*(minor): small refactor

passbook/policies/hibp/models.py

@@ -0,0 +1,46 @@
+"""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()
+
+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.policies.hibp.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')