LDAPInvalidFilterError Username is not escaped

https://github.com/jupyterhub/ldapauthenticator/blob/24f11eb5d2517d6a1bd9cc616653cc000a044811/ldapauthenticator/ldapauthenticator.py#L430

https://github.com/jupyterhub/ldapauthenticator/blob/1.3.2/ldapauthenticator/ldapauthenticator.py#L430:L448

When escape_userdn = True the ldapauthenticator escapes special chars in userdn but does not escapes special chars in username. This does not cause an issue when allowed_groups is null but it does cause an issue when allowed_groups is not null. I suggest that the username is also escaped when escape_userdn = True or add another parameter dedicated to escape username.

I am using:

z2jh | 2.0.0
jupyterhub | 3.0.0
ldapauthenticator | 1.3.2

z2jh hub-pod logs:

[D JupyterHub ldapauthenticator:256] Looking up user with:
        search_base = 'OU=AADDC Users,DC=xxxxxx,DC=com'
        search_filter = '(sAMAccountName=my_username)'
        attributes = 'sAMAccountName'
[D ldapauthenticator:379] Attempting to bind My Full Name **(**6B4563DA**)** with CN=My Full Name **\28**6B4563DA**\29**,OU=AADDC Users,DC=xxxxxx,DC=com
[D ldapauthenticator:392] Status of user bind My Full Name **(**6B4563DA**)** with CN=My Full Name **\28**6B4563DA**\29**,OU=AADDC Users,DC=xxxxxx,DC=com : True
[D ldapauthenticator:431] username:My Full Name **(**6B4563DA**)** Using dn CN=My Full Name **\28**6B4563DA**\29**,OU=AADDC Users,DC=xxxxxx,DC=com
[E JupyterHub web:1798] Uncaught exception POST /hub/login?next=%2Fhub%2F (::ffff:xx.xx.xx.xx)
    HTTPServerRequest(protocol='http', host='xxx.xxx.xxx.xxx:3xxxx', method='POST', uri='/hub/login?next=%2Fhub%2F', version='HTTP/1.1', remote_ip='::ffff:xx.xx.xx.xx')
    Traceback (most recent call last):
      File "/usr/local/lib/python3.9/site-packages/tornado/web.py", line 1713, in _execute
        result = await result
      File "/usr/local/lib/python3.9/site-packages/jupyterhub/handlers/login.py", line 153, in post
        user = await self.login_user(data)
      File "/usr/local/lib/python3.9/site-packages/jupyterhub/handlers/base.py", line 801, in login_user
        authenticated = await self.authenticate(data)
      File "/usr/local/lib/python3.9/site-packages/jupyterhub/auth.py", line 491, in get_authenticated_user
        authenticated = await maybe_future(self.authenticate(handler, data))
      File "/usr/local/lib/python3.9/site-packages/**ldapauthenticator/ldapauthenticator.py**", line **443**, in **authenticate**
        **found = conn.search(**
      File "/usr/local/lib/python3.9/site-packages/ldap3/core/connection.py", line 838, in search
        request = search_operation(search_base,
      File "/usr/local/lib/python3.9/site-packages/ldap3/operation/search.py", line 371, in search_operation
        request['filter'] = compile_filter(parse_filter(search_filter, schema, auto_escape, auto_encode, validator, check_names).elements[0])  # parse the searchFilter string and compile it starting from the root node
      File "/usr/local/lib/python3.9/site-packages/ldap3/operation/search.py", line 214, in parse_filter
        raise **LDAPInvalidFilterError('malformed filter')**
    **ldap3.core.exceptions.LDAPInvalidFilterError: malformed filter**

jupyterhub / ldapauthenticator

LDAPInvalidFilterError Username is not escaped #225