Add protocol for session bound physical input events

Bug: 78908935
Change-Id: I080d89831c6e1553dfbd9f4a1180075170c22fa0
diff --git a/nugget/proto/nugget/app/keymaster/keymaster.proto b/nugget/proto/nugget/app/keymaster/keymaster.proto
index 256031b..c85af6e 100644
--- a/nugget/proto/nugget/app/keymaster/keymaster.proto
+++ b/nugget/proto/nugget/app/keymaster/keymaster.proto
@@ -85,6 +85,12 @@
    */
   rpc GetHmacSharingParameters (GetHmacSharingParametersRequest) returns (GetHmacSharingParametersResponse);
   rpc ComputeSharedHmac (ComputeSharedHmacRequest) returns (ComputeSharedHmacResponse);
+
+  /*
+   * DTup input session methods.
+   */
+  rpc HandshakeDTup (DTupHandshakeRequest) returns (DTupHandshakeResponse);
+  rpc FetchDTupInputEvent (DTupFetchInputEventRequest) returns (DTupFetchInputEventResponse);
 }
 
 /*
@@ -323,3 +329,21 @@
   ErrorCode error_code = 1;
   bytes sharing_check = 2;
 }
+
+message DTupHandshakeRequest {
+  bytes nonce_client = 1;
+}
+
+message DTupHandshakeResponse {
+  DTupError error_code = 1;
+  bytes nonce_citadel = 2;
+  bytes signature = 3;
+}
+
+message DTupFetchInputEventRequest {}
+
+message DTupFetchInputEventResponse {
+  DTupError error_code = 1;
+  DTupKeyEvent event = 2;
+  bytes signature = 3;
+}