drakken.model module

ORM module.

Warning

SQLAlchemy doesn’t escape raw SQl so to prevent SQL injection attacks always use the ORM.

class drakken.model.Base(**kwargs: Any)

Bases: DeclarativeBase

metadata: ClassVar[MetaData] = MetaData()

Refers to the _schema.MetaData collection that will be used for new _schema.Table objects.

See also

orm_declarative_metadata

registry: ClassVar[_RegistryType] = <sqlalchemy.orm.decl_api.registry object>

Refers to the _orm.registry in use where new _orm.Mapper objects will be associated.

class drakken.model.RateLimit(**kwargs)

Bases: Base

Email rate limit table.

count

id

name

start_time

class drakken.model.Session(**kwargs)

Bases: Base

Session table.

csrf_token

date_created

ip_address

session_token

user

user_agent

user_id

class drakken.model.User(**kwargs)

Bases: Base

User account table.

active

date_joined

email

id

last_login

pwhash

salt

drakken.model.authenticate(**kwargs)

Authenticate user.

Parameters:

• username (str) – user name.

• email (str) – email address.

• password (str) – password.

Raises:

AuthenticateFail – username/email and password don’t match the database.

drakken.model.create_user(email, password, username='')

Create a user.

Parameters:

• email (str) – must be unique if not using a username.

• password (str) – must be within MIN_PASSWORD_LENGTH and

• MAX_PASSWORD_LENGTH.

• username (str) – must be unique. Optional.

Note

The password hashing algorithm is deliberately computationally expensive to slow down hackers. Very long passwords can take so long to compute they can be used in a denial of service attack per OWASP. Which is why we check for too long passwords.

Raises:

• EmailAddressTaken – email address is already in the database.

• PasswordLength – password is too long or too short.

• UserNameTaken – user name is already in the database.

drakken.model.get_session(request)

Return session object.

Parameters:

request (drakken.message.Request) – Request object.

Raises:

• LoginFail – session ID is missing or not in database, request user

• agent doesn't match session user agent, or session has expired. –

drakken.model.login(**kwargs)

Login user and set response cookie.

Parameters:

• username (str) – user name.

• email (str) – email address.

• password (str) – password.

• request (message.Request) – Request object.

• response (message.Response) – Response object.

drakken.model.login_required(func=None, redirect=True)

Validate session token in cookie.

Use as a decorator.

Parameters:

• request (message.Request) – Request object.

• response (message.Response) – Response object.

• kwargs (dict) – URL keyword arguments.

Raises:

• HTTPRedirect – redirect to config.LOGIN_URL if set and redirect == True.

• LoginFail – if config.LOGIN_URL not set or redirect == False.

drakken.model.logout(request, response)

Log out user, delete session and cookie.

Parameters:

• request (message.Request) – Request object.

• response (message.Response) – Response object.

drakken.model.session_scope()

Context manager for database operations.

Automatically handles database commit, rollback, and close. Taken from SQLAlchemy docs.

Example:

from drakken.model import session_scope, User
from drakken.security import gensalt, slow_hash

email = 'stuart@gmail.com'
password = 'FoundInTheSwamp'
salt = gensalt()
hashed = security.slow_hash(password, salt)

with session_scope() as session:
    user = User(email=email, pwhash=hashed, salt=salt)
    session.add(user)

drakken.model.setup()

Configure database, creating tables if needed.

drakken.model.update_password(userid, password)

Change password for user.

Parameters:

• userid (int) – user ID.

• password (str) – new password.

drakken.model.validate_CSRF(request)

Return CSRF token if valid.

Parameters:

request (drakken.message.Request) – Request object.

Raises:

• CSRFTokenFail – CSRF token not found in session database.

• LoginFail – user agent mismatch, or session expired.