Added hashing algorithm to the user signup and login

src/main/java/CreateUser.java

@@ -10,6 +10,9 @@ import java.util.List;
 import java.io.FileWriter;
 import java.io.IOException;
 
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
 import java.util.UUID;
 
 class CreateUser {
@@ -18,18 +21,18 @@ class CreateUser {
     private String password;
     private String birthday;
     private String firstName;
-    private String surName;
+    private String surname;
     private boolean stayLoggedIn;
     
 
     // Constructor
-    public CreateUser(String id, String name, String password, String birthday) {
+    public CreateUser(String id, String name, String password, String birthday, String firstName, String surname) {
     this.id = id;
     	this.userName = name;
-    this.password = password;
+    this.password = hashPassword(password);
     this.birthday = birthday;
     this.firstName = firstName;
-    this.surName = surName;
+    this.surname = surname;
     }
 
     // Getters and Setters
@@ -73,6 +76,14 @@ class CreateUser {
             this.firstName = firstName;
             }
             
+            public String surname() {
+                return firstName;
+                }
+
+                public void surname(String firstName) {
+                this.firstName = firstName;
+                }
+        
         public boolean isStayLoggedIn() {
         return stayLoggedIn;
         }
@@ -82,7 +93,7 @@ class CreateUser {
         }
 
     // Function to create user with validation
-    public static CreateUser createUser(String id, String userName, String password, String birthday) {
+    public static CreateUser createUser(String id, String userName, String password, String birthday, String firstName, String surname) {
     	if (userName == null || userName.isEmpty()) {
         throw new IllegalArgumentException("Username cannot be empty");
         }
@@ -91,7 +102,25 @@ class CreateUser {
         }
         if (password.length() < 6) {
         throw new IllegalArgumentException("Password must be at least 6 characters long");
-        }    return new CreateUser(id, userName, password, birthday);
+        }    return new CreateUser(id, userName, password, birthday, firstName, surname);
+    }
+    
+ // Function to hash the password using SHA-256 algorithm
+    private String hashPassword(String password) {
+    	try {
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            byte[] hash = digest.digest(password.getBytes());
+            StringBuilder hexString = new StringBuilder();
+            for (byte b : hash) {
+                String hex = Integer.toHexString(0xff & b);
+                if (hex.length() == 1) hexString.append('0');
+                hexString.append(hex);
+            }
+            return hexString.toString();
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+            return null;
+        }
     }
     
  // Function to save to JSON file, replace with database call later
@@ -147,7 +176,7 @@ class CreateUser {
         try {
             // Example usage
         	UUID randomUUID = UUID.randomUUID();
-        	CreateUser user = createUser(randomUUID.toString(), "Test User", "TestPasswort123", "01.01.2000");
+        	CreateUser user = createUser(randomUUID.toString(), "Hash Test", "123456", "01.01.2000", "Hans", "Wurst");
 
             // Example of accessing properties
             System.out.println("UserID: " + user.getId());

src/main/java/LoginGUI.java

@@ -5,6 +5,9 @@ import java.util.List;
 import java.awt.event.KeyEvent;
 import java.awt.event.KeyListener;
 
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
 public class LoginGUI extends JFrame implements ActionListener {
     private JTextField usernameField;
     private JPasswordField passwordField;
@@ -103,14 +106,37 @@ public class LoginGUI extends JFrame implements ActionListener {
         List<CreateUser> userList = CreateUser.readUserListFromJsonFile("user.json");
         if (userList != null) {
         	for (CreateUser user : userList) {
-            if (user.getUserName().equals(username) && user.getPassword().equals(password)) {
+                if (user.getUserName().equals(username)) {
+                // Hash the user input password
+                String hashedPassword = hashPassword(password);
+                // Compare the hashed passwords
+                if (user.getPassword().equals(hashedPassword)) {
              return true; // Success
            }
             }
         }
+        }
         return false; // Fail
     }
 
+        private String hashPassword(String password) {
+            try {
+                MessageDigest digest = MessageDigest.getInstance("SHA-256");
+                byte[] hash = digest.digest(password.getBytes());
+                StringBuilder hexString = new StringBuilder();
+                for (byte b : hash) {
+                String hex = Integer.toHexString(0xff & b);
+                if (hex.length() == 1) {
+                hexString.append('0');
+                }
+                hexString.append(hex);
+                }
+                return hexString.toString();
+            } catch (NoSuchAlgorithmException e) {
+                e.printStackTrace();
+                return null;
+            }
+        }
 
     private class EnterKeyListener implements KeyListener {
         @Override

src/main/java/SignUpGUI.java

@@ -75,6 +75,8 @@ public class SignUpGUI extends JFrame implements ActionListener {
             String password = passwordField.getText();
             String confirmPassword = confirmPasswordField.getText();
             String birthday = birthdayField.getText();
+            String firstName = firstNameField.getText(); 
+            String surname = surnameField.getText();
 
             if (!password.equals(confirmPassword)) {
                 JOptionPane.showMessageDialog(this, "Passwords do not match!", "Sign Up Error", JOptionPane.ERROR_MESSAGE);
@@ -87,7 +89,7 @@ public class SignUpGUI extends JFrame implements ActionListener {
             }
             try {
                 UUID randomUUID = UUID.randomUUID();
-                CreateUser user = CreateUser.createUser(randomUUID.toString(), username, password, birthday);
+                CreateUser user = CreateUser.createUser(randomUUID.toString(), username, password, birthday, firstName, surname);
                 user.saveToJsonFile("user.json");
                 JOptionPane.showMessageDialog(this, "User signed up successfully!");
                 dispose();

user.json

@@ -1,30 +1,20 @@
 [
   {
-    "id": "a2864d79-1079-4cbb-8d77-f5f84995580d",
-    "userName": "Another Test User",
-    "password": "TestPasswort123",
-    "birthday": "01.01.2000",
-    "stayLoggedIn": false
-  },
-  {
-    "id": "3690702d-9c7e-48fb-8a01-ef89b3b76268",
-    "userName": "TestUser2",
-    "password": "123456",
-    "birthday": "01.01.2000",
-    "stayLoggedIn": false
-  },
-  {
-    "id": "685bc3a6-e706-4214-a5e1-8443d1a5258e",
-    "userName": "Test User",
-    "password": "Test",
-    "birthday": "01.01.2000",
+    "id": "d7ae19fe-4684-4d69-a73d-4cca612962a3",
+    "userName": "Test",
+    "password": "8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92",
+    "birthday": "",
+    "firstName": "",
+    "surname": "",
     "stayLoggedIn": false
   },
   {
-    "id": "57b7fb2e-50c1-4027-8871-58cbfc8405c8",
-    "userName": "New",
-    "password": "123456",
+    "id": "2ec2c0c5-677c-4262-8958-fef98d11cc63",
+    "userName": "Test2",
+    "password": "8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92",
     "birthday": "",
+    "firstName": "",
+    "surname": "",
     "stayLoggedIn": false
   }
 ]