Support library enhancements, to ease transition of vold to KM4
Keymaster clients need to see all the available devices and figure out
which they want to use. This method finds them all and returns them
in a vector sorted from most secure to least, according to a heuristic
defined in Keymaster::VersionResult::operator<
This CL also makes a few other minor improvements to the support
library, providing more information in VersionResult and adding some
more convenience methods in AuthorizationSetBuilder.
Test: Build & boot
Change-Id: I876238ee9ff72573c30d60e1cec665dd610bcde6
diff --git a/keymaster/4.0/support/Keymaster.cpp b/keymaster/4.0/support/Keymaster.cpp
new file mode 100644
index 0000000..bf52c47
--- /dev/null
+++ b/keymaster/4.0/support/Keymaster.cpp
@@ -0,0 +1,90 @@
+/*
+ ** Copyright 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 <keymasterV4_0/Keymaster.h>
+
+#include <android-base/logging.h>
+#include <android/hidl/manager/1.0/IServiceManager.h>
+#include <keymasterV4_0/Keymaster3.h>
+#include <keymasterV4_0/Keymaster4.h>
+
+namespace android {
+namespace hardware {
+namespace keymaster {
+namespace V4_0 {
+namespace support {
+
+using ::android::sp;
+using ::android::hidl::manager::V1_0::IServiceManager;
+
+template <typename Wrapper>
+std::vector<std::unique_ptr<Keymaster>> enumerateDevices(
+ const sp<IServiceManager>& serviceManager) {
+ std::vector<std::unique_ptr<Keymaster>> result;
+
+ bool foundDefault = false;
+ auto& descriptor = Wrapper::WrappedIKeymasterDevice::descriptor;
+ serviceManager->listByInterface(descriptor, [&](const hidl_vec<hidl_string>& names) {
+ for (auto& name : names) {
+ if (name == "default") foundDefault = true;
+ auto device = Wrapper::WrappedIKeymasterDevice::getService();
+ CHECK(device) << "Failed to get service for " << descriptor << " with interface name "
+ << name;
+ result.push_back(std::unique_ptr<Keymaster>(new Wrapper(device, name)));
+ }
+ });
+
+ if (!foundDefault) {
+ // "default" wasn't provided by listByInterface. Maybe there's a passthrough
+ // implementation.
+ auto device = Wrapper::WrappedIKeymasterDevice::getService("default");
+ if (device) result.push_back(std::unique_ptr<Keymaster>(new Wrapper(device, "default")));
+ }
+
+ return result;
+}
+
+std::vector<std::unique_ptr<Keymaster>> Keymaster::enumerateAvailableDevices() {
+ auto serviceManager = IServiceManager::getService();
+ CHECK(serviceManager) << "Could not retrieve ServiceManager";
+
+ auto km4s = enumerateDevices<Keymaster4>(serviceManager);
+ auto km3s = enumerateDevices<Keymaster3>(serviceManager);
+
+ auto result = std::move(km4s);
+ result.insert(result.end(), std::make_move_iterator(km3s.begin()),
+ std::make_move_iterator(km3s.end()));
+
+ std::sort(result.begin(), result.end(),
+ [](auto& a, auto& b) { return a->halVersion() > b->halVersion(); });
+
+ size_t i = 1;
+ LOG(INFO) << "List of Keymaster HALs found:";
+ for (auto& hal : result) {
+ auto& version = hal->halVersion();
+ LOG(INFO) << "Keymaster HAL #" << i << ": " << version.keymasterName << " from "
+ << version.authorName << " SecurityLevel: " << toString(version.securityLevel)
+ << " HAL : " << hal->descriptor() << " instance " << hal->instanceName();
+ }
+
+ return result;
+}
+
+} // namespace support
+} // namespace V4_0
+} // namespace keymaster
+} // namespace hardware
+}; // namespace android