OAuth authentication is the process in which Users grant access to their Protected Resources without sharing their credentials with the Consumer.

OAuth Authentication is done in three steps:

In order for RESTEasy to provide the two URL endpoints where the Client will request unauthorized Request Tokens and exchange authorized Request Tokens for Access Tokens, you need to enable the OAuthServlet in your web.xml:

                

<!-- The OAuth Servlet handles token exchange -->

<servlet>

  <servlet-name>OAuth</servlet-name>

  <servlet-class>org.jboss.RESTEasy.auth.oauth.OAuthServlet</servlet-class>

</servlet>



<!-- This will be the base for the token exchange endpoint URL -->

<servlet-mapping>

  <servlet-name>OAuth</servlet-name>

  <url-pattern>/oauth/*</url-pattern>

</servlet-mapping>

                

            

The following configuration options are available using <context-param> elements:

After successfully receiving the Access Token and Token Secret, the Consumer is able to access the Protected Resources on behalf of the User.

RESTEasy supports OAuth authentication for protected resources using a servlet filter which should be mapped in your web.xml for all protected resources:

                

<!-- The OAuth Filter handles authentication for protected resources -->

<filter>

  <filter-name>OAuth Filter</filter-name>

  <filter-class>org.jboss.RESTEasy.auth.oauth.OAuthFilter</filter-class>

</filter>

    

<!-- This defines the URLs which should require OAuth authentication for your protected resources -->

<filter-mapping>

  <filter-name>OAuth Filter</filter-name>

  <url-pattern>/rest/*</url-pattern>

</filter-mapping>

                

            

The following configuration options are available using <context-param> elements:

Once authenticated, the OAuth Servlet Filter will set your request's Principal and Roles, which can then be accessed using the JAX-RS SecurityContext. You can also protect your resources using Roles as described in the section "Securing JAX-RS and RESTeasy".

In order for RESTEasy to implement OAuth it needs you to provide an instance of OAuthProvider which will provide access to the list of Consumer, Request and Access Tokens. Because one size doesn’t fit all we cannot know if you wish to store your Tokens and Consumer credentials in a configuration file, in memory, or on persistent storage.

All you need to do is implement the OAuthProvider interface:

public interface OAuthProvider {
	String getRealm();

	OAuthConsumer getConsumer(String consumerKey)throws OAuthException;
	OAuthToken getRequestToken(String consumerKey, String requestToken) throws OAuthException;
	OAuthToken getAccessToken(String consumerKey, String accessToken) throws OAuthException;
	
	OAuthToken makeRequestToken(String consumerKey, String callback) throws OAuthException;
	OAuthToken makeAccessToken(String consumerKey, String requestToken, String verifier) throws OAuthException;

	String authoriseRequestToken(String consumerKey, String requestToken) throws OAuthException;

	void checkTimestamp(OAuthToken token, long timestamp) throws OAuthException;
}

			

If a Consumer Key, or Token doesn’t exist, or if the timestamp is not valid, simply throw an OAuthException.

The rest of the interfaces used in OAuthProvider are:

public interface OAuthConsumer {
	String getKey();
	String getSecret();
}

public interface OAuthToken {
	OAuthConsumer getConsumer();
	String getToken();
	String getSecret();
	Principal getPrincipal();
	Set<String> getRoles();
}