ImproperlyConfigured: hasher not found: django_sha2.hashers.bcrypt2012_06_01

[fwenzel]

ImproperlyConfigured: hasher not found: django_sha2.hashers.bcrypt2012_06_01

[fwenzel]

@tallowen wrote some code to dynamically generate hashers for HMAC/Bcrypt, there might be something broken there.

[tallowen]

Give me a day - i'll look into this tomorrow

On Wed, Jun 6, 2012 at 3:16 PM, Fred Wenzel <
[email protected]

wrote:

@tallowen wrote some code to dynamically generate hashers for HMAC/Bcrypt,
there might be something broken there.

---

Reply to this email directly or view it on GitHub:
#14 (comment)

Owen Coutts
University of Waterloo

Email: [email protected]
Phone: [phone]

[kumar303]

fwiw I only saw this when upgrading an old app to the new Playdoh. I did not see this error when configuring the latest Playdoh out of the box.

[tallowen]

Hmm. For some reason the password hasher isn't being created. Its created dynamically at import time - it creates one per hmac_key in the settings. This probably means that django_sha2 isn't seeing the hmac_keys properly but I'm not sure why that would be the case.

[talebbits]

To produce:

1. Create new project
2. run syncdb
3. add superusers

Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "***/lib/python2.7/site-packages/django/core/management/__init__.py", line 443, in execute_from_command_line
    utility.execute()
  File "***/lib/python2.7/site-packages/django/core/management/__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 196, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 371, in handle
    return self.handle_noargs(**options)
  File "***/lib/python2.7/site-packages/south/management/commands/syncdb.py", line 90, in handle_noargs
    syncdb.Command().execute(**options)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 371, in handle
    return self.handle_noargs(**options)
  File "***/lib/python2.7/site-packages/django/core/management/commands/syncdb.py", line 110, in handle_noargs
    emit_post_sync_signal(created_models, verbosity, interactive, db)
  File "***/lib/python2.7/site-packages/django/core/management/sql.py", line 189, in emit_post_sync_signal
    interactive=interactive, db=db)
  File "***/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 172, in send
    response = receiver(signal=self, sender=sender, **named)
  File "***/lib/python2.7/site-packages/django/contrib/auth/management/__init__.py", line 73, in create_superuser
    call_command("createsuperuser", interactive=True, database=db)
  File "***/lib/python2.7/site-packages/django/core/management/__init__.py", line 150, in call_command
    return klass.execute(*args, **defaults)
  File "***/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "***/lib/python2.7/site-packages/django/contrib/auth/management/commands/createsuperuser.py", line 124, in handle
    User.objects.db_manager(database).create_superuser(username, email, password)
  File "***/lib/python2.7/site-packages/django/contrib/auth/models.py", line 164, in create_superuser
    u = self.create_user(username, email, password)
  File "***/lib/python2.7/site-packages/django/contrib/auth/models.py", line 159, in create_user
    user.set_password(password)
  File "***/lib/python2.7/site-packages/django/contrib/auth/models.py", line 294, in set_password
    self.password = make_password(raw_password)
  File "***/lib/python2.7/site-packages/django/contrib/auth/hashers.py", line 62, in make_password
    hasher = get_hasher(hasher)
  File "***/lib/python2.7/site-packages/django/contrib/auth/hashers.py", line 107, in get_hasher
    load_hashers()
  File "***/lib/python2.7/site-packages/django/contrib/auth/hashers.py", line 84, in load_hashers
    raise ImproperlyConfigured("hasher not found: %s" % backend)
django.core.exceptions.ImproperlyConfigured: hasher not found: django_sha2.hashers.bcrypt2011_01_01

[l-hedgehog]

Looks like this error can be fixed by merge this change mozilla/playdoh@abafbf0 into older settings/local.py

[kumar303]

if you put that in settings/local.py then you've disabled the HMAC key (since it's commented out). I also got it working that way but for an app I knew I didn't need bcrypt for since it didn't work with users.

[fwenzel]

Did you guys narrow this down yet? Looks like the dynamic generation of hashers is not run, perhaps?

[mindcruzer]

If you look at hashers.py in django.contrib.auth the code that would import the dynamically generated password hasher looks like this:

# django.contrib.auth.hashers
...
try:
    mod_path, cls_name = backend.rsplit('.', 1)
    mod = importlib.import_module(mod_path)  
    hasher_cls = getattr(mod, cls_name) 
except (AttributeError, ImportError, ValueError):
    raise ImproperlyConfigured("hasher not found: %s" % backend)
...

The key here is that it's catching ImportError, but which import error?

# django_sha2.hashers

import base64
import hmac
import hashlib
import logging

import bcrypt

from django.conf import settings
from django.contrib.auth.hashers import (BCryptPasswordHasher,
                                         BasePasswordHasher, mask_hash)
from django.utils.crypto import constant_time_compare
from django.utils.encoding import smart_str
from django.utils.datastructures import SortedDict
...

The odd one out is bcrypt, so my guess would be that this error is just occurring because py-bcrypt hasn't been installed. Sure enough, this is what was causing the error for me. This also explains why commenting out the HMAC_KEYS makes the whole thing work. If there are no HMAC_KEYS, django_sha2.hashers never gets executed, and thus there is no ImportError raised. Maybe add a reminder in the docs to install py-bcrypt.

[kumar303]

Catching any and all import errors here is confusing

[kumar303]

Everytime I hit this I have to google for this issue to remember how to fix it :( Dear future self, in summary, here's what to check:

• Does import bcrypt succeed in your environment?
• Is HMAC_KEYS defined and is it not an empty dict?
• In the exact settings file you define HMAC_KEYS are you also calling get_password_hashers(...) underneath it?

[groovecoder]

fwiw, I hit this error when HMAC_KEYS was empty.

[gene1wood]

This error occurred for me with an empty and a populated HMAC_KEYS. I did what @kumar303 suggested and ran import bcrypt which errored out. I then installed bcrypt on Ubuntu with

sudo apt-get install python-bcrypt

So which package is it that needs to have this dependency added to it's dependency list? Is this a Django issue or a Playdoh issue? (or something else)