Spring Security OAuth2 pure resource server

Question

We already have an OAuth2 authorization server set up, so I need to create a corresponding resource server (separate server). We plan to use the Spring Security OAuth2 project.

Answer 1

Yes its possible. Like you have already mentioned in your question, RemoteTokenServices is the solution.

I have created one sample which has separate auth and resource server. Its just a sample to give a quick idea about the concept and open for extension.

Spring-AngularJS-OAuth2-Sample

Answer 2

This is possible as long as the authorization server and resource server(s) access a shared tokenStore (e.g. using JdbcTokenStore with a common dataSource). You can just use DefaultTokenServices with a reference to your shared tokenStore. Below is an example Spring config which you should be able to tweak to fit your needs:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:security="http://www.springframework.org/schema/security"
   xmlns:oauth2="http://www.springframework.org/schema/security/oauth2"
   xsi:schemaLocation="
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/security
    http://www.springframework.org/schema/security/spring-security-3.1.xsd
    http://www.springframework.org/schema/security/oauth2
    http://www.springframework.org/schema/security/spring-security-oauth2.xsd">

<bean id="tokenStore" class="org.springframework.security.oauth2.provider.token.JdbcTokenStore">
    <constructor-arg name="dataSource" ref="dataSource" />
</bean>

<bean id="tokenServices" class="org.springframework.security.oauth2.provider.token.DefaultTokenServices">
    <property name="tokenStore" ref="tokenStore" />
</bean>

<bean id="authenticationEntryPoint" class="org.springframework.security.oauth2.provider.error.OAuth2AuthenticationEntryPoint">
    <property name="realmName" value="myRealm" />
</bean>

<bean id="oauthAccessDeniedHandler" class="org.springframework.security.oauth2.provider.error.OAuth2AccessDeniedHandler" />

<bean id="accessDecisionManager" class="org.springframework.security.access.vote.UnanimousBased">
    <constructor-arg>
        <list>
            <bean class="org.springframework.security.oauth2.provider.vote.ScopeVoter" />
            <bean class="org.springframework.security.access.vote.RoleVoter" />
            <bean class="org.springframework.security.access.vote.AuthenticatedVoter" />
        </list>
    </constructor-arg>
</bean>

<!-- This is not actually used, but it's required by Spring Security -->
<security:authentication-manager alias="authenticationManager" />

<oauth2:expression-handler id="oauthExpressionHandler" />

<oauth2:web-expression-handler id="oauthWebExpressionHandler" />

<security:global-method-security pre-post-annotations="enabled" proxy-target-class="true">
    <security:expression-handler ref="oauthExpressionHandler" />
</security:global-method-security>

<oauth2:resource-server id="myResource" resource-id="myResourceId" token-services-ref="tokenServices" />

<security:http pattern="/myPattern/**" create-session="never"
    entry-point-ref="authenticationEntryPoint" access-decision-manager-ref="accessDecisionManager">
    <security:anonymous enabled="false" />
    <security:intercept-url pattern="/**" access="SCOPE_READ" method="GET" />
    <security:intercept-url pattern="/**" access="SCOPE_READ" method="HEAD" />
    <security:intercept-url pattern="/**" access="SCOPE_READ" method="OPTIONS" />
    <security:intercept-url pattern="/**" access="SCOPE_WRITE" method="PUT" />
    <security:intercept-url pattern="/**" access="SCOPE_WRITE" method="POST" />
    <security:intercept-url pattern="/**" access="SCOPE_WRITE" method="DELETE" />
    <security:custom-filter ref="myResource" before="PRE_AUTH_FILTER" />
    <security:access-denied-handler ref="oauthAccessDeniedHandler" />
    <security:expression-handler ref="oauthWebExpressionHandler" />
</security:http>
</beans>