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Comment: Migrated to Confluence 5.3

Policy Model

The current policy model has been around for a while and needs a review in light of what we have learned over the last six months, a number of issues that have come up and ongoing work at OASIS;

http://www.osoa.org/jira/browse/POLICY-15
https://issues.apache.org/jira/browse/TUSCANY-2553
http://issues.apache.org/jira/browse/TUSCANY-2499
http://www.mail-archive.com/dev%40tuscany.apache.org/msg01772.html

Summary of issues with the current arrangement

  • Better separation of policy model from assembly model
    • implementation policy sets held by component due to reuse of implementation model objects
    • OASIS are talking about moving to an external attachment model so we need flexibility to follow that move if necessary
  • "Applies to" happens right at the start of contribution and is not subject to later builder processing
  • Consistency of model style between assembly and policy models
  • Separate any policy processing from policy model
  • Consistency of policy extension model
  • definitions.xml processing should be domain wide and not restricted to a single contribution

Idealistic policy model

The make sure I understand the model I reproduced my version of it from the existing spec resources. It's slightly different from what we have at present as the code model is somewhat optimized but I want to use this as my baseline for reviewing what we have in the implementations

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Policy model reading follows the assembly model in having read and resolve phases. The read phase will create dummy objects with "unresolved = true" set to represent any unresolved references. These dummy objects are replaced with the real thing at the resolve stage.

Policy and assembly model relationship

The assembly model starts life with manually configured intents and policy sets on individual assembly elements. The result of applying the intent and policySet inheritance rules and the intent and policySet matching rules leads to a final set of relationships between assembly artifacts and policySets. I started to draw these externalized from the assembly model but expect that they will resolve to placing the correct policySet QNames on appropriate assembly artifacts. These relationships drive the configuration of each binding and implementation and with wires in between.

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Policy touch points

A summary of what parts of the runtime are affected by policies.

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Policy Runtime

Policy implementations are provided by interceptors and by the bindings and implementations themselves. The assembly model relationships shown at the top of this diagram are as they are at the moment I believe. Need to look see if rationalization is required.

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Implementation Policy

Service Policy

Reference Policy

Binding Policy

...

Current Policy Providers

o.a.t.s.policy.logging

...

Policy set and sample available

Authentication -

...

User Defined

No implementation yet. User defined authentication tokens could be useful when the Tuscany user has their own single sign on framework.

1. The client application authenticates and receives a token by some means out of band to Tuscany
2. The client application sends messages to Tuscany including the authenticated token. The intent is either authentication.message or authentication.transport
3. The tuscany runtime (host, binding, policy code) allows extensible policy support to validate the token against some 3rd party identitiy system.

To make this work there are a number of moving parts that we need to think about.

Decide what format the security token is going to take. From a general Tuscany point of view we don't actually have to decide what the token will look like but we have to understand what formats are valid, of particular standards are allowed etc.

JMS
Assume authentication.message is required here
It's likely the security token will travel in a JMS message property so the JMS binding needs to be extended to be able to call out to policy providers in order to authenticate the token and retrieve the Subject. The Token/Subject should then be placed in the Tuscany message context.

...

These steps require a closer integration between the bindings and the policy providers than we have currently.

Example of how binding.ws is configured in this scenario

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Authentication - HTTP Basic

No implementation yet

Need same capability as described in single sign on to get close to the web service binding and configure the transport (reference side) extract transport context (service side).

Definitions.xml

Code Block

    <sca:policySet name="WSBasicAuthenticationPolicySet"
                   provides="authentication"
                   appliesTo="sca:reference/sca:binding.ws">
                   
        <tuscany:wsBasicAuthentication>
          <tuscany:userName>myname</tuscany:userName>
          <tuscany:password>mypassword</tuscany:password>
        </tuscany:wsBasicAuthentication>
        
     	<tuscany:wsAxisOption>
                <propertySetter name="org.apache.tuscany.sca.binding.ws.axis2.policy.authentication.basic.WSBasicAuthenticationReferencePolicyAxisOptions"/>
     		<property name="_NTLM_DIGEST_BASIC_AUTHENTICATION_"/>
                <authenticator>
                   <authScheme>Basic</authScheme>
                   <premtiveAuthentication>true</premtiveAuthentication>
                </authenticator>
          	</property>
     	</tuscany:wsAxisOption>
        
    </sca:policySet>
    
    <sca:policySet name="WSBasicAuthenticationPolicySet"
                   provides="authentication"
                   appliesTo="sca:service/sca:binding.ws">
                   
        <tuscany:wsBasicAuthentication>
          <tuscany:userName>myname</tuscany:userName>
          <tuscany:password>mypassword</tuscany:password>
        </tuscany:wsBasicAuthentication>
        
    </sca:policySet>

Reference side interceptor:

Code Block

public class WSBasicAuthenticationReferencePolicyInterceptor implements Interceptor {
    public static final QName policySetQName = new QName(Constants.SCA10_TUSCANY_NS, "wsBasicAuthentication");

    private Invoker next;
    private Operation operation;
    private PolicySet policySet = null;
    private String context;
    private WSBasicAuthenticationPolicy policy;

    public WSBasicAuthenticationReferencePolicyInterceptor(String context, Operation operation, PolicySet policySet) {
        super();
        this.operation = operation;
        this.policySet = policySet;
        this.context = context;
        init();
    }

    private void init() {
        if (policySet != null) {
            for (Object policyObject : policySet.getPolicies()){
                if (policyObject instanceof WSBasicAuthenticationPolicy){
                    policy = (WSBasicAuthenticationPolicy)policyObject;
                    break;
                }
            }
        }
    }

    public Message invoke(Message msg) {
        // could call out here to some 3rd part system to get credentials
        msg.getQoSContext().put(WSBasicAuthenticationPolicy.WS_BASIC_AUTHENTICATION_USERNAME,
                                policy.getUserName());
        msg.getQoSContext().put(WSBasicAuthenticationPolicy.WS_BASIC_AUTHENTICATION_PASSWORD,
                policy.getPassword());
        
        return getNext().invoke(msg);
    }

    public Invoker getNext() {
        return next;
    }

    public void setNext(Invoker next) {
        this.next = next;
    }
}

Service side interceptor

Code Block

public class WSBasicAuthenticationServicePolicyInterceptor implements Interceptor {
    public static final QName policySetQName = new QName(Constants.SCA10_TUSCANY_NS, "wsBasicAuthentication");

    private Invoker next;
    private Operation operation;
    private PolicySet policySet = null;
    private String context;
    private WSBasicAuthenticationPolicy policy;

    public WSBasicAuthenticationServicePolicyInterceptor(String context, Operation operation, PolicySet policySet) {
        super();
        this.operation = operation;
        this.policySet = policySet;
        this.context = context;
        init();
    }

    private void init() {
        if (policySet != null) {
            for (Object policyObject : policySet.getPolicies()){
                if (policyObject instanceof WSBasicAuthenticationPolicy){
                    policy = (WSBasicAuthenticationPolicy)policyObject;
                    break;
                }
            }
        }
    }

    public Message invoke(Message msg) {
        Object[] header = msg.getHeader();
        
        Map httpHeaderProperties = (Map)Object[0];
        
        String basicAuthString = (String)httpHeaderProperties.get("Authorization");
        String decodedBasicAuthString = null;
        String username = null;
        String password = null;
        
        if (basicAuthString != null) {
            basicAuthString = basicAuthString.trim();
            
            if (basicAuthString.startsWith("Basic ")) {
                decodedBasicAuthString = new String(Base64.decode(basicAuthString.substring(6)));
            }
            
            int collonIndex = decodedBasicAuthString.indexOf(':');
            
            if (collonIndex == -1){
                username = decodedBasicAuthString;
            } else {
                username = decodedBasicAuthString.substring(0, collonIndex);
                password = decodedBasicAuthString.substring(collonIndex + 1);
            }
            
            // could call out here to some 3rd part system to do whatever you 
            // need to turn credentials into a principal            
            
            msg.getQoSContext().put(Message.QOS_CTX_SECURITY_PRINCIPAL, username);             
        }
    
        return getNext().invoke(msg);
    }

    public Invoker getNext() {
        return next;
    }

    public void setNext(Invoker next) {
        this.next = next;
    }
}
Code Block

public class WSBasicAuthenticationReferencePolicyAxisOptions {
    
    public WSBasicAuthenticationReferencePolicyAxisOptions(){
    }
    
    public void setServiceOptions(ServiceClient serviceClient) {
    }
    
    public void setOperationOptions(OperationClient operationClient, Message msg) {
        
        // get security context
        String securityPrincipal = (String)msg.getQoSContext().get(Message.QOS_CTX_SECURITY_PRINCIPAL);
        String username = null;
        String password = null;
        
        // could use the security principal to look up basic auth credentials
        if (  securityPrincipal != null ) {
            // look up usename and password based on security principal
        } else {
           // take the message username and password
            username = (String)msg.getQoSContext().get(WSBasicAuthenticationPolicy.WS_BASIC_AUTHENTICATION_USERNAME);
            password = (String)msg.getQoSContext().get(WSBasicAuthenticationPolicy.WS_BASIC_AUTHENTICATION_PASSWORD);
        }
        
        if (username == null || password == null ){
            throw new ServiceRuntimeException("Basic authenication username or password is null");
        }
        
        HttpTransportProperties.Authenticator authenticator = new HttpTransportProperties.Authenticator();
        List<String> auth = new ArrayList<String>();
        auth.add(Authenticator.BASIC);
        authenticator.setAuthSchemes(auth);
        authenticator.setPreemptiveAuthentication(true);
        authenticator.setUsername(username);
        authenticator.setPassword(password);
    
        operationClient.getOptions().setProperty(HTTPConstants.AUTHENTICATE,
                                                 authenticator);
    }
    
    public void setMessageOptions(MessageContext messageContext) {
        
    }

}

Confidentiality - WS Security

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