Add the ability to define multiple authentication services

src/main/java/de/sebastianvonhelmersen/Database.java

@@ -46,7 +46,7 @@ public class Database {
         }
     }
 
-    public void addPlayer(String uuid, String mcusername, LdapUser user) {
+    public void addPlayer(String uuid, String mcusername, user user) {
         String query = "insert into players values (?, ?, ?, ?, ?, ?, ?)";
         try(PreparedStatement prep_query = this.statement.getConnection().prepareStatement(query)){
             prep_query.setString(1, uuid);

src/main/java/de/sebastianvonhelmersen/User.java

@@ -5,7 +5,7 @@ import javax.naming.directory.Attributes;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class LdapUser {
+public class User {
     public String firstName;
     public String lastName;
     public String email;
@@ -13,7 +13,16 @@ public class LdapUser {
     public int gid;
     public String ldapName;
 
-    public LdapUser(Attributes attributes) {
+    public User(String firstName, String lastName, String email, int uid, int gid, String ldapName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.email = email;
+        this.uid = uid;
+        this.gid = gid;
+        this.ldapName = ldapName;
+    }
+
+    public User(Attributes attributes) {
         firstName = trimAttribute(attributes.get("givenname"));
         lastName = trimAttribute(attributes.get("sn"));
         email = trimAttribute(attributes.get("mail"));

src/main/java/de/sebastianvonhelmersen/authentication/Authenticator.java

@@ -0,0 +1,8 @@
+package de.sebastianvonhelmersen.authentication;
+
+import de.sebastianvonhelmersen.User;
+
+public interface Authenticator {
+    public boolean authenticate(String username, String token);
+    public User getUser(String username);
+}

src/main/java/de/sebastianvonhelmersen/authentication/FetSite.java

@@ -0,0 +1,55 @@
+package de.sebastianvonhelmersen.authentication;
+
+import de.sebastianvonhelmersen.User;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+import java.util.Base64;
+
+public class FetSite implements Authenticator {
+    private final byte[] masterPassword;
+    private final MessageDigest digest;
+    public FetSite(String masterPassword) {
+        this.masterPassword = masterPassword.getBytes(StandardCharsets.UTF_8);
+
+        // Setup hashing Class
+        try {
+            this.digest = MessageDigest.getInstance("SHA-256");
+        }
+        catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /*
+    Token: base64(hash(<username>) XOR <masterpasswd>)
+     */
+    public boolean authenticate(String username, String token) {
+        byte[] byteToken = token.getBytes(StandardCharsets.UTF_8);
+
+
+        // Hash username to make comparison
+        byte[] userNameHash = digest.digest(username.getBytes(StandardCharsets.UTF_8));
+
+        // Decode token
+        // Ensure both have the same length
+        int length = Math.min(byteToken.length, userNameHash.length);
+        byte[] result = new byte[length];
+
+        // XOR each byte
+        for (int i = 0; i < length; i++) {
+            result[i] = (byte) (byteToken[i] ^ this.masterPassword[i]);
+        }
+
+        byte[] dec_token = Base64.getDecoder().decode(result);
+
+        // Compare hash and decoded token
+       return Arrays.equals(dec_token, userNameHash);
+    }
+
+    public User getUser(String username) {
+        return new User("", "", "", 0, 0, username);
+    }
+}

src/main/java/de/sebastianvonhelmersen/authentication/Ldap.java

@@ -1,4 +1,7 @@
-package de.sebastianvonhelmersen;
+package de.sebastianvonhelmersen.authentication;
+
+import de.sebastianvonhelmersen.User;
+import de.sebastianvonhelmersen.user;
 
 import javax.naming.Context;
 import javax.naming.NamingEnumeration;
@@ -16,7 +19,7 @@ public class Ldap {
     private static final String LDAP_URL = "ldap://juri:389";
     private static final String BASE_DN = "dc=fet,dc=htu,dc=tuwien,dc=ac,dc=at";
     private static final String ADMIN_DN = "cn=admin,dc=fet,dc=htu,dc=tuwien,dc=ac,dc=at"; // service account
-    public static LdapUser authenticate(String username, String password) {
+    public static User authenticate(String username, String password) {
 
         try {
             // 1. Bind as admin/service account
@@ -75,7 +78,7 @@ public class Ldap {
 
             new InitialDirContext(authEnv).close(); // bind attempt
 
-            return new LdapUser(result.getAttributes()); // success
+            return new user(result.getAttributes()); // success
 
         } catch (Exception e) {
             e.printStackTrace();

src/main/java/de/sebastianvonhelmersen/fetmcplugin.java

@@ -1,5 +1,8 @@
 package de.sebastianvonhelmersen;
 
+import de.sebastianvonhelmersen.authentication.Authenticator;
+import de.sebastianvonhelmersen.authentication.FetSite;
+import de.sebastianvonhelmersen.authentication.Ldap;
 import net.kyori.adventure.text.Component;
 import org.bukkit.Bukkit;
 import org.bukkit.GameMode;
@@ -23,11 +26,13 @@ import java.util.logging.Level;
 public class fetmcplugin extends JavaPlugin implements Listener {
     private Database db;
     private Map<UUID, AuthInfos> allInfos = HashMap.newHashMap(0);
+    private Authenticator authenticator;
 
     @Override
     public void onEnable() {
         // Make sure the plugin's data folder exists
         File dataFolder = this.getDataFolder();
+        this.authenticator = new FetSite("MyokpBxpqxw9Eo8IduwH9IFSnBy4qII6");
 
         if (!dataFolder.exists()) {
             dataFolder.mkdirs();
@@ -145,10 +150,10 @@ public class fetmcplugin extends JavaPlugin implements Listener {
                         Component.text("§eBitte gib das Password deines FET Accounts ein!"));
                 break;
             case AUTH_WAITING_PASSWORD:
-                LdapUser user = checkLdap(info.getUsername(), message.trim());
+                boolean valid = validate(info.getUsername(), message.trim());
                 event.setCancelled(true);
                 event.getRecipients().clear();
-                if(user != null) {
+                if(valid) {
                     allInfos.remove(uuid);
                     this.db.addPlayer(uuid.toString(), event.getPlayer().getName(), user);
                     Bukkit.getScheduler().runTask(this, () -> {
@@ -177,11 +182,16 @@ public class fetmcplugin extends JavaPlugin implements Listener {
         return;
 
     }
-
-    private LdapUser checkLdap(String username, String password) {
+    /*
+     *  This function uses the defined Authenticator instance to authenticate the User against their
+     *  provided username - token combination
+     *  @param username the username used to authenticate the player with the provider
+     *  @param token some sort of authentication methon. Can be Password, AppPassword or some other form of token the
+     *         provider takes to authenticate the user
+     */
+    private boolean validate(String username, String token) {
         getLogger().log(Level.INFO, "Checking LDAP for user " + username);
-        return Ldap.authenticate(username, password);
-        //return true;
+        return authenticator.authenticate(username, token);
     }
 
 }