From 67e06d2c5022e82984b0c7e6651876b5b0e7410d Mon Sep 17 00:00:00 2001
From: zhao liwei <zlw5307@163.com>
Date: Thu, 17 Dec 2020 15:23:33 +0800
Subject: [PATCH] feat(security): treat negotiation succeed if server is old
 version (#694)

---
 src/runtime/security/client_negotiation.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/runtime/security/client_negotiation.cpp b/src/runtime/security/client_negotiation.cpp
index 09d0ec5530..7aef0359c7 100644
--- a/src/runtime/security/client_negotiation.cpp
+++ b/src/runtime/security/client_negotiation.cpp
@@ -50,7 +50,15 @@ void client_negotiation::list_mechanisms()
 void client_negotiation::handle_response(error_code err, const negotiation_response &&response)
 {
     if (err != ERR_OK) {
-        fail_negotiation();
+        // ERR_HANDLER_NOT_FOUND means server is old version, which doesn't support authentication
+        if (ERR_HANDLER_NOT_FOUND == err && !FLAGS_mandatory_auth) {
+            ddebug_f("{}: treat negotiation succeed because server is old version, which doesn't "
+                     "support authentication",
+                     _name);
+            succ_negotiation();
+        } else {
+            fail_negotiation();
+        }
         return;
     }