Clients with mysql_native_password cannot connect to TiDB

[djshow832]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

dbaddr := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8", "root", "", "127.0.0.1", 4000, "test")
mdb, err := sql.Open("mysql", dbaddr)
if err != nil {
    println("open error:", err.Error())
    return
}
err = mdb.Ping()
if err != nil {
    println("ping error:", err.Error())
    return
}
mdb.Close()

with

require github.com/go-sql-driver/mysql v1.3.0

Note: mysql v1.6.0 is OK.

2. What did you expect to see? (Required)

No error

3. What did you see instead (Required)

ping error: this user requires mysql native password authentication.

4. What is your TiDB version? (Required)

master

This is caused by https://github.com/pingcap/tidb/pull/32338/files#diff-412615e1c1d4c6ae11a7885a11c879778bf401e0967c9c13c4b9dfd1f13ed29aR900

if resp.Capability&mysql.ClientPluginAuth > 0 {              // Previously, there is another condition before it: resp.AuthPlugin != mysql.AuthNativePassword
	resp.AuthPlugin = mysql.AuthNativePassword
	authData, err := cc.authSwitchRequest(ctx, mysql.AuthNativePassword)
	if err != nil {
		return nil, err
	}
	return authData, nil
}

[djshow832]

I prefer to revert it for now because it's a compatibility breaker and release blocker.

[bb7133]

Thanks for reporting this. It's hard to say that this a bug of TiDB since I found that it is a known bug of go-sql-driver which has been fixed since 1.4.0:

go-sql-driver/mysql#785

However, I agree with @djshow832 with #33142 because:

• We do not know how many TiDB users are using go-sql-driver 1.3.0 and this issue will break their workloads.
• The time for code freeze of v6.0 is close and it's hard to dig deeper for a 'fine solution'.

So we can revert the change temporarily and make a careful decision for it after v6.0.

[bb7133]

We will try to think about a 'fine solution' for it.