* Examples

** List the DNs of all users in our QAUsers group

: ad_query --subst  --attr=dn
:      ^OU=QAUsers,$domain&sub&(&(objectcategory=person)(objectclass=user))

** List the DN using the user's mail address

: ad_query --subst --attr=dn,userAccountControl
:                   (&(objectcategory=person)(objectclass=user)
:                     (|(userPrincipalName=dd9jn@w32demo.g10code.de)
:                       (mail=dd9jn@w32demo.g10code.de)))

After that the userControlFlags should be checked - see below for
the bit flags. For a non-disabled user use:

: if ((userControlFlags & 0x0212) == 0x200))
:   use_this_user()


* Useful attributes

** userAccountControl

These are bit flags.  For details see
https://learn.microsoft.com/en-us/windows/win32/api/iads/ne-iads-ads_user_flag_enum

- 0x00000002 :: ADS_UF_ACCOUNTDISABLE, the account is disabled.
- 0x00000010 :: ADS_UF_LOCKOUT, the account is temporarily locked out.
- 0x00000100 :: ADS_UF_TEMP_DUPLICATE_ACCOUNT, this is an account for
                a user whose primary account is in another domain.
- 0x00000200 :: ADS_UF_NORMAL_ACCOUNT, the default account type that
                represents a typical user.
- 0x00000800 :: ADS_UF_INTERDOMAIN_TRUST_ACCOUNT, the account for a
                domain-to-domain trust.
- 0x00001000 :: ADS_UF_WORKSTATION_ACCOUNT, the computer account for a
                computer that is a member of this domain.
- 0x00002000 :: ADS_UF_SERVER_TRUST_ACCOUNT, the computer account for
                a DC.
- 0x00010000 :: ADS_UF_DONT_EXPIRE_PASSWD, the password will not expire.
- 0x04000000 :: ADS_UF_PARTIAL_SECRETS_ACCOUNT, the computer account
                for an RODC.

For example to select only user accounts which are not disabled or
are locked out could naivly be used:

:  (userAccountControl:1.2.840.113556.1.4.803:=512)

1.2.840.113556.1.4.803 is bit wise AND, 1.2.840.113556.1.4.804 is bit
wise OR.  However, because a mask can't be specified, this is not really
useful.  Thus the above needs to be replaced by explicit checks; i.e.

:  (&(userAccountControl:1.2.840.113556.1.4.804:=512)
:    (!(userAccountControl:1.2.840.113556.1.4.804:=2))
:    (!(userAccountControl:1.2.840.113556.1.4.804:=16)))

I'd suggest to also add explict checks on the returned data.


* Resources

- https://qa.social.technet.microsoft.com/wiki/contents/articles/5392.active-directory-ldap-syntax-filters.aspx