@aid-on/auth-providers

Framework-agnostic OAuth 2.0 authentication providers by Aid-On.

This library can be used in:

• Cloud Functions (GCP, AWS Lambda)
• Edge Functions (Vercel, Cloudflare Workers)
• Next.js API Routes
• Express/Fastify servers
• Client-side (with proper security measures)

Installation

npm install @aid-on/auth-providers
# or
yarn add @aid-on/auth-providers

Usage

Cloud Functions Example

import { createLineAuthHandler } from '@aid-on/auth-providers/line'

const lineAuth = createLineAuthHandler({
  clientId: process.env.LINE_CLIENT_ID!,
  clientSecret: process.env.LINE_CLIENT_SECRET!,
  redirectUri: 'https://your-domain.com/api/auth/callback'
})

// Start authentication
export async function startAuth(req: Request) {
  const { authUrl, state } = lineAuth.startAuth()
  
  // Save state to session/cookie for CSRF protection
  const response = Response.redirect(authUrl)
  response.headers.set('Set-Cookie', `auth_state=${state}; HttpOnly; Secure; SameSite=Lax`)
  
  return response
}

// Handle callback
export async function handleCallback(req: Request) {
  const url = new URL(req.url)
  const code = url.searchParams.get('code')!
  const state = url.searchParams.get('state')!
  
  // Get expected state from cookie
  const expectedState = getCookie(req, 'auth_state')
  
  const { user, tokens } = await lineAuth.handleCallback({
    code,
    state,
    expectedState
  })
  
  // Save user and tokens to your database
  await saveUser(user)
  await saveTokens(tokens)
  
  return Response.json({ success: true, user })
}

Direct Client Usage

import { LineAuthClient } from '@aid-on/auth-providers/line'

const client = new LineAuthClient({
  clientId: 'YOUR_CLIENT_ID',
  clientSecret: 'YOUR_CLIENT_SECRET',
  redirectUri: 'https://your-domain.com/callback'
})

// Generate authorization URL
const state = client.generateState()
const authUrl = client.getAuthorizationUrl({ state })

// Exchange code for tokens
const tokens = await client.getAccessToken(code)

// Get user profile
const user = await client.getUserProfile(tokens.access_token)

// Refresh token
const newTokens = await client.refreshAccessToken(tokens.refresh_token)

// Revoke token
await client.revokeAccessToken(tokens.access_token)

Available Providers

LINE

Full OAuth 2.0 implementation for LINE Login

• Authorization URL generation
• Token exchange
• User profile retrieval
• Token refresh
• Token revocation

Security Considerations

1. Never expose client secrets in client-side code
2. Always validate state parameter for CSRF protection
3. Store tokens securely (encrypted in database)
4. Use HTTPS for all OAuth callbacks
5. Implement proper session management

License

MIT