420 likes | 490 Views
Constructing a successful and simple API is the lifeblood of your developer community, and REST is a simple standard through which this can be accomplished. As we construct our API and need to secure the system to authenticate and track applications making requests, the open standard of OAuth 2 provides us with a secure and open source method of doing just this. In this talk, we will explore REST and OAuth 2 as standards for building out a secure API infrastructure, exploring many of the architectural decisions that PayPal took in choosing variations in the REST standard and specific implementations of OAuth 2.
E N D
Securing RESTful APIs Using OAuth 2 and OpenID Connect Jonathan LeBlanc (@jcleblanc) Head of Developer Evangelism PayPal North America
What We’re Covering Auth History and REST Concepts Adding in an Auth Mechanism Integration in Practice (server + client side integrations)
The Ultimate Decision Security Usability
What a RESTful API isn’t Our API is RESTful, we support GET, PUT, POST, and DELETE requests No…actually you just support HTTP…like the rest of the web.
What a RESTful API is Honor HTTP request verbs Use proper HTTP status codes No version numbering in URIs Return format via HTTP Accept header
Does Anyone Actually Do That? Very few APIs follow pragmatic REST principles
"links": [{ "href": "https://api.sandbox.paypal.com/v1/payments/ payment/PAY-6RV75EKEYSZ6Y", "rel": "self", "method": "GET" },{ "href": "https://www.sandbox.paypal.com/webscr? cmd=_express-checkout&token=EC-6019609", "rel": "approval_url", "method": "REDIRECT" },{ "href": "https://api.sandbox.paypal.com/v1/payments/ payment/PAY-6RV75EKEYSZ6Y/execute", "rel": "execute", "method": "POST" } ]
Reasons for Auth Rate Limiting and Attack Vector Protection Having the ability to revoke application access Needing to allow users to revoke an applications access to their data
A Few Different Flavors of Usage User login (authentication) User Involvement (authorization) Application only (bearer tokens)
Fetching the Access Token Fetch the Access Token Access Token Endpoint client_id client_secret grant_type HTTP POST Access Token Endpoint
Fetching the Access Token curl https://api.sandbox.paypal.com/v1/oauth2/token \ -H "Accept: application/json" \ -H "Accept-Language: en_US" \ -u "EOJ2S-Z6OoN_le_KS1d75wsZ6y0SFd…" \ -d "grant_type=client_credentials"
Access Token Response { "scope": "https://api.paypal.com/v1/payments/.* https://api.paypal.com/v1/vault/credit-card", "access_token": "EEwJ6tF9x5WCIZDYzyZGaz6K…", "token_type": "Bearer", "app_id": "APP-6XR95014SS315863X", "expires_in": 28800 }
Using the Access Token Fetch Privileged Resources Resource Endpoint Token Type (Authorization header) Access Token (Authorization header) HTTP GET / PUT / POST / DELETE Resource Endpoint
Using the Access Token curl -v https://api.sandbox.paypal.com/v1/payments/payment \ -H "Content-Type:application/json" \ -H "Authorization:Bearer EMxItHE7Zl4cMdkv…" \ -d "{...}"
A few implementation differences Endpoints Scopes (dynamic / static) Using the Access Token in a request
The Complexities of JavaScript The same-origin policy Keeping private keys private Not having to provide a hacked experience
The Ways we Made it Work Server-side proxy Flash / iframe proxy Private token storage mechanism
User Agent Flow: Redirect Prepare the Redirect URI Authorization Endpoint client_id response_type (token) scope redirect_uri Browser Redirect Redirect URI
User Agent Flow: Redirect Building the redirect link var auth_uri = auth_endpoint + "?response_type=token" + "&client_id=" + client_id + "&scope=profile" + "&redirect_uri=" + window.location; $("#auth_btn").attr("href", auth_uri);
User Agent Flow: Hash Mod Fetch the Hash Mod access_token refresh_token expires_in Extract Access Token
User Agent Flow: Hash Mod Extracting the access token from the hash http://site.com/callback#access_token=rBEGu1FQr5 4AzqE3Q&refresh_token=rEBt51FZr54HayqE3V4a& expires_in=3600 var hash = document.location.hash; var match = hash.match(/access_token=(\w+)/);
User Agent Flow: Get Resources Set Request Headers + URI Resource Endpoint Header: token type + access token Header: accept data type HTTPS Request
User Agent Flow: Get Resources Making an authorized request $.ajax({ url: resource_uri, beforeSend: function (xhr) { xhr.setRequestHeader('Authorization', 'OAuth ' + token); xhr.setRequestHeader('Accept', 'application/json'); }, success: function (response) { //use response object } });
How it’s Normally Used Access user details Push data through user social streams
But why? Access token as a control structure Improve Existing Products Our showcase: Seamless Checkout
The Last Considerations REST and OAuth are specifications, not religions Don’t alienate your developers with security Open source is your friend
A Few Code Links OAuth2 & OpenID Connect Samples https://github.com/jcleblanc/oauth https://github.com/paypal/paypal-access Log in with PayPal http://bit.ly/loginwithpaypal
Thank You! Questions? http://slideshare.net/jcleblanc Jonathan LeBlanc (@jcleblanc) Head of Developer Evangelism PayPal North America