OAuth 2.0 and Authentication: Secure User Access
November 18, 2024•1 min read
OAuthAuthenticationSecurityBackend
# OAuth 2.0 and Authentication: Secure User Access
OAuth 2.0 is the industry standard for authorization, enabling secure access to resources without sharing passwords.
## OAuth 2.0 Flows
### Authorization Code Flow
Most secure flow for web applications:
```typescript
// Step 1: Redirect to authorization server
const authUrl = `https://oauth.provider.com/authorize?
client_id=${CLIENT_ID}&
redirect_uri=${REDIRECT_URI}&
response_type=code&
scope=read write`;
// Step 2: Exchange code for token
const tokenResponse = await fetch('https://oauth.provider.com/token', {
method: 'POST',
body: new URLSearchParams({
grant_type: 'authorization_code',
code: authorizationCode,
redirect_uri: REDIRECT_URI,
client_id: CLIENT_ID,
client_secret: CLIENT_SECRET,
}),
});
```
### Client Credentials Flow
For server-to-server communication:
```typescript
const tokenResponse = await fetch('https://oauth.provider.com/token', {
method: 'POST',
body: new URLSearchParams({
grant_type: 'client_credentials',
client_id: CLIENT_ID,
client_secret: CLIENT_SECRET,
scope: 'read write',
}),
});
```
## Implementation
```typescript
@Injectable()
export class AuthService {
async authenticate(code: string) {
const token = await this.exchangeCodeForToken(code);
const user = await this.getUserInfo(token);
return this.createSession(user);
}
}
```
## Security Best Practices
- Use HTTPS
- Store secrets securely
- Validate state parameter
- Implement token refresh
- Use PKCE for mobile apps
## Conclusion
OAuth 2.0 provides secure authorization. Implement proper flows and security measures for production applications.