Update Login-System.py

Author: rogers-cyber

20-Simple-login-system/Login-System.py

@@ -1,106 +1,170 @@
 import tkinter as tk
 from tkinter import messagebox
-import hashlib
 import json
 import os
+import re
+
+from argon2 import PasswordHasher
+from argon2.exceptions import VerifyMismatchError
+
+
+# -------------------- Config --------------------
 
 USER_FILE = 'users.json'
 
+ph = PasswordHasher(
+    time_cost=3,        # iterations
+    memory_cost=65536,  # 64 MB
+    parallelism=4,
+    hash_len=32,
+    salt_len=16
+)
+
+
+# -------------------- Storage --------------------
+
 def load_users():
     if os.path.exists(USER_FILE):
         with open(USER_FILE, 'r') as f:
             return json.load(f)
     return {}
 
+
 def save_users(users):
     with open(USER_FILE, 'w') as f:
-        json.dump(users, f)
+        json.dump(users, f, indent=4)
+
+
+# -------------------- Password Security --------------------
+
+def hash_password(password: str) -> str:
+    return ph.hash(password)
+
+
+def verify_password(password: str, stored_hash: str) -> bool:
+    try:
+        return ph.verify(stored_hash, password)
+    except VerifyMismatchError:
+        return False
+
 
-def hash_password(password):
-    return hashlib.sha256(password.encode()).hexdigest()
+def validate_password_strength(password: str) -> str | None:
+    if len(password) < 12:
+        return "Password must be at least 12 characters long"
+
+    if not re.search(r"[A-Z]", password):
+        return "Password must contain an uppercase letter"
+
+    if not re.search(r"[a-z]", password):
+        return "Password must contain a lowercase letter"
+
+    if not re.search(r"\d", password):
+        return "Password must contain a digit"
+
+    if not re.search(r"[!@#$%^&*(),.?\":{}|<>]", password):
+        return "Password must contain a special character"
+
+    return None
+
+
+# -------------------- App --------------------
 
 class LoginApp:
     def __init__(self, root):
         self.root = root
-        self.root.title('Modern Login System')
+        self.root.title('Secure Login System')
         self.root.geometry('450x550')
         self.root.configure(bg='#1f2f3a')
         self.root.resizable(False, False)
+
         self.users = load_users()
         self.create_login_screen()
 
     def clear_screen(self):
         for widget in self.root.winfo_children():
             widget.destroy()
 
+    # -------------------- Login Screen --------------------
+
     def create_login_screen(self):
         self.clear_screen()
-        tk.Label(self.root, text='Welcome Back!', font=('Helvetica', 28, 'bold'), bg='#1f2f3a', fg='#ffffff').pack(pady=30)
-
-        # Username input
-        username_frame = tk.Frame(self.root, bg='#1f2f3a')
-        username_frame.pack(pady=10)
-        tk.Label(username_frame, text='Username', font=('Helvetica', 12), bg='#1f2f3a', fg='#bdc3c7').pack(anchor='w')
-        self.username_entry = tk.Entry(username_frame, font=('Helvetica', 14), bd=0, highlightthickness=2, highlightbackground='#2980b9', width=30)
-        self.username_entry.pack(pady=5, ipady=6)  # ipady increases vertical padding inside entry
-
-        # Password input
-        password_frame = tk.Frame(self.root, bg='#1f2f3a')
-        password_frame.pack(pady=10)
-        tk.Label(password_frame, text='Password', font=('Helvetica', 12), bg='#1f2f3a', fg='#bdc3c7').pack(anchor='w')
-        self.password_entry = tk.Entry(password_frame, font=('Helvetica', 14), bd=0, highlightthickness=2, highlightbackground='#2980b9', show='*', width=30)
-        self.password_entry.pack(pady=5, ipady=6)
-
-        # Buttons
-        btn_frame = tk.Frame(self.root, bg='#1f2f3a')
-        btn_frame.pack(pady=20)
-
-        login_btn = tk.Button(btn_frame, text='Login', command=self.login, bg='#2980b9', fg='white', font=('Helvetica', 12, 'bold'), width=25, height=2, bd=0, activebackground='#3498db', cursor='hand2')
-        login_btn.pack(pady=5)
-        register_btn = tk.Button(btn_frame, text='Register', command=self.create_register_screen, bg='#27ae60', fg='white', font=('Helvetica', 12, 'bold'), width=25, height=2, bd=0, activebackground='#2ecc71', cursor='hand2')
-        register_btn.pack(pady=5)
-        forgot_btn = tk.Button(btn_frame, text='Forgot Password?', command=self.forgot_password, bg='#e67e22', fg='white', font=('Helvetica', 12, 'bold'), width=25, height=2, bd=0, activebackground='#f39c12', cursor='hand2')
-        forgot_btn.pack(pady=5)
+
+        tk.Label(
+            self.root,
+            text='Welcome Back!',
+            font=('Helvetica', 28, 'bold'),
+            bg='#1f2f3a',
+            fg='#ffffff'
+        ).pack(pady=30)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=10)
+
+        tk.Label(frame, text='Username', fg='#bdc3c7', bg='#1f2f3a').pack(anchor='w')
+        self.username_entry = tk.Entry(frame, font=('Helvetica', 14), width=30)
+        self.username_entry.pack(ipady=6)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=10)
+
+        tk.Label(frame, text='Password', fg='#bdc3c7', bg='#1f2f3a').pack(anchor='w')
+        self.password_entry = tk.Entry(frame, font=('Helvetica', 14), show='*', width=30)
+        self.password_entry.pack(ipady=6)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=20)
+
+        tk.Button(frame, text='Login', height=2, width=46, command=self.login).pack(pady=5)
+        tk.Button(frame, text='Register', height=2, width=46, command=self.create_register_screen).pack(pady=5)
+        tk.Button(frame, text='Forgot Password?', height=2, width=46, command=self.forgot_password).pack(pady=5)
+
+    # -------------------- Register Screen --------------------
 
     def create_register_screen(self):
         self.clear_screen()
-        tk.Label(self.root, text='Create Account', font=('Helvetica', 28, 'bold'), bg='#1f2f3a', fg='#ffffff').pack(pady=30)
-
-        # Username
-        username_frame = tk.Frame(self.root, bg='#1f2f3a')
-        username_frame.pack(pady=10)
-        tk.Label(username_frame, text='Username', font=('Helvetica', 12), bg='#1f2f3a', fg='#bdc3c7').pack(anchor='w')
-        self.reg_username = tk.Entry(username_frame, font=('Helvetica', 14), bd=0, highlightthickness=2, highlightbackground='#27ae60', width=30)
-        self.reg_username.pack(pady=5, ipady=6)
-
-        # Password
-        password_frame = tk.Frame(self.root, bg='#1f2f3a')
-        password_frame.pack(pady=10)
-        tk.Label(password_frame, text='Password', font=('Helvetica', 12), bg='#1f2f3a', fg='#bdc3c7').pack(anchor='w')
-        self.reg_password = tk.Entry(password_frame, font=('Helvetica', 14), bd=0, highlightthickness=2, highlightbackground='#27ae60', show='*', width=30)
-        self.reg_password.pack(pady=5, ipady=6)
-
-        # Confirm Password
-        confirm_frame = tk.Frame(self.root, bg='#1f2f3a')
-        confirm_frame.pack(pady=10)
-        tk.Label(confirm_frame, text='Confirm Password', font=('Helvetica', 12), bg='#1f2f3a', fg='#bdc3c7').pack(anchor='w')
-        self.reg_confirm = tk.Entry(confirm_frame, font=('Helvetica', 14), bd=0, highlightthickness=2, highlightbackground='#27ae60', show='*', width=30)
-        self.reg_confirm.pack(pady=5, ipady=6)
-
-        # Buttons
-        btn_frame = tk.Frame(self.root, bg='#1f2f3a')
-        btn_frame.pack(pady=20)
-
-        register_btn = tk.Button(btn_frame, text='Register', command=self.register, bg='#27ae60', fg='white', font=('Helvetica', 12, 'bold'), width=25, height=2, bd=0, activebackground='#2ecc71', cursor='hand2')
-        register_btn.pack(pady=5)
-        back_btn = tk.Button(btn_frame, text='Back to Login', command=self.create_login_screen, bg='#c0392b', fg='white', font=('Helvetica', 12, 'bold'), width=25, height=2, bd=0, activebackground='#e74c3c', cursor='hand2')
-        back_btn.pack(pady=5)
+
+        tk.Label(
+            self.root,
+            text='Create Account',
+            font=('Helvetica', 28, 'bold'),
+            bg='#1f2f3a',
+            fg='#ffffff'
+        ).pack(pady=30)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=10)
+
+        tk.Label(frame, text='Username', fg='#bdc3c7', bg='#1f2f3a').pack(anchor='w')
+        self.reg_username = tk.Entry(frame, font=('Helvetica', 14), width=30)
+        self.reg_username.pack(ipady=6)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=10)
+
+        tk.Label(frame, text='Password', fg='#bdc3c7', bg='#1f2f3a').pack(anchor='w')
+        self.reg_password = tk.Entry(frame, font=('Helvetica', 14), show='*', width=30)
+        self.reg_password.pack(ipady=6)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=10)
+
+        tk.Label(frame, text='Confirm Password', fg='#bdc3c7', bg='#1f2f3a').pack(anchor='w')
+        self.reg_confirm = tk.Entry(frame, font=('Helvetica', 14), show='*', width=30)
+        self.reg_confirm.pack(ipady=6)
+
+        frame = tk.Frame(self.root, bg='#1f2f3a')
+        frame.pack(pady=20)
+
+        tk.Button(frame, text='Register', height=2, width=46, command=self.register).pack(pady=5)
+        tk.Button(frame, text='Back', height=2, width=46, command=self.create_login_screen).pack(pady=5)
+
+    # -------------------- Logic --------------------
 
     def login(self):
         username = self.username_entry.get()
         password = self.password_entry.get()
-        hashed = hash_password(password)
-        if username in self.users and self.users[username] == hashed:
+
+        if username in self.users and verify_password(password, self.users[username]):
             messagebox.showinfo('Success', f'Welcome {username}!')
         else:
             messagebox.showerror('Error', 'Invalid username or password')
@@ -113,25 +177,39 @@ def register(self):
         if not username or not password:
             messagebox.showerror('Error', 'All fields are required')
             return
+
+        if username in self.users:
+            messagebox.showerror('Error', 'Username already exists')
+            return
+
         if password != confirm:
             messagebox.showerror('Error', 'Passwords do not match')
             return
-        if username in self.users:
-            messagebox.showerror('Error', 'Username already exists')
+
+        strength_error = validate_password_strength(password)
+        if strength_error:
+            messagebox.showerror('Weak Password', strength_error)
             return
 
         self.users[username] = hash_password(password)
         save_users(self.users)
+
         messagebox.showinfo('Success', 'Registration successful!')
         self.create_login_screen()
 
     def forgot_password(self):
         username = self.username_entry.get()
         if username in self.users:
-            messagebox.showinfo('Password Reset', f'Password reset link sent to {username} (mock)')
+            messagebox.showinfo(
+                'Password Reset',
+                f'Password reset link sent to {username} (mock)'
+            )
         else:
             messagebox.showerror('Error', 'Username not found')
 
+
+# -------------------- Run --------------------
+
 if __name__ == '__main__':
     root = tk.Tk()
     app = LoginApp(root)