Requests has support for diverse kinds of authentication procedures, and it is built in such a way that the method of authentication feels very rewarding. This tutorial highlights various types of authentication procedures that various tech giants use for accessing web resources. We will cover Basic authentication, Digest authentication, Kerberos authentication, OAuth authentication, and more.

There are several authentication techniques that can be used with the Python requests library to authenticate HTTP requests.

1. Basic Authentication: This is the most basic and simple form of authentication, where the client sends an HTTP request with a username and password in the headers. The server then verifies the credentials and returns the response.
2. Digest Authentication: This is a more secure form of basic authentication, where the server sends a nonce value in the headers and the client uses this value to calculate a response value and sends it back to the server.
3. Token-based Authentication: In this type of authentication, the client sends an HTTP request with a token in the headers. The server verifies the token and returns the response.
4. OAuth: OAuth (Open Authorization) is an open standard for authorization that allows users to grant third-party access to their resources without sharing their credentials. It is widely used for authorization in APIs and web services.
5. SSL/TLS Client Certificate Authentication: In this type of authentication, the client presents a certificate to the server to authenticate itself. The server verifies the certificate and returns the response.

To use these authentication techniques with the requests library, you can pass the appropriate authentication parameters as keyword arguments to the requests.get(), requests.post(), or other request methods. For example:

import requests

# Basic Authentication
response = requests.get('https://example.com/protected', auth=('username', 'password'))

# Digest Authentication
response = requests.get('https://example.com/protected', auth=requests.auth.HTTPDigestAuth('username', 'password'))

# Token-based Authentication
response = requests.get('https://example.com/protected', headers={'Authorization': 'Token token=<TOKEN>'})

# OAuth
response = requests.get('https://example.com/protected', auth=requests.auth.OAuth1('consumer_key', 'consumer_secret', 'access_token', 'access_token_secret'))

# SSL/TLS Client Certificate Authentication
response = requests.get('https://example.com/protected', cert='/path/to/client.pem')