Authentication mechanisms in MongoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Output of user authentication command

What is the output of the following MongoDB command when authenticating a user with correct credentials?

MongoDB

db.auth('username', 'correct_password')

A 1

B 0

C null

D throws an error

💡 Hint

The auth() method returns 1 on successful authentication.

In MongoDB, the auth() method returns 1 if the username and password are correct, indicating successful authentication.

🧠 Conceptual

intermediate

Default authentication mechanism in MongoDB

Which authentication mechanism does MongoDB use by default when authentication is enabled?

A X.509 certificates

B SCRAM-SHA-256

C Kerberos

D LDAP

💡 Hint

SCRAM is a challenge-response mechanism used by default.

MongoDB uses SCRAM-SHA-256 as the default authentication mechanism since version 4.0 for secure password-based authentication.

📝 Syntax

advanced

Correct syntax for creating a user with SCRAM authentication

Which of the following commands correctly creates a user with SCRAM authentication in MongoDB?

MongoDB

db.createUser({user: 'alice', pwd: 'password123', roles: ['readWrite']})

A db.addUser('alice', 'password123', ['readWrite'])

B db.createUser({username: 'alice', password: 'password123', roles: ['readWrite']})

C db.createUser({user: 'alice', pwd: 'password123', roles: ['readWrite']})

D db.createUser({user: 'alice', password: 'password123', roles: ['readWrite']})

💡 Hint

The correct keys are 'user' and 'pwd' for username and password.

The createUser method requires 'user' and 'pwd' keys to specify username and password respectively. Other keys like 'username' or 'password' are invalid.

🔧 Debug

advanced

Identify the cause of authentication failure

A user tries to authenticate with db.auth('bob', 'wrongpass') but always gets 0. What is the most likely cause?

A The password is incorrect

B The user 'bob' does not exist

C The database is not running

D The user 'bob' has no roles assigned

💡 Hint

db.auth returns 0 when authentication fails due to wrong credentials.

If the user exists but the password is wrong, db.auth returns 0. If the user does not exist, it also returns 0, but the most common cause is wrong password.

❓ optimization

expert

Best practice to secure MongoDB authentication in production

Which option is the best practice to enhance security of MongoDB authentication in a production environment?

A Use default settings without authentication for faster access

B Disable authentication and rely on network firewall only

C Store passwords in plain text for easy retrieval

D Enable SCRAM-SHA-256 and use TLS encryption for connections

💡 Hint

Combining strong authentication with encrypted connections improves security.

Enabling SCRAM-SHA-256 ensures strong password authentication, and TLS encrypts data in transit, protecting credentials and data from interception.