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

Aleksander Slominski

Indiana University Extreme! Lab

XML Web Services Fusion

WS/XMLService

Transport

(ex. HTTP)

Secu

rity

(XM

L dsig.

)

RPCstyle

ReliableMessaging

Type

Map

ping

Future?

WS-Stuff

Indiana University Extreme! Lab

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"

Indiana University Extreme! Lab

More Bricks,More Fun

HTTP Transport SMTP Transport

RPC Layer DSig LayerReliable Messaging Layer

Indiana University Extreme! Lab

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

Indiana University Extreme! Lab

Legend: depends on

Server StackClient Stack

XSUL Layers

HTTP 1.x Client(HTTP 1.x POST/GET)

Common / Utility

Invokersend XML document

SOAP/HTTP Invoker

Soap RPC ClientInvoke Java interface

XML Infoset

HTTP 1.x Server(HTTP 1.x POST/GET)

Processorreceive XML document

SOAP/HTTP Processor

Soap RPC ServiceUse Java Object

Globus / XMLDigital sig.

Type Mapping(XML Java)

PluggableModule

Modules

Theory vs. Practice

Indiana University Extreme! Lab

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

Indiana University Extreme! Lab

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);

Indiana University Extreme! Lab

SOAP RPC ClientTypeHandlerRegistry 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");

Indiana University Extreme! Lab

Client Stack• RPC 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?

Indiana University Extreme! Lab

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; }};

Adding DSig Module To Client App

Indiana University Extreme! Lab

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 }}

Indiana University Extreme! Lab

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!

Indiana University Extreme! Lab

SOAP RPC ServerTypeHandlerRegistry 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; }};

Indiana University Extreme! Lab

Server Stack• RPC 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?

Indiana University Extreme! Lab

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; }};

Using DSig/Authz in App

Indiana University Extreme! Lab

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

Indiana University Extreme! Lab

Conclusions• Encourages experimentation

– 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 …

Indiana University Extreme! Lab

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; }};

Adding Caching to Improve DSig Performance

Indiana University Extreme! Lab

DSig Steps Breakdown

• Generate SOAP call• Sign• Send

… wait • Receive• Verify DSig• Pass result

• Receive SOAP Message• Verify DSig• Reflection Based Invocation• Sign• Send SOAP Message

Client Server

Indiana University Extreme! Lab

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 …}

Indiana University Extreme! Lab

WSDL/RMIGlobalWeatherSoap gws = (GlobalWeatherSoap)

WsdlNaming.lookup("http://www.example.com/weather?WSDL");String s = gws.GetWeather(cityName, countryName)

WSDL/Dynamic Proxy StubGlobalWeatherSoap ref = (GlobalWeatherSoap) WsdlNaming.lookup("http://www.example.com/weather?WSDL“,

GlobalWeatherSoap.class);String s = gws.GetWeather(cityName, countryName)

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");

Client Side APIs