AI API PROXY OAUTH 2.0

🛰️ Protocol Overview

The OAuth 2.0 protocol functions as a space station docking mechanism, allowing secure access delegation between different orbital systems (applications). This guide explores comprehensive implementation strategies for AI API proxies.

🔄 Grant Type Selection

Choose the appropriate OAuth 2.0 grant type based on your application architecture and security requirements:

🚀 Implementation Guide

// Authorization server configuration
const oauth2orize = require('oauth2orize');
const server = oauth2orize.createServer();

// Token endpoint
server.exchange(oauth2orize.exchange.code((client, code, redirectURI, done) => {
    // Validate authorization code
    AuthorizationCode.findOne({ code: code }, (err, authCode) => {
        if (err) return done(err);
        if (!authCode || authCode.clientId !== client.id) {
            return done(null, false);
        }
        if (authCode.redirectUri !== redirectURI) {
            return done(null, false);
        }
        
        // Issue access token
        const token = uuid.v4();
        const refreshToken = uuid.v4();
        const accessToken = new AccessToken({
            token: token,
            clientId: client.id,
            userId: authCode.userId,
            scope: authCode.scope
        });
        
        accessToken.save((err) => {
            if (err) return done(err);
            done(null, token, refreshToken, { 
                expires_in: 3600,
                scope: authCode.scope 
            });
        });
    });
}));

// Client-side PKCE implementation
async function initiateAuthorization() {
    // Generate code verifier and challenge
    const codeVerifier = generateRandomString(128);
    const codeChallenge = await generateCodeChallenge(codeVerifier);
    
    // Store verifier for later validation
    sessionStorage.setItem('code_verifier', codeVerifier);
    
    // Construct authorization URL
    const authUrl = new URL('https://auth-server.com/authorize');
    authUrl.searchParams.append('response_type', 'code');
    authUrl.searchParams.append('client_id', CLIENT_ID);
    authUrl.searchParams.append('redirect_uri', REDIRECT_URI);
    authUrl.searchParams.append('scope', 'api:read api:write');
    authUrl.searchParams.append('code_challenge', codeChallenge);
    authUrl.searchParams.append('code_challenge_method', 'S256');
    authUrl.searchParams.append('state', generateRandomString(16));
    
    // Redirect to authorization server
    window.location.href = authUrl.toString();
}

async function handleCallback(code) {
    const codeVerifier = sessionStorage.getItem('code_verifier');
    
    // Exchange code for token
    const response = await fetch('https://auth-server.com/token', {
        method: 'POST',
        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
        body: new URLSearchParams({
            grant_type: 'authorization_code',
            code: code,
            redirect_uri: REDIRECT_URI,
            client_id: CLIENT_ID,
            code_verifier: codeVerifier
        })
    });
    
    const tokens = await response.json();
    // Store tokens securely
    secureTokenStorage.set('access_token', tokens.access_token);
    secureTokenStorage.set('refresh_token', tokens.refresh_token);
}

// Token validation middleware
const jwt = require('jsonwebtoken');
const jwksClient = require('jwks-rsa');

const client = jwksClient({
    jwksUri: 'https://auth-server.com/.well-known/jwks.json'
});

function getKey(header, callback) {
    client.getSigningKey(header.kid, (err, key) => {
        const signingKey = key.getPublicKey();
        callback(null, signingKey);
    });
}

function validateToken(req, res, next) {
    const authHeader = req.headers.authorization;
    
    if (!authHeader || !authHeader.startsWith('Bearer ')) {
        return res.status(401).json({ error: 'Missing authorization token' });
    }
    
    const token = authHeader.split(' ')[1];
    
    jwt.verify(token, getKey, {
        algorithms: ['RS256'],
        issuer: 'https://auth-server.com',
        audience: 'api-gateway'
    }, (err, decoded) => {
        if (err) {
            return res.status(401).json({ error: 'Invalid token' });
        }
        
        // Token is valid
        req.user = decoded;
        req.token = token;
        next();
    });
}

// Protect API routes
app.use('/api/protected', validateToken);
app.get('/api/protected/data', (req, res) => {
    res.json({ 
        message: 'Access granted',
        user: req.user.sub,
        scope: req.user.scope 
    });
});

🛡️ Security Matrix

📡 Related Protocols