Django Auth LDAP - Direct Bind using sAMAccountName

Question

There are two ways to authenticate a user using Django Auth LDAP

1. Search/Bind and
2. Direct Bind.

The first one involves connecting to the LDAP server either anonymously or with a fixed account and searching for the distinguished name of the authenticating user. Then we can attempt to bind again with the user’s password.

The second method is to derive the user’s DN from his username and attempt to bind as the user directly.

I want to be able to do a direct bind using the userid (sAMAccountName) and password of the user who is trying to gain access to the application. Please let me know if there is a way to achieve this? At the moment, I cannot seem to make this work due to the problem explained below.

In my case, the DN of users in LDAP is of the following format

**'CN=Steven Jones,OU=Users,OU=Central,OU=US,DC=client,DC=corp'**

This basically translates to 'CN=FirstName LastName,OU=Users,OU=Central,OU=US,DC=client,DC=corp'

This is preventing me from using Direct Bind as the sAMAccountName of the user is sjones and this is the parameter that corresponds to the user name (%user) and I can't figure out a way to frame a proper AUTH_LDAP_USER_DN_TEMPLATE to derive the User's DN using.

Due to the above explained problem, I am using Search/Bind for now but this requires me to have a fixed user credential to be specified in AUTH_LDAP_BIND_DN and AUTH_LDAP_BIND_PASSWORD.

Here is my current settings.py configuration

AUTH_LDAP_SERVER_URI = "ldap://10.5.120.161:389"
AUTH_LDAP_BIND_DN='CN=Steven Jones,OU=Users,OU=Central,OU=US,DC=client,DC=corp'
AUTH_LDAP_BIND_PASSWORD='fga.1234'
#AUTH_LDAP_USER_DN_TEMPLATE = 'CN=%(user)s,OU=Appl Groups,OU=Central,OU=US,DC=client,DC=corp'
AUTH_LDAP_USER_SEARCH = LDAPSearchUnion(
    LDAPSearch("OU=Users, OU=Central,OU=US,DC=client,DC=corp",ldap.SCOPE_SUBTREE, "(sAMAccountName=%(user)s)"),
    LDAPSearch("OU=Users,OU=Regional,OU=Locales,OU=US,DC=client,DC=corp",ldap.SCOPE_SUBTREE, "(sAMAccountName=%(user)s)"),
    )
AUTH_LDAP_USER_ATTR_MAP = {"first_name": "givenName", "last_name": "sn","email":"mail"}
AUTH_LDAP_GROUP_SEARCH = LDAPSearch("CN=GG_BusinessApp_US,OU=Appl Groups,OU=Central,OU=US,DC=client,DC=corp",ldap.SCOPE_SUBTREE, "(objectClass=groupOfNames)")
AUTH_LDAP_GROUP_TYPE = GroupOfNamesType()
AUTH_LDAP_REQUIRE_GROUP = 'CN=GG_BusinessApp_US,OU=Appl Groups,OU=Central,OU=US,DC=client,DC=corp'

Looking forward for some guidance from the wonderful folks in here.

Answer 1

I had the same issue.

I ran across ticket 21 in the now-deleted bitbucket repository. (cant-bind-and-search-on-activedirectory). The issues were not migrated to their github, but the author brought up a way to change the library files for django-auth-ldap so that it could do a direct bind.

It came down to changing <python library path>/django_auth_ldap/backend.py to include two lines in _authenticate_user_dn:

if sticky and ldap_settings.AUTH_LDAP_USER_SEARCH:
    self._search_for_user_dn()

I was able to get this to work on my local machine that was running Arch Linux 3.9.8-1-ARCH, but I was unable to replicate it on the dev server running Ubuntu 13.04.

Hopefully this can help.

Answer 2

(This is actually a comment to @amethystdragon's answer, but it's a bunch of code, so posting as a separate answer.) The problem still seems to exist with django_auth_ldap 1.2.5. Here's an updated patch. If you don't want or can't modify the source code, monkey-patching is possible. Just put this code to eg. end of settings.py. (And yes, I know monkey-patching is ugly.)

import ldap
from django_auth_ldap import backend

def monkey(self, password):
  """
  Binds to the LDAP server with the user's DN and password. Raises
  AuthenticationFailed on failure.
  """
  if self.dn is None:
    raise self.AuthenticationFailed("failed to map the username to a DN.")

  try:
    sticky = self.settings.BIND_AS_AUTHENTICATING_USER

    self._bind_as(self.dn, password, sticky=sticky)

    #### The fix -->
    if sticky and self.settings.USER_SEARCH:
      self._search_for_user_dn()
    #### <-- The fix

  except ldap.INVALID_CREDENTIALS:
    raise self.AuthenticationFailed("user DN/password rejected by LDAP server.")

backend._LDAPUser._authenticate_user_dn = monkey

Answer 3

I also had this issue, but I didn't want to modify the settings.py file. The fix for me was to comment out the line "AUTH_LDAP_USER_DN_TEMPLATE = "uid=%(user)s,ou=path,dc=to,dc=domain"". I also added NestedActiveDirectoryGroupType as part of my troubleshooting. Not sure if it's necessary, but it's working now so I'm leaving it. Here's my ldap_config.py file.

import ldap

# Server URI
AUTH_LDAP_SERVER_URI = "ldap://urlForLdap"

# The following may be needed if you are binding to Active Directory.
AUTH_LDAP_CONNECTION_OPTIONS = {
       # ldap.OPT_DEBUG_LEVEL: 1,
    ldap.OPT_REFERRALS: 0
}

# Set the DN and password for the NetBox service account.
AUTH_LDAP_BIND_DN = "CN=Netbox,OU=xxx,DC=xxx,DC=xxx"
AUTH_LDAP_BIND_PASSWORD = "password"

# Include this setting if you want to ignore certificate errors. This might be needed to accept a self-signed cert.
# Note that this is a NetBox-specific setting which sets:
#     ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, ldap.OPT_X_TLS_NEVER)
LDAP_IGNORE_CERT_ERRORS = True

from django_auth_ldap.config import LDAPSearch, NestedActiveDirectoryGroupType

# This search matches users with the sAMAccountName equal to the provided username. This is required if the user's
# username is not in their DN (Active Directory).
AUTH_LDAP_USER_SEARCH = LDAPSearch("OU=xxx,DC=xxx,DC=xxx",
                                    ldap.SCOPE_SUBTREE,
                                    "(sAMAccountName=%(user)s)")

# If a user's DN is producible from their username, we don't need to search.
# AUTH_LDAP_USER_DN_TEMPLATE = "uid=%(user)s,ou=users,dc=corp,dc=loc"

# You can map user attributes to Django attributes as so.
AUTH_LDAP_USER_ATTR_MAP = {
    "first_name": "givenName",
    "last_name": "sn",
    "email": "mail"
}

from django_auth_ldap.config import LDAPSearch, GroupOfNamesType, NestedActiveDirectoryGroupType

# This search ought to return all groups to which the user belongs. django_auth_ldap uses this to determine group
# heirarchy.
AUTH_LDAP_GROUP_SEARCH = LDAPSearch("dc=xxx,dc=xxx", ldap.SCOPE_SUBTREE,
                                    "(objectClass=group)")
AUTH_LDAP_GROUP_TYPE = NestedActiveDirectoryGroupType()

# Define a group required to login.
AUTH_LDAP_REQUIRE_GROUP = "CN=NetBox_Users,OU=NetBox,OU=xxx,DC=xxx,DC=xxx"

# Define special user types using groups. Exercise great caution when assigning superuser status.
AUTH_LDAP_USER_FLAGS_BY_GROUP = {
    "is_active": "CN=NetBox_Active,OU=NetBox,OU=xxx,DC=xxx,DC=xxx",
    "is_staff": "CN=NetBox_Staff,OU=NetBox,OU=xxx,DC=xxx,DC=xxx",
    "is_superuser": "CN=NetBox_Superuser,OU=NetBox,OU=xxx,DC=xxx,DC=xxx"
}

# For more granular permissions, we can map LDAP groups to Django groups.
AUTH_LDAP_FIND_GROUP_PERMS = True

# Cache groups for one hour to reduce LDAP traffic
AUTH_LDAP_CACHE_GROUPS = True
AUTH_LDAP_GROUP_CACHE_TIMEOUT = 3600