From 5c3c78e097529d688d80d74bb45449a9d8eb3801 Mon Sep 17 00:00:00 2001
From: poma <Semenov.Roman@mail.ru>
Date: Fri, 4 Oct 2019 16:43:15 +0300
Subject: [PATCH] allow verifier keys update, and an option to permanently
 disable it

---
 contracts/Mixer.sol | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/contracts/Mixer.sol b/contracts/Mixer.sol
index 262967c..f4b5431 100644
--- a/contracts/Mixer.sol
+++ b/contracts/Mixer.sol
@@ -19,6 +19,7 @@ contract IVerifier {
 
 contract Mixer is MerkleTreeWithHistory {
   bool public isDepositsEnabled = true;
+  bool public isVerifierUpdateAllowed = true;
   // operator can disable new deposits in case of emergency
   // it also receives a relayer fee
   address payable public operator;
@@ -96,6 +97,17 @@ contract Mixer is MerkleTreeWithHistory {
     isDepositsEnabled = !isDepositsEnabled;
   }
 
+  function updateVerifier(address newVerifier) external {
+    require(isVerifierUpdateAllowed, "verifier updates are disabled");
+    require(msg.sender == operator, "unauthorized");
+    verifier = IVerifier(newVerifier);
+  }
+
+  function disableVerifierUpdate() external {
+    require(msg.sender == operator, "unauthorized");
+    isVerifierUpdateAllowed = false;
+  }
+
   function changeOperator(address payable _newAccount) external {
     require(msg.sender == operator, "unauthorized");
     operator = _newAccount;