Java tutorial
/******************************************************************************* * * Copyright 2011-2014 Spiffy UI Team * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ******************************************************************************/ package org.spiffyui.server; import java.io.BufferedReader; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.io.Writer; import java.net.MalformedURLException; import java.net.URI; import java.net.URL; import java.net.URLEncoder; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.security.KeyManagementException; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.util.logging.Logger; import javax.net.ssl.SSLException; import javax.net.ssl.SSLSession; import javax.net.ssl.SSLSocket; import javax.net.ssl.SSLContext; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.codec.binary.Base64; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpPost; import org.apache.http.conn.ssl.SSLSocketFactory; import org.apache.http.conn.ssl.X509HostnameVerifier; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.conn.ClientConnectionManager; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.conn.scheme.Scheme; import org.json.JSONException; import org.json.JSONObject; import org.spiffyui.client.rest.util.RESTAuthConstants; /** * This servlet is a passthrough for authentication requests. */ public final class AuthServlet extends HttpServlet { private static final Logger LOGGER = Logger.getLogger(AuthServlet.class.getName()); private static final String BASIC_AUTH = "BASIC"; /** * This is a constant indicating the authentication server returned invalid JSON */ public static final String INVALID_JSON_RESPONSE = "InvalidJSONReseponse"; private static final long serialVersionUID = -1L; /** * This is the default content type for an HTML file. */ public static final String CONTENT_TYPE = "application/json"; static { setHostnameVerifier(); } private static AuthURLValidator g_validator; private static void setHostnameVerifier() { SSLSocketFactory.getSocketFactory().setHostnameVerifier(new HostVerifier()); } /** * Sets the URL validator for this authentication servlet. * * @param validator the validator */ public static void setUrlValidator(AuthURLValidator validator) { g_validator = validator; } @Override public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType(CONTENT_TYPE); String auth = null; /* * We are manually reading the request as bytes and * then converting it to characters. This is extra * work and we should be able to just call getReader * insted of getInputStream. However, the JBoss * implementation of the reader here has a bug that * sometiems shows up where the index of the reader * is wrong so we can work around it using the input * stream directly. * * https://jira.jboss.org/browse/JBAS-7817 */ InputStream in = request.getInputStream(); ByteArrayOutputStream out = new ByteArrayOutputStream(); int read; byte[] buf = new byte[1024]; try { while ((read = in.read(buf)) > 0) { out.write(buf, 0, read); } } finally { if (in != null) { in.close(); } } if (request.getCharacterEncoding() != null) { auth = out.toString(request.getCharacterEncoding()); } else { /* * There are some cases where the requested character encoding is null. * This happens with some application servers and with IE7. We need to * use some encoding in that case so we just use UTF-8. */ auth = out.toString("UTF-8"); } try { JSONObject authObj = new JSONObject(auth); if (request.getMethod().equals("POST")) { doLogin(request, response, authObj.getString(RESTAuthConstants.USERNAME_TOKEN), authObj.getString(RESTAuthConstants.PASSWORD_TOKEN), authObj.getString(RESTAuthConstants.AUTH_URL_TOKEN), authObj.getString(RESTAuthConstants.AUTH_LOGOUT_URL_TOKEN)); return; } else if (request.getMethod().equals("DELETE")) { doLogout(request, response, authObj.getString(RESTAuthConstants.USER_TOKEN), authObj.getString(RESTAuthConstants.AUTH_URL_TOKEN)); return; } } catch (JSONException e) { LOGGER.throwing(AuthServlet.class.getName(), "service", e); returnError(response, e.getMessage(), RESTAuthConstants.INVALID_JSON); } } private boolean validateURI(HttpServletRequest request, String uri) throws MalformedURLException { if (g_validator != null) { return g_validator.validateURI(request, uri); } else { /* The server trusts the client to pass the authentication URL. If the client is compromised (like with an XSS attack) then it could pass the URL to a bogus authentication server and get this servlet to forward the user's credentials there. This is especially dangerous since this serverlet is not governed by the same origin policy. To protect against this we are using a white list of approved authentication servers. Right now that list is just the server containing the client WAR. */ URI.create(uri); URL tsUrl = new URL(uri); URL serverUrl = new URL(request.getRequestURL().toString()); /* * The first test is to make sure they are using the host name * or localhost */ boolean isHostValid = tsUrl.getHost().equals(serverUrl.getHost()) || tsUrl.getHost().equals("localhost") || tsUrl.getHost().startsWith("127.0.0."); return isHostValid && getPort(tsUrl) == getPort(serverUrl) && tsUrl.getProtocol().equals(serverUrl.getProtocol()); } } /** * The JDK will return -1 for the port number if no port is specified, but the URLs can * also have a default port. This method handles getting the port number including the * default ports for the URL. * * @param url the URL to get the port for * * @return the port from the URL */ private int getPort(URL url) { if (url.getPort() == -1) { return url.getDefaultPort(); } else { return url.getPort(); } } private void doLogin(HttpServletRequest request, HttpServletResponse response, String user, String pwd, String tsUrl, String logoutUrl) throws ServletException, IOException, JSONException { LOGGER.info("Making login request for " + user + " to server " + tsUrl); OutputStreamWriter out = new OutputStreamWriter(response.getOutputStream(), "UTF-8"); if (user == null || pwd == null || tsUrl == null) { returnError(response, "Login requires a username, password, and token server URL", RESTAuthConstants.INVALID_LOGIN_REQUEST); return; } try { if (!validateURI(request, tsUrl)) { returnError(response, tsUrl, RESTAuthConstants.INVALID_TS_URL); return; } } catch (IllegalArgumentException iae) { returnError(response, iae.getMessage(), RESTAuthConstants.INVALID_TS_URL); return; } catch (MalformedURLException iae) { returnError(response, iae.getMessage(), RESTAuthConstants.INVALID_TS_URL); return; } HttpClient httpclient = new DefaultHttpClient(); URI.create(tsUrl); URL url = new URL(tsUrl); if (url.getProtocol() != null && url.getProtocol().equalsIgnoreCase("https")) { setupClientSSL(httpclient, url.getPort()); } HttpPost httppost = new HttpPost(tsUrl); httppost.setHeader("Accept", "application/json"); httppost.setHeader("Accept-Charset", "UTF-8"); httppost.setHeader("Authorization", BASIC_AUTH + " " + new String(Base64.encodeBase64(new String(user + ":" + pwd).getBytes("UTF-8")))); httppost.setHeader("NovellRptSignOffUri", logoutUrl); // Execute the request HttpResponse authResponse = httpclient.execute(httppost); int status = authResponse.getStatusLine().getStatusCode(); if (status == 404) { returnError(response, "The token server URL was not found", RESTAuthConstants.NOTFOUND_TS_URL); return; } sendLoginResponse(response, authResponse, status, httppost, out, httpclient); } private void sendLoginResponse(HttpServletResponse response, HttpResponse authResponse, int status, HttpPost httppost, Writer out, HttpClient httpclient) throws ServletException, IOException, JSONException { // Get hold of the response entity HttpEntity entity = authResponse.getEntity(); StringBuffer authResponseData = new StringBuffer(); // If the response does not enclose an entity, there is no need // to worry about connection release if (entity != null) { InputStream instream = entity.getContent(); BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(instream)); // do something useful with the response authResponseData.append(reader.readLine()); } catch (RuntimeException ex) { // In case of an unexpected exception you may want to abort // the HTTP request in order to shut down the underlying // connection and release it back to the connection manager. httppost.abort(); LOGGER.throwing(AuthServlet.class.getName(), "doLogin", ex); throw ex; } finally { // Closing the input stream will trigger connection release if (reader != null) { reader.close(); } } // When HttpClient instance is no longer needed, // shut down the connection manager to ensure // immediate deallocation of all system resources httpclient.getConnectionManager().shutdown(); } //Now we write the response back to our client. if (authResponse.containsHeader("WWW-Authenticate")) { // // If the authentication server responded with a 401 it means // that the specified username and password weren't valid. We // should be returning a 401 to the client, but doing that causes // Firefox to prompt for login using the default login dialog // and we don't want that. // response.setHeader("WWW-Authenticate", authResponse.getFirstHeader("WWW-Authenticate").getValue()); response.setStatus(400); } else { response.setStatus(status); } out.write(authResponseData.toString()); out.flush(); out.close(); } /** * If the authentication URL uses SSL then we need to use an SSLContext to connect to * it. The JDK provides on by default that will work fine for us, but it is possible * for some code running in some other place of the JVM to set a new default and that * new default might not be compatible with the type of connection we want to create. * * The solution is to always set our own SSLContext. In that case we will use a context * that allows any connection since we let administrators control this connection using * the whitelist so we know that we will only connect to trusted servers. * * @param httpclient the HTTPClient making the connection * @param port the port of the connection */ private void setupClientSSL(HttpClient httpclient, int port) { try { SSLSocketFactory sslSocketFactory = null; SSLContext sslContext = SSLContext.getInstance("TLS"); TrustManager relaxedTrustManager = new X509TrustManager() { @Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { /* We accept all certs so there is nothing to test here. */ } @Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { /* We accept all certs so there is nothing to test here. */ } @Override public X509Certificate[] getAcceptedIssuers() { /* This indicates that we accept all certificates */ return null; } }; sslContext.init(null, new TrustManager[] { relaxedTrustManager }, new SecureRandom()); sslSocketFactory = new SSLSocketFactory(sslContext); sslSocketFactory.setHostnameVerifier(new HostVerifier()); /* No that we've configured our SSLContext we'll make sure our request uses it. */ ClientConnectionManager connMgr = httpclient.getConnectionManager(); SchemeRegistry schemeReg = connMgr.getSchemeRegistry(); schemeReg.unregister("https"); if (port != -1) { schemeReg.register(new Scheme("https", sslSocketFactory, port)); } else { /* If the port is -1 it means they were access the server without a port. 443 is the default port for SSL so we fill that in when making the connection. */ schemeReg.register(new Scheme("https", sslSocketFactory, 443)); } } catch (NoSuchAlgorithmException nsae) { LOGGER.throwing(AuthServlet.class.getName(), "setupClientSSL", nsae); } catch (KeyManagementException mke) { LOGGER.throwing(AuthServlet.class.getName(), "setupClientSSL", mke); } } private void doLogout(HttpServletRequest request, HttpServletResponse response, String token, String tsUrl) throws ServletException, IOException { if (token == null || tsUrl == null) { returnError(response, "Logout requires a token and a token server URL", RESTAuthConstants.INVALID_LOGOUT_REQUEST); return; } LOGGER.info("Making logout request for " + token + " to server " + tsUrl); try { validateURI(request, tsUrl); } catch (IllegalArgumentException iae) { returnError(response, iae.getMessage(), RESTAuthConstants.INVALID_TS_URL); return; } HttpClient httpclient = new DefaultHttpClient(); URI.create(tsUrl); URL url = new URL(tsUrl); LOGGER.info("url: " + url); if (url.getProtocol() != null && url.getProtocol().equalsIgnoreCase("https")) { setupClientSSL(httpclient, url.getPort()); } HttpDelete httpdel = new HttpDelete(tsUrl + "/" + URLEncoder.encode(token, "UTF-8")); httpdel.setHeader("Accept", "application/json"); httpdel.setHeader("Accept-Charset", "UTF-8"); httpdel.setHeader("Authorization", request.getHeader("Authorization")); httpdel.setHeader("TS-URL", request.getHeader("TS-URL")); // Execute the request HttpResponse authResponse = httpclient.execute(httpdel); int status = authResponse.getStatusLine().getStatusCode(); if (status == 404) { LOGGER.info("The authentication server " + tsUrl + " was not found."); returnError(response, "The token server URL was not found", RESTAuthConstants.NOTFOUND_TS_URL); return; } // Get hold of the response entity HttpEntity entity = authResponse.getEntity(); StringBuffer authResponseData = new StringBuffer(); // If the response does not enclose an entity, there is no need // to worry about connection release if (entity != null) { InputStream instream = entity.getContent(); BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(instream)); // do something useful with the response authResponseData.append(reader.readLine()); } catch (RuntimeException ex) { // In case of an unexpected exception you may want to abort // the HTTP request in order to shut down the underlying // connection and release it back to the connection manager. httpdel.abort(); LOGGER.throwing(AuthServlet.class.getName(), "doLogout", ex); throw ex; } finally { // Closing the input stream will trigger connection release if (reader != null) { reader.close(); } } // When HttpClient instance is no longer needed, // shut down the connection manager to ensure // immediate deallocation of all system resources httpclient.getConnectionManager().shutdown(); } //Now we write the response back to our client. response.setStatus(status); OutputStreamWriter out = new OutputStreamWriter(response.getOutputStream(), "UTF-8"); out.write(authResponseData.toString()); out.flush(); out.close(); } private void returnError(HttpServletResponse response, String message, String sCode) throws ServletException, IOException { try { JSONObject base = new JSONObject(); JSONObject fault = new JSONObject(); JSONObject code = new JSONObject(); code.put("Value", sCode); JSONObject subcode = new JSONObject(); subcode.put("Value", ""); code.put("Subcode", subcode); fault.put("Code", code); JSONObject reason = new JSONObject(); reason.put("Text", message); fault.put("Reason", reason); base.put("Fault", fault); response.getOutputStream().println(base.toString()); } catch (JSONException e) { /* This should never happen */ LOGGER.throwing(getClass().getName(), "returnError", e); } } } /** * Normally the Java URL connection is very restrictive about what * certificates it will accept for an SSL connection and it requires * the host name and the certificate name to match exactly. We don't * want to be that strict so we had a custom host name verifier. */ class HostVerifier implements X509HostnameVerifier { @Override public void verify(String host, SSLSocket ssl) throws IOException { // no-op } @Override public void verify(String host, X509Certificate cert) throws SSLException { // no-op } @Override public boolean verify(String host, SSLSession session) { return true; } @Override public void verify(String host, String[] cns, String[] subjectAlts) throws SSLException { //no-op } }