from __future__ import unicode_literals
import gzip
import os
import re
from difflib import SequenceMatcher
from django.conf import settings
from django.core.exceptions import (
FieldDoesNotExist, ImproperlyConfigured, ValidationError,
)
from django.utils import lru_cache
from django.utils._os import upath
from django.utils.encoding import force_text
from django.utils.functional import lazy
from django.utils.html import format_html
from django.utils.module_loading import import_string
from django.utils.six import string_types, text_type
from django.utils.translation import ugettext as _, ungettext
@lru_cache.lru_cache(maxsize=None)
def get_default_password_validators():
return get_password_validators(settings.AUTH_PASSWORD_VALIDATORS)
[docs]def get_password_validators(validator_config):
validators = []
for validator in validator_config:
try:
klass = import_string(validator['NAME'])
except ImportError:
msg = "The module in NAME could not be imported: %s. Check your AUTH_PASSWORD_VALIDATORS setting."
raise ImproperlyConfigured(msg % validator['NAME'])
validators.append(klass(**validator.get('OPTIONS', {})))
return validators
[docs]def validate_password(password, user=None, password_validators=None):
"""
Validate whether the password meets all validator requirements.
If the password is valid, return ``None``.
If the password is invalid, raise ValidationError with all error messages.
"""
errors = []
if password_validators is None:
password_validators = get_default_password_validators()
for validator in password_validators:
try:
validator.validate(password, user)
except ValidationError as error:
errors.append(error)
if errors:
raise ValidationError(errors)
[docs]def password_changed(password, user=None, password_validators=None):
"""
Inform all validators that have implemented a password_changed() method
that the password has been changed.
"""
if password_validators is None:
password_validators = get_default_password_validators()
for validator in password_validators:
password_changed = getattr(validator, 'password_changed', lambda *a: None)
password_changed(password, user)
[docs]def password_validators_help_texts(password_validators=None):
"""
Return a list of all help texts of all configured validators.
"""
help_texts = []
if password_validators is None:
password_validators = get_default_password_validators()
for validator in password_validators:
help_texts.append(validator.get_help_text())
return help_texts
def _password_validators_help_text_html(password_validators=None):
"""
Return an HTML string with all help texts of all configured validators
in an <ul>.
"""
help_texts = password_validators_help_texts(password_validators)
help_items = [format_html('<li>{}</li>', help_text) for help_text in help_texts]
return '<ul>%s</ul>' % ''.join(help_items) if help_items else ''
password_validators_help_text_html = lazy(_password_validators_help_text_html, text_type)
[docs]class MinimumLengthValidator(object):
"""
Validate whether the password is of a minimum length.
"""
def __init__(self, min_length=8):
self.min_length = min_length
def validate(self, password, user=None):
if len(password) < self.min_length:
raise ValidationError(
ungettext(
"This password is too short. It must contain at least %(min_length)d character.",
"This password is too short. It must contain at least %(min_length)d characters.",
self.min_length
),
code='password_too_short',
params={'min_length': self.min_length},
)
def get_help_text(self):
return ungettext(
"Your password must contain at least %(min_length)d character.",
"Your password must contain at least %(min_length)d characters.",
self.min_length
) % {'min_length': self.min_length}
[docs]class UserAttributeSimilarityValidator(object):
"""
Validate whether the password is sufficiently different from the user's
attributes.
If no specific attributes are provided, look at a sensible list of
defaults. Attributes that don't exist are ignored. Comparison is made to
not only the full attribute value, but also its components, so that, for
example, a password is validated against either part of an email address,
as well as the full address.
"""
DEFAULT_USER_ATTRIBUTES = ('username', 'first_name', 'last_name', 'email')
def __init__(self, user_attributes=DEFAULT_USER_ATTRIBUTES, max_similarity=0.7):
self.user_attributes = user_attributes
self.max_similarity = max_similarity
def validate(self, password, user=None):
if not user:
return
for attribute_name in self.user_attributes:
value = getattr(user, attribute_name, None)
if not value or not isinstance(value, string_types):
continue
value_parts = re.split(r'\W+', value) + [value]
for value_part in value_parts:
if SequenceMatcher(a=password.lower(), b=value_part.lower()).quick_ratio() >= self.max_similarity:
try:
verbose_name = force_text(user._meta.get_field(attribute_name).verbose_name)
except FieldDoesNotExist:
verbose_name = attribute_name
raise ValidationError(
_("The password is too similar to the %(verbose_name)s."),
code='password_too_similar',
params={'verbose_name': verbose_name},
)
def get_help_text(self):
return _("Your password can't be too similar to your other personal information.")
[docs]class CommonPasswordValidator(object):
"""
Validate whether the password is a common password.
The password is rejected if it occurs in a provided list, which may be gzipped.
The list Django ships with contains 1000 common passwords, created by Mark Burnett:
https://xato.net/passwords/more-top-worst-passwords/
"""
DEFAULT_PASSWORD_LIST_PATH = os.path.join(
os.path.dirname(os.path.realpath(upath(__file__))), 'common-passwords.txt.gz'
)
def __init__(self, password_list_path=DEFAULT_PASSWORD_LIST_PATH):
try:
with gzip.open(password_list_path) as f:
common_passwords_lines = f.read().decode('utf-8').splitlines()
except IOError:
with open(password_list_path) as f:
common_passwords_lines = f.readlines()
self.passwords = {p.strip() for p in common_passwords_lines}
def validate(self, password, user=None):
if password.lower().strip() in self.passwords:
raise ValidationError(
_("This password is too common."),
code='password_too_common',
)
def get_help_text(self):
return _("Your password can't be a commonly used password.")
[docs]class NumericPasswordValidator(object):
"""
Validate whether the password is alphanumeric.
"""
def validate(self, password, user=None):
if password.isdigit():
raise ValidationError(
_("This password is entirely numeric."),
code='password_entirely_numeric',
)
def get_help_text(self):
return _("Your password can't be entirely numeric.")
Jun 14, 2020