Authentication mechanisms in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the authentication mechanism when connecting to MongoDB.

MongoDB

mongo --username user --password pass --authenticationMechanism [1]

Drag options to blanks, or click blank then click option'

ANoAuth

BSCRAM-SHA-256

COAuth

DLDAP

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'NoAuth' which disables authentication and is insecure.

Confusing LDAP with MongoDB's default authentication.

The SCRAM-SHA-256 mechanism is a common and secure authentication method used in MongoDB.

2fill in blank

medium

Complete the code to create a user with SCRAM-SHA-1 authentication mechanism in MongoDB.

MongoDB

db.createUser({user: 'alice', pwd: 'secret', roles: ['readWrite'], [1]: ["SCRAM-SHA-1"]})

Drag options to blanks, or click blank then click option'

AauthMechanism

Bmechanism

Cmechanisms

DauthMethod

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'authMechanism' which is not recognized in this context.

Using 'mechanism' or 'authMethod' which are invalid keys.

The correct field to specify the authentication mechanism when creating a user is mechanisms.

3fill in blank

hard

Fix the error in the connection string to use the correct authentication mechanism.

MongoDB

mongodb://user:pass@host:27017/db?authMechanism=[1]

Drag options to blanks, or click blank then click option'

APLAIN

BMONGODB-X509

CSCRAM-SHA-1

DSCRAM-SHA-256

Attempts:

3 left

💡 Hint

Common Mistakes

Using SCRAM-SHA-1 which is less secure.

Using PLAIN without TLS which is insecure.

Using SCRAM-SHA-256 is recommended as it is more secure than SCRAM-SHA-1.

4fill in blank

hard

Fill both blanks to configure MongoDB to use X.509 certificate authentication.

MongoDB

mongo --host [1] --ssl --sslPEMKeyFile [2] --authenticationMechanism MONGODB-X509

Drag options to blanks, or click blank then click option'

Acluster0.mongodb.net

B/etc/ssl/mongodb.pem

Clocalhost

D/home/user/key.pem

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'localhost' as host when connecting to a remote cluster.

Using a wrong or missing PEM key file path.

The host should be the MongoDB cluster address, and the PEM key file is the certificate file path.

5fill in blank

hard

Fill all three blanks to create a user with LDAP authentication and assign the read role.

MongoDB

db.createUser({user: '[1]', roles: ['[2]'], [3]: ["PLAIN"]})

Drag options to blanks, or click blank then click option'

AldapUser

Bread

Cmechanisms

Dwrite

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'write' role instead of 'read'.

Using wrong key for authentication mechanism.

The user name is 'ldapUser', the role is 'read', and the authentication mechanism key is mechanisms with value ['PLAIN'] for LDAP.

Practice

1. What is the main purpose of authentication in MongoDB?

easy

A. To create indexes on collections

B. To backup the database automatically

C. To optimize query performance

D. To verify the identity of a user before granting access

Solution

1. Step 1: Understand authentication concept

   Authentication means checking who you are before allowing access.

2. Step 2: Identify the purpose in MongoDB

   MongoDB uses authentication to verify user identity to protect data.

3. Final Answer:

   To verify the identity of a user before granting access -> Option D

4. Quick Check:

   Authentication = Verify identity [OK]

Hint: Authentication means checking who you are [OK]

Common Mistakes:

• Confusing authentication with backup
• Thinking authentication improves query speed
• Mixing authentication with indexing

2. Which of the following is the correct syntax to authenticate a user in MongoDB shell?

easy

A. db.auth('username', 'password')

B. db.authenticate('username', 'password')

C. db.login('username', 'password')

D. db.userAuth('username', 'password')

Solution

1. Step 1: Recall MongoDB authentication method

   The correct method to authenticate is db.auth().

2. Step 2: Match syntax with options

   Only db.auth('username', 'password') matches the correct syntax.

3. Final Answer:

   db.auth('username', 'password') -> Option A

4. Quick Check:

   Authenticate = db.auth() [OK]

Hint: Use db.auth() to log in with username and password [OK]

Common Mistakes:

• Using db.authenticate() which does not exist
• Using db.login() which is invalid
• Confusing method names with userAuth()

3. Consider this MongoDB shell command sequence:

use admin
var result = db.auth('alice', 'mypassword')

What will be the value of result if authentication succeeds?

medium

A. 1

B. false

C. true

D. null

Solution

1. Step 1: Understand db.auth() return value

   When authentication succeeds, db.auth() returns 1.

2. Step 2: Match return value with options

   Only 1 matches the expected numeric return value.

3. Final Answer:

   1 -> Option A

4. Quick Check:

   Success returns 1 [OK]

Hint: db.auth() returns 1 if login works [OK]

Common Mistakes:

• Expecting boolean true instead of numeric 1
• Thinking it returns false on success
• Assuming it returns null or undefined

4. You run db.auth('bob', 'wrongpass') but it always returns 1. What is the most likely cause?

medium

A. The user 'bob' does not exist

B. The password is case-insensitive

C. You are already authenticated as 'bob' or another user

D. MongoDB does not check passwords

Solution

1. Step 1: Understand db.auth() behavior when already logged in

   If already authenticated, db.auth() returns 1 without rechecking password.

2. Step 2: Analyze why wrong password still returns 1

   This happens because the session is already authenticated as 'bob' or another user.

3. Final Answer:

   You are already authenticated as 'bob' or another user -> Option C

4. Quick Check:

   Already logged in means db.auth() returns 1 [OK]

Hint: db.auth() returns 1 if already logged in [OK]

Common Mistakes:

• Assuming wrong password always returns false
• Thinking MongoDB ignores passwords
• Believing user must exist for true return

5. You want to create a user with read-only access to the sales database. Which command correctly creates this user with proper authentication roles?

hard

A. db.addUser('readonly', 'pass123', 'read')

B. db.createUser({user: 'readonly', pwd: 'pass123', roles: [{role: 'read', db: 'sales'}]})

C. db.createUser({username: 'readonly', password: 'pass123', roles: ['read']})

D. db.createUser({user: 'readonly', pwd: 'pass123', roles: ['readWrite']})

Solution

1. Step 1: Identify correct syntax for creating user with roles

   The correct syntax uses db.createUser() with user, pwd, and roles as an array of objects specifying role and database.

2. Step 2: Match read-only role on 'sales' database

   db.createUser({user: 'readonly', pwd: 'pass123', roles: [{role: 'read', db: 'sales'}]}) correctly assigns role 'read' on database 'sales'.

3. Final Answer:

   db.createUser({user: 'readonly', pwd: 'pass123', roles: [{role: 'read', db: 'sales'}]}) -> Option B

4. Quick Check:

   Create user with roles array = db.createUser({user: 'readonly', pwd: 'pass123', roles: [{role: 'read', db: 'sales'}]}) [OK]

Hint: Use db.createUser() with roles array for access control [OK]

Common Mistakes:

• Using deprecated db.addUser() method
• Incorrect field names like username instead of user
• Assigning wrong roles like readWrite for read-only access