MySQL Bugs: #90676: error no. 2058 collision / double-use

Bug #90676	error no. 2058 collision / double-use
Submitted:	28 Apr 2018 8:55	Modified:	2 May 2018 9:00
Reporter:	Peter Laursen (Basic Quality Contributor)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Errors	Severity:	S3 (Non-critical)
Version:	8.0.11	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
According to https://dev.mysql.com/doc/refman/5.5/en/error-messages-client.html error 2058 is "This handle is already connected. Use a separate handle for each connection."

However the error "Plugin <some authentication plugin> could not be loaded: The specified module could not be found." also has error no. 2058

How to repeat:
Create a user that IDENTIFIES WITH caching_sha2_password - next conenct with a client that does not have plugin support for this particular authentication method.  You will get "error 2058: Plugin caching_sha2_password could not be loaded: The specified module could not be found." 

Suggested fix:
No idea.

Error as appearing in SQLyog. But pre-MySQL_8 CLI should also reproduce.

Attachment: e2058.PNG (image/png, text), 28.96 KiB.

Thank you for the bug report. Please read:

https://dev.mysql.com/doc/refman/8.0/en/caching-sha2-pluggable-authentication.html

"
Important

In MySQL 8.0, caching_sha2_password is the default authentication plugin rather than mysql_native_password. For information about the implications of this change for server operation and compatibility of the server with clients and connectors, see caching_sha2_password as the Preferred Authentication Plugin."

https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-cachin...

 Important

If your MySQL installation must serve pre-8.0 clients and you encounter compatibility issues after upgrading to MySQL 8.0.4 or later, the simplest way to address those issues and restore pre-8.0 compatibility is to reconfigure the server to revert to the previous default authentication plugin (mysql_native_password). For example, use these lines in the server option file:

[mysqld]
default_authentication_plugin=mysql_native_password

That setting enables pre-8.0 clients to connect to 8.0 servers until such time as the clients and connectors in use at your installation are upgraded to know about caching_sha2_password. However, the setting should be viewed as temporary, not as a long term or permanent solution, because it causes new accounts created with the setting in effect to forego the improved authentication security provided by caching_sha2_password. 

Then looks expected behavior. Thanks.

I am pasting a relevant part of the docs.  Firstly,  it seems like 2059 is what the docs state is returned so why you're seeing 2058 which is a wrong code?

https://dev.mysql.com/doc/refman/8.0/en/error-messages-client.html

Error: 2058 (CR_ALREADY_CONNECTED)
Message: This handle is already connected. Use a separate handle for each connection.

Error: 2059 (CR_AUTH_PLUGIN_CANNOT_LOAD)
Message: Authentication plugin '%s' cannot be loaded: %s

According the screenshot you attached is returned 2058 when should be 2059 according the documentation:

miguel@tikal:~/dbsd $ 5.6/bin/mysql -uroot -p --socket=/tmp/mysql80.sock
Enter password:
ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded: /home/miguel/dbsd/5.6/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory

Which client library was used to link with your tool, because testing with the mysql command I get 2059 error:

C:\dbs\5.5\bin>mysql -uroot -p
Enter password: **********
ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded: The specified module could not be found.

Thanks.

Ahh .. good point!  

The client libray is MariaDB Connector/C v. 2.3.3. So this should be complained about to MariaDB instead!

Thank you for the feedback. Please test with a tool linked with our library if you will get 2059 then the reporter will be closed as !bug. Thanks.

MariaDb confirmed that this is an issue with their Connector/C v. 2.x: It is fix in 3.x but not yet backported to 2.x.

So closing!