Reject userOp if sigFailed is true during simulation (#120)

Author: hazim-j

pkg/errors/rpc.go

@@ -8,6 +8,7 @@ var (
 	BANNED_OR_THROTTLED_PAYMASTER = -32504
 	INVALID_PAYMASTER_STAKE       = -32505
 	INVALID_AGGREGATOR            = -32506
+	INVALID_SIGNATURE             = -32507
 	INVALID_FIELDS                = -32602
 
 	EXECUTION_REVERTED = -32521

pkg/modules/checks/standalone.go

@@ -77,11 +77,18 @@ func (s *Standalone) SimulateOp() modules.UserOpHandlerFunc {
 		gc := getCodeWithEthClient(s.eth)
 		g := new(errgroup.Group)
 		g.Go(func() error {
-			_, err := simulation.SimulateValidation(s.rpc, ctx.EntryPoint, ctx.UserOp)
+			sim, err := simulation.SimulateValidation(s.rpc, ctx.EntryPoint, ctx.UserOp)
 
 			if err != nil {
 				return errors.NewRPCError(errors.REJECTED_BY_EP_OR_ACCOUNT, err.Error(), err.Error())
 			}
+			if sim.ReturnInfo.SigFailed {
+				return errors.NewRPCError(
+					errors.INVALID_SIGNATURE,
+					"invalid userOp or paymaster signature",
+					nil,
+				)
+			}
 			return nil
 		})
 		g.Go(func() error {