Password Validators

validators.py

"""
# Password validation
# https://docs.djangoproject.com/en/5.2/ref/settings/#auth-password-validators

# Your password can’t be too similar to your other personal information.
# Your password must contain at least 10 characters.
# Your password can’t be a commonly used password.
# Your password can’t be entirely numeric.
# Your password must contain at least 1 symbol: ()[]{}|\`~!@#$%^&*_-+=;:'",<>./?
# Your password must contain at least 1 number, 0-9.
# Your password cannot be expired
# Your new password cannot be a previous password.

Set this in your settings.py:

AUTH_PASSWORD_VALIDATORS = [
    {
        "NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
        "OPTIONS": {
            "min_length": 10,
        },
    },
    {
        "NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",
    },
    {
        "NAME": "core.validators.SymbolValidator",
    },
    {
        "NAME": "core.validators.NumberValidator",
    },
    {
        "NAME": "core.validators.PreviousPasswordsValidator",
    },
]

"""


import re
from django.core.exceptions import ValidationError
from django.contrib.auth.hashers import check_password
from django.utils.translation import gettext_lazy as _

from authentication.models import UserPasswordLog

class SymbolValidator:
    """ Validates presence of symbol in password """
    def __init__(self) -> None:
        return

    def validate(self, password, user=None):
        if not re.findall('[()[\]{}|\\`~!@#$%^&*_\-+=;:\'",<>./?]', password):
            raise ValidationError(
                _("The password must contain at least 1 symbol: " +
                  "()[]{}|\`~!@#$%^&*_-+=;:'\",<>./?"),
                code='password_no_symbol',
            )

    def get_help_text(self):
        return _(
            "Your password must contain at least 1 symbol: " +
            "()[]{}|\`~!@#$%^&*_-+=;:'\",<>./?"
        )

class NumberValidator:
    """ Validates presence of number in password """
    def validate(self, password, user=None):
        if not re.findall('\d', password):
            raise ValidationError(
                _("Your password must contain at least 1 number, 0-9."),
                code='password_no_number',
            )

    def get_help_text(self):
        return _(
            "Your password must contain at least 1 number, 0-9."
        )

class PreviousPasswordsValidator:
    """ Validates password is not a previously used one """
    def validate(self, password, user):
        limit = 4

        if limit is not None and limit != 0:
            previous_passwords = []
            last_used = UserPasswordLog.objects.filter(user=user).order_by('-created')[:limit]

            # Delete old password logs
            UserPasswordLog.objects.filter(user=user).exclude(pk__in=last_used).delete()

            for password_log in last_used:
                previous_passwords.append(password_log.password)

            for previous_password in previous_passwords:
                match = check_password(password, previous_password)
                if match:
                    raise ValidationError(
                    _(f"You cannot reuse one of your previous {limit} passwords."),
                    code='password_previously_used',
                )

    def get_help_text(self):
        return _(
            "You cannot reuse a previously used password."
        )