| | 1 | from django.conf import settings |
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| | 2 | from django.contrib.auth.models import User |
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| | 3 | |
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| | 4 | class LDAPBackend(object): |
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| | 5 | """ |
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| | 6 | Authenticate a user against LDAP. |
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| | 7 | Requires python-ldap to be installed. |
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| | 8 | |
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| | 9 | Requires the following things to be in settings.py: |
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| | 10 | LDAP_SERVER_URI -- string, ldap uri. |
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| | 11 | default: 'ldap://localhost' |
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| | 12 | LDAP_SEARCHDN -- string of the LDAP dn to use for searching |
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| | 13 | default: 'dc=localhost' |
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| | 14 | LDAP_SCOPE -- one of: ldap.SCOPE_*, used for searching |
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| | 15 | see python-ldap docs for the search function |
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| | 16 | default = ldap.SCOPE_SUBTREE |
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| | 17 | LDAP_SEARCH_FILTER -- formated string, the filter to use for searching for a |
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| | 18 | user. Used as: filterstr = LDAP_SEARCH_FILTER % username |
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| | 19 | default = 'cn=%s' |
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| | 20 | LDAP_UPDATE_FIELDS -- boolean, do we sync the db with ldap on each auth |
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| | 21 | default = True |
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| | 22 | |
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| | 23 | Required unless LDAP_FULL_NAME is set: |
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| | 24 | LDAP_FIRST_NAME -- string, LDAP attribute to get the given name from |
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| | 25 | LDAP_LAST_NAME -- string, LDAP attribute to get the last name from |
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| | 26 | |
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| | 27 | Optional Settings: |
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| | 28 | LDAP_FULL_NAME -- string, LDAP attribute to get name from, splits on ' ' |
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| | 29 | LDAP_GID -- string, LDAP attribute to get group name/number from |
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| | 30 | LDAP_SU_GIDS -- list of strings, group names/numbers that are superusers |
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| | 31 | LDAP_STAFF_GIDS -- list of strings, group names/numbers that are staff |
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| | 32 | LDAP_EMAIL -- string, LDAP attribute to get email from |
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| | 33 | LDAP_DEFAULT_EMAIL_SUFFIX -- string, appened to username if no email found |
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| | 34 | LDAP_OPTIONS -- hash, python-ldap global options and their values |
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| | 35 | {ldap.OPT_X_TLS_CACERTDIR: '/etc/ldap/ca/'} |
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| | 36 | |
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| | 37 | You must pick a method for determining the DN of a user and set the needed |
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| | 38 | settings: |
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| | 39 | - You can set LDAP_BINDDN and LDAP_BIND_ATTRIBUTE like: |
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| | 40 | LDAP_BINDDN = 'ou=people,dc=example,dc=com' |
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| | 41 | LDAP_BIND_ATTRIBUTE = 'uid' |
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| | 42 | and the user DN would be: |
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| | 43 | 'uid=%s,ou=people,dc=example,dc=com' % username |
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| | 44 | |
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| | 45 | - Look for the DN on the directory, this is what will happen if you do |
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| | 46 | not define the LDAP_BINDDN setting. In that case you may need to |
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| | 47 | define LDAP_PREBINDDN and LDAP_PREBINDPW if your LDAP server does not |
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| | 48 | allow anonymous queries. The search will be performed with the |
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| | 49 | LDAP_SEARCH_FILTER setting. |
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| | 50 | |
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| | 51 | - Override the _pre_bind() method, which receives the ldap object and |
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| | 52 | the username as it's parameters and should return the DN of the user. |
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| | 53 | |
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| | 54 | By inheriting this class you can change: |
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| | 55 | - How the dn to bind with is produced by overriding _pre_bind() |
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| | 56 | - What type of user object to use by overriding: _get_user_by_name(), |
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| | 57 | _create_user_object(), and get_user() |
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| | 58 | """ |
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| | 59 | |
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| | 60 | import ldap |
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| | 61 | from django.conf import settings |
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| | 62 | from django.contrib.auth.models import User |
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| | 63 | |
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| | 64 | settings = { |
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| | 65 | 'LDAP_SERVER_URI': 'ldap://localhost', |
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| | 66 | 'LDAP_SEARCHDN': 'dc=localhost', |
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| | 67 | 'LDAP_SCOPE': ldap.SCOPE_SUBTREE, |
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| | 68 | 'LDAP_SEARCH_FILTER': 'cn=%s', |
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| | 69 | 'LDAP_UPDATE_FIELDS': True, |
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| | 70 | 'LDAP_BINDDN': None, |
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| | 71 | 'LDAP_BIND_ATTRIBUTE': None, |
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| | 72 | 'LDAP_FIRST_NAME': None, |
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| | 73 | 'LDAP_LAST_NAME': None, |
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| | 74 | 'LDAP_FULL_NAME': None, |
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| | 75 | 'LDAP_GID': None, |
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| | 76 | 'LDAP_SU_GIDS': None, |
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| | 77 | 'LDAP_STAFF_GIDS': None, |
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| | 78 | 'LDAP_EMAIL': None, |
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| | 79 | 'LDAP_DEFAULT_EMAIL_SUFFIX': None, |
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| | 80 | 'LDAP_OPTIONS': None, |
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| | 81 | 'LDAP_BINDDN': None, |
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| | 82 | 'LDAP_BIND_ATTRIBUTE': None, |
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| | 83 | 'LDAP_PREBINDDN': None, |
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| | 84 | 'LDAP_PREBINDPW': None, |
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| | 85 | } |
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| | 86 | |
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| | 87 | def __init__(self): |
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| | 88 | # Load settings from settings.py, put them on self.settings |
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| | 89 | # overriding the defaults. |
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| | 90 | for var in self.settings.iterkeys(): |
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| | 91 | if hasattr(settings, var): |
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| | 92 | self.settings[var] = settings.__getattr__(var) |
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| | 93 | |
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| | 94 | def authenticate(self, username=None, password=None): |
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| | 95 | # Make sure we have a user and pass |
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| | 96 | if not username and password is not None: |
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| | 97 | return None |
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| | 98 | |
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| | 99 | if self.settings['LDAP_OPTIONS']: |
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| | 100 | for k in self.settings['LDAP_OPTIONS']: |
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| | 101 | self.ldap.set_option(k, self.settings.LDAP_OPTIONS[k]) |
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| | 102 | |
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| | 103 | l = self.ldap.initialize(self.settings['LDAP_SERVER_URI']) |
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| | 104 | |
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| | 105 | bind_string = self._pre_bind(l, username) |
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| | 106 | |
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| | 107 | try: |
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| | 108 | # Try to bind as the provided user. We leave the bind until |
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| | 109 | # the end for other ldap.search_s call to work authenticated. |
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| | 110 | l.bind_s(bind_string, password) |
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| | 111 | except (self.ldap.INVALID_CREDENTIALS, |
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| | 112 | self.ldap.UNWILLING_TO_PERFORM): |
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| | 113 | # Failed user/pass (or missing password) |
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| | 114 | l.unbind_s() |
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| | 115 | return None |
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| | 116 | |
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| | 117 | try: |
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| | 118 | user = self._get_user_by_name(username) |
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| | 119 | except User.DoesNotExist: |
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| | 120 | user = self._get_ldap_user(l, username) |
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| | 121 | |
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| | 122 | if user is not None: |
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| | 123 | if self.settings['LDAP_UPDATE_FIELDS']: |
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| | 124 | self._update_user(l, user) |
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| | 125 | |
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| | 126 | l.unbind_s() |
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| | 127 | return user |
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| | 128 | |
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| | 129 | # Functions provided to override to customize to your LDAP configuration. |
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| | 130 | def _pre_bind(self, l, username): |
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| | 131 | """ |
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| | 132 | Function that returns the dn to bind against ldap with. |
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| | 133 | called as: self._pre_bind(ldapobject, username) |
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| | 134 | """ |
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| | 135 | if not self.settings['LDAP_BINDDN']: |
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| | 136 | # When the LDAP_BINDDN setting is blank we try to find the |
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| | 137 | # dn binding anonymously or using LDAP_PREBINDDN |
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| | 138 | if self.settings['LDAP_PREBINDDN']: |
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| | 139 | try: |
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| | 140 | l.simple_bind_s(self.settings['LDAP_PREBINDDN'], |
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| | 141 | self.settings['LDAP_PREBINDPW']) |
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| | 142 | except ldap.LDAPError: |
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| | 143 | return None |
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| | 144 | |
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| | 145 | # Now do the actual search |
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| | 146 | filter = self.settings['LDAP_SEARCH_FILTER'] % username |
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| | 147 | result = l.search_s(self.settings['LDAP_SEARCHDN'], |
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| | 148 | self.settings['LDAP_SCOPE'], filter, attrsonly=1) |
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| | 149 | |
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| | 150 | if self.settings['LDAP_PREBINDDN']: |
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| | 151 | l.unbind_s() |
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| | 152 | if len(result) != 1: |
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| | 153 | return None |
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| | 154 | return result[0][0] |
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| | 155 | else: |
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| | 156 | # LDAP_BINDDN is set so we use it as a template. |
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| | 157 | return "%s=%s,%s" % (self.settings['LDAP_BIND_ATTRIBUTE'], username, |
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| | 158 | self.settings['LDAP_BINDDN']) |
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| | 159 | |
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| | 160 | def _get_user_by_name(self, username): |
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| | 161 | """ |
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| | 162 | Returns an object of contrib.auth.models.User that has a matching |
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| | 163 | username. |
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| | 164 | called as: self._get_user_by_name(username) |
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| | 165 | """ |
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| | 166 | return User.objects.get(username=username) |
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| | 167 | |
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| | 168 | def _create_user_object(self, username, password): |
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| | 169 | """ |
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| | 170 | Creates and returns an object of contrib.auth.models.User. |
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| | 171 | called as: self._create_user_object(username, password) |
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| | 172 | """ |
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| | 173 | return User(username=username, password=password) |
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| | 174 | |
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| | 175 | # Required for an authentication backend |
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| | 176 | def get_user(self, user_id): |
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| | 177 | try: |
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| | 178 | return User.objects.get(pk=user_id) |
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| | 179 | except: |
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| | 180 | return None |
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| | 181 | # End of functions to override |
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| | 182 | |
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| | 183 | def _get_ldap_user(self, l, username): |
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| | 184 | """ |
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| | 185 | Helper method, makes a user object and call update_user to populate |
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| | 186 | """ |
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| | 187 | |
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| | 188 | # Generate a random password string. |
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| | 189 | from random import choice |
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| | 190 | import string |
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| | 191 | password = ''.join([choice(string.printable) for i in range(10)]) |
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| | 192 | |
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| | 193 | user = self._create_user_object(username, password) |
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| | 194 | return user |
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| | 195 | |
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| | 196 | def _update_user(self, l, user): |
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| | 197 | """ |
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| | 198 | Helper method, populates a user object with various attributes from |
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| | 199 | LDAP. |
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| | 200 | """ |
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| | 201 | |
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| | 202 | username = user.username |
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| | 203 | filter = self.settings['LDAP_SEARCH_FILTER'] % username |
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| | 204 | |
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| | 205 | # Get results of search and make sure something was found. |
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| | 206 | # At this point this shouldn't fail. |
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| | 207 | hold = l.search_s(self.settings['LDAP_SEARCHDN'], |
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| | 208 | self.settings['LDAP_SCOPE'], filter) |
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| | 209 | if len(hold) < 1: |
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| | 210 | raise AssertionError('No results found with: %s' % (filter)) |
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| | 211 | |
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| | 212 | dn = hold[0][0] |
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| | 213 | attrs = hold[0][1] |
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| | 214 | firstn = self.settings['LDAP_FIRST_NAME'] or None |
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| | 215 | lastn = self.settings['LDAP_LAST_NAME'] or None |
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| | 216 | emailf = self.settings['LDAP_EMAIL'] or None |
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| | 217 | |
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| | 218 | if firstn: |
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| | 219 | if firstn in attrs: |
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| | 220 | user.first_name = attrs[firstn][0] |
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| | 221 | else: |
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| | 222 | raise NameError('Missing attribute: %s in result for %s' |
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| | 223 | % (firstn, dn)) |
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| | 224 | if lastn: |
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| | 225 | if lastn in attrs: |
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| | 226 | user.last_name = attrs[lastn][0] |
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| | 227 | else: |
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| | 228 | raise NameError('Missing attribute: %s in result for %s' |
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| | 229 | % (lastn, dn)) |
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| | 230 | if not firstn and not lastn and self.settings['LDAP_FULL_NAME']: |
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| | 231 | fulln = self.settings['LDAP_FULL_NAME'] |
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| | 232 | if fulln in attrs: |
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| | 233 | tmp = attrs[fulln][0] |
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| | 234 | user.first_name = tmp.split(' ')[0] |
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| | 235 | user.last_name = ' '.join(tmp.split(' ')[1:]) |
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| | 236 | else: |
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| | 237 | raise NameError('Missing attribute: %s in result for %s' |
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| | 238 | % (fulln, dn)) |
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| | 239 | |
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| | 240 | if emailf and emailf in attrs: |
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| | 241 | user.email = attrs[emailf][0] |
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| | 242 | elif self.settings['LDAP_DEFAULT_EMAIL_SUFFIX']: |
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| | 243 | user.email = username + self.settings['LDAP_DEFAULT_EMAIL_SUFFIX'] |
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| | 244 | |
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| | 245 | if (hasattr(settings, 'LDAP_GID') |
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| | 246 | and settings.LDAP_GID in attrs |
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| | 247 | and hasattr(settings, 'LDAP_SU_GIDS') |
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| | 248 | and attrs[settings.LDAP_GID][0] in settings.LDAP_SU_GIDS): |
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| | 249 | user.is_superuser = True |
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| | 250 | user.is_staff = True |
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| | 251 | elif (hasattr(settings, 'LDAP_GID') |
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| | 252 | and settings.LDAP_GID in attrs |
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| | 253 | and hasattr(settings, 'LDAP_STAFF_GIDS') |
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| | 254 | and attrs[settings.LDAP_GID][0] in settings.LDAP_STAFF_GIDS): |
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| | 255 | user.is_superuser = False |
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| | 256 | user.is_staff = True |
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| | 257 | else: |
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| | 258 | user.is_superuser = False |
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| | 259 | user.is_staff = False |
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| | 260 | |
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| | 261 | user.save() |
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| | 262 | |