Comment 0 for bug 1825867

wrt to the recent community change https://github.com/openstack/keystone/commit/eca0829c4c65e6b64f08023ce2d5a55dc329248f related to py3 in ldap, we have used bytes_mode=False to support py2 ldap.
But while configuring ldap with user (say flügel), we are getting the below error.

[Mon Apr 22 08:04:36.723781 2019] [:error] [pid 46754] [remote ] ref = driver.authenticate(entity_id, password)
[Mon Apr 22 08:04:36.723802 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 62, in authenticate
[Mon Apr 22 08:04:36.724054 2019] [:error] [pid 46754] [remote ] user_ref = self._get_user(user_id)
[Mon Apr 22 08:04:36.724082 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 81, in _get_user
[Mon Apr 22 08:04:36.724122 2019] [:error] [pid 46754] [remote ] return self.user.get(user_id)
[Mon Apr 22 08:04:36.724145 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 309, in get
[Mon Apr 22 08:04:36.724184 2019] [:error] [pid 46754] [remote ] obj = super(UserApi, self).get(user_id, ldap_filter=ldap_filter)
[Mon Apr 22 08:04:36.724208 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1843, in get
[Mon Apr 22 08:04:36.724958 2019] [:error] [pid 46754] [remote ] ref = super(EnabledEmuMixIn, self).get(object_id, ldap_filter)
[Mon Apr 22 08:04:36.724989 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1545, in get
[Mon Apr 22 08:04:36.725031 2019] [:error] [pid 46754] [remote ] res = self._ldap_get(object_id, ldap_filter)
[Mon Apr 22 08:04:36.725055 2019] [:error] [pid 46754] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1453, in _ldap_get
[Mon Apr 22 08:04:36.725108 2019] [:error] [pid 46754] [remote ] six.text_type(object_id)),
[Mon Apr 22 08:04:36.725163 2019] [:error] [pid 46754] [remote ] UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2: ordinal not in range(128)

It fails at six.text_type which is basically trying to convert the string to unicode. But what if we are already getting a unicode value there, in those cases the execution fails.

IMO we should rather be using utf8_decode() from /usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py.

Once the above is fixed we get the below similar error,

[Mon Apr 22 05:00:30.699425 2019] [:error] [pid 121709] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 471, in get_all_filtered
[Mon Apr 22 05:00:30.699444 2019] [:error] [pid 121709] [remote ] for group in self.get_all(query, hints)]
[Mon Apr 22 05:00:30.699455 2019] [:error] [pid 121709] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1564, in get_all
[Mon Apr 22 05:00:30.711297 2019] [:error] [pid 121709] [remote ] for x in self._ldap_get_all(hints, ldap_filter)]
[Mon Apr 22 05:00:30.711359 2019] [:error] [pid 121709] [remote ] File "/usr/lib/python2.7/site-packages/keystone/common/driver_hints.py", line 42, in wrapper
[Mon Apr 22 05:00:30.720098 2019] [:error] [pid 121709] [remote ] return f(self, hints, *args, **kwargs)
[Mon Apr 22 05:00:30.720134 2019] [:error] [pid 121709] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1499, in _ldap_get_all
[Mon Apr 22 05:00:30.720188 2019] [:error] [pid 121709] [remote ] self.id_attr)
[Mon Apr 22 05:00:30.720259 2019] [:error] [pid 121709] [remote ] UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 13: ordinal not in range(128)

Here,

query = u'(&%s(objectClass=%s)(%s=*))' % (ldap_filter or self.ldap_filter or '',
            self.object_class, self.id_attr) line fails coz ldap_filter is not a unicode string. Its a string having special characters. We need to decode the string in cases like these.

After resolving the above, we get the below error while trying to get the role assignments for the group after we configuring a ldap group with special character (flügel).

[Mon Apr 22 10:49:26.263074 2019] [:error] [pid 99824] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 129, in list_users_in_group
[Mon Apr 22 10:49:26.263097 2019] [:error] [pid 99824] [remote ] for user_id in self._transform_group_member_ids(group_members):
[Mon Apr 22 10:49:26.263108 2019] [:error] [pid 99824] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/core.py", line 123, in _transform_group_member_ids
[Mon Apr 22 10:49:26.263125 2019] [:error] [pid 99824] [remote ] user_id = self.user._dn_to_id(user_key)
[Mon Apr 22 10:49:26.263136 2019] [:error] [pid 99824] [remote ] File "/usr/lib/python2.7/site-packages/keystone/identity/backends/ldap/common.py", line 1298, in _dn_to_id
[Mon Apr 22 10:49:26.263153 2019] [:error] [pid 99824] [remote ] return ldap.dn.str2dn(dn)[0][0][1]
[Mon Apr 22 10:49:26.263163 2019] [:error] [pid 99824] [remote ] File "/usr/lib64/python2.7/site-packages/ldap/dn.py", line 53, in str2dn
[Mon Apr 22 10:49:26.263205 2019] [:error] [pid 99824] [remote ] return ldap.functions._ldap_function_call(None,_ldap.str2dn,dn,flags)
[Mon Apr 22 10:49:26.263236 2019] [:error] [pid 99824] [remote ] File "/usr/lib64/python2.7/site-packages/ldap/functions.py", line 66, in _ldap_function_call
[Mon Apr 22 10:49:26.263257 2019] [:error] [pid 99824] [remote ] result = func(*args,**kwargs)
[Mon Apr 22 10:49:26.263283 2019] [:error] [pid 99824] [remote ] UnicodeEncodeError: 'ascii' codec can't encode character u'\\xfc' in position 5: ordinal not in range(128)

Here while trying to list users (having special characters) in group (having special characters), the user dn is unicode & we are trying to convert that into a str (using _dn_to_id() in common.py). First we need to make sure that the user is string & not some unicode value which will cause UnicodeEncodeError.