Basic authentication in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add the Authorization header for Basic authentication.

Rest API

headers = {"Authorization": "Basic [1]"}

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

Ab64encode(b'user:pass').decode('utf-8')

Bbase64.encode('user:pass')

Cbase64.b64decode('user:pass')

Db64encode('user:pass')

Attempts:

3 left

💡 Hint

Common Mistakes

Encoding the string directly without converting to bytes.

Using base64 decode instead of encode.

Not decoding the base64 bytes back to string.

The Authorization header for Basic authentication requires the username and password encoded in base64 as a UTF-8 string.

2fill in blank

medium

Complete the code to create the Basic authentication header value correctly.

Rest API

auth_value = "Basic " + [1]

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

Abase64.b64encode('username:password')

Bbase64.b64encode(b'username:password').decode('utf-8')

Cbase64.b64decode(b'username:password').decode('utf-8')

Dbase64.encode('username:password')

Attempts:

3 left

💡 Hint

Common Mistakes

Encoding a string directly without converting to bytes.

Using decode before encoding.

Using base64 decode instead of encode.

The credentials must be base64 encoded from bytes and then decoded to a UTF-8 string before adding to the header.

3fill in blank

hard

Fix the error in the code to correctly set the Basic authentication header.

Rest API

import base64
credentials = 'admin:1234'
encoded = base64.b64encode([1])
headers = {'Authorization': 'Basic ' + encoded.decode('utf-8')}

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

Abase64.b64decode(credentials)

Bcredentials

Cencoded

Dcredentials.encode('utf-8')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a string directly to b64encode causing a TypeError.

Using base64 decode instead of encode.

Trying to encode the already encoded variable.

The string credentials must be converted to bytes before base64 encoding.

4fill in blank

hard

Fill both blanks to create a Basic authentication header with username and password.

Rest API

import base64
user = 'user1'
passw = 'pass1'
creds = f"[1]:[2]"
encoded = base64.b64encode(creds.encode('utf-8')).decode('utf-8')
headers = {'Authorization': 'Basic ' + encoded}

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

Auser

Bpassw

Cusername

Dpassword

Attempts:

3 left

💡 Hint

Common Mistakes

Using undefined variable names.

Swapping username and password variables.

Forgetting the colon separator.

The credentials string must be username and password joined by a colon.

5fill in blank

hard

Fill all three blanks to build a Basic authentication header from variables and encode it properly.

Rest API

import base64
username = 'alice'
password = 'wonderland'
credentials = f"[1]:[2]"
encoded_credentials = base64.b64encode(credentials.encode('utf-8')).decode([3])
headers = {'Authorization': 'Basic ' + encoded_credentials}

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

Ausername

Bpassword

C'utf-8'

D'ascii'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names.

Decoding with 'ascii' which may cause errors.

Not joining username and password with a colon.

The credentials string is username and password joined by a colon. The encoded bytes are decoded using 'utf-8' to get a string for the header.

Practice

1. What does Basic Authentication in REST API primarily use to verify a user?

easy

A. An API key sent as a query parameter

B. A username and password encoded in base64 sent in the Authorization header

C. OAuth tokens in the request body

D. IP address filtering

Solution

1. Step 1: Understand Basic Authentication mechanism

   Basic Authentication sends a username and password encoded in base64 in the Authorization header.

2. Step 2: Compare with other authentication methods

   API keys, OAuth tokens, and IP filtering are different methods, not Basic Authentication.

3. Final Answer:

   A username and password encoded in base64 sent in the Authorization header -> Option B

4. Quick Check:

   Basic Auth = username:password base64 in header [OK]

Hint: Basic Auth always uses base64 username:password in header [OK]

Common Mistakes:

• Confusing Basic Auth with API key or OAuth
• Thinking credentials are sent in URL or body
• Ignoring base64 encoding step

2. Which of the following is the correct format of the Authorization header for Basic Authentication?

easy

A. Authorization: ApiKey base64encodedstring

B. Authorization: Bearer base64encodedstring

C. Authorization: Token base64encodedstring

D. Authorization: Basic base64encodedstring

Solution

1. Step 1: Recall the header format for Basic Authentication

   The header must start with the word 'Basic' followed by a space and then the base64 encoded credentials.

2. Step 2: Eliminate other header types

   'Bearer', 'Token', and 'ApiKey' are used in other authentication schemes, not Basic Auth.

3. Final Answer:

   Authorization: Basic base64encodedstring -> Option D

4. Quick Check:

   Basic Auth header starts with 'Basic' [OK]

Hint: Basic Auth header always starts with 'Basic ' [OK]

Common Mistakes:

• Using 'Bearer' instead of 'Basic'
• Omitting the space after 'Basic'
• Confusing with other auth schemes

3. Given the username 'user' and password 'pass', what is the value of the Authorization header in Basic Authentication?

medium

A. Authorization: Basic dXNlcjpwYXNz

B. Authorization: Basic dXNlcjpwYXNzCg==

C. Authorization: Basic dXNlcjpwYXNzdA==

D. Authorization: Basic dXNlcjpwYXNzZA==

Solution

1. Step 1: Combine username and password with colon

   Combine 'user' and 'pass' as 'user:pass'.

2. Step 2: Encode 'user:pass' in base64

   Encoding 'user:pass' in base64 results in 'dXNlcjpwYXNzdA=='.

3. Final Answer:

   Authorization: Basic dXNlcjpwYXNzdA== -> Option C

4. Quick Check:

   Base64('user:pass') = dXNlcjpwYXNzdA== [OK]

Hint: Encode 'username:password' in base64 for header value [OK]

Common Mistakes:

• Encoding username and password separately
• Adding extra characters or padding incorrectly
• Using wrong base64 string

4. What is wrong with this Basic Authentication header?
Authorization: Basic user:pass

medium

A. The username and password are not base64 encoded

B. The header should be 'Bearer' not 'Basic'

C. The colon ':' should be replaced with a comma ','

D. The header is missing the word 'Authorization'

Solution

1. Step 1: Check the format of the Authorization header

   The header must have the credentials base64 encoded after 'Basic '.

2. Step 2: Identify the error in the given header

   The given header has 'user:pass' in plain text, not base64 encoded.

3. Final Answer:

   The username and password are not base64 encoded -> Option A

4. Quick Check:

   Basic Auth requires base64 encoding [OK]

Hint: Credentials must be base64 encoded, not plain text [OK]

Common Mistakes:

• Sending plain text credentials
• Confusing 'Basic' with 'Bearer'
• Misplacing colon or other punctuation

5. You want to protect a REST API endpoint using Basic Authentication. Which of the following is the best practice?

hard

A. Use HTTPS to encrypt the connection and send base64 encoded credentials in the Authorization header

B. Send username and password in plain text over HTTP

C. Send credentials as URL parameters for easy access

D. Use Basic Authentication without encoding credentials

Solution

1. Step 1: Understand security risks of Basic Authentication

   Basic Auth sends credentials encoded but not encrypted, so it must be used over HTTPS to protect data.

2. Step 2: Identify best practice for secure API protection

   Using HTTPS encrypts the entire connection, making base64 encoded credentials safe to transmit.

3. Final Answer:

   Use HTTPS to encrypt the connection and send base64 encoded credentials in the Authorization header -> Option A

4. Quick Check:

   Basic Auth + HTTPS = secure transmission [OK]

Hint: Always use HTTPS with Basic Auth for security [OK]

Common Mistakes:

• Sending credentials over HTTP (not secure)
• Putting credentials in URL parameters
• Skipping base64 encoding