ConfirmationUI HAL definition

HAL definition for high assurance confirmation providers.
High assurance confirmation providers allow relying parties
to prompt the user for confirming a short piece of information.
If the user confirms, the result is a signed message indicating
that the user has seen the message. For a high assurance confirmation
provider this must also be true if Android and the Linux kernel
are compromised.

Bug: 63928580
Test: VTS tests in the following commit
Change-Id: I72017b39c01b4333d0146c648637a19fafcb7278
diff --git a/confirmationui/1.0/IConfirmationUI.hal b/confirmationui/1.0/IConfirmationUI.hal
new file mode 100644
index 0000000..db8055d
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+++ b/confirmationui/1.0/IConfirmationUI.hal
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+package android.hardware.confirmationui@1.0;
+
+import android.hardware.keymaster@4.0::HardwareAuthToken;
+import IConfirmationResultCallback;
+
+interface IConfirmationUI {
+    /**
+     * Asynchronously initiates a confirmation UI dialog prompting the user to confirm a given text.
+     * The TUI prompt must be implemented in such a way that a positive response indicates with
+     * high confidence that a user has seen the given prompt text even if the Android framework
+     * including the kernel was compromised.
+     *
+     * @param resultCB Implementation of IResultCallback. Used by the implementation to report
+     *                 the result of the current pending user prompt.
+     *
+     * @param promptText UTF-8 encoded string which is to be presented to the user.
+     *
+     * @param extraData A binary blob that must be included in the formatted output message as is.
+     *                  It is opaque to the implementation. Implementations must neither interpret
+     *                  nor modify the content.
+     *
+     * @param locale String specifying the locale that must be used by the TUI dialog. The string
+     *                      is an IETF BCP 47 tag.
+     *
+     * @param uiOptions A set of uiOptions manipulating how the confirmation prompt is displayed.
+     *                  Refer to UIOption in types.hal for possible options.
+     *
+     * @return error  - OK: IFF the dialog was successfully started. In this case, and only in this
+     *                      case, the implementation must, eventually, call the callback to
+     *                      indicate completion.
+     *                - OperationPending: Is returned when the confirmation provider is currently
+     *                      in use.
+     *                - SystemError: An error occurred trying to communicate with the confirmation
+     *                      provider (e.g. trusted app).
+     *                - UIError: The confirmation provider encountered an issue with displaying
+     *                      the prompt text to the user.
+     */
+    promptUserConfirmation(IConfirmationResultCallback resultCB, string promptText,
+                           vec<uint8_t> extraData, string locale, vec<UIOption> uiOptions)
+        generates(ResponseCode error);
+
+    /**
+     * DeliverSecureInput is used by the framework to deliver a secure input event to the
+     * confirmation provider.
+     *
+     * VTS test mode:
+     * This function can be used to test certain code paths non-interactively. See TestModeCommands
+     * in types.hal for details.
+     *
+     * @param secureInputToken An authentication token as generated by Android authentication
+     *                         providers.
+     *
+     * @return error - Ignored: Unless used for testing (See TestModeCommands).
+     */
+    deliverSecureInputEvent(HardwareAuthToken secureInputToken)
+        generates(ResponseCode error);
+
+    /**
+     * Aborts a pending user prompt. This allows the framework to gracefully end a TUI dialog.
+     * If a TUI operation was pending the corresponding call back is informed with
+     * ErrorCode::Aborted.
+     */
+    abort();
+};
+