# Flask Security

***

**1. User Registration and Login**

```python
@app.route('/register', methods=['GET', 'POST'])
def register():
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = RegisterForm()
    if form.validate_on_submit():
        user = User(email=form.email.data,
                    password=security.hash_password(form.password.data))
        db.session.add(user)
        db.session.commit()
        security.login_user(user)
        return redirect(url_for('home'))
    return render_template('register.html', form=form)


@app.route('/login', methods=['GET', 'POST'])
def login():
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
        if user and security.check_password_hash(user.password, form.password.data):
            security.login_user(user)
            return redirect(url_for('home'))
        return render_template('login.html', form=form, error='Invalid credentials')
    return render_template('login.html', form=form)
```

**2. User Profile**

```python
@app.route('/profile', methods=['GET', 'POST'])
@login_required
def profile():
    form = ProfileForm(current_user.email, current_user.password)
    if form.validate_on_submit():
        current_user.email = form.email.data
        if form.password.data:
            current_user.password = security.hash_password(form.password.data)
        db.session.commit()
        security.login_user(current_user)
        return redirect(url_for('profile'))
    return render_template('profile.html', form=form)
```

**3. User Roles and Permissions**

```python
class Role(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    description = db.Column(db.String(255))

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(255), unique=True)
    password = db.Column(db.String(255))
    roles = db.relationship('Role', secondary='roles_users',
                            backref=db.backref('users', lazy='dynamic'))

class Permission(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    description = db.Column(db.String(255))

class RolePermission(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    role_id = db.Column(db.Integer, db.ForeignKey('role.id'))
    permission_id = db.Column(db.Integer, db.ForeignKey('permission.id'))
```

**4. Role-Based Access Control (RBAC)**

```python
@app.route('/secret')
@roles_required('admin')
def secret():
    return 'This is a secret page'
```

**5. Permission-Based Access Control (PBAC)**

```python
@app.route('/protected')
@has_permission('access_protected_page')
def protected():
    return 'This is a protected page'
```

**6. Multiple Roles and Permissions**

```python
@app.route('/special')
@roles_required('admin', 'moderator')
@has_permission('create_post')
def special():
    return 'This is a special page'
```

**7. Multiple Login Methods (e.g., email, username)**

```python
@security.login_manager.user_loader
def load_user(identifier):
    return User.query.get(identifier) or User.query.filter_by(email=identifier).first()
```

**8. OAuth Login**

```python
# Configure OAuth providers
app.config['SECURITY_OAUTH2_PROVIDERS'] = {
    'facebook': {
        'client_id': 'your_client_id',
        'client_secret': 'your_client_secret'
    },
    'google': {
        'client_id': 'your_client_id',
        'client_secret': 'your_client_secret'
    }
}

# Callback routes for OAuth providers
@app.route('/oauth2callback/facebook')
def facebook_callback():
    return security.process_social_login('facebook')

@app.route('/oauth2callback/google')
def google_callback():
    return security.process_social_login('google')
```

**9. Passwordless Authentication (via Email)**

```python
# Configure email settings for passwordless authentication
app.config['SECURITY_PASSWORDLESS_EMAIL_LOGIN'] = True
app.config['SECURITY_PASSWORDLESS_EMAIL_SENDER'] = 'email_sender@example.com'

# Callback for handling passwordless login
@app.route('/passwordless', methods=['GET', 'POST'])
def passwordless():
    if request.method == 'GET':
        return render_template('passwordless.html')
    email = request.form.get('email')
    security.send_passwordless_login_email(email)
    return 'Email sent'
```

**10. TOTP (Two-Factor Authentication)**

```python
# Configure TOTP settings
app.config['SECURITY_TOTP_SECRET_LENGTH'] = 16
app.config['SECURITY_TOTP_TIME_STEP'] = 30
app.config['SECURITY_TOTP_DIGITS'] = 6
app.config['SECURITY_TOTP_ALGORITHM'] = 'sha1'

# Enable TOTP for users
@app.route('/enable_totp', methods=['GET', 'POST'])
@login_required
def enable_totp():
    if request.method == 'GET':
        return render_template('enable_totp.html')
    if request.method == 'POST':
        secret = security.generate_totp_secret()
        security.store_totp_secret(current_user, secret)
        return redirect(url_for('profile'))
```

**11. CSRF Protection**

```python
# Install Flask-WTF or Flask-Form to use CSRF tokens
csrf = CSRFProtect(app)
```

**12. Token-Based Authentication (JWT)**

```python
# Install Flask-JWT-Extended to use JWTs
app.config['JWT_SECRET_KEY'] = 'your_secret_key'
jwt = JWTManager(app)

@app.route('/protected')
@jwt_required
def protected():
    current_user = get_jwt_identity()
    return 'This is a protected page'
```

**13. User Tracking and Auditing**

```python
# Enable Flask-Login's user tracking
app.config['SECURITY_TRACK_USER_LOGIN'] = True
app.config['SECURITY_TRACK_USER_CHANGE_PASSWORD'] = True
```

**14. Password Reset**

```python
@app.route('/reset', methods=['GET', 'POST'])
def reset():
    if request.method == 'GET':
        return render_template('reset.html')
    email = request.form.get('email')
    user = User.query.filter_by(email=email).first()
    if user:
        security.send_reset_password_email(user)
        return 'Email sent'
```

**15. Password Hash Caching**

```python
# Enable password hash caching to improve performance
app.config['SECURITY_PASSWORD_HASH_CACHE'] = True
```

**16. Password Verification Customization**

```python
# Custom password verification function
def verify_password(password, hashed_password):
    # Your custom password verification logic
    return True

# Register your custom password verification function
security.verify_password = verify_password
```

**17. Role and Permission Customization**

```python
# Custom role and permission models
class Role(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)

class Permission(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)

# Register your custom role and permission models
security.datastore.role_model = Role
security.datastore.permission_model = Permission
```

**18. User Authentication Handler Customization**

```python
# Custom user authentication handler
class MyAuthenticationHandler(security.AuthenticationHandler):
    def authenticate(self, email, password):
        # Your custom authentication logic
        return True

# Register your custom authentication handler
security.authentication_handler = MyAuthenticationHandler
```

**19. User Registration Handler Customization**

```python
# Custom user registration handler
class MyRegistrationHandler(security.RegistrationHandler):
    def register(self, email, password):
        # Your custom registration logic
        return True

# Register your custom registration handler
security.registration_handler = MyRegistrationHandler
```

**20. Password Reset Handler Customization**

```python
# Custom password reset handler
class MyResetPasswordHandler(security.ResetPasswordHandler):
    def reset(self, user):
        # Your custom password reset logic
        return True

# Register your custom password reset handler
security.reset_password_handler = MyResetPasswordHandler
```

**21. Token Handler Customization**

```python
# Custom token handler
class MyTokenHandler(security.TokenHandler):
    def generate_token(self, user):
        # Your custom token generation logic
        return 'your_custom_token'

# Register your custom token handler
security.token_handler = MyTokenHandler
```

**22. User Deactivation**

```python
@app.route('/deactivate')
@login_required
def deactivate():
    security.deactivate_user(current_user)
    return redirect(url_for('login'))
```

**23. User Reactivation**

```python
@app.route('/reactivate')
@login_required
def reactivate():
    security.reactivate_user(current_user)
    return redirect(url_for('home'))
```

**24. User Confirmation**

```python
# Enable user confirmation
app.config['SECURITY_CONFIRMABLE'] = True

# Customize email for user confirmation
app.config['SECURITY_CONFIRM_EMAIL_SENDER'] = 'email_sender@example.com'

# Callback for handling user confirmation
@app.route('/confirm/<token>')
def confirm(token):
    security.confirm_user(token)
    return 'Email confirmed'
```

**25. User Tracking**

```python
# Install Flask-Login-Tracker to track user activity
user_tracker = LoginTracker(app)
```

**26. Email Multi-Factor Authentication**

```python
# Enable email multi-factor authentication
app.config['SECURITY_TWO_FACTOR_ENABLED'] = True
app.config['SECURITY_TWO_FACTOR_METHODS'] = ['email']

# Callback for handling second factor authentication
@app.route('/mfa')
@login_required
def mfa():
    security.send_two_factor_email(current_user)
    return render_template('mfa.html')

@app.route('/mfa/verify', methods=['GET', 'POST'])
@login_required
def mfa_verify():
    token = request.args.get('token')
    security.verify_two_factor_token(current_user, token)
    return redirect(url_for('home'))
```

**27. reCAPTCHA Integration**

```python
# Install Flask-ReCAPTCHA to integrate reCAPTCHA
app.config['RECAPTCHA_PUBLIC_KEY'] = 'your_public_key'
app.config['RECAPTCHA_PRIVATE_KEY'] = 'your_private_key'

# Add reCAPTCHA to registration and login forms
class RegisterForm(Form):
    recaptcha = RecaptchaField()

class LoginForm(Form):
    recaptcha = RecaptchaField()
```

**28. Social Registration**

```python
# Configure social registration providers
app.config['SECURITY_SOCIAL_PROVIDERS'] = {
    'facebook': {
        'client_id': 'your_client_id',
        'client_secret': 'your_client_secret'
    },
    'google': {
        'client_id': 'your_client_id',
        'client_secret': 'your_client_secret'
    }
}

# Callback routes for social registration providers
@app.route('/social/login/facebook')
def facebook_login():
    return security.process_social_registration('facebook')

@app.route('/social/login/google')
def google_login():
    return security.process_social_registration('google')
```

**29. Social Link**

```python
# Add social link buttons to user profile
@app.route('/profile')
@login_required
def profile():
    return render_template('profile.html', social_links=security.get_social_links(current_user))
```

**30. Custom User Model**

```python
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(255), unique=True)
    password = db.Column(db.String(255))
    active = db.Column(db.Boolean())

# Register your custom user model
security.datastore.user_model = User
```

**31. Custom Role Model**

```python
class Role(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    description = db.Column(db.String(255))

# Register your custom role model
security.datastore.role_model = Role
```

**32. Custom Permission Model**

```python
class Permission(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    description = db.Column(db.String(255))

# Register your custom permission model
security.datastore.permission_model = Permission
```

**33. Custom Role Endpoint**

```python
@app.route('/roles')
@login_required
def roles():
    return render_template('roles.html', roles=security.datastore.find_all_roles())
```

**34. Custom Permission Endpoint**

```python
@app.route('/permissions')
@login_required
def permissions():
    return render_template('permissions.html', permissions=security.datastore.find_all_permissions())
```

**35. Custom User Endpoint**

```python
@app.route('/users')
@login_required
def users():
    return render_template('users.html', users=security.datastore.find_all_users())
```

**36. Custom Token Endpoint**

```python
@app.route('/tokens')
@login_required
def tokens():
    return render_template('tokens.html', tokens=security.datastore.find_all_tokens())
```