commit b5cb957254201f19a434898c249d59752e2a88b7
author Prabir Pradhan <prabirmsp@google.com> Fri Sep 24 06:35:16 2021 -0700
committer Prabir Pradhan <prabirmsp@google.com> Mon Oct 04 04:00:44 2021 -0700
tree 1448609838a4c522f11ee3454eb227d2f83dee9e
parent c2872295a47436c5507c38ddac0393b76d5471d1

VerifiedMotionEvent: Sign transformed raw values

The values for axes X/Y that are stored in MotionEvent are
transformed to values used for its getRaw API based on the source.
This is because non-pointer sources should not have translation applied
to them.

We need to ensure that we use the same raw coordinates when we sign a
VerifiedMotionEvent in InputDispatcher that we would get with the
MotionEvent#getRaw API. To do this, we re-use the same logic used to
transform the raw coordinates in MotionEvent in InputDispatcher.

Bug: 179274888
Test: atest inputflinger_tests
Test: atest VerifyInputEventTest
Change-Id: I552f94064f15573ddda8f7c0b588cd3b984b6a94

services/inputflinger/dispatcher/InputDispatcher.cpp

diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 695dd17..52a88d7 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -3360,16 +3360,18 @@
 
 const std::array<uint8_t, 32> InputDispatcher::getSignature(
         const MotionEntry& motionEntry, const DispatchEntry& dispatchEntry) const {
-    int32_t actionMasked = dispatchEntry.resolvedAction & AMOTION_EVENT_ACTION_MASK;
-    if ((actionMasked == AMOTION_EVENT_ACTION_UP) || (actionMasked == AMOTION_EVENT_ACTION_DOWN)) {
+    const int32_t actionMasked = dispatchEntry.resolvedAction & AMOTION_EVENT_ACTION_MASK;
+    if (actionMasked != AMOTION_EVENT_ACTION_UP && actionMasked != AMOTION_EVENT_ACTION_DOWN) {
         // Only sign events up and down events as the purely move events
         // are tied to their up/down counterparts so signing would be redundant.
-        VerifiedMotionEvent verifiedEvent = verifiedMotionEventFromMotionEntry(motionEntry);
-        verifiedEvent.actionMasked = actionMasked;
-        verifiedEvent.flags = dispatchEntry.resolvedFlags & VERIFIED_MOTION_EVENT_FLAGS;
-        return sign(verifiedEvent);
+        return INVALID_HMAC;
     }
-    return INVALID_HMAC;
+
+    VerifiedMotionEvent verifiedEvent =
+            verifiedMotionEventFromMotionEntry(motionEntry, dispatchEntry.rawTransform);
+    verifiedEvent.actionMasked = actionMasked;
+    verifiedEvent.flags = dispatchEntry.resolvedFlags & VERIFIED_MOTION_EVENT_FLAGS;
+    return sign(verifiedEvent);
 }
 
 const std::array<uint8_t, 32> InputDispatcher::getSignature(