t kYearMatch = 1;
+constexpr size_t kMonthMatch = 2;
+constexpr size_t kPlatformPatchlevelMatchCount = kMonthMatch + 1;
+
+uint32_t match_to_uint32(const char* expression, const regmatch_t& match) {
+    if (match.rm_so == -1) return 0;
+
+    size_t len = match.rm_eo - match.rm_so;
+    std::string s(expression + match.rm_so, len);
+    return std::stoul(s);
+}
+
+std::string wait_and_get_property(const char* prop) {
+    std::string prop_value;
+    while (!::android::base::WaitForPropertyCreation(prop))
+        ;
+    prop_value = ::android::base::GetProperty(prop, "" /* default */);
+    return prop_value;
+}
+
+}  // anonymous namespace
+
+uint32_t getOsVersion(const char* version_str) {
+    regex_t regex;
+    if (regcomp(&regex, kPlatformVersionRegex, REG_EXTENDED)) {
+        return 0;
+    }
+
+    regmatch_t matches[kPlatformVersionMatchCount];
+    int not_match =
+            regexec(&regex, version_str, kPlatformVersionMatchCount, matches, 0 /* flags */);
+    regfree(&regex);
+    if (not_match) {
+        return 0;
+    }
+
+    uint32_t major = match_to_uint32(version_str, matches[kMajorVersionMatch]);
+    uint32_t minor = match_to_uint32(version_str, matches[kMinorVersionMatch]);
+    uint32_t subminor = match_to_uint32(version_str, matches[kSubminorVersionMatch]);
+
+    return (major * 100 + minor) * 100 + subminor;
+}
+
+uint32_t getOsVersion() {
+    std::string version = wait_and_get_property(kPlatformVersionProp);
+    return getOsVersion(version.c_str());
+}
+
+uint32_t getOsPatchlevel(const char* patchlevel_str) {
+    regex_t regex;
+    if (regcomp(&regex, kPlatformPatchlevelRegex, REG_EXTENDED) != 0) {
+        return 0;
+    }
+
+    regmatch_t matches[kPlatformPatchlevelMatchCount];
+    int not_match =
+            regexec(&regex, patchlevel_str, kPlatformPatchlevelMatchCount, matches, 0 /* flags */);
+    regfree(&regex);
+    if (not_match) {
+        return 0;
+    }
+
+    uint32_t year = match_to_uint32(patchlevel_str, matches[kYearMatch]);
+    uint32_t month = match_to_uint32(patchlevel_str, matches[kMonthMatch]);
+
+    if (month < 1 || month > 12) {
+        return 0;
+    }
+    return year * 100 + month;
+}
+
+uint32_t getOsPatchlevel() {
+    std::string patchlevel = wait_and_get_property(kPlatformPatchlevelProp);
+    return getOsPatchlevel(patchlevel.c_str());
+}
+
+}  // namespace android::hardware::security::keymint