Initial commit (v1)

bin/rmireg.bat

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+javac *.java && start rmiregistry

bin/startClient.bat

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+javac *.java && java AuctionClient

bin/startServer.bat

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+javac *.java && java AuctionServer

src/Auction.java

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+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class represents the auction server.
+ **/
+ 
+import java.io.*;
+import java.util.*;
+import java.security.*;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <me+auctionprog@bengoldsworthy.net>
+ **   @version 1.0
+ **/
+public interface Auction extends java.rmi.Remote {	
+   /**
+    **   Creates an auction with the given details, generating a new ID for 
+    **   it.
+    **   
+    **   @param desc The auction description.
+    **   @param owner The auction owner/creator.
+    **   @param startingPrice The auction starting price.
+    **   @param reserve The auction reserve price.
+    **/
+   public void createAuction(String desc, UserWrapper owner, float startingPrice, float reserve) throws java.rmi.RemoteException;
+
+   /**
+    **   Removes an auction, provided the user calling the method owns it.
+    **   If the reserve price was met, also returns the winning bidder.
+    **   
+    **   @param id The ID of the auction to remove.
+    **   @param currentUser The user calling the method.
+    **   @return The `UserWrapper` of the highest bidder, if applicable.
+    **/
+   public UserWrapper removeAuction(int id, UserWrapper currentUser) throws java.rmi.RemoteException;
+
+   /**
+    **   Bids on a given auction, provided the bid is more than the
+    **   current highest price.
+    **   
+    **   @param id The ID of the auction in question.
+    **   @param bidder The user bidding on the auction.
+    **   @param price The amount bid.
+    **/
+   public void bidOnAuction(int id, UserWrapper bidder, float price) throws java.rmi.RemoteException;
+   
+   /**
+    **   Accessor Method. Retrieves a list of all the auctions.
+    **   
+    **   @return An `ArrayList` of `AuctionWrapper`s.
+    **/
+   public ArrayList<AuctionWrapper> getAuctions() throws java.rmi.RemoteException;
+    
+   /**
+    **   Accessor Method. Gets a user, or creates a new one if non 
+    **   exists with the given details.
+    **   
+    **   @param name The user's name.
+    **   @param email The user's email address.
+    **   @return The relevant `UserWrapper`.
+    **/
+   public UserWrapper getUser(String username) throws java.rmi.RemoteException;   
+   
+   public UserWrapper registerUser(String name, String email, String username) throws java.rmi.RemoteException;
+   
+   public void close() throws java.rmi.RemoteException;
+   
+   public PublicKey getPublicKey() throws java.rmi.RemoteException;
+   public void sendPublicKey(PublicKey key, String username) throws java.rmi.RemoteException;
+            
+   /**
+    **   Accessor Method. Gets the status resulting from the last action
+    **   attempted.
+    **   
+    **   @return The status message.
+    **/
+   public String getStatusofLast() throws java.rmi.RemoteException;
+   
+   public byte[] challengeServer(byte[] challenge) throws java.rmi.RemoteException;
+   
+   public byte[] getChallenge() throws java.rmi.RemoteException;
+   public boolean returnChallenge(byte[] retChal, String username) throws java.rmi.RemoteException;
+}
+

src/AuctionClient.java

@@ -0,0 +1,342 @@
+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class presents the client view for interacting with the program.
+ **/
+
+import java.io.*;
+import java.rmi.Naming;
+import java.rmi.RemoteException;
+import java.net.MalformedURLException;
+import java.rmi.NotBoundException;
+import java.util.*;
+import java.util.Scanner;
+import java.util.regex.Pattern;
+import java.security.*;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <bgoldsworthy96 @ gmail.com>
+ **   @version 1.0
+ **/
+public class AuctionClient {
+   // This regex is used to ensure the email address entered is a valid
+   // email address format
+   // (Source: http://stackoverflow.com/a/153751/4580273)
+   private static final Pattern rfc2822 = Pattern.compile("^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$");
+   
+   /**
+    **   Displays the UI.
+    **   
+    **   @param args Command-line arguments.
+    **/
+   public static void main(String[] args) {
+      try {
+         // Create the reference to the remote object through the 
+         // remiregistry. This comes first because if it fails we can 
+         // skip doing everything else.
+         Auction a = (Auction) Naming.lookup("rmi://localhost/AuctionService");
+       
+         // Declares some variables that'll be used later on.
+         Scanner in = new Scanner(System.in);
+         UserWrapper currentUser = null;
+         int id;      
+         float price;
+         
+         // Authenticates the user, if the program is run with a username
+         // as an argument. Otherwise, prompts the user to create a new
+         // user.
+         currentUser = login(a, (args.length > 0) ? args[0] : "server");
+        
+         while(true) {
+            // Resets the variables after each run through.
+            price = 0.0f;
+            
+            printOptions();
+            
+            switch(in.nextLine()) {
+            // This case takes auction details from the user and then
+            // creates a new auction with those.
+            case "1":
+               createNewAuction(a, currentUser);
+               break;
+            // This case removes the auction with the given ID, provided it
+            // is owned by the current user.
+            case "2":
+               deleteAuction(a, currentUser);
+               break;
+            // This case displays all the currently-available auctions.
+            case "3":
+               displayAuctions(a);
+               break;
+            // This case places a bid on an auction.
+            case "4":
+               placeBid(a, currentUser);
+               break; 
+            // This case exits the program.
+            case "5":
+               System.exit(1);
+               break;
+            // The below cases are remote debug commands.
+            // This case remotely shuts down the server.
+            case "6":
+               a.close();
+               break;
+            default:
+               break;
+            }
+         }
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+      System.exit(-1);
+   }
+   
+   private static UserWrapper login(Auction a, String username) throws java.rmi.RemoteException, java.security.NoSuchAlgorithmException, java.security.InvalidKeyException, java.security.SignatureException {
+      UserWrapper user = null;
+      
+      // If the user has run the program with a username argument,
+      // authenticate that user.
+      if (!username.equals("server")) {
+         boolean verifies;
+         byte[] challenge, serverResponse, userResponse;
+         Signature signed, signing;
+         
+         // Sends the server a number to sign with its private key.
+         System.out.println("Authenticating server...");
+         
+         challenge = new byte[1024];
+         new Random().nextBytes(challenge);
+         serverResponse = a.challengeServer(challenge);
+         
+         signed = Signature.getInstance("SHA1withDSA");
+         signed.initVerify(readKey());
+         signed.update(challenge);
+         
+         verifies = signed.verify(serverResponse);
+         System.out.println("server signature verifies: " + verifies);
+         
+         // Receives a number from the server to sign with the user's
+         // private key.
+         System.out.println("Authenticating user '"+username+"'...");
+         
+         challenge = a.getChallenge();
+         
+         signing = Signature.getInstance("SHA1withDSA"); 
+         signing.initSign(readKey(username));
+         signing.update(challenge);
+         userResponse = signing.sign();
+         
+         verifies = a.returnChallenge(userResponse, username);
+         System.out.println(username+" authenticated by server: " + verifies);
+         
+         // Closes the program on authentication fail.
+         if (!verifies) System.exit(-1);
+         
+         // Otherwise, load the user and move on.
+         user = a.getUser(username);
+         System.out.println(a.getStatusofLast());
+      // If the user has run the program with no arguments, they are
+      // prompted to create a new user.
+      } else {  
+         String name = "", email = "";
+         Scanner in = new Scanner(System.in);
+         
+         while (user == null) {
+            System.out.print("Enter name: ");
+            name = in.nextLine();
+            
+            System.out.print("Enter email: ");
+            while (!rfc2822.matcher(email).matches()) {
+               email = in.nextLine();
+               if (!rfc2822.matcher(email).matches()) System.out.println("\nError: invalid email address\n");
+            }
+            
+            while (username.equals("server")) {
+               System.out.print("Enter username ('server' is prohibited): ");
+               username = in.nextLine();
+            }
+                     
+            user = a.registerUser(name, email, username);
+            System.out.println(a.getStatusofLast());
+         }
+         
+         // Upon a successful user creation, new keys are generated and
+         // exchanged with the server.
+         KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
+         SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
+         keyGen.initialize(1024, random);
+
+         KeyPair pair = keyGen.generateKeyPair();   
+         writeKey(pair.getPrivate(), username);
+         a.sendPublicKey(pair.getPublic(), username);
+         writeKey(a.getPublicKey(), "server");
+      }
+      return user;
+   }
+   
+   private static void printOptions() {
+      System.out.println("1\tCreate auction\n2\tDelete auction\n3\tView auctions\n4\tBid on auction\n5\tQuit\n6\tClose server");
+      System.out.print("Choose option: ");   
+   }
+   
+   private static void createNewAuction(Auction a, UserWrapper currentUser) throws java.rmi.RemoteException {
+      float startPrice = 0.0f;
+      float reservePrice = 0.0f;
+      Scanner in = new Scanner(System.in);
+      
+      try {
+         System.out.print("Enter description: ");
+         String desc = in.nextLine();
+         
+         System.out.print("Enter starting price: \u00A3");
+         startPrice = Float.parseFloat(in.nextLine());
+         
+         while (reservePrice <= startPrice) {
+            System.out.print("Enter reserve price (must be higher than starting price): \u00A3");
+            reservePrice = Float.parseFloat(in.nextLine());
+         }
+         
+         a.createAuction(desc, currentUser, startPrice, reservePrice);
+         System.out.println(a.getStatusofLast());
+      } catch(NumberFormatException ex){
+         System.out.println("\nError: not a valid price\n");
+      }   
+   }
+   
+   private static void deleteAuction(Auction a, UserWrapper currentUser) throws java.rmi.RemoteException {
+      int id;
+      UserWrapper winner;
+      Scanner in = new Scanner(System.in);
+      
+      if (!a.getAuctions().isEmpty()) {
+         System.out.print("Enter auction number: ");
+         id = Integer.parseInt(in.nextLine());
+         
+         try {
+            winner = a.removeAuction(id, currentUser);
+            System.out.println("\nAuction won by: "+winner.getName()+" <"+winner.getEmail()+">\n");
+         } catch(NullPointerException e) {
+            System.out.println(a.getStatusofLast());
+         }
+      } else {
+         System.out.println("\nNo auctions available\n");
+      }
+   }
+   
+   private static void displayAuctions(Auction a) throws java.rmi.RemoteException {
+      if (!a.getAuctions().isEmpty()) {
+         System.out.println("#\tOwner\tPrice\tDesc");
+         for (int i = 0; i < 80; i++) System.out.print("-");
+         for(AuctionWrapper auction: a.getAuctions()){
+            System.out.println(auction.getID()+"\t"+auction.getOwner().getUsername()+"\t\u00A3"+String.format("%.2f", auction.getPrice())+"\t"+auction.getDesc());
+         }
+         System.out.println("");
+      } else {
+         System.out.println("\nNo auctions available\n");
+      }
+   }
+   
+   private static void placeBid(Auction a, UserWrapper currentUser) throws java.rmi.RemoteException {
+      Scanner in = new Scanner(System.in);
+      
+      if (!a.getAuctions().isEmpty()) {
+         try{
+            int id;
+            float price;
+            
+            System.out.print("Enter auction number: ");
+            id = Integer.parseInt(in.nextLine());
+            
+            System.out.print("Enter bid amount: \u00A3");
+            price = Float.parseFloat(in.nextLine());
+            
+            a.bidOnAuction(id, currentUser, price);
+            System.out.println(a.getStatusofLast());
+         } catch(NumberFormatException ex){
+            System.out.println("\nError: not a valid price\n");
+         }
+      } else {
+         System.out.println("\nNo auctions available\n");
+      }   
+   }
+   
+   private static PrivateKey readKey(String username) {
+      try {
+         FileInputStream keyfis = new FileInputStream(username + "priv.key");
+         byte[] encKey = new byte[keyfis.available()];
+         keyfis.read(encKey);
+         keyfis.close();
+
+         PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(encKey);
+
+         KeyFactory keyFactory = KeyFactory.getInstance("DSA");
+         return keyFactory.generatePrivate(privKeySpec);
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+         return null;
+      }
+   }
+   private static PublicKey readKey() {
+      try {
+         FileInputStream keyfis = new FileInputStream("serverpub.key");
+         byte[] encKey = new byte[keyfis.available()];
+         keyfis.read(encKey);
+         keyfis.close();   
+         
+         X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encKey);
+         
+         KeyFactory keyFactory = KeyFactory.getInstance("DSA");
+         return keyFactory.generatePublic(pubKeySpec);
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+         return null;
+      }
+   }
+   
+   private static void writeKey(PrivateKey pKey, String username) {
+      wK(pKey, username, "priv");
+   }
+   private static void writeKey(PublicKey pKey, String username) {
+      wK(pKey, username, "pub");
+   }
+   private static void wK(Key pKey, String username, String type) {
+      try {
+         byte[] key = pKey.getEncoded();
+         FileOutputStream keyfos = new FileOutputStream(username+type+".key");
+         keyfos.write(key);
+         keyfos.close();
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+   }
+}

src/AuctionImpl.java

@@ -0,0 +1,389 @@
+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class provides the impementation for the AuctionServer.
+ **/
+
+import java.io.*;
+import java.util.*;
+import java.security.*;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <me+auctionprog@bengoldsworthy.net>
+ **   @version 1.0
+ **/
+public class AuctionImpl extends java.rmi.server.UnicastRemoteObject implements Auction {
+   private ArrayList<AuctionWrapper> auctions;
+   private ArrayList<UserWrapper> users;
+   String status;
+   byte[] challenge = new byte[1024];
+   
+   /**   
+    **   Constructor Method. Required to declare the `RemoteException`
+    **   instance.
+    **/
+   public AuctionImpl() throws java.rmi.RemoteException {
+      super();
+      
+      System.out.println("Server initilising...");
+      
+      auctions = new ArrayList<AuctionWrapper>();
+      users = new ArrayList<UserWrapper>();
+      status = "";
+      generateKeys();
+      
+      System.out.println("Server start successful.");
+   }
+   
+   private void generateKeys() {
+      try {
+         KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
+         SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
+         keyGen.initialize(1024, random);
+         
+         KeyPair pair = keyGen.generateKeyPair();
+         writeKey(pair.getPublic());
+         writeKey(pair.getPrivate());
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+   }
+   
+   /**
+    **   Creates an auction with the given details, generating a new ID for 
+    **   it.
+    **   
+    **   @param desc The auction description.
+    **   @param owner The auction owner/creator.
+    **   @param startingPrice The auction starting price.
+    **   @param reserve The auction reserve price.
+    **/
+   public void createAuction(String desc, UserWrapper owner, float startingPrice, float reserve) throws java.rmi.RemoteException {
+      int id = 0;
+      String preamble = "Create new auction: ";
+      
+      lines();
+      System.out.println(preamble + "begin.");
+      
+      // Gives the new auction the lowest unclaimed ID.
+      for(AuctionWrapper item: auctions){
+         if (id <= item.getID()) {
+            id = item.getID();
+         }
+      }
+      
+      auctions.add(new AuctionWrapper(++id, desc, owner, startingPrice, reserve));
+      System.out.println(preamble + "auction "+id+" successfully created.");
+      status = "Auction no. "+id+" successfully created.";
+      
+      System.out.println(preamble + "end.");
+      lines();
+   }
+   
+   /**
+    **   Removes an auction, provided the user calling the method owns it.
+    **   If the reserve price was met, also returns the winning bidder.
+    **   
+    **   @param id The ID of the auction to remove.
+    **   @param currentUser The user calling the method.
+    **   @return The `UserWrapper` of the highest bidder, if applicable.
+    **/
+   public UserWrapper removeAuction(int id, UserWrapper currentUser) throws java.rmi.RemoteException {
+      AuctionWrapper auction = this.getAuction(id);
+      UserWrapper response = null;
+      String preamble = "Close auction "+id+": ";
+      
+      lines();
+      System.out.println(preamble + "begin.");
+      
+      if (auction.getOwner().getUsername().equals(currentUser.getUsername())) {
+         System.out.println(preamble + "ownership rights confirmed.");
+         auctions.remove(auction);
+         System.out.println(preamble + "auction successfully closed.");
+         status = "Auction no. "+id+" successfully removed";
+         if (auction.getPrice() >= auction.getReserve()) {
+            System.out.println(preamble + "auction closed with winner.");
+            status = "Auction closed - winner";
+            response = auction.getHighestBidder();
+         } else {
+            System.out.println(preamble + "auction closed with no winner.");
+            status = "Auction closed - no winner";
+         }
+      } else {     
+         System.out.println(preamble + "invalid ownership rights.");
+         status = "Auction no. "+id+" could not be removed - you do not own this auction";
+      }
+      
+      System.out.println(preamble + "end.");
+      lines();
+      return response;
+   }
+   
+   /**
+    **   Bids on a given auction, provided the bid is more than the
+    **   current highest price.
+    **   
+    **   @param id The ID of the auction in question.
+    **   @param bidder The user bidding on the auction.
+    **   @param price The amount bid.
+    **/
+   public void bidOnAuction(int id, UserWrapper bidder, float price) 
+      throws java.rmi.RemoteException {
+      AuctionWrapper auction;
+      String preamble = "Bid on auction "+id+": ";
+      
+      lines();
+      System.out.println(preamble + "begin.");
+      
+      if ((auction = this.getAuction(id)) != null) {
+         if (price > auction.getPrice()) {
+            this.getAuction(id).setBid(bidder, price);
+            System.out.println(preamble + "bid successful.");
+            status = "Bid successful";
+         } else {
+            System.out.println(preamble + "bid less than current highest bid.");
+            status = "Price less than highest bid";
+         }
+      } else {
+         System.out.println(preamble + "auction ID not found.");
+         status = "Invalid auction ID";
+      }
+      
+      System.out.println(preamble + "end.");
+      lines();
+   }
+   
+   /**
+    **   Accessor Method. Retrieves an auction by its ID.
+    **   
+    **   @param id The ID of the auction to retrieve.
+    **   @return The `AuctionWrapper` indicated.
+    **/
+   private AuctionWrapper getAuction(int id) {
+      for(AuctionWrapper auction: auctions){
+         if (auction.getID() == id) {
+            return auction;
+         }
+      }
+      return null;
+   }
+   
+   /**
+    **   Accessor Method. Retrieves a list of all the auctions.
+    **   
+    **   @return An `ArrayList` of `AuctionWrapper`s.
+    **/
+   public ArrayList<AuctionWrapper> getAuctions() throws java.rmi.RemoteException {
+      return auctions;
+   }
+   
+   /**
+    **   Accessor Method. Gets a user, or creates a new one if non 
+    **   exists with the given details.
+    **   
+    **   @param name The user's name.
+    **   @param email The user's email address.
+    **   @return The relevant `UserWrapper`.
+    **/
+   public UserWrapper getUser(String username) throws java.rmi.RemoteException {
+      for(UserWrapper user: users){
+         if (user.getUsername().equals(username)) {
+            status = "Welcome back, "+user.getName()+".";
+            return user;
+         }
+      }
+      status = "No such user.";
+      return null;
+   }
+   
+   public UserWrapper registerUser(String name, String email, String username) throws java.rmi.RemoteException {
+      for(UserWrapper user: users){
+         if (user.getUsername().equals(username)) {
+            status = "Username taken. Either choose a new username or, if trying to login to an existing account, rerun the program as 'AuctionClient <username>'.";
+            return null;
+         }
+      }
+      
+      UserWrapper user = new UserWrapper(name, email, username);
+      users.add(user);
+      status = "New user created. Hello "+name+".";
+      return user;
+   }
+   
+   /**
+    **   Accessor Method. Gets the status resulting from the last action
+    **   attempted.
+    **   
+    **   @return The status message.
+    **/
+   public String getStatusofLast() {
+      return "\n"+status+"\n";
+   }
+   
+   public PublicKey getPublicKey() throws java.rmi.RemoteException {
+      return this.readKey("server");
+   }
+   
+   public void sendPublicKey(PublicKey key, String username) throws java.rmi.RemoteException {
+      this.writeKey(key, username);
+   }
+   
+   private static void writeKey(PrivateKey pKey) throws java.rmi.RemoteException {
+      try {
+         byte[] key = pKey.getEncoded();
+         FileOutputStream keyfos = new FileOutputStream("../key/serverpriv.key");
+         keyfos.write(key);
+         keyfos.close();
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+   }
+   
+   private static void writeKey(PublicKey pKey) throws java.rmi.RemoteException {
+      try {
+         byte[] key = pKey.getEncoded();
+         FileOutputStream keyfos = new FileOutputStream("../key/serverpub.key");
+         keyfos.write(key);
+         keyfos.close();
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+   }
+   
+   private static void writeKey(PublicKey pKey, String username) throws java.rmi.RemoteException {
+      try {
+         byte[] key = pKey.getEncoded();
+         FileOutputStream keyfos = new FileOutputStream("../key/"+username+"pub.key");
+         keyfos.write(key);
+         keyfos.close();
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+      }
+   }
+   
+   private static PrivateKey readKey() throws java.rmi.RemoteException {
+      try {
+         FileInputStream keyfis = new FileInputStream("../key/serverpriv.key");
+         byte[] encKey = new byte[keyfis.available()];
+         keyfis.read(encKey);
+         keyfis.close();
+
+         PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(encKey);
+
+         KeyFactory keyFactory = KeyFactory.getInstance("DSA");
+         return keyFactory.generatePrivate(privKeySpec);
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+         return null;
+      }
+   }
+   
+   private static PublicKey readKey(String username) throws java.rmi.RemoteException {
+      try {
+         FileInputStream keyfis = new FileInputStream("../key/"+username+"pub.key");
+         byte[] encKey = new byte[keyfis.available()];  
+         keyfis.read(encKey);
+
+         keyfis.close();
+         
+         X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encKey);
+         
+         KeyFactory keyFactory = KeyFactory.getInstance("DSA");
+      return keyFactory.generatePublic(pubKeySpec);
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+         return null;
+      }
+   }
+
+   
+   public byte[] challengeServer(byte[] challenge) throws java.rmi.RemoteException {   
+      try {
+         Signature dsa = Signature.getInstance("SHA1withDSA"); 
+         dsa.initSign(this.readKey());
+         dsa.update(challenge);
+         byte[] realSig = dsa.sign();
+         
+         return realSig;
+      } catch (Exception e) {
+         System.out.println();
+         System.out.println("Exception");
+         System.out.println(e);
+         return null;
+      }
+   }
+   
+   public byte[] getChallenge() throws java.rmi.RemoteException {
+      challenge = new byte[1024];
+      new Random().nextBytes(this.challenge);
+      return this.challenge;
+   }
+   
+   public boolean returnChallenge(byte[] retChal, String username) throws java.rmi.RemoteException {
+      System.out.println("Authenticating user '"+username+"'...");
+      for(UserWrapper user: users){
+         if (user.getUsername().equals(username)) {
+            try {
+               Signature sig = Signature.getInstance("SHA1withDSA");
+               sig.initVerify(this.readKey(username));
+
+               sig.update(this.challenge);
+               
+               boolean verifies = sig.verify(retChal);
+               System.out.println(username+" signature verifies: " + verifies);
+               return verifies;
+            } catch (Exception e) {
+               System.out.println();
+               System.out.println("Exception");
+               System.out.println(e);
+            }
+         }
+      }
+      System.out.println("User '"+username+"' not found.");
+      return false;
+   }
+   
+   public void close() throws java.rmi.RemoteException {
+      System.exit(-1);
+   }
+   
+   private void lines() {
+      for (int i = 0; i < 80; i++) System.out.print("-");
+      System.out.print("\n");
+   }
+}
+

src/AuctionServer.java

@@ -0,0 +1,54 @@
+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class sets up the auction server using RMI.
+ **/
+
+import java.rmi.Naming;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <me+auctionprog@bengoldsworthy.net>
+ **   @version 1.0
+ **/
+public class AuctionServer {
+   /**   
+    **   Constructor Method.
+    **/
+   public AuctionServer() {
+      try {
+       	Auction a = new AuctionImpl();
+       	Naming.rebind("rmi://localhost/AuctionService", a);
+      } catch (Exception e) {
+         System.out.println("Server Error: " + e);
+      }
+   }
+
+   /**   
+    **   Runs the server.
+    **
+    **   @param args Command-line arguments.
+    **/
+   public static void main(String args[]) {
+      new AuctionServer();
+   }
+}

src/AuctionWrapper.java

@@ -0,0 +1,123 @@
+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class represents an Auction.
+ **/
+ 
+import java.io.*;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <me+auctionprog@bengoldsworthy.net>
+ **   @version 1.0
+ **/
+public class AuctionWrapper implements Serializable {
+   private int id;
+   private String desc;
+   private UserWrapper owner;
+   private UserWrapper highestBidder;
+   private float price;
+   private float reserve;
+
+   /**   
+    **   Constructor Method.
+    **   @param id The ID of the auction.
+    **   @param desc The description of the auction.
+    **   @param owner The user creating the auction.
+    **   @param startingPrice The starting price of the auction.
+    **   @param reserve The reserve price of the auction.
+    **/
+	public AuctionWrapper(int id, String desc, UserWrapper owner, float startingPrice, float reserve){
+		this.id = id;
+		this.desc = desc;
+		this.owner = owner;
+      this.highestBidder = null;
+      this.price = startingPrice;
+      this.reserve = reserve;
+	}
+   
+   /**   
+    **   Returns whether the auction has been sold on close.
+    **   @return Whether the auction has been sold or not.
+    **/
+   public boolean isSold() {
+      return (this.price >= this.reserve) ? true : false;
+   }
+   
+   /**   
+    **   Mutator Method. Sets the current highest bid.
+    **   @param bidder The user bidding.
+    **   @param price The bid price.
+    **/
+   public void setBid(UserWrapper bidder, float price) {
+      this.highestBidder = bidder;
+      this.price = price;
+   }
+   
+   /**   
+    **   Accessor Method. Gets the auction ID.
+    **   @return The auction ID.
+    **/
+	public int getID() {
+		return this.id;
+	}
+   
+   /**   
+    **   Accessor Method. Gets the auction description.
+    **   @return The auction description.
+    **/
+   public String getDesc() {
+		return this.desc;
+	}
+   
+   /**   
+    **   Accessor Method. Gets the auction owner.
+    **   @return The auction owner.
+    **/
+   public UserWrapper getOwner() {
+		return this.owner;
+	}
+   
+   /**   
+    **   Accessor Method. Gets the highest bidder on the auction.
+    **   @return The highest bidder on the auction.
+    **/
+   public UserWrapper getHighestBidder() {
+		return this.highestBidder;
+	}
+   
+   /**   
+    **   Accessor Method. Gets the current auction price.
+    **   @return The current auction price.
+    **/
+   public float getPrice() {
+		return this.price;
+	}
+   
+   /**   
+    **   Accessor Method. Gets the auction reserve price.
+    **   @return The auction reserve price.
+    **/
+   public float getReserve() {
+		return this.reserve;
+	}
+}

src/GenSig.java

@@ -0,0 +1,47 @@
+import java.io.*;
+import java.security.*;
+
+class GenSig {
+   public static void main(String[] args) {
+      /* Generate a DSA signature */
+
+      if (args.length != 1) {
+         System.out.println("Usage: GenSig nameOfFileToSign");
+      } else try {
+         KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA", "SUN");
+         SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
+         keyGen.initialize(1024, random);
+         
+         KeyPair pair = keyGen.generateKeyPair();
+         PrivateKey priv = pair.getPrivate();
+         PublicKey pub = pair.getPublic();
+         
+         Signature dsa = Signature.getInstance("SHA1withDSA", "SUN"); 
+         dsa.initSign(priv);
+
+         FileInputStream fis = new FileInputStream(args[0]);
+         BufferedInputStream bufin = new BufferedInputStream(fis);
+         byte[] buffer = new byte[1024];
+         int len;
+         while ((len = bufin.read(buffer)) >= 0) {
+             dsa.update(buffer, 0, len);
+         };
+         bufin.close();
+         
+         byte[] realSig = dsa.sign();
+         
+         /* save the signature in a file */
+         FileOutputStream sigfos = new FileOutputStream("sig");
+         sigfos.write(realSig);
+         sigfos.close();
+         
+         /* save the public key in a file */
+         byte[] key = pub.getEncoded();
+         FileOutputStream keyfos = new FileOutputStream("suepk");
+         keyfos.write(key);
+         keyfos.close();
+      } catch (Exception e) {
+         System.err.println("Caught exception " + e.toString());
+      }
+   }
+}

src/UserWrapper.java

@@ -0,0 +1,69 @@
+/*
+ *                             AuctionProg 1.0                        
+ *                  Copyright © 2016 Ben Goldsworthy (rumps)        
+ *                                                                      
+ * A program to facilitate a networked auction system.             
+ *                                                                           
+ * This file is part of AuctionProg.                                         
+ *                                                                            
+ * AuctionProg is free software: you can redistribute it and/or modify        
+ * it under the terms of the GNU General Public License as published by       
+ * the Free Software Foundation, either version 3 of the License, or          
+ * (at your option) any later version.                                        
+ *                                                                            
+ * AuctionProg is distributed in the hope that it will be useful,             
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of             
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              
+ * GNU General Public License for more details.                               
+ *                                                                            
+ * You should have received a copy of the GNU General Public License          
+ * along with AuctionProg.  If not, see <http://www.gnu.org/licenses/>.       
+ */
+
+/**
+ ** This class represents a User.
+ **/
+
+import java.io.*;
+
+/**
+ **   @author  Ben Goldsworthy (rumps) <me+auctionprog@bengoldsworthy.net>
+ **   @version 1.0
+ **/
+public class UserWrapper implements Serializable {
+   private String name;
+   private String email;
+   private String username;
+
+   /**   
+    **   Constructor Method.
+    **   @param id The ID of the user.
+    **   @param name The user's name.
+    **   @param email The user's email address.
+    **/
+	public UserWrapper(String name, String email, String username){
+		this.name = name;
+      this.email = email;
+      this.username = username;
+	}
+   
+   /**   
+    **   Accessor Method. Returns the user's name.
+    **   @param The user's name.
+    **/
+	public String getName() {
+		return this.name;
+	}
+   
+	public String getUsername() {
+		return this.username;
+	}
+   
+   /**   
+    **   Accessor Method. Returns the user's email address.
+    **   @param The user's email address.
+    **/
+   public String getEmail() {
+		return this.email;
+	}
+}