Basic authentication in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What does Basic Authentication encode?

In Basic Authentication, what is the format of the encoded string sent in the Authorization header?

A MD5 hash of the username only

B Base64 encoding of username and password joined by a colon

C Plain text username and password separated by a comma

D SHA256 hash of the password only

💡 Hint

Think about how username and password are combined before encoding.

Basic Authentication sends the username and password joined by a colon, then encoded in Base64. This string is sent in the Authorization header.

❓ Predict Output

intermediate

What is the Authorization header value?

Given username 'user1' and password 'pass123', what is the correct Authorization header value in Basic Authentication?

Postman

import base64
credentials = 'user1:pass123'
encoded = base64.b64encode(credentials.encode()).decode()
print(f'Basic {encoded}')

A Basic dXNlcjE6cGFzczEyMw==

B Basic dXNlcjE6cGFzczEyMw

C Basic dXNlcjE7cGFzczEyMw==

D Basic dXNlcjE6cGFzczEyMw===

💡 Hint

Check the exact Base64 encoding of 'user1:pass123'.

The string 'user1:pass123' encoded in Base64 is 'dXNlcjE6cGFzczEyMw=='. The Authorization header must be 'Basic ' plus this string.

❓ locator

advanced

Identify the correct Postman setting for Basic Auth

Where in Postman do you set the username and password for Basic Authentication?

A Under the Authorization tab, select 'Basic Auth' and enter username and password fields

B In the Headers tab, manually add 'Authorization' header with encoded value

C In the Params tab, add username and password as query parameters

D In the Body tab, add username and password as form-data

💡 Hint

Postman has a dedicated place for authentication types.

Postman provides an Authorization tab where you can select Basic Auth and enter credentials. It automatically encodes and adds the header.

❓ assertion

advanced

Which test script assertion verifies Basic Auth success?

In Postman test scripts, which assertion correctly checks that the server accepted Basic Authentication by returning status 200?

Postman

pm.test('Basic Auth success', () => {
    pm.response.to.have.status(200);
});

A pm.test('Basic Auth success', () => { pm.response.to.have.status(500); });

B pm.test('Basic Auth success', () => { pm.response.to.have.status(401); });

C pm.test('Basic Auth success', () => { pm.response.to.have.status(200); });

D pm.test('Basic Auth success', () => { pm.response.to.have.status(404); });

💡 Hint

Success means HTTP 200 OK status.

A 200 status code means the server accepted the credentials and authorized the request.

🔧 Debug

expert

Why does this Postman Basic Auth test fail?

This Postman test script fails even though the username and password are correct. What is the likely cause? pm.test('Check Auth', () => { pm.response.to.have.status(200); pm.expect(pm.request.headers.get('Authorization')).to.eql('Basic dXNlcjE6cGFzczEyMw=='); });

A The Authorization header value is case sensitive and must be 'basic' lowercase

B The Authorization header is automatically removed by Postman before sending

C The Authorization header value includes 'Basic ' prefix, missing in the assertion

D The Authorization header value is dynamic and should be retrieved from pm.request.headers without hardcoding

💡 Hint

Check how the Authorization header is accessed and compared in the test.

The test compares the Authorization header to a hardcoded string. If credentials change or encoding differs, the test fails. It's better to dynamically check or decode the header.