If you have installed MySQL version 8.0 or later and tried to establish a connection to its database, you might run into this error:Authentication plugin 'caching_sha2_password' cannot be loaded: dlopen[/usr/local/mysql/lib/plugin/caching_sha2_password.so, 2]: image not found
What is caching_sha2_password Authentication Plugin?
caching_sha2_password
is MySQL’s latest authentication plugin which brings some major advancements to the connection
encryption, compared to the other authentication mechanisms. The first is, an in-memory cache for faster authentication. Next is a RSA-based password exchange that is independent of the SSL library against which MySQL is linked. And finally, it supports Unix socket-files and shared-memory protocols.
You can read more about its features here.
Why I can’t connect to MySQL 8.0?
The reason for this is while MySQL 8.0 uses caching_sha2_password as the default authentication plugin, your MySQL client hasn’t been compatible with it yet. It uses the older versions of libmysqlclient which do not support this caching_sha2_password plugin. Thus it failed to connect.
For example, Sequel Pro users have been experiencing this due to the fact that Sequel Pro hasn’t supported MySQL 8 [issue #2699] and the caching_sha2_password plugin is missing [issue 3037].
Note from the Sequel Pro team on Jun 20:
Side note: Support for caching_sha2_password will probably not happen anytime soon.
Sequel Pro currently uses the 5.5 MySQL client library and this plugin is only included with the most recent 8.0 library.
Since there may be internal changes between those versions and we made some customizations ourselves, we have to go 5.5 -> 5.6 -> 5.7 -> 8.0 and check compatibility at each step.
But not even the switch to 5.6 is scheduled for the next release.
Well, that sucks!
Until now, there are a couple solutions for this:
1. Change to legacy password for MySQL Server:- Go to System Preferences -> MySQL
- From Instance tab, choose Initialize Database
- Choose Use legacy Password Encryption
- Restart the Server
Now you might be able to connect to the database again.
2. Usemysql_native_password
You can use the ALTER
command to change the encryption of the password to mysql_native_password
instead of the latest authentication plugin caching_sha2_password
ALTER USER 'username'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
3.
Roll back to the earlier version of MySQLBack to MySQL 5.7 for example:
But those are just temporary solutions. It’s not recommended if you want to use the latest encryption method.
4. Use another GUI Client which supports MySQL 8- Download TablePlus here or update the TablePlus app to the latest version.
- Connect to any version of MySQL, even it requires two-step authentication.
- Enjoy coding!
TablePlus is a modern, native client with intuitive GUI tools to create, access, query & edit multiple relational databases: MySQL, PostgreSQL, SQLite, Microsoft SQL Server, Amazon Redshift, MariaDB, CockroachDB, Vertica, Cassandra, Oracle, and Redis.
It’s native, beautiful, and available for free.
Introduction
MySQL is an open-source database management system, commonly installed as part of the popular LAMP [Linux, Apache, MySQL, PHP/Python/Perl] stack. It implements the relational model and uses Structured Query Language [better known as SQL] to manage its data.
This tutorial will go over how to install MySQL version 8.0 on an Ubuntu 20.04 server. By completing it, you will have a working relational database that you can use to build your next website or application.
Prerequisites
To follow this tutorial, you will need:
- One Ubuntu 20.04 server with a non-root administrative user and a firewall configured with UFW. To set this up, follow our initial server setup guide for Ubuntu 20.04.
Step 1 — Installing MySQL
On Ubuntu 20.04, you can install MySQL using the APT package repository. At the time of this writing, the version of MySQL available in the default Ubuntu repository is version 8.0.27.
To install it, update the package index on your server if you’ve not done so recently:
- sudo apt update
Then install the mysql-server
package:
- sudo apt install mysql-server
Ensure that the server is running using the systemctl start
command:
- sudo systemctl start mysql.service
These commands will install and start MySQL, but will not prompt you to set a password or make any other configuration changes. Because this leaves your installation of MySQL insecure, we will address this next.
Step 2 — Configuring MySQL
For fresh installations of MySQL, you’ll want to run the DBMS’s included security script. This script changes some of the less secure default options for things like remote root logins and sample users.
Warning: As of July 2022, an error will occur when you run the mysql_secure_installation
script without some further configuration. The reason is that this script will attempt to set a password for the
installation’s root MySQL account but, by default on Ubuntu installations, this account is not configured to connect using a password.
Prior to July 2022, this script would silently fail after attempting to set the root account password and continue on with the rest of the prompts. However, as of this writing the script will return the following error after you enter and confirm a password:
Output
... Failed! Error: SET PASSWORD has no significance for user 'root'@'localhost' as the authentication method used doesn't store authentication data in the MySQL server. Please consider using ALTER USER instead if you want to change authentication parameters.
New password:
This will lead the script into a recursive loop which you can only get out of by closing your terminal window.
Because the mysql_secure_installation
script performs a number of other actions that are useful for keeping your MySQL installation secure, it’s still recommended that you run it before you begin using MySQL to manage your data. To avoid entering this recursive loop, though, you’ll need to first adjust how your root MySQL user authenticates.
First, open up the MySQL prompt:
- sudo mysql
Then run the following ALTER USER
command
to change the root user’s authentication method to one that uses a password. The following example changes the authentication method to mysql_native_password
:
- ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
After making this change, exit the MySQL prompt:
- exit
Following that, you can run the mysql_secure_installation
script without issue.
Once the security script completes, you can then reopen MySQL and change the root user’s authentication method back to the default, auth_socket
. To authenticate as the
root MySQL user using a password, run this command:
- mysql -u root -p
Then go back to using the default authentication method using this command:
- ALTER USER 'root'@'localhost' IDENTIFIED WITH auth_socket;
This will mean that you can once again connect to MySQL as your root user using the sudo mysql
command.
Run the security script with sudo
:
- sudo mysql_secure_installation
This will take you through a series of prompts where you can make some changes to your MySQL installation’s security options. The first prompt will ask whether you’d like to set up the Validate Password Plugin, which can be used to test the password strength of new MySQL users before deeming them valid.
If you elect to set up the Validate Password Plugin, any MySQL user you create that authenticates with a password will be required to have a password that satisfies the policy you select. The strongest policy level — which you can select by entering 2
— will require passwords to be at least eight characters long and include a mix of
uppercase, lowercase, numeric, and special characters:
Output
Securing the MySQL server deployment.
Connecting to MySQL using a blank password.
VALIDATE PASSWORD COMPONENT can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD component?
Press y|Y for Yes, any other key for No: Y
There are three levels of password validation policy:
LOW Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary file
Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG:
2
Regardless of whether you choose to set up the Validate Password Plugin, the next prompt will be to set a password for the MySQL root user. Enter and then confirm a secure password of your choice:
Output
Please set the password for root here.
New password:
Re-enter new password:
Note that even though you’ve set a password for the root MySQL user, this user is not currently configured to authenticate with a password when connecting to the MySQL shell.
If you
used the Validate Password Plugin, you’ll receive feedback on the strength of your new password. Then the script will ask if you want to continue with the password you just entered or if you want to enter a new one. Assuming you’re satisfied with the strength of the password you just entered, enter Y
to continue the script:
Output
Estimated strength of the password: 100
Do you wish to continue with the password provided?[Press y|Y for Yes, any other key for No] : Y
From there, you can press Y
and then ENTER
to accept the defaults for all the subsequent questions. This will remove some anonymous users and
the test database, disable remote root logins, and load these new rules so that MySQL immediately respects the changes you have made.
Once the script completes, your MySQL installation will be secured. You can now move on to creating a dedicated database user with the MySQL client.
Step 3 — Creating a Dedicated MySQL User and Granting Privileges
Upon installation, MySQL creates a root user account which you can use to manage your database. This user has full privileges over the MySQL server, meaning it has complete control over every database, table, user, and so on. Because of this, it’s best to avoid using this account outside of administrative functions. This step outlines how to use the root MySQL user to create a new user account and grant it privileges.
In Ubuntu systems running MySQL 5.7
[and later versions], the root MySQL user
is set to authenticate using the auth_socket
plugin by default rather than with a password. This plugin requires that the name of the operating system user that invokes the MySQL client matches the name of the MySQL user specified in the command, so you must invoke mysql
with sudo
privileges to gain access to the root MySQL user:
- sudo mysql
Note: If you installed MySQL with another tutorial and enabled password authentication for root, you will need to use a different command to access the MySQL shell. The following will run your MySQL client with regular user privileges, and you will only gain administrator privileges within the database by authenticating:
- mysql -u root -p
Once you have access to the MySQL prompt, you can create a new user with a CREATE USER
statement. These follow this general syntax:
- CREATE USER 'username'@'host' IDENTIFIED WITH authentication_plugin BY 'password';
After CREATE USER
, you specify a username. This is immediately followed by an @
sign and then the hostname from which
this user will connect. If you only plan to access this user locally from your Ubuntu server, you can specify localhost
. Wrapping both the username and host in single quotes isn’t always necessary, but doing so can help to prevent errors.
You have several options when it comes to choosing your user’s authentication plugin. The auth_socket
plugin mentioned previously can be convenient, as it provides strong security without requiring valid users to enter a password to access the database. But
it also prevents remote connections, which can complicate things when external programs need to interact with MySQL.
As an alternative, you can leave out the WITH authentication_plugin
portion of the syntax entirely to have the user authenticate with MySQL’s default plugin, caching_sha2_password
. The MySQL documentation recommends this plugin for users who want to log in with a password due to its strong security features.
Run the following command to create a user that authenticates with caching_sha2_password
. Be sure to
change sammy
to your preferred username and password
to a strong password of your choosing:
- CREATE USER 'sammy'@'localhost' IDENTIFIED BY 'password';
Note: There is a known issue with some versions of PHP that causes problems with caching_sha2_password
. If you plan to use this database with a PHP application — phpMyAdmin, for example — you may want to create a user that will authenticate with the older, though still secure, mysql_native_password
plugin instead:
- CREATE USER 'sammy'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
If you aren’t sure, you can always create a user that authenticates with
caching_sha2_plugin
and then ALTER
it later on with this command:
- ALTER USER 'sammy'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
After creating your new user, you can grant them the appropriate privileges. The general syntax for granting user privileges is as follows:
- GRANT PRIVILEGE ON database.table TO 'username'@'host';
The PRIVILEGE
value in this example syntax defines what actions the user is allowed to perform on the specified database
and table
. You can grant multiple privileges to the same user in one command by separating each with a comma. You can also grant a user privileges
globally by entering asterisks [*
] in place of the database and table names. In SQL, asterisks are special characters used to represent “all” databases or tables.
To illustrate, the following command grants a user global privileges to CREATE
, ALTER
, and DROP
databases, tables, and users, as well as the power to INSERT
, UPDATE
, and DELETE
data from any table on the server. It also grants the user the ability to query data with SELECT
, create foreign keys with the
REFERENCES
keyword, and perform FLUSH
operations with the RELOAD
privilege. However, you should only grant users the permissions they need, so feel free to adjust your own user’s privileges as necessary.
You can find the full list of available privileges in the official MySQL documentation.
Run this GRANT
statement, replacing sammy
with your own MySQL user’s name, to grant these privileges to your user:
- GRANT CREATE, ALTER, DROP, INSERT, UPDATE, DELETE, SELECT, REFERENCES, RELOAD on *.* TO 'sammy'@'localhost' WITH GRANT OPTION;
Note that this statement also includes
WITH GRANT OPTION
. This will allow your MySQL user to grant any permissions that it has to other users on the system.
Warning: Some users may want to grant their MySQL user the ALL PRIVILEGES
privilege, which will provide them with broad superuser privileges akin to the root user’s privileges, like so:
- GRANT ALL PRIVILEGES ON *.* TO 'sammy'@'localhost' WITH GRANT OPTION;
Such broad privileges should not be granted lightly, as anyone with access to this MySQL user will have complete control over every database on the server.
Following this, it’s good practice to run the FLUSH PRIVILEGES
command. This will free up any memory that the server cached as a result of the preceding CREATE USER
and GRANT
statements:
- FLUSH PRIVILEGES;
Then you can exit the MySQL client:
- exit
In the future, to log in as your new MySQL user, you’d use a command like the following:
- mysql -u sammy -p
The -p
flag will cause the MySQL client to prompt you for your MySQL user’s password in order to
authenticate.
Finally, let’s test the MySQL installation.
Step 4 — Testing MySQL
Regardless of how you installed it, MySQL should have started running automatically. To test this, check its status.
- systemctl status mysql.service
You’ll see output similar to the following:
Output
● mysql.service - MySQL Community Server
Loaded: loaded [/lib/systemd/system/mysql.service; enabled; vendor preset: enabled]
Active: active [running] since Tue 2020-04-21 12:56:48 UTC; 6min ago
Main PID: 10382 [mysqld]
Status: "Server is operational"
Tasks: 39 [limit: 1137]
Memory: 370.0M
CGroup: /system.slice/mysql.service
└─10382 /usr/sbin/mysqld
If MySQL isn’t running, you can start it with sudo systemctl start mysql
.
For an additional check, you can try connecting to the database using the mysqladmin
tool, which is a client that lets you run
administrative commands. For example, this command says to connect as a MySQL user named sammy [-u sammy
], prompt for a password [-p
], and return the version. Be sure to change sammy
to the name of your dedicated MySQL user, and enter that user’s password when prompted:
- sudo mysqladmin -p -u sammy version
You should see output similar to this:
Output
mysqladmin Ver 8.0.19-0ubuntu5 for Linux on x86_64 [[Ubuntu]]
Copyright [c] 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Server version 8.0.19-0ubuntu5
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/run/mysqld/mysqld.sock
Uptime: 10 min 44 sec
Threads: 2 Questions: 25 Slow queries: 0 Opens: 149 Flush tables: 3 Open tables: 69 Queries per second avg: 0.038
This means MySQL is up and running.
Conclusion
You now have a basic MySQL setup installed on your server. Here are a few examples of next steps you can take:
- Set up a LAMP stack or a LEMP stack
- Practice running queries with SQL
- Manage your MySQL installation with phpMyAdmin