Database Utility Module
import sqlite3 import click import re # Much from https://flask.palletsprojects.com/en/3.0.x/tutorial/database/ from flask import current_app, g # Apparently g is a sort of a general per-request bucket, so that # multiple parallel requests won't collide. # Initializes the connection and stores it in g. def get_db(): if 'db' not in g: g.db = sqlite3.connect( current_app.config['DATABASE'], detect_types=sqlite3.PARSE_DECLTYPES ) return g.db # Close and remove from g. def close_db(e=None): db = g.pop('db', None) if db is not None: db.close() # This iniitalizes the database. Will empty our table if called. def init_db(): db = get_db() with current_app.open_resource('schema.sql') as f: db.executescript(f.read().decode('utf8')) # The click doesn't really accompish anything here. Useful for getting # command line args, and for fancy CLI interfaces, but this ain't that. @click.command('init-db') def init_db_command(): """Clear the existing data and create new tables.""" init_db() click.echo('Initialized the database.') # Patterns to check for classes of characters. Got to be a better # way to do this. let_pat = re.compile("[A-Za-z]") dig_pat = re.compile("[0-9]") special_pat = re.compile("[~!@#$%^&*()_+=:;<>.,{}\[\]\"\'-]") from werkzeug.security import generate_password_hash, check_password_hash # Check a password against the security rules. If password2 is sent, # also verify that they match. Returns an error message, or None if # no error def vet_new_passwd(userid, passwd, passwd2=None): if passwd2 != None and passwd != passwd2: return "Passwords do not match." if len(passwd) < 6: return "Password is too short (need 6)" if bool(let_pat.search(passwd)) + bool(dig_pat.search(passwd)) + \ bool(special_pat.search(passwd)) < 2: return "Password needs at least two of letters, digits, special" return None # Set the password of an existing user. def set_passwd(userid, passwd, passwd2=None): err = vet_new_passwd(userid, passwd, passwd2) if err != None: return err db = get_db() try: t = db.execute("UPDATE users SET password = ? WHERE userid = ?", (generate_password_hash(passwd), userid)) rc = t.rowcount db.commit() if rc < 1: return f"No such user {userid}" except db.DatabaseError as error: return f"User {userid} password store failed: " + \ error.sqlite_errorname return None # Vet a password for a user. Return (success, msg), where # success is a boolean success, and msg is an error message, or # human name. def vet_passwd(userid, passwd): db = get_db() p = db.execute("SELECT username, password FROM users WHERE userid = ?", \ (userid,)).fetchone() if p == None: return (False, f"No such user {userid}") if p[1] == None: return (False, f"User {userid} has no password set") if not check_password_hash(p[1], passwd): return (False, f"Incorrect password for {userid}") return (True, p[0]) # RE for allowable username. At least six characters, starts with # a letter, ends with a letter or digit, and can have a few other # characters internally. user_pat = re.compile('^[a-zA-Z][a-zA-Z0-9_:.-]*[a-zA-Z0-9]$') # Insert a user into the database. If a password is sent, it is vetted # and inserted. If two are sent, vetting includes making sure they match. def add_user(userid, username, passwd = None, passwd2 = None): # Vet the userid. if user_pat.match(userid) is None: return f"User {userid} too short (< 2), or "+\ "contains forbidden characters." # Vet the passwd(s) if passwd != None: err = vet_new_passwd(userid, passwd, passwd2) if err != None: return err # Create the record. db = get_db() try: db.execute("INSERT INTO users (userid, username, password) "+ "VALUES (?, ?, ?)", (userid, username, None if passwd == None else generate_password_hash(passwd))) db.commit() except db.IntegrityError: return f"User {userid} is already registered." return None @click.command('add-user') @click.option('--userid', prompt='Account name') @click.option('--name', prompt='Human name') def add_user_cmd(userid, name): """Add indicated user""" r = add_user(userid,name) if r is None: click.echo(f"User {userid} ({name}) added") else: click.echo(r) @click.command('set-passwd') @click.option('--userid', prompt='Account name') @click.password_option() def set_passwd_cmd(userid, password): """Set password for specified user""" r = set_passwd(userid,password) if r is None: click.echo(f"User {userid} password set") else: click.echo(r) # This is to be called by the factory. It adds the operations to the # context to be called automatically. def init_app(app): app.teardown_appcontext(close_db) app.cli.add_command(init_db_command) app.cli.add_command(add_user_cmd) app.cli.add_command(set_passwd_cmd)