OpenID Connect Implementation Guide

OpenID Connect (OIDC) is an authentication protocol that enables third-party applications to securely access user resources on a server. This guide will walk you through the steps to implement OpenID Connect in your application.

Prerequisites

Before you begin, make sure you have the following prerequisites:

A server with a valid SSL/TLS certificate
An OpenID Provider (OP) that supports OpenID Connect
An application that needs to authenticate users

Step 1: Register Your Application

Go to your OpenID Provider and register your application.
Fill in the required information, such as the application name, redirect URI, and description.
Once registered, you will receive a client ID and client secret.

Step 2: Implement the Authorization Code Flow

The authorization code flow is the most common way to implement OpenID Connect. Here's a high-level overview:

Redirect the user to the authorization endpoint of the OP with the client ID, redirect URI, and scope.
The OP will ask the user to log in and grant permission to your application.
After the user grants permission, the OP will redirect the user back to your redirect URI with an authorization code.
Exchange the authorization code for an access token using the client secret.

Example

from urllib.parse import urlencode
from requests import post

# OP authorization endpoint
authorization_endpoint = "https://example.com/auth"

# Client ID and secret
client_id = "your-client-id"
client_secret = "your-client-secret"

# Redirect URI
redirect_uri = "https://your-app.com/callback"

# Scope
scope = "openid profile email"

# Build the authorization URL
params = {
    "response_type": "code",
    "client_id": client_id,
    "redirect_uri": redirect_uri,
    "scope": scope,
}

authorization_url = f"{authorization_endpoint}?{urlencode(params)}"

# Redirect the user to the authorization URL
# ...

Step 3: Exchange the Authorization Code for an Access Token

Once you have the authorization code, you can exchange it for an access token using the client secret.

# OP token endpoint
token_endpoint = "https://example.com/token"

# Exchange the authorization code for an access token
data = {
    "grant_type": "authorization_code",
    "client_id": client_id,
    "client_secret": client_secret,
    "redirect_uri": redirect_uri,
    "code": authorization_code,
}

response = post(token_endpoint, data=data)

# Check for errors
if response.status_code == 200:
    access_token = response.json().get("access_token")
else:
    # Handle error
    # ...

Step 4: Use the Access Token to Access User Resources

With the access token, you can access user resources on the server.

# OP user info endpoint
user_info_endpoint = "https://example.com/userinfo"

headers = {
    "Authorization": f"Bearer {access_token}",
}

response = get(user_info_endpoint, headers=headers)

# Check for errors
if response.status_code == 200:
    user_info = response.json()
else:
    # Handle error
    # ...

Additional Resources

For more information, please refer to the following resources: