First working version of the confirmationui HAL service

This implementation does not provide any security guaranties.
 * The input method (NotSoSecureInput) runs a crypto protocols that is
   sufficiently secure IFF the end point is implemented on a trustworthy
   secure input device. But since the endpoint is currently in the HAL
   service itself this implementation is not secure.
 * This implementation provides most of the functionality, but not the
   secure UI infrastructure required to run Android Protected
   Confirmation.

Bug: 146078942
Test: VtsHalConfirmationUIV1_0TargetTest
Change-Id: I14717b5fa4ef15db960cdd506b8c6fe5369aec8d
diff --git a/trusty/confirmationui/TrustyConfirmationUI.h b/trusty/confirmationui/TrustyConfirmationUI.h
new file mode 100644
index 0000000..3a7c7ef
--- /dev/null
+++ b/trusty/confirmationui/TrustyConfirmationUI.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2020, 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.
+ */
+
+#ifndef ANDROID_HARDWARE_CONFIRMATIONUI_V1_0_TRUSTY_CONFIRMATIONUI_H
+#define ANDROID_HARDWARE_CONFIRMATIONUI_V1_0_TRUSTY_CONFIRMATIONUI_H
+
+#include <android/hardware/confirmationui/1.0/IConfirmationUI.h>
+#include <android/hardware/keymaster/4.0/types.h>
+#include <hidl/Status.h>
+
+#include <atomic>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <teeui/generic_messages.h>
+#include <thread>
+
+#include "TrustyApp.h"
+
+namespace android {
+namespace hardware {
+namespace confirmationui {
+namespace V1_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+using ::android::trusty::TrustyApp;
+
+class TrustyConfirmationUI : public IConfirmationUI {
+  public:
+    TrustyConfirmationUI();
+    virtual ~TrustyConfirmationUI();
+    // Methods from ::android::hardware::confirmationui::V1_0::IConfirmationUI
+    // follow.
+    Return<ResponseCode> promptUserConfirmation(const sp<IConfirmationResultCallback>& resultCB,
+                                                const hidl_string& promptText,
+                                                const hidl_vec<uint8_t>& extraData,
+                                                const hidl_string& locale,
+                                                const hidl_vec<UIOption>& uiOptions) override;
+    Return<ResponseCode> deliverSecureInputEvent(
+        const ::android::hardware::keymaster::V4_0::HardwareAuthToken& secureInputToken) override;
+    Return<void> abort() override;
+
+  private:
+    std::weak_ptr<TrustyApp> app_;
+    std::thread callback_thread_;
+
+    enum class ListenerState : uint32_t {
+        None,
+        Starting,
+        SetupDone,
+        Interactive,
+        Terminating,
+    };
+
+    /*
+     * listener_state is protected by listener_state_lock. It makes transitions between phases
+     * of the confirmation operation atomic.
+     * (See TrustyConfirmationUI.cpp#promptUserConfirmation_ for details about operation phases)
+     */
+    ListenerState listener_state_;
+    /*
+     * abort_called_ is also protected by listener_state_lock_ and indicates that the HAL user
+     * called abort.
+     */
+    bool abort_called_;
+    std::mutex listener_state_lock_;
+    std::condition_variable listener_state_condv_;
+    ResponseCode prompt_result_;
+    bool secureInputDelivered_;
+
+    std::tuple<teeui::ResponseCode, teeui::MsgVector<uint8_t>, teeui::MsgVector<uint8_t>>
+    promptUserConfirmation_(const teeui::MsgString& promptText,
+                            const teeui::MsgVector<uint8_t>& extraData,
+                            const teeui::MsgString& locale,
+                            const teeui::MsgVector<teeui::UIOption>& uiOptions);
+};
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace confirmationui
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_CONFIRMATIONUI_V1_0_TRUSTY_CONFIRMATIONUI_H