WS/XML Service Utility Library (WS and LEGO?) Aleksander Slominski

XML Web Services Fusion Transport (ex. HTTP) Security (XML dsig.) WS/XML Service RPC style Reliable Messaging Type Mapping Future? WS-Stuff

WS/LEGO Game Puzzle of WS-Standards? How to connect blocks? XML Infoset Unlimited Number Of Connections As much as you need?! Build Your Own LEGO Set Keep Experimenting! LEGO comes from Danish words "LEg GOdt" meaning "play well". Ironically, in Latin the lego means "I study" or "I put together"

More Bricks, More Fun Reliable Messaging Layer RPC Layer DSig Layer HTTP Transport SMTP Transport

Virtual Laboratory Toolset: Very Quick XML Service Creation Allow Building Any Kind of XML Services From XML router to RMI runtime Encourage Experimentations Set of Small Modules Allow Easy Code Recombination XML Infoset as connecting glue

XSUL Layers Client Stack Server Stack Soap RPC Client Invoke Java interface Type Mapping (XML  Java) Soap RPC Service Use Java Object Invoker send XML document Processor receive XML document Pluggable Module SOAP/HTTP Invoker SOAP/HTTP Processor Globus / XML Digital sig. HTTP 1.x Client (HTTP 1.x POST/GET) HTTP 1.x Server (HTTP 1.x POST/GET) Common / Utility Legend: depends on XML Infoset

Modules Theory vs. Practice

HTTP Client private HttpClientConnectionManager connMgr = HttpClientConnectionManager.newInstance(); HttpClientRequest req = connMgr.connect(host, port, 4 * 60 * 1000); req.setRequestLine("POST", requestUri, "HTTP/1.0"); HttpClientResponse resp = req.sendHeaders(); OutputStream out = resp.getBodyOutputStream(); Writer utf8Writer = new Utf8Writer(out, 8*1024); … more

Invoker (SOAP 1.1 / HTTP) Soap11HttpDynamicInfosetInvoker invoker = new Soap11HttpDynamicInfosetInvoker() invoker.setLocation("http://localhost:"+port); XmlElement request = builder.parseFragmentFromReader(new StringReader("<getN><arg>/hello</></>")); XmlElement response = invoker.invokeMessage(request);

SOAP RPC Client TypeHandlerRegistry typeMapping = XsdTypeHandlerRegistry.getInstance(); Soap11InvocationHandler handler = new Soap11InvocationHandler(invoker, typeMapping); XDirectoryService ref = (XDirectoryService) Proxy.newProxyInstance( Thread.currentThread().getContextClassLoader(), new Class[] { XDirectoryService.class }, handler); XmlNode result = ref.getNode("/hello");

Client Stack RPC Client Invoker (SOAP 1.1 / HTTP) HTTP Client Translates Java Interface into XML message Invoker (SOAP 1.1 / HTTP) XML Message is wrapped into SOAP 1.1 Envelope and serialized into transport output stream HTTP Client Actual sending happens here! Design Issues Can add new transport (new invoker)? Can inject XML processing layers? XML transformations: digital signatures?

Adding DSig Module To Client App Soap11HttpDynamicInfosetInvoker invoker = new Soap11HttpDynamicInfosetInvoker() { public XmlDocument invokeXml(XmlDocument request) throws DynamicInfosetInvokerException { // WSRMHandler.getInstance().augmentRequest(request); XmlDocument signedRequest = GlobusCredSOAPEnvelopeSigner.getInstance().signSoapMessage(request); XmlDocument response = super.invokeXml(signedRequest); GlobusCredSOAPEnvelopeVerifier.getInstance().verifySoapMessage(response); // WSRMHandler.getInstance().processResponse(response); return response; } };

HTTP Server server = new HttpMiniServer(serverPort); servlet= new MyServlet(); server.useServlet(servlet); server.startServer(); class MyServlet extends HttpMiniServlet { public void service(HttpServerRequest req, HttpServerResponse res) { … more }

Processor (SOAP 1.1 / HTTP) Soap11HttpDynamicInfosetProcessor processor = new Soap11HttpDynamicInfosetProcessor() { public XmlElement processMessage(XmlElement message) { message.setParent(null); message.setName(message.getName()+"Response"); return message; } }; processor.setServerPort(port); processor.start(); Full SOAP Echo Service Impl!

SOAP RPC Server TypeHandlerRegistry typeMapping = XsdTypeHandlerRegistry.getInstance() XDirectoryService serviceLogic = new XDirectoryServiceImpl(); final Soap11ReflectionBasedService service = new Soap11ReflectionBasedService(serviceLogic, typeMapping); … Soap11HttpDynamicInfosetProcessor processor = new Soap11HttpDynamicInfosetProcessor() { public XmlElement processMessage(XmlElement requestMsg) XmlElement responseMsg = service.processMessage(requestMsg); return responseMsg; } };

Server Stack RPC Server Processor (SOAP 1.1 / HTTP) HTTP Server User Java Reflection to convert XML message into Java invocation Processor (SOAP 1.1 / HTTP) Accept XML Message that is wrapped into SOAP 1.1 Envelope and unwrap it HTTP Server Listen for XML messages! Design Issues Can add new transport (new listening server) Can inject XML processing layers XML transformations: digital signatures and authorization checks?

Using DSig/Authz in App Soap11HttpDynamicInfosetProcessor processor = new Soap11HttpDynamicInfosetProcessor() { public XmlDocument processSoap11Envelope(XmlElement envelope) { XmlDocument respDoc = null; SignatureInfo si = SOAPEnvelopeVerifier.getInstance().verifySoapMessage(envelope); if(!isAuthorized(si.getSubjectDn(), envelope)) { XmlDocument fault = Soap11Util.wrapBodyContent(Soap11Util.generateSoap11Fault( XmlConstants.NS_URI_SOAP11, "Client", "unathorized access")); respDoc = fault; } else { respDoc = super.processSoap11Envelope(envelope); } XmlDocument signedDoc = GlobusCredSOAPEnvelopeSigner.getInstance().signSoapMessage(respDoc); return signedDoc; };

WORK IN PROGRESS!!! OSS site (CVS hosted in SourceForge) www.extreme.indiana.edu/xgws/xsul www.extreme.indiana.edu/viewcvs/xsul WikiWiki And Blog portal.extreme.indiana.edu:3456/xsul Place to Track Progress And Gather Feedback Bugzilla www.extreme.indiana.edu/bugs Your Feedback is Welcome Use Modules and Build Your Own Module

Conclusions Encourages experimentation Easy to add new modules LEGO “experience” Easy to add new modules WS-RM, WSS4J, WSDL Invoker, … Better Than CORBA? Maybe … … but higher “playability” level  Add what needed Piece by piece …

Addendum As More is Better …

Adding Caching to Improve DSig Performance Soap11HttpDynamicInfosetProcessor processor = new Soap11HttpDynamicInfosetProcessor() { public XmlDocument processSoap11Envelope(XmlElement envelope) { XmlDocument respDoc = null; if( (respDoc = lookupCachedResponse(envelope) ) != null ) { { //NOTE: needs to check that request is idempotent and resource is not changed! return respDoc; } SignatureInfo si = GlobusCredSOAPEnvelopeVerifier.getInstance().verifySoapMessage(envelope); if(!isAuthorized(si.getSubjectDn(), envelope)) { XmlDocument fault = Soap11Util.wrapBodyContent(Soap11Util.generateSoap11Fault( XmlConstants.NS_URI_SOAP11, "Client", "unathorized access")); respDoc = fault; } else { XmlDocument respDoc = super.processSoap11Envelope(envelope); XmlDocument signedDoc = GlobusCredSOAPEnvelopeSigner.getInstance().signSoapMessage(respDoc); return signedDoc; };

DSig Steps Breakdown Client Server Generate SOAP call Sign Send … wait Receive Verify DSig Pass result Receive SOAP Message Verify DSig Reflection Based Invocation Sign Send SOAP Message

RPC Client implementation details (Using Dynamic Proxy, without WSDL) class Soap11InvocationHandler implements InvocationHandler { public Object invoke(Object proxy, Method method, Object[] params) throws Throwable { String methodName = method.getName(); XmlElement request = builder.newFragment( methodName ); for (int i = 0; i < params.length; i++) { XmlElement param = registry.javaToXmlElement(params[i],null, "param"+i); request.addChild(param); } XmlElement response = invoker.invokeMessage(request); // map back to Java return type or Exception if S:Fault …

Client Side APIs WSDL/RMI GlobalWeatherSoap gws = (GlobalWeatherSoap) WsdlNaming.lookup("http://www.example.com/weather?WSDL"); String s = gws.GetWeather(cityName, countryName) WSDL/Dynamic Proxy Stub GlobalWeatherSoap ref = (GlobalWeatherSoap) WsdlNaming.lookup("http://www.example.com/weather?WSDL“, GlobalWeatherSoap.class); WSDL/Dynamic Invocation Interface (DII) WsdlDynamicInfosetInvoker dii = WsdlNaming.lookup("http://www.example.com/weather?WSDL"); //NOTE: invoke() uses new JDK 1.5 multi args. “...” instead new Object[] {}); XmlElement result = dii.invoke("GetWeather", cityName, countryName); String cityName = result.string("cityName");