For RedisClient exists, make sure no space or tab in key

Signed-off-by: Jipan Yang <jipan.yang@alibaba-inc.com>

Author: jipanyang

common/redisclient.cpp

@@ -23,6 +23,11 @@ int64_t RedisClient::del(const string &key)
 bool RedisClient::exists(const string &key)
 {
     RedisCommand rexists;
+    if (key.find_first_of(" \t") != string::npos)
+    {
+        SWSS_LOG_ERROR("EXISTS failed, invalid space or tab in single key: %s", key.c_str());
+        throw runtime_error("EXISTS failed, invalid space or tab in single key");
+    }
     rexists.format("EXISTS %s", key.c_str());
     RedisReply r(m_db, rexists, REDIS_REPLY_INTEGER);
     return (r.getContext()->integer > 0);