ldap: changed plugin to help with debugging and error handling.

- mostly based from support.

rhodecode/authentication/plugins/auth_ldap.py

@@ -1,535 +1,551 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2010-2019 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 """
 RhodeCode authentication plugin for LDAP
 """
 
 import logging
 import traceback
 
 import colander
 from rhodecode.translation import _
 from rhodecode.authentication.base import (
     RhodeCodeExternalAuthPlugin, AuthLdapBase, hybrid_property)
 from rhodecode.authentication.schema import AuthnPluginSettingsSchemaBase
 from rhodecode.authentication.routes import AuthnPluginResourceBase
 from rhodecode.lib.colander_utils import strip_whitespace
 from rhodecode.lib.exceptions import (
     LdapConnectionError, LdapUsernameError, LdapPasswordError, LdapImportError
 )
 from rhodecode.lib.utils2 import safe_unicode, safe_str
 from rhodecode.model.db import User
 from rhodecode.model.validators import Missing
 
 log = logging.getLogger(__name__)
 
 try:
     import ldap
 except ImportError:
     # means that python-ldap is not installed, we use Missing object to mark
     # ldap lib is Missing
     ldap = Missing
 
 
 class LdapError(Exception):
     pass
 
 
 def plugin_factory(plugin_id, *args, **kwargs):
     """
     Factory function that is called during plugin discovery.
     It returns the plugin instance.
     """
     plugin = RhodeCodeAuthPlugin(plugin_id)
     return plugin
 
 
 class LdapAuthnResource(AuthnPluginResourceBase):
     pass
 
 
 class AuthLdap(AuthLdapBase):
     default_tls_cert_dir = '/etc/openldap/cacerts'
 
+    scope_labels = {
+        ldap.SCOPE_BASE: 'SCOPE_BASE',
+        ldap.SCOPE_ONELEVEL: 'SCOPE_ONELEVEL',
+        ldap.SCOPE_SUBTREE: 'SCOPE_SUBTREE',
+    }
+
     def __init__(self, server, base_dn, port=389, bind_dn='', bind_pass='',
                  tls_kind='PLAIN', tls_reqcert='DEMAND', tls_cert_file=None,
                  tls_cert_dir=None, ldap_version=3,
                  search_scope='SUBTREE', attr_login='uid',
                  ldap_filter='', timeout=None):
         if ldap == Missing:
             raise LdapImportError("Missing or incompatible ldap library")
 
         self.debug = False
         self.timeout = timeout or 60 * 5
         self.ldap_version = ldap_version
         self.ldap_server_type = 'ldap'
 
         self.TLS_KIND = tls_kind
 
         if self.TLS_KIND == 'LDAPS':
             port = port or 636
             self.ldap_server_type += 's'
 
         OPT_X_TLS_DEMAND = 2
         self.TLS_REQCERT = getattr(ldap, 'OPT_X_TLS_%s' % tls_reqcert, OPT_X_TLS_DEMAND)
         self.TLS_CERT_FILE = tls_cert_file or ''
         self.TLS_CERT_DIR = tls_cert_dir or self.default_tls_cert_dir
 
         # split server into list
         self.SERVER_ADDRESSES = self._get_server_list(server)
         self.LDAP_SERVER_PORT = port
 
         # USE FOR READ ONLY BIND TO LDAP SERVER
         self.attr_login = attr_login
 
         self.LDAP_BIND_DN = safe_str(bind_dn)
         self.LDAP_BIND_PASS = safe_str(bind_pass)
 
         self.SEARCH_SCOPE = getattr(ldap, 'SCOPE_%s' % search_scope)
         self.BASE_DN = safe_str(base_dn)
         self.LDAP_FILTER = safe_str(ldap_filter)
 
     def _get_ldap_conn(self):
 
         if self.debug:
             ldap.set_option(ldap.OPT_DEBUG_LEVEL, 255)
 
         if self.TLS_CERT_FILE and hasattr(ldap, 'OPT_X_TLS_CACERTFILE'):
             ldap.set_option(ldap.OPT_X_TLS_CACERTFILE, self.TLS_CERT_FILE)
 
         elif hasattr(ldap, 'OPT_X_TLS_CACERTDIR'):
             ldap.set_option(ldap.OPT_X_TLS_CACERTDIR, self.TLS_CERT_DIR)
 
         if self.TLS_KIND != 'PLAIN':
             ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, self.TLS_REQCERT)
 
         ldap.set_option(ldap.OPT_REFERRALS, ldap.OPT_OFF)
         ldap.set_option(ldap.OPT_RESTART, ldap.OPT_ON)
 
         # init connection now
         ldap_servers = self._build_servers(
             self.ldap_server_type,  self.SERVER_ADDRESSES, self.LDAP_SERVER_PORT)
         log.debug('initializing LDAP connection to:%s', ldap_servers)
         ldap_conn = ldap.initialize(ldap_servers)
         ldap_conn.set_option(ldap.OPT_NETWORK_TIMEOUT, self.timeout)
         ldap_conn.set_option(ldap.OPT_TIMEOUT, self.timeout)
         ldap_conn.timeout = self.timeout
 
         if self.ldap_version == 2:
             ldap_conn.protocol = ldap.VERSION2
         else:
             ldap_conn.protocol = ldap.VERSION3
 
         if self.TLS_KIND == 'START_TLS':
             ldap_conn.start_tls_s()
 
         if self.LDAP_BIND_DN and self.LDAP_BIND_PASS:
             log.debug('Trying simple_bind with password and given login DN: %r',
                       self.LDAP_BIND_DN)
             ldap_conn.simple_bind_s(self.LDAP_BIND_DN, self.LDAP_BIND_PASS)
         log.debug('simple_bind successful')
         return ldap_conn
 
-    def fetch_attrs_from_simple_bind(self, server, dn, username, password):
+    def fetch_attrs_from_simple_bind(self, ldap_conn, dn, username, password):
+        scope = ldap.SCOPE_BASE
+        scope_label = self.scope_labels.get(scope)
+        ldap_filter = '(objectClass=*)'
+
         try:
-            log.debug('Trying simple bind with %r', dn)
-            server.simple_bind_s(dn, safe_str(password))
-            _dn, attrs = server.search_ext_s(
-                dn, ldap.SCOPE_BASE, '(objectClass=*)', )[0]
+            log.debug('Trying authenticated search bind with dn: %r SCOPE: %s (and filter: %s)',
+                      dn, scope_label, ldap_filter)
+            ldap_conn.simple_bind_s(dn, safe_str(password))
+            response = ldap_conn.search_ext_s(dn, scope, ldap_filter, attrlist=['*', '+'])
 
+            if not response:
+                log.error('search bind returned empty results: %r', response)
+                return {}
+            else:
+                _dn, attrs = response[0]
             return attrs
 
         except ldap.INVALID_CREDENTIALS:
-            log.debug(
-                "LDAP rejected password for user '%s': %s, org_exc:",
+            log.debug("LDAP rejected password for user '%s': %s, org_exc:",
                 username, dn, exc_info=True)
 
     def authenticate_ldap(self, username, password):
         """
         Authenticate a user via LDAP and return his/her LDAP properties.
 
         Raises AuthenticationError if the credentials are rejected, or
         EnvironmentError if the LDAP server can't be reached.
 
         :param username: username
         :param password: password
         """
 
         uid = self.get_uid(username, self.SERVER_ADDRESSES)
         user_attrs = {}
         dn = ''
 
         self.validate_password(username, password)
         self.validate_username(username)
+        scope_label = self.scope_labels.get(self.SEARCH_SCOPE)
 
         ldap_conn = None
         try:
             ldap_conn = self._get_ldap_conn()
             filter_ = '(&%s(%s=%s))' % (
                 self.LDAP_FILTER, self.attr_login, username)
-            log.debug("Authenticating %r filter %s", self.BASE_DN, filter_)
+            log.debug("Authenticating %r filter %s and scope: %s",
+                      self.BASE_DN, filter_, scope_label)
 
-            lobjects = ldap_conn.search_ext_s(
-                self.BASE_DN, self.SEARCH_SCOPE, filter_)
+            ldap_objects = ldap_conn.search_ext_s(
+                self.BASE_DN, self.SEARCH_SCOPE, filter_, attrlist=['*', '+'])
 
-            if not lobjects:
+            if not ldap_objects:
                 log.debug("No matching LDAP objects for authentication "
                           "of UID:'%s' username:(%s)", uid, username)
                 raise ldap.NO_SUCH_OBJECT()
 
-            log.debug('Found matching ldap object, trying to authenticate')
-            for (dn, _attrs) in lobjects:
+            log.debug('Found %s matching ldap object[s], trying to authenticate on each one now...', len(ldap_objects))
+            for (dn, _attrs) in ldap_objects:
                 if dn is None:
                     continue
 
                 user_attrs = self.fetch_attrs_from_simple_bind(
                     ldap_conn, dn, username, password)
+
                 if user_attrs:
+                    log.debug('Got authenticated user attributes from DN:%s', dn)
                     break
             else:
                 raise LdapPasswordError(
-                    'Failed to authenticate user `{}` '
-                    'with given password'.format(username))
+                    'Failed to authenticate user `{}` with given password'.format(username))
 
         except ldap.NO_SUCH_OBJECT:
             log.debug("LDAP says no such user '%s' (%s), org_exc:",
                       uid, username, exc_info=True)
             raise LdapUsernameError('Unable to find user')
         except ldap.SERVER_DOWN:
             org_exc = traceback.format_exc()
             raise LdapConnectionError(
-                "LDAP can't access authentication "
-                "server, org_exc:%s" % org_exc)
+                "LDAP can't access authentication server, org_exc:%s" % org_exc)
         finally:
             if ldap_conn:
                 log.debug('ldap: connection release')
                 try:
                     ldap_conn.unbind_s()
                 except Exception:
                     # for any reason this can raise exception we must catch it
                     # to not crush the server
                     pass
 
         return dn, user_attrs
 
 
 class LdapSettingsSchema(AuthnPluginSettingsSchemaBase):
     tls_kind_choices = ['PLAIN', 'LDAPS', 'START_TLS']
     tls_reqcert_choices = ['NEVER', 'ALLOW', 'TRY', 'DEMAND', 'HARD']
     search_scope_choices = ['BASE', 'ONELEVEL', 'SUBTREE']
 
     host = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('Host[s] of the LDAP Server \n'
                       '(e.g., 192.168.2.154, or ldap-server.domain.com.\n '
                       'Multiple servers can be specified using commas'),
         preparer=strip_whitespace,
         title=_('LDAP Host'),
         widget='string')
     port = colander.SchemaNode(
         colander.Int(),
         default=389,
         description=_('Custom port that the LDAP server is listening on. '
                       'Default value is: 389, use 636 for LDAPS (SSL)'),
         preparer=strip_whitespace,
         title=_('Port'),
         validator=colander.Range(min=0, max=65536),
         widget='int')
 
     timeout = colander.SchemaNode(
         colander.Int(),
         default=60 * 5,
         description=_('Timeout for LDAP connection'),
         preparer=strip_whitespace,
         title=_('Connection timeout'),
         validator=colander.Range(min=1),
         widget='int')
 
     dn_user = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('Optional user DN/account to connect to LDAP if authentication is required. \n'
                       'e.g., cn=admin,dc=mydomain,dc=com, or '
                       'uid=root,cn=users,dc=mydomain,dc=com, or [e-mail]'),
         missing='',
         preparer=strip_whitespace,
         title=_('Bind account'),
         widget='string')
     dn_pass = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('Password to authenticate for given user DN.'),
         missing='',
         preparer=strip_whitespace,
         title=_('Bind account password'),
         widget='password')
     tls_kind = colander.SchemaNode(
         colander.String(),
         default=tls_kind_choices[0],
         description=_('TLS Type'),
         title=_('Connection Security'),
         validator=colander.OneOf(tls_kind_choices),
         widget='select')
     tls_reqcert = colander.SchemaNode(
         colander.String(),
         default=tls_reqcert_choices[0],
         description=_('Require Cert over TLS?. Self-signed and custom '
                       'certificates can be used when\n `RhodeCode Certificate` '
                       'found in admin > settings > system info page is extended.'),
         title=_('Certificate Checks'),
         validator=colander.OneOf(tls_reqcert_choices),
         widget='select')
     tls_cert_file = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('This specifies the PEM-format file path containing '
                       'certificates for use in TLS connection.\n'
                       'If not specified `TLS Cert dir` will be used'),
         title=_('TLS Cert file'),
         missing='',
         widget='string')
     tls_cert_dir = colander.SchemaNode(
         colander.String(),
         default=AuthLdap.default_tls_cert_dir,
         description=_('This specifies the path of a directory that contains individual '
                       'CA certificates in separate files.'),
         title=_('TLS Cert dir'),
         widget='string')
     base_dn = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('Base DN to search. Dynamic bind is supported. Add `$login` marker '
                       'in it to be replaced with current user username \n'
                       '(e.g., dc=mydomain,dc=com, or ou=Users,dc=mydomain,dc=com)'),
         missing='',
         preparer=strip_whitespace,
         title=_('Base DN'),
         widget='string')
     filter = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('Filter to narrow results \n'
                       '(e.g., (&(objectCategory=Person)(objectClass=user)), or \n'
                       '(memberof=cn=rc-login,ou=groups,ou=company,dc=mydomain,dc=com)))'),
         missing='',
         preparer=strip_whitespace,
         title=_('LDAP Search Filter'),
         widget='string')
 
     search_scope = colander.SchemaNode(
         colander.String(),
         default=search_scope_choices[2],
         description=_('How deep to search LDAP. If unsure set to SUBTREE'),
         title=_('LDAP Search Scope'),
         validator=colander.OneOf(search_scope_choices),
         widget='select')
     attr_login = colander.SchemaNode(
         colander.String(),
         default='uid',
         description=_('LDAP Attribute to map to user name (e.g., uid, or sAMAccountName)'),
         preparer=strip_whitespace,
         title=_('Login Attribute'),
         missing_msg=_('The LDAP Login attribute of the CN must be specified'),
         widget='string')
     attr_email = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('LDAP Attribute to map to email address (e.g., mail).\n'
                       'Emails are a crucial part of RhodeCode. \n'
                       'If possible add a valid email attribute to ldap users.'),
         missing='',
         preparer=strip_whitespace,
         title=_('Email Attribute'),
         widget='string')
     attr_firstname = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('LDAP Attribute to map to first name (e.g., givenName)'),
         missing='',
         preparer=strip_whitespace,
         title=_('First Name Attribute'),
         widget='string')
     attr_lastname = colander.SchemaNode(
         colander.String(),
         default='',
         description=_('LDAP Attribute to map to last name (e.g., sn)'),
         missing='',
         preparer=strip_whitespace,
         title=_('Last Name Attribute'),
         widget='string')
 
 
 class RhodeCodeAuthPlugin(RhodeCodeExternalAuthPlugin):
     uid = 'ldap'
     # used to define dynamic binding in the
     DYNAMIC_BIND_VAR = '$login'
     _settings_unsafe_keys = ['dn_pass']
 
     def includeme(self, config):
         config.add_authn_plugin(self)
         config.add_authn_resource(self.get_id(), LdapAuthnResource(self))
         config.add_view(
             'rhodecode.authentication.views.AuthnPluginViewBase',
             attr='settings_get',
             renderer='rhodecode:templates/admin/auth/plugin_settings.mako',
             request_method='GET',
             route_name='auth_home',
             context=LdapAuthnResource)
         config.add_view(
             'rhodecode.authentication.views.AuthnPluginViewBase',
             attr='settings_post',
             renderer='rhodecode:templates/admin/auth/plugin_settings.mako',
             request_method='POST',
             route_name='auth_home',
             context=LdapAuthnResource)
 
     def get_settings_schema(self):
         return LdapSettingsSchema()
 
     def get_display_name(self):
         return _('LDAP')
 
     @classmethod
     def docs(cls):
         return "https://docs.rhodecode.com/RhodeCode-Enterprise/auth/auth-ldap.html"
 
     @hybrid_property
     def name(self):
         return u"ldap"
 
     def use_fake_password(self):
         return True
 
     def user_activation_state(self):
         def_user_perms = User.get_default_user().AuthUser().permissions['global']
         return 'hg.extern_activate.auto' in def_user_perms
 
     def try_dynamic_binding(self, username, password, current_args):
         """
         Detects marker inside our original bind, and uses dynamic auth if
         present
         """
 
         org_bind = current_args['bind_dn']
         passwd = current_args['bind_pass']
 
         def has_bind_marker(username):
             if self.DYNAMIC_BIND_VAR in username:
                 return True
 
         # we only passed in user with "special" variable
         if org_bind and has_bind_marker(org_bind) and not passwd:
             log.debug('Using dynamic user/password binding for ldap '
                       'authentication. Replacing `%s` with username',
                       self.DYNAMIC_BIND_VAR)
             current_args['bind_dn'] = org_bind.replace(
                 self.DYNAMIC_BIND_VAR, username)
             current_args['bind_pass'] = password
 
         return current_args
 
     def auth(self, userobj, username, password, settings, **kwargs):
         """
         Given a user object (which may be null), username, a plaintext password,
         and a settings object (containing all the keys needed as listed in
         settings()), authenticate this user's login attempt.
 
         Return None on failure. On success, return a dictionary of the form:
 
             see: RhodeCodeAuthPluginBase.auth_func_attrs
         This is later validated for correctness
         """
 
         if not username or not password:
             log.debug('Empty username or password skipping...')
             return None
 
         ldap_args = {
             'server': settings.get('host', ''),
             'base_dn': settings.get('base_dn', ''),
             'port': settings.get('port'),
             'bind_dn': settings.get('dn_user'),
             'bind_pass': settings.get('dn_pass'),
             'tls_kind': settings.get('tls_kind'),
             'tls_reqcert': settings.get('tls_reqcert'),
             'tls_cert_file': settings.get('tls_cert_file'),
             'tls_cert_dir': settings.get('tls_cert_dir'),
             'search_scope': settings.get('search_scope'),
             'attr_login': settings.get('attr_login'),
             'ldap_version': 3,
             'ldap_filter': settings.get('filter'),
             'timeout': settings.get('timeout')
         }
 
         ldap_attrs = self.try_dynamic_binding(username, password, ldap_args)
 
         log.debug('Checking for ldap authentication.')
 
         try:
             aldap = AuthLdap(**ldap_args)
             (user_dn, ldap_attrs) = aldap.authenticate_ldap(username, password)
             log.debug('Got ldap DN response %s', user_dn)
 
             def get_ldap_attr(k):
                 return ldap_attrs.get(settings.get(k), [''])[0]
 
             # old attrs fetched from RhodeCode database
             admin = getattr(userobj, 'admin', False)
             active = getattr(userobj, 'active', True)
             email = getattr(userobj, 'email', '')
             username = getattr(userobj, 'username', username)
             firstname = getattr(userobj, 'firstname', '')
             lastname = getattr(userobj, 'lastname', '')
             extern_type = getattr(userobj, 'extern_type', '')
 
             groups = []
 
             user_attrs = {
                 'username': username,
                 'firstname': safe_unicode(get_ldap_attr('attr_firstname') or firstname),
                 'lastname': safe_unicode(get_ldap_attr('attr_lastname') or lastname),
                 'groups': groups,
                 'user_group_sync': False,
                 'email': get_ldap_attr('attr_email') or email,
                 'admin': admin,
                 'active': active,
                 'active_from_extern': None,
                 'extern_name': user_dn,
                 'extern_type': extern_type,
             }
 
             log.debug('ldap user: %s', user_attrs)
             log.info('user `%s` authenticated correctly', user_attrs['username'])
 
             return user_attrs
 
         except (LdapUsernameError, LdapPasswordError, LdapImportError):
             log.exception("LDAP related exception")
             return None
         except (Exception,):
             log.exception("Other exception")
             return None
 
 
 def includeme(config):
     plugin_id = 'egg:rhodecode-enterprise-ce#{}'.format(RhodeCodeAuthPlugin.uid)
     plugin_factory(plugin_id).includeme(config)