Chapter 118. Spring Security
Spring Security
Available as of Camel 2.3
The camel-spring-security component provides role-based authorization for Camel routes. It leverages the authentication and user services provided by Spring Security (formerly Acegi Security) and adds a declarative, role-based policy system to control whether a route can be executed by a given principal.
If you are not familiar with the Spring Security authentication and authorization system, please review the current reference documentation on the SpringSource web site linked above.
Creating authorization policies
Access to a route is controlled by an instance of a
SpringSecurityAuthorizationPolicy
object. A policy object contains the name of the Spring Security authority (role) required to run a set of endpoints and references to Spring Security AuthenticationManager
and AccessDecisionManager
objects used to determine whether the current principal has been assigned that role. Policy objects may be configured as Spring beans or by using an <authorizationPolicy>
element in Spring XML.
The
<authorizationPolicy>
element may contain the following attributes:
Name | Default Value | Description |
---|---|---|
id
|
null
|
The unique Spring bean identifier which is used to reference the policy in routes (required) |
access
|
null
|
The Spring Security authority name that is passed to the access decision manager (required) |
authenticationManager
|
authenticationManager
|
The name of the Spring Security AuthenticationManager object in the context
|
accessDecisionManager
|
accessDecisionManager
|
The name of the Spring Security AccessDecisionManager object in the context
|
authenticationAdapter
|
DefaultAuthenticationAdapter |
Camel 2.4 The name of a camel-spring-securityAuthenticationAdapter object in the context that is used to convert a javax.security.auth.Subject into a Spring Security Authentication instance.
|
useThreadSecurityContext
|
true
|
If a javax.security.auth.Subject cannot be found in the In message header under Exchange.AUTHENTICATION, check the Spring Security SecurityContextHolder for an Authentication object.
|
alwaysReauthenticate
|
false
|
If set to true, the SpringSecurityAuthorizationPolicy will always call AuthenticationManager.authenticate() each time the policy is accessed.
|
Controlling access to Camel routes
A Spring Security
AuthenticationManager
and AccessDecisionManager
are required to use this component. Here is an example of how to configure these objects in Spring XML using the Spring Security namespace:
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:spring-security="http://www.springframework.org/schema/security" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd"> <bean id="accessDecisionManager" class="org.springframework.security.access.vote.AffirmativeBased"> <property name="allowIfAllAbstainDecisions" value="true"/> <property name="decisionVoters"> <list> <bean class="org.springframework.security.access.vote.RoleVoter"/> </list> </property> </bean> <spring-security:authentication-manager alias="authenticationManager"> <spring-security:authentication-provider user-service-ref="userDetailsService"/> </spring-security:authentication-manager> <spring-security:user-service id="userDetailsService"> <spring-security:user name="jim" password="jimspassword" authorities="ROLE_USER, ROLE_ADMIN"/> <spring-security:user name="bob" password="bobspassword" authorities="ROLE_USER"/> </spring-security:user-service> </beans>
Now that the underlying security objects are set up, we can use them to configure an authorization policy and use that policy to control access to a route:
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:spring-security="http://www.springframework.org/schema/security" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd http://camel.apache.org/schema/spring-security http://camel.apache.org/schema/spring-security/camel-spring-security.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd"> <!-- import the spring security configuration --> <import resource="classpath:org/apache/camel/component/spring/security/commonSecurity.xml"/> <authorizationPolicy id="admin" access="ROLE_ADMIN" authenticationManager="authenticationManager" accessDecisionManager="accessDecisionManager" xmlns="http://camel.apache.org/schema/spring-security"/> <camelContext id="myCamelContext" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <!-- The exchange should be authenticated with the role of ADMIN before it is send to mock:endpoint --> <policy ref="admin"> <to uri="mock:end"/> </policy> </route> </camelContext> </beans>
In this example, the endpoint
mock:end
will not be executed unless a Spring Security Authentication
object that has been or can be authenticated and contains the ROLE_ADMIN
authority can be located by the adminSpringSecurityAuthorizationPolicy
.
Authentication
The process of obtaining security credentials that are used for authorization is not specified by this component. You can write your own processors or components which get authentication information from the exchange depending on your needs. For example, you might create a processor that gets credentials from an HTTP request header originating in the camel-jetty component. No matter how the credentials are collected, they need to be placed in the In message or the
SecurityContextHolder
so the camel-spring-security component can access them:
import javax.security.auth.Subject; import org.apache.camel.*; import org.apache.commons.codec.binary.Base64; import org.springframework.security.authentication.*; public class MyAuthService implements Processor { public void process(Exchange exchange) throws Exception { // get the username and password from the HTTP header // http://en.wikipedia.org/wiki/Basic_access_authentication String userpass = new String(Base64.decodeBase64(exchange.getIn().getHeader("Authorization", String.class))); String[] tokens= userpass.split(":"); // create an Authentication object UsernamePasswordAuthenticationToken authToken = new UsernamePasswordAuthenticationToken(tokens[0], tokens[1]); // wrap it in a Subject Subject subject = new Subject(); subject.getPrincipals().add(token); // place the Subject in the In message exchange.getIn().setHeader(Exchange.AUTHENTICATION, subject); // you could also do this if useThreadSecurityContext is set to true // SecurityContextHolder.getContext().setAuthentication(authToken); } }
The
SpringSecurityAuthorizationPolicy
will automatically authenticate the Authentication
object if necessary.
There are two issues to be aware of when using the
SecurityContextHolder
instead of or in addition to the Exchange.AUTHENTICATION
header. First, the context holder uses a thread-local variable to hold the Authentication
object. Any routes that cross thread boundaries, like seda or jms, will lose the Authentication
object. Second, the Spring Security system appears to expect that an Authentication
object in the context is already authenticated and has roles (see the Technical Overview section 5.3.1 for more details).
The default behavior of camel-spring-security is to look for a
Subject
in the Exchange.AUTHENTICATION
header. This Subject
must contain at least one principal, which must be a subclass of org.springframework.security.core.Authentication
. You can customize the mapping of Subject
to Authentication
object by providing an implementation of the org.apache.camel.component.spring.security.AuthenticationAdapter
to your <authorizationPolicy>
bean. This can be useful if you are working with components that do not use Spring Security but do provide a Subject
. At this time, only the camel-cxf component populates the Exchange.AUTHENTICATION
header.
Handling authentication and authorization errors
If authentication or authorization fails in the
SpringSecurityAuthorizationPolicy
, a CamelAuthorizationException
will be thrown. This can be handled using Camel's standard exception handling methods, like the Exception clause. The CamelAuthorizationException
will have a reference to the ID of the policy which threw the exception so you can handle errors based on the policy as well as the type of exception:
<onException> <exception>org.springframework.security.authentication.AccessDeniedException</exception> <choice> <when> <simple>${exception.policyId} == 'user'</simple> <transform> <constant>You do not have ROLE_USER access!</constant> </transform> </when> <when> <simple>${exception.policyId} == 'admin'</simple> <transform> <constant>You do not have ROLE_ADMIN access!</constant> </transform> </when> </choice> </onException>
Dependencies
Maven users will need to add the following dependency to their
pom.xml
for this component:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-security</artifactId> <version>2.4.0</version> </dependency>
This dependency will also pull in
org.springframework.security:spring-security-core:3.0.3.RELEASE
and org.springframework.security:spring-security-config:3.0.3.RELEASE
.