mysql connector errors NotSupportedError Authentication plugin caching sha2 password is not supported

import mysql.connector
from mysql.connector import Error

try:
connection = mysql.connector.connect(host=’localhost’,
database=’Electronics’,
user=’root’,
password=’root’,

auth_plugin=’mysql_native_password’

)
if connection.is_connected():
db_Info = connection.get_server_info()
print(“Connected to MySQL Server version “, db_Info)
cursor = connection.cursor()
cursor.execute(“select database();”)
record = cursor.fetchone()
print(“You’re connected to database: “, record)

except Error as e:
print(“Error while connecting to MySQL”, e)
finally:
if connection.is_connected():
cursor.close()
connection.close()
print(“MySQL connection is closed”)

Why Does the “Authentication plugin ‘caching_sha2_password’ is not supported” Error Occur?

To understand why this error arises, let’s walk through an example scenario by creating a sample users table for reference.

CREATE TABLE users (
  id INT PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(50)
);

INSERT INTO users (name) VALUES 
  ('John'),
  ('Sarah'), 
  ('Peter');

When attempting to connect to this database using the mysql-connector library in Python, you might encounter the following issue:

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="myuser",
  password="mypass"
)

Error:

mysql.connector.errors.NotSupportedError: Authentication plugin 'caching_sha2_password' is not supported

Why Does This Happen?

This error occurs because MySQL version 8.0 and later uses a more secure password authentication method called caching_sha2_password for new user accounts. However, the mysql-connector library in Python does not support this updated authentication plugin. It only supports the older mysql_native_password plugin used in earlier MySQL versions. Consequently, the mismatch between the MySQL server’s authentication plugin and the one supported by the mysql-connector causes the connection to fail.

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How to Fix the “Authentication plugin ‘caching_sha2_password’ is not supported” Error

There are several ways to resolve this error:

1. Change User Authentication Plugin in MySQL

You can switch the authentication plugin used for your MySQL user account to mysql_native_password:

ALTER USER 'myuser'@'localhost' IDENTIFIED WITH mysql_native_password BY 'mypass';

Now, your Python code will successfully connect:

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="myuser",
  password="mypass"
)

print(mydb)  # <mysql.connector.connection_cext.CMySQLConnection object>

Note: This method lowers security because mysql_native_password is less secure than caching_sha2_password.

2. Use the mysql-connector-python Library

A better approach is to use the mysql-connector-python library, which supports the caching_sha2_password plugin.

1. First, uninstall the mysql-connector package:

   pip uninstall mysql-connector

2. Then, install mysql-connector-python:

   pip install mysql-connector-python

Now, your connection code will work without compromising security:

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="myuser",
  password="mypass"
)

print(mydb)  # <mysql.connector.connection_cext.CMySQLConnection object>

Recommendation: This approach maintains MySQL’s enhanced security features.

3. Specify the Authentication Plugin in the Connection Call

You can also specify the mysql_native_password plugin explicitly when connecting:

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="myuser",
  password="mypass",
  auth_plugin='mysql_native_password'
)

Warning: This method is not recommended as it uses a less secure authentication plugin.

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Comparing the Solutions

Solution	Security	Extra Steps	Compatibility
Change MySQL User Auth Plugin	Compromised	Run ALTER USER	Yes
Use mysql-connector-python	Intact	Install library	Yes
Specify Auth Plugin in Code	Compromised	None	Yes

---

Real-World Example: Connecting a Flask App to MySQL

Consider a Flask application that needs to connect to MySQL:

Error-Prone Code:

from flaskext.mysql import MySQL

mysql = MySQL()

app = Flask(__name__)
# MySQL configurations
app.config['MYSQL_DATABASE_USER'] = 'myuser'
app.config['MYSQL_DATABASE_PASSWORD'] = 'mypass'
app.config['MYSQL_DATABASE_DB'] = 'mydb'
app.config['MYSQL_DATABASE_HOST'] = 'localhost'
mysql.init_app(app)

conn = mysql.connect()  # ERROR!

Solution:
Switch to using mysql-connector-python:

import mysql.connector

mysql = MySQLconnector()

app = Flask(__name__)
app.config['MYSQL_HOST'] = 'localhost'
app.config['MYSQL_USER'] = 'myuser'
app.config['MYSQL_PASSWORD'] = 'mypass'
app.config['MYSQL_DB'] = 'mydb'

mysql.init_app(app)

conn = mysql.connect()  # Works!

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Summary

• The error arises due to a mismatch between the MySQL plugin and the Python MySQL connector.
• Using mysql-connector-python is the best solution to maintain security.
• Changing the plugin in MySQL works but compromises security.
• Explicitly specifying the mysql_native_password plugin is possible but not recommended due to security vulnerabilities.

By understanding these solutions, you can effectively establish secure connections from Python to MySQL databases.