Password policies in MySQL

Introduction

Password policies help keep user accounts safe by setting rules for creating strong passwords.

When you want to make sure users create passwords that are hard to guess.

When you need to require users to change their passwords regularly.

When you want to prevent users from reusing old passwords.

When you want to enforce minimum password length and complexity.

When you want to improve overall security of your database system.

Syntax

MySQL

SHOW VARIABLES LIKE 'validate_password%';

-- To set password policy variables:
SET GLOBAL validate_password.length = 8;
SET GLOBAL validate_password.policy = 1;
SET GLOBAL validate_password.mixed_case_count = 1;
SET GLOBAL validate_password.number_count = 1;
SET GLOBAL validate_password.special_char_count = 1;

These commands check and set password policy rules in MySQL.

You need proper privileges to change global variables.

Examples

Shows current password policy settings.

MySQL

SHOW VARIABLES LIKE 'validate_password%';

Sets minimum password length to 10 characters.

MySQL

SET GLOBAL validate_password.length = 10;

Sets password policy to 'STRONG' requiring mixed characters.

MySQL

SET GLOBAL validate_password.policy = 2;

Requires at least 2 numeric characters in passwords.

MySQL

SET GLOBAL validate_password.number_count = 2;

Sample Program

This query shows the current password policy settings in MySQL.

MySQL

SHOW VARIABLES LIKE 'validate_password%';

Important Notes

Password policies help protect your database from unauthorized access.

Changing password policies affects new passwords, not existing ones.

You can adjust policies to balance security and user convenience.

Summary

Password policies set rules for creating strong passwords.

MySQL uses variables starting with 'validate_password' to control policies.

You can view and change these settings with SHOW VARIABLES and SET GLOBAL commands.

Practice

1. What is the purpose of MySQL's validate_password_policy variable?

easy

A. To set rules for creating strong passwords

B. To control user access privileges

C. To define database storage engines

D. To manage query cache size

Solution

1. Step 1: Understand the variable name

   The variable validate_password_policy relates to password validation rules.

2. Step 2: Identify its function

   It sets rules to ensure passwords are strong and secure.

3. Final Answer:

   To set rules for creating strong passwords -> Option A

4. Quick Check:

   Password policy = Set rules for strong passwords [OK]

Hint: Policy variables control password strength rules [OK]

Common Mistakes:

• Confusing password policy with user privileges
• Thinking it manages database storage
• Assuming it controls query cache

2. Which of the following is the correct syntax to check the current password policy level in MySQL?

easy

A. SHOW PASSWORD POLICY;

B. SELECT * FROM validate_password_policy;

C. SHOW VARIABLES LIKE 'validate_password_policy';

D. GET VARIABLES 'validate_password_policy';

Solution

1. Step 1: Recall how to view system variables

   MySQL uses SHOW VARIABLES LIKE 'variable_name'; to display variable values.

2. Step 2: Match the variable name

   The variable for password policy is validate_password_policy, so the correct syntax is SHOW VARIABLES LIKE 'validate_password_policy';

3. Final Answer:

   SHOW VARIABLES LIKE 'validate_password_policy'; -> Option C

4. Quick Check:

   SHOW VARIABLES LIKE 'validate_password_policy' [OK]

Hint: Use SHOW VARIABLES LIKE for system settings [OK]

Common Mistakes:

• Using SELECT on a variable name
• Trying non-existent commands like SHOW PASSWORD POLICY
• Using GET VARIABLES which is invalid syntax

3. Given the following commands executed in MySQL:

SET GLOBAL validate_password_length = 10;
SHOW VARIABLES LIKE 'validate_password_length';

What will be the output of the SHOW VARIABLES command?

medium

A. Variable_name: validate_password_length, Value: 10

B. Variable_name: validate_password_length, Value: 8

C. Syntax error

D. Variable_name: validate_password_policy, Value: 10

Solution

1. Step 1: Understand the SET GLOBAL command

   The command sets the global password length requirement to 10 characters.

2. Step 2: SHOW VARIABLES output

   The SHOW VARIABLES LIKE 'validate_password_length'; will display the current value, which is now 10.

3. Final Answer:

   Variable_name: validate_password_length, Value: 10 -> Option A

4. Quick Check:

   SET GLOBAL changes variable, SHOW displays updated value [OK]

Hint: SET GLOBAL changes variable, SHOW displays current value [OK]

Common Mistakes:

• Expecting default value instead of updated
• Confusing variable names
• Assuming syntax error from SET GLOBAL

4. You tried to set the password policy level with this command:

SET GLOBAL validate_password_policy = 'STRONG';

But MySQL returned an error. What is the likely cause?

medium

A. The command requires quotes around the variable name

B. The variable name is incorrect

C. You must use SET SESSION instead of SET GLOBAL

D. The value should be an integer, not a string

Solution

1. Step 1: Check variable type for validate_password_policy

   This variable expects an integer value (0,1,2) representing policy levels, not strings.

2. Step 2: Understand error cause

   Using a string like 'STRONG' causes a type mismatch error.

3. Final Answer:

   The value should be an integer, not a string -> Option D

4. Quick Check:

   Policy level = integer, not string [OK]

Hint: Policy levels use numbers, not words [OK]

Common Mistakes:

• Using string values instead of integers
• Mistyping variable name
• Confusing SET GLOBAL with SET SESSION

5. You want to enforce a password policy that requires passwords to be at least 12 characters long, include mixed case letters, numbers, and special characters. Which combination of MySQL variables should you set to achieve this?

hard

A. SET GLOBAL validate_password_length = 10; SET GLOBAL validate_password_policy = 0;

B. SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 2;

C. SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 1;

D. SET GLOBAL validate_password_length = 8; SET GLOBAL validate_password_policy = 0;

Solution

1. Step 1: Understand password length requirement

   You want at least 12 characters, so validate_password_length must be set to 12.

2. Step 2: Understand policy levels

   Policy level 2 (STRONG) requires mixed case, numbers, and special characters.

3. Step 3: Match variables to requirements

   Setting validate_password_policy = 2 and length to 12 enforces all requirements.

4. Final Answer:

   SET GLOBAL validate_password_length = 12; SET GLOBAL validate_password_policy = 2; -> Option B

5. Quick Check:

   Length 12 + policy 2 = strong password rules [OK]

Hint: Policy 2 = strong; length sets minimum characters [OK]

Common Mistakes:

• Using policy 0 or 1 which are weaker
• Setting length less than required
• Confusing policy levels with string values