From c00e5532994f03f8bc61f147259bc5d353a0d2c9 Mon Sep 17 00:00:00 2001
From: poma <Semenov.Roman@mail.ru>
Date: Sun, 3 Nov 2019 11:25:58 +0300
Subject: [PATCH] check return data length for tokens

---
 contracts/ERC20Mixer.sol | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/contracts/ERC20Mixer.sol b/contracts/ERC20Mixer.sol
index 8a7c7d7..2e99231 100644
--- a/contracts/ERC20Mixer.sol
+++ b/contracts/ERC20Mixer.sol
@@ -57,6 +57,7 @@ contract ERC20Mixer is Mixer {
 
     // if contract returns some data let's make sure that is `true` according to standard
     if (data.length > 0) {
+      require(data.length == 32, "data length should be either 0 or 32 bytes");
       assembly {
         success := mload(add(data, 0x20))
       }
@@ -78,6 +79,7 @@ contract ERC20Mixer is Mixer {
 
     // if contract returns some data let's make sure that is `true` according to standard
     if (data.length > 0) {
+      require(data.length == 32, "data length should be either 0 or 32 bytes");
       assembly {
         success := mload(add(data, 0x20))
       }