authentik/passbook/hibp_policy/models.py

"""passbook HIBP Models"""
from hashlib import sha1

from django.db import models
from django.utils.translation import gettext as _
from requests import get
from structlog import get_logger

from passbook.core.models import Policy, PolicyResult, User

LOGGER = get_logger(__name__)

class HaveIBeenPwendPolicy(Policy):
    """Check if password is on HaveIBeenPwned's list by upload the first
    5 characters of the SHA1 Hash."""

    allowed_count = models.IntegerField(default=0)

    form = 'passbook.hibp_policy.forms.HaveIBeenPwnedPolicyForm'

    def passes(self, user: User) -> PolicyResult:
        """Check if password is in HIBP DB. Hashes given Password with SHA1, uses the first 5
        characters of Password in request and checks if full hash is in response. Returns 0
        if Password is not in result otherwise the count of how many times it was used."""
        # Only check if password is being set
        if not hasattr(user, '__password__'):
            return PolicyResult(True)
        password = getattr(user, '__password__')
        pw_hash = sha1(password.encode('utf-8')).hexdigest() # nosec
        url = 'https://api.pwnedpasswords.com/range/%s' % pw_hash[:5]
        result = get(url).text
        final_count = 0
        for line in result.split('\r\n'):
            full_hash, count = line.split(':')
            if pw_hash[5:] == full_hash.lower():
                final_count = int(count)
        LOGGER.debug("Got count %d for hash %s", final_count, pw_hash[:5])
        if final_count > self.allowed_count:
            message = _("Password exists on %(count)d online lists." % {'count': final_count})
            return PolicyResult(False, message)
        return PolicyResult(True)

    class Meta:

        verbose_name = _('Have I Been Pwned Policy')
        verbose_name_plural = _('Have I Been Pwned Policies')