gateway-shell/src/main/java/org/apache/knox/gateway/shell/KnoxSh.java - knox - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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.apache.knox.gateway.shell;

 import org.apache.knox.gateway.shell.knox.token.Get;
 import org.apache.knox.gateway.shell.knox.token.Token;
 import org.apache.knox.gateway.shell.util.ClientTrustStoreHelper;
 import org.apache.knox.gateway.util.JsonUtils;
 import org.apache.knox.gateway.util.X509CertificateUtil;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.net.Socket;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.attribute.PosixFilePermission;
 import java.security.KeyStore;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.TimeZone;

 import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLException;
 import javax.net.ssl.SSLSocket;
 import javax.net.ssl.TrustManager;
 import javax.net.ssl.TrustManagerFactory;
 import javax.net.ssl.X509TrustManager;

 public class KnoxSh {

   private static final String USAGE_PREFIX = "KnoxSh {cmd} [options]";
   private static final String COMMANDS =
       "   [--help]\n" +
       "   [" + KnoxBuildTrustStore.USAGE + "]\n" +
       "   [" + KnoxInit.USAGE + "]\n" +
       "   [" + KnoxDestroy.USAGE + "]\n" +
       "   [" + KnoxList.USAGE + "]\n";

   /** allows stdout to be captured if necessary */
   PrintStream out = System.out;
   /** allows stderr to be captured if necessary */
   PrintStream err = System.err;

   private Command command;
   private String gateway;

   public int run(String[] args) throws Exception {
     int exitCode;
     try {
       exitCode = init(args);
       if (exitCode != 0) {
         return exitCode;
       }
       if (command != null && command.validate()) {
         command.execute();
       } else {
         out.println("ERROR: Invalid Command" + "\n" + "Unrecognized option:" +
             args[0] + "\n" +
             "A fatal exception has occurred. Program will exit.");
         exitCode = -2;
       }
     } catch (Exception e) {
       e.printStackTrace( err );
       err.flush();
       return -3;
     }
     return exitCode;
   }

   /**
    * Parse the command line arguments and initialize the data
    * <pre>
    * % knoxcli version
    * % knoxcli service-test [--u user] [--p password] [--cluster clustername] [--hostname name] [--port port]
    *
    * </pre>
    * @param args command line arguments
    * @return exit code
    * @throws IOException exception on init
    */
   private int init(String[] args) throws IOException {
     if (args.length == 0) {
       printKnoxShellUsage();
       return -1;
     }
     for (int i = 0; i < args.length; i++) { // parse command line
       if ( args[i].equals("destroy") ) {
         command = new KnoxDestroy();
       } else if ( args[i].equals("buildTrustStore") ) {
         command = new KnoxBuildTrustStore();
       } else if ( args[i].equals("init") ) {
         command = new KnoxInit();
       } else if ( args[i].equals("list") ) {
         command = new KnoxList();
       } else if (args[i].equals("--gateway")) {
         if( i+1 >= args.length || args[i+1].startsWith( "-" ) ) {
           printKnoxShellUsage();
           return -1;
         }
         this.gateway = args[++i];
       } else if (args[i].equals("--help")) {
         printKnoxShellUsage();
         return -1;
       } else {
         printKnoxShellUsage();
         //ToolRunner.printGenericCommandUsage(System.err);
         return -1;
       }
     }
     return 0;
   }

   private void printKnoxShellUsage() {
     out.println( USAGE_PREFIX + "\n" + COMMANDS );
     if ( command != null ) {
       out.println(command.getUsage());
     } else {
       char[] chars = new char[79];
       Arrays.fill( chars, '=' );
       String div = new String( chars );

       out.println( div );
       out.println( KnoxInit.USAGE + "\n\n" + KnoxInit.DESC );
       out.println();
       out.println( div );
       out.println(KnoxDestroy.USAGE + "\n\n" + KnoxDestroy.DESC);
       out.println();
       out.println( div );
       out.println(KnoxList.USAGE + "\n\n" + KnoxList.DESC);
       out.println();
       out.println( div );
     }
   }

   private abstract class Command {
     public boolean validate() {
       return true;
     }

     public abstract void execute() throws Exception;

     public abstract String getUsage();
   }

   class KnoxBuildTrustStore extends Command {

     private static final String USAGE = "buildTrustStore --gateway server-url";
     private static final String DESC = "Downloads the gateway server's public certificate and builds a trust store.";
     private static final String GATEWAY_CERT_NOT_EXPORTED = "Finished work without building truststore";
     private static final String GATEWAY_CERT_EXPORTED_MESSAGE_PREFIX = "Gateway server's certificate is exported into ";

     @Override
     public void execute() throws Exception {
       String result = GATEWAY_CERT_NOT_EXPORTED;
       try {
         final X509Certificate[] gatewayServerPublicCerts = fetchPublicCertsFromGatewayServer();
         if (gatewayServerPublicCerts != null) {
           final File trustStoreFile = ClientTrustStoreHelper.getClientTrustStoreFile();
           final String trustStorePassword = ClientTrustStoreHelper.getClientTrustStoreFilePassword();
           X509CertificateUtil.writeCertificatesToJks(gatewayServerPublicCerts, trustStoreFile, trustStorePassword);
           result = GATEWAY_CERT_EXPORTED_MESSAGE_PREFIX + trustStoreFile.getAbsolutePath();
         }
       } catch(Exception e) {
         throw new KnoxShellException("Error while building trust store", e);
       }
       out.println(result);
     }

     private X509Certificate[] fetchPublicCertsFromGatewayServer() throws Exception {
       final TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
       trustManagerFactory.init((KeyStore) null);
       final X509TrustManager defaultTrustManager = (X509TrustManager) trustManagerFactory.getTrustManagers()[0];
       final CertificateChainAwareTrustManager trustManagerWithCertificateChain = new CertificateChainAwareTrustManager(defaultTrustManager);
       final SSLContext sslContext = SSLContext.getInstance("TLS");
       sslContext.init(null, new TrustManager[] { trustManagerWithCertificateChain }, null);

       final URL url = new URL(gateway);
       final int port = url.getPort() == -1 ? url.getDefaultPort() : url.getPort();
       out.println("Opening connection to " + url.getHost() + ":" + port + "...");
       try (Socket socket = sslContext.getSocketFactory().createSocket(url.getHost(), port)) {
         socket.setSoTimeout(10000);
         out.println("Starting SSL handshake...");
         ((SSLSocket) socket).startHandshake();
         out.println("No errors, certificate is already trusted");
         return null; //we already trust the given site's certs; it does not make sense to build a new truststore
       } catch (SSLException e) {
         // NOP; this is expected in case the gateway server's certificate is not in the
         // trust store the JVM uses
       }

       return trustManagerWithCertificateChain.serverCertificateChain;
     }

     @Override
     public String getUsage() {
       return USAGE + ":\n\n" + DESC;
     }

     private class CertificateChainAwareTrustManager implements X509TrustManager {
       private final X509TrustManager defaultTrustManager;
       private X509Certificate[] serverCertificateChain;

       CertificateChainAwareTrustManager(X509TrustManager tm) {
         this.defaultTrustManager = tm;
       }

       @Override
       public X509Certificate[] getAcceptedIssuers() {
         return defaultTrustManager.getAcceptedIssuers();
       }

       @Override
       public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
         defaultTrustManager.checkClientTrusted(chain, authType);
       }

       @Override
       public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
         this.serverCertificateChain = chain;
         defaultTrustManager.checkServerTrusted(chain, authType);
       }
     }
   }

   private class KnoxInit extends Command {

     public static final String USAGE = "init --gateway topology-url";
     public static final String DESC = "Initializes a Knox token session.";

     @Override
     public void execute() throws Exception {
       Credentials credentials = new Credentials();
       credentials.add("ClearInput", "Enter username: ", "user")
                       .add("HiddenInput", "Enter password: ", "pass");
       credentials.collect();

       String username = credentials.get("user").string();
       String pass = credentials.get("pass").string();

       KnoxSession session = null;
       Get.Response response;
       try {
         session = KnoxSession.login(gateway, username, pass);

         response = Token.get( session ).now();
         String text = response.getString();
         Map<String, String> json = JsonUtils.getMapFromJsonString(text);

         //println "Access Token: " + json.access_token
         System.out.println("knoxinit successful!");
         displayTokenDetails(json);

         File tokenfile = new File(System.getProperty("user.home"), ".knoxtokencache");
         try( OutputStream fos = Files.newOutputStream(tokenfile.toPath()) ) {
           fos.write(text.getBytes(StandardCharsets.UTF_8));
           Set<PosixFilePermission> perms = new HashSet<>();
           //add owners permission only
           perms.add(PosixFilePermission.OWNER_READ);
           perms.add(PosixFilePermission.OWNER_WRITE);
           Files.setPosixFilePermissions(Paths.get(System.getProperty("user.home") + "/.knoxtokencache"), perms);
         }
       } catch(KnoxShellException he) {
         System.out.println("Failure to acquire token. Please verify your credentials and Knox URL and try again.");
       }
       if ( session != null ) {
         session.shutdown();
       }
     }

     @Override
     public String getUsage() {
       return USAGE + ":\n\n" + DESC;
     }

   }

   private class KnoxDestroy extends Command {

     public static final String USAGE = "destroy";
     public static final String DESC = "Destroys an Knox token session.";

     @Override
     public void execute() throws Exception {
       File tokenfile = new File(System.getProperty("user.home"), ".knoxtokencache");
       tokenfile.delete();
     }

     @Override
     public String getUsage() {
       return USAGE + ":\n\n" + DESC;
     }

   }

   private class KnoxList extends Command {

     public static final String USAGE = "list";
     public static final String DESC = "Displays Knox token details.";

     @Override
     public void execute() throws Exception {
       String tokenFilePath = System.getProperty("user.home") +
           File.separator + ".knoxtokencache";
       if (new File(tokenFilePath).exists()) {
         String tokenfile = readFile(tokenFilePath);

         if (tokenfile != null) {
           Map<String, String> json = JsonUtils.getMapFromJsonString(tokenfile);
           displayTokenDetails(json);
         }
       }
       else {
         System.out.println("Knox token cache does not exist. Please login with init.");
       }
     }

     @Override
     public String getUsage() {
       return USAGE + ":\n\n" + DESC;
     }

   }

   private void displayTokenDetails(Map<String, String> json) {
     System.out.println("Token Type: " + json.get("token_type"));

     DateFormat formatter = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss", Locale.getDefault());

     long milliSeconds= Long.parseLong(json.get("expires_in"));

     Calendar calendar = Calendar.getInstance(TimeZone.getDefault(), Locale.getDefault());
     calendar.setTimeInMillis(milliSeconds);
     System.out.println("Expires On: " + formatter.format(calendar.getTime()));
     String targetUrl = json.get("target_url");
     if (targetUrl != null) {
       System.out.println("Target URL: " + json.get("target_url"));
     } else {
       System.out.println("No specific target URL configured.");
     }
   }

   private String readFile(String file) throws IOException {
     try (InputStream inputStream = Files.newInputStream(Paths.get(file));
          InputStreamReader inputStreamReader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
          BufferedReader reader = new BufferedReader(inputStreamReader)) {
       String line;
       StringBuilder stringBuilder = new StringBuilder();
       String ls = System.getProperty("line.separator");
       while ((line = reader.readLine()) != null) {
         stringBuilder.append(line);
         stringBuilder.append(ls);
       }
       return stringBuilder.toString();
     }
   }

   /**
    * @param args command line arguments
    * @throws Exception thrown if there is an issue
    */
   public static void main(String[] args) throws Exception {
     KnoxSh sh = new KnoxSh();
     int res = sh.run(args);
     System.exit(res);
   }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.apache.knox.gateway.shell;

	import org.apache.knox.gateway.shell.knox.token.Get;
	import org.apache.knox.gateway.shell.knox.token.Token;
	import org.apache.knox.gateway.shell.util.ClientTrustStoreHelper;
	import org.apache.knox.gateway.util.JsonUtils;
	import org.apache.knox.gateway.util.X509CertificateUtil;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.OutputStream;
	import java.io.PrintStream;
	import java.net.Socket;
	import java.net.URL;
	import java.nio.charset.StandardCharsets;
	import java.nio.file.Files;
	import java.nio.file.Paths;
	import java.nio.file.attribute.PosixFilePermission;
	import java.security.KeyStore;
	import java.security.cert.CertificateException;
	import java.security.cert.X509Certificate;
	import java.text.DateFormat;
	import java.text.SimpleDateFormat;
	import java.util.Arrays;
	import java.util.Calendar;
	import java.util.HashSet;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Set;
	import java.util.TimeZone;

	import javax.net.ssl.SSLContext;
	import javax.net.ssl.SSLException;
	import javax.net.ssl.SSLSocket;
	import javax.net.ssl.TrustManager;
	import javax.net.ssl.TrustManagerFactory;
	import javax.net.ssl.X509TrustManager;

	public class KnoxSh {

	private static final String USAGE_PREFIX = "KnoxSh {cmd} [options]";
	private static final String COMMANDS =
	" [--help]\n" +
	" [" + KnoxBuildTrustStore.USAGE + "]\n" +
	" [" + KnoxInit.USAGE + "]\n" +
	" [" + KnoxDestroy.USAGE + "]\n" +
	" [" + KnoxList.USAGE + "]\n";

	/** allows stdout to be captured if necessary */
	PrintStream out = System.out;
	/** allows stderr to be captured if necessary */
	PrintStream err = System.err;

	private Command command;
	private String gateway;

	public int run(String[] args) throws Exception {
	int exitCode;
	try {
	exitCode = init(args);
	if (exitCode != 0) {
	return exitCode;
	}
	if (command != null && command.validate()) {
	command.execute();
	} else {
	out.println("ERROR: Invalid Command" + "\n" + "Unrecognized option:" +
	args[0] + "\n" +
	"A fatal exception has occurred. Program will exit.");
	exitCode = -2;
	}
	} catch (Exception e) {
	e.printStackTrace( err );
	err.flush();
	return -3;
	}
	return exitCode;
	}

	/**
	* Parse the command line arguments and initialize the data
	* <pre>
	* % knoxcli version
	* % knoxcli service-test [--u user] [--p password] [--cluster clustername] [--hostname name] [--port port]
	*
	* </pre>
	* @param args command line arguments
	* @return exit code
	* @throws IOException exception on init
	*/
	private int init(String[] args) throws IOException {
	if (args.length == 0) {
	printKnoxShellUsage();
	return -1;
	}
	for (int i = 0; i < args.length; i++) { // parse command line
	if ( args[i].equals("destroy") ) {
	command = new KnoxDestroy();
	} else if ( args[i].equals("buildTrustStore") ) {
	command = new KnoxBuildTrustStore();
	} else if ( args[i].equals("init") ) {
	command = new KnoxInit();
	} else if ( args[i].equals("list") ) {
	command = new KnoxList();
	} else if (args[i].equals("--gateway")) {
	if( i+1 >= args.length \|\| args[i+1].startsWith( "-" ) ) {
	printKnoxShellUsage();
	return -1;
	}
	this.gateway = args[++i];
	} else if (args[i].equals("--help")) {
	printKnoxShellUsage();
	return -1;
	} else {
	printKnoxShellUsage();
	//ToolRunner.printGenericCommandUsage(System.err);
	return -1;
	}
	}
	return 0;
	}

	private void printKnoxShellUsage() {
	out.println( USAGE_PREFIX + "\n" + COMMANDS );
	if ( command != null ) {
	out.println(command.getUsage());
	} else {
	char[] chars = new char[79];
	Arrays.fill( chars, '=' );
	String div = new String( chars );

	out.println( div );
	out.println( KnoxInit.USAGE + "\n\n" + KnoxInit.DESC );
	out.println();
	out.println( div );
	out.println(KnoxDestroy.USAGE + "\n\n" + KnoxDestroy.DESC);
	out.println();
	out.println( div );
	out.println(KnoxList.USAGE + "\n\n" + KnoxList.DESC);
	out.println();
	out.println( div );
	}
	}

	private abstract class Command {
	public boolean validate() {
	return true;
	}

	public abstract void execute() throws Exception;

	public abstract String getUsage();
	}

	class KnoxBuildTrustStore extends Command {

	private static final String USAGE = "buildTrustStore --gateway server-url";
	private static final String DESC = "Downloads the gateway server's public certificate and builds a trust store.";
	private static final String GATEWAY_CERT_NOT_EXPORTED = "Finished work without building truststore";
	private static final String GATEWAY_CERT_EXPORTED_MESSAGE_PREFIX = "Gateway server's certificate is exported into ";

	@Override
	public void execute() throws Exception {
	String result = GATEWAY_CERT_NOT_EXPORTED;
	try {
	final X509Certificate[] gatewayServerPublicCerts = fetchPublicCertsFromGatewayServer();
	if (gatewayServerPublicCerts != null) {
	final File trustStoreFile = ClientTrustStoreHelper.getClientTrustStoreFile();
	final String trustStorePassword = ClientTrustStoreHelper.getClientTrustStoreFilePassword();
	X509CertificateUtil.writeCertificatesToJks(gatewayServerPublicCerts, trustStoreFile, trustStorePassword);
	result = GATEWAY_CERT_EXPORTED_MESSAGE_PREFIX + trustStoreFile.getAbsolutePath();
	}
	} catch(Exception e) {
	throw new KnoxShellException("Error while building trust store", e);
	}
	out.println(result);
	}

	private X509Certificate[] fetchPublicCertsFromGatewayServer() throws Exception {
	final TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
	trustManagerFactory.init((KeyStore) null);
	final X509TrustManager defaultTrustManager = (X509TrustManager) trustManagerFactory.getTrustManagers()[0];
	final CertificateChainAwareTrustManager trustManagerWithCertificateChain = new CertificateChainAwareTrustManager(defaultTrustManager);
	final SSLContext sslContext = SSLContext.getInstance("TLS");
	sslContext.init(null, new TrustManager[] { trustManagerWithCertificateChain }, null);

	final URL url = new URL(gateway);
	final int port = url.getPort() == -1 ? url.getDefaultPort() : url.getPort();
	out.println("Opening connection to " + url.getHost() + ":" + port + "...");
	try (Socket socket = sslContext.getSocketFactory().createSocket(url.getHost(), port)) {
	socket.setSoTimeout(10000);
	out.println("Starting SSL handshake...");
	((SSLSocket) socket).startHandshake();
	out.println("No errors, certificate is already trusted");
	return null; //we already trust the given site's certs; it does not make sense to build a new truststore
	} catch (SSLException e) {
	// NOP; this is expected in case the gateway server's certificate is not in the
	// trust store the JVM uses
	}

	return trustManagerWithCertificateChain.serverCertificateChain;
	}

	@Override
	public String getUsage() {
	return USAGE + ":\n\n" + DESC;
	}

	private class CertificateChainAwareTrustManager implements X509TrustManager {
	private final X509TrustManager defaultTrustManager;
	private X509Certificate[] serverCertificateChain;

	CertificateChainAwareTrustManager(X509TrustManager tm) {
	this.defaultTrustManager = tm;
	}

	@Override
	public X509Certificate[] getAcceptedIssuers() {
	return defaultTrustManager.getAcceptedIssuers();
	}

	@Override
	public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
	defaultTrustManager.checkClientTrusted(chain, authType);
	}

	@Override
	public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
	this.serverCertificateChain = chain;
	defaultTrustManager.checkServerTrusted(chain, authType);
	}
	}
	}

	private class KnoxInit extends Command {

	public static final String USAGE = "init --gateway topology-url";
	public static final String DESC = "Initializes a Knox token session.";

	@Override
	public void execute() throws Exception {
	Credentials credentials = new Credentials();
	credentials.add("ClearInput", "Enter username: ", "user")
	.add("HiddenInput", "Enter password: ", "pass");
	credentials.collect();

	String username = credentials.get("user").string();
	String pass = credentials.get("pass").string();

	KnoxSession session = null;
	Get.Response response;
	try {
	session = KnoxSession.login(gateway, username, pass);

	response = Token.get( session ).now();
	String text = response.getString();
	Map<String, String> json = JsonUtils.getMapFromJsonString(text);

	//println "Access Token: " + json.access_token
	System.out.println("knoxinit successful!");
	displayTokenDetails(json);

	File tokenfile = new File(System.getProperty("user.home"), ".knoxtokencache");
	try( OutputStream fos = Files.newOutputStream(tokenfile.toPath()) ) {
	fos.write(text.getBytes(StandardCharsets.UTF_8));
	Set<PosixFilePermission> perms = new HashSet<>();
	//add owners permission only
	perms.add(PosixFilePermission.OWNER_READ);
	perms.add(PosixFilePermission.OWNER_WRITE);
	Files.setPosixFilePermissions(Paths.get(System.getProperty("user.home") + "/.knoxtokencache"), perms);
	}
	} catch(KnoxShellException he) {
	System.out.println("Failure to acquire token. Please verify your credentials and Knox URL and try again.");
	}
	if ( session != null ) {
	session.shutdown();
	}
	}

	@Override
	public String getUsage() {
	return USAGE + ":\n\n" + DESC;
	}

	}

	private class KnoxDestroy extends Command {

	public static final String USAGE = "destroy";
	public static final String DESC = "Destroys an Knox token session.";

	@Override
	public void execute() throws Exception {
	File tokenfile = new File(System.getProperty("user.home"), ".knoxtokencache");
	tokenfile.delete();
	}

	@Override
	public String getUsage() {
	return USAGE + ":\n\n" + DESC;
	}

	}

	private class KnoxList extends Command {

	public static final String USAGE = "list";
	public static final String DESC = "Displays Knox token details.";

	@Override
	public void execute() throws Exception {
	String tokenFilePath = System.getProperty("user.home") +
	File.separator + ".knoxtokencache";
	if (new File(tokenFilePath).exists()) {
	String tokenfile = readFile(tokenFilePath);

	if (tokenfile != null) {
	Map<String, String> json = JsonUtils.getMapFromJsonString(tokenfile);
	displayTokenDetails(json);
	}
	}
	else {
	System.out.println("Knox token cache does not exist. Please login with init.");
	}
	}

	@Override
	public String getUsage() {
	return USAGE + ":\n\n" + DESC;
	}

	}

	private void displayTokenDetails(Map<String, String> json) {
	System.out.println("Token Type: " + json.get("token_type"));

	DateFormat formatter = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss", Locale.getDefault());

	long milliSeconds= Long.parseLong(json.get("expires_in"));

	Calendar calendar = Calendar.getInstance(TimeZone.getDefault(), Locale.getDefault());
	calendar.setTimeInMillis(milliSeconds);
	System.out.println("Expires On: " + formatter.format(calendar.getTime()));
	String targetUrl = json.get("target_url");
	if (targetUrl != null) {
	System.out.println("Target URL: " + json.get("target_url"));
	} else {
	System.out.println("No specific target URL configured.");
	}
	}

	private String readFile(String file) throws IOException {
	try (InputStream inputStream = Files.newInputStream(Paths.get(file));
	InputStreamReader inputStreamReader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
	BufferedReader reader = new BufferedReader(inputStreamReader)) {
	String line;
	StringBuilder stringBuilder = new StringBuilder();
	String ls = System.getProperty("line.separator");
	while ((line = reader.readLine()) != null) {
	stringBuilder.append(line);
	stringBuilder.append(ls);
	}
	return stringBuilder.toString();
	}
	}

	/**
	* @param args command line arguments
	* @throws Exception thrown if there is an issue
	*/
	public static void main(String[] args) throws Exception {
	KnoxSh sh = new KnoxSh();
	int res = sh.run(args);
	System.exit(res);
	}
	}