Problems to use LDAP again AD directory with disabled anonymous logon

Hi
I am exited to see that with the latest patch we have LDAP support in pgAdmin
I tried to make it work but did not succeed.

We use Microsoft AD. We have a global catalog that allows LDAP access but anonymous access is disabled.

I have a technical user SVCLDAP that I can use to auth against LDAP and search for a user via UPN and did some ldapsearch tests before I changed the config of pgAdmin:

ldapsearch -H ldap://ldap.mgi.de:389 -D "CN=SVCLDAP, CN=Users, DC=ASF, DC=madm, DC=net" -W -b "dc=R2, dc=madm,dc=net" "(userPrincipalName=heiko(dot)onnebrink(at)metronom(dot)com)"
Enter LDAP Password: somepwd

# extended LDIF
#
# LDAPv3
# base <dc=madm,dc=net> with scope subtree
# filter: (userPrincipalName=heiko(dot)onnebrink(at)metronom(dot)com)
# requesting: ALL
#

# Onnebrink Heiko, HQ01-DUS, Users, DE, MSYS, r2.madm.net
dn: CN=Onnebrink Heiko,OU=HQ01-DUS,OU=Users,OU=DE,OU=MSYS,DC=r2,DC=madm,DC=net
..

If I do the same query without providing a bind DN gives an sasl error

ldapsearch -H ldap://ldap.mgi.de:389 -b "dc=R2, dc=madm,dc=net" "(userPrincipalName=heiko(dot)onnebrink(at)metronom(dot)com)"

SASL/GSSAPI authentication started
ldap_sasl_interactive_bind_s: Local error (-2)
additional info: SASL(-1): generic failure: GSSAPI Error: Unspecified GSS failure. Minor code may provide more information (No Kerberos credentials available (default cache: FILE:/tmp/krb5cc_500))

If I disable SASL (-x) it works but returns no data:

ldapsearch -H ldap://ldap.mgi.de:389 -x -b "dc=R2, dc=madm,dc=net" "(userPrincipalName=heiko(dot)onnebrink(at)metronom(dot)com)"
# extended LDIF
#
# LDAPv3
# base <dc=R2, dc=madm,dc=net> with scope subtree
# filter: (userPrincipalName=heiko(dot)onnebrink(at)metronom(dot)com)
# requesting: ALL
#

# search result
search: 2
result: 0 Success

# numResponses: 1

I transferred now the above settings to the pgAdmin config (docker is used here)

docker run -p 443:443 --name pgadminssl -e 'PGADMIN_CONFIG_LDAP_SERVER_URI="ldap://ldap.mgi.de:389"' -e 'PGADMIN_CONFIG_LDAP_USERNAME_ATTRIBUTE="userPrincipalName"' -e 'PGADMIN_CONFIG_LDAP_BASE_DN="(dc=madm,dc=net)"' -e 'PGADMIN_CONFIG_SEARCH_SCOPE="SUBTREE"' -e
'PGADMIN_CONFIG_AUTHENTICATION_SOURCES="ldap","internal"' -v '/dockerdata/pgadmin/servers.json:/servers.json' -v '/dockerdata/pgadmin/server.cert:/certs/server.cert' -v '/dockerdata/pgadmin/server.key:/certs/server.key' -e PGADMIN_ENABLE_TLS=TRUE -e
PGADMIN_DEFAULT_PASSWORD=admin -e
PGADMIN_DEFAULT_EMAIL=admin(at)metronom(dot)com registry.metroscales.io/rdb-dev/pgadmin:latest

2020-05-05 10:27:46,936: ERROR
flask.app: Error binding to the LDAP server.
Traceback (most recent call last):
File "/pgadmin4/pgadmin/authenticate/ldap.py", line 115, in connect
auto_bind=True
File "/usr/local/lib/python3.7/site-packages/ldap3/core/connection.py", line 355, in __init__
self.do_auto_bind()
File "/usr/local/lib/python3.7/site-packages/ldap3/core/connection.py", line 384, in do_auto_bind
raise LDAPBindError(self.last_error)
ldap3.core.exceptions.LDAPBindError: None

From config description I do not see how I pass a bind user that would required (as we do not allow anonymous access) so that an LDAP query can be executed that finds the logon user via his UPN. Once record is found we have the DN that can be used to bind the user with his entered password to verify that password is valid.

Thanks for sharing how it works internally and what mistake I have here in my config..

cheers
Heiko

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