pam_winbind: unknown option require_membership_of

Question

I'm trying to configure the VSFTPD with Winbind to restrict users authenticated by Active Directory, only to those that belong to specific group.

I'm using a generic conf file for the vsftpd, with few changes:

$ cat /etc/vsftpd/vsftpd.conf
anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=022
dirmessage_enable=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_std_format=YES
chroot_local_user=YES
allow_writeable_chroot=YES
local_root=/data/ftp
listen=YES
listen_ipv6=NO
pam_service_name=vsftpd
userlist_enable=YES
tcp_wrappers=YES
pasv_enable=Yes
pasv_max_port=51000
pasv_min_port=50000
port_enable=yes
local_max_rate=0
use_localtime=YES
session_support=YES

Winbind is configured and the server sussessful joined to the Domain:

$ wbinfo -u
administrator
guest
...

In the PAM config files, I had put those config files:

$ cat /etc/pam.d/vsftpd
... (Default settings) ...
# Calls the vsftpd-winbind PAM config file:
auth     include   vsftpd-winbind
account  include   vsftpd-winbind
session  include   vsftpd-winbind

$ /etc/pam.d/vsftpd-winbind
auth        required      pam_env.so debug
auth        required      pam_winbind.so require_membership_of=GROUPNAME debug debug_state
auth        sufficient    pam_winbind.so require_membership_of=GROUPNAME debug debug_state
auth        required      pam_deny.so debug
account     sufficient    pam_winbind.so require_membership_of=GROUPNAME debug debug_state
account     required      pam_deny.so
password    required      pam_cracklib.so retry=3
password    sufficient    pam_unix.so nullok use_authtok md5 shadow
password    required      pam_deny.so
session     required      pam_mkhomedir.so skel=/etc/skel/ umask=0022
session     required      pam_limits.so
session     required      pam_unix.so

When I'm test the vsftpd, the error below is returned in /var/log/secure:

Jun 15 16:48:01 localhost vsftpd[2615]: pam_unix(vsftpd:auth): authentication failure; logname= uid=0 euid=0 tty=ftp ruser=joao rhost=rj1.ticorporativa.alog.com.br  user=joao
Jun 15 16:48:01 localhost vsftpd[2615]: pam_krb5[2615]: error reading keytab 'FILE:/etc/krb5.keytab'
Jun 15 16:48:01 localhost vsftpd[2615]: pam_krb5[2615]: TGT verified
Jun 15 16:48:01 localhost vsftpd[2615]: pam_krb5[2615]: authentication succeeds for 'joao' (joao@LAB-RJ2.VMWARE)
Jun 15 16:48:01 localhost vsftpd[2615]: pam_winbind(vsftpd:account): user 'joao' granted access
Jun 15 16:48:01 localhost vsftpd[2615]: pam_winbind(vsftpd:account): pam_parse: unknown option: require_membership_of=GROUPNAME

Inicially, I thought that it was a syntax error, but I've tried with several sintaxes in PAM config file:

require_membership_of=GROUPNAME debug debug_state
require_membership_of="GROUPNAME" debug debug_state
require_membership_of=DOMAIN\\GROUPNAME debug debug_state
require_membership_of="DOMAIN\\GROUPNAME" debug debug_state
require_membership_of=GROUP_SID debug debug_state
require_membership_of="GROUP_SID" debug debug_state

In these sintaxes with the "DOMAIN\", I relied in PAM_WINBIND manpage: https://www.samba.org/samba/docs/current/man-html/pam_winbind.8.html

If I remove the "require_membership_of" from the PAM config file, the FTP works, but obviously, the GROUP Membership filter is no apllied.

Has anyone ever had something similar and can help?

score 0 · Answer 1 · answered Apr 10 '20 at 01:01

Did you use the Gentoo tutorial, right? I tried to use it, but didn't work to me. When the /etc/pam.d/vsftpd is created, it imports the common-account, common-auth and common-session files. If you used the pam-auth-update command, PAM works fine, but vsftpd no.

If you are working with Debian, copy the content from files above, but change it. Put the follow content in /etc/pam.d/vsftpd:

auth    required                        pam_winbind.so require_membership_of=GROUPNAME krb5_auth krb5_ccache_type=FILE cached_login try_first_pass
auth    [success=3 default=ignore]      pam_krb5.so minimum_uid=1000
auth    [success=2 default=ignore]      pam_unix.so nullok_secure try_first_pass
auth    requisite                       pam_deny.so
auth    required                        pam_permit.so

account [success=1 new_authtok_reqd=done default=ignore]        pam_winbind.so
account requisite                       pam_deny.so
account required                        pam_permit.so
account required                        pam_krb5.so minimum_uid=1000

session [default=1]                     pam_permit.so
session requisite                       pam_deny.so
session required                        pam_permit.so
session optional                        pam_krb5.so minimum_uid=1000
session required        pam_unix.so
session optional                        pam_winbind.so
session optional        pam_systemd.so
session optional                        pam_mkhomedir.so

## Note: vsftpd handles anonymous logins on its own. Do not enable pam_ftp.so.

# See: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/managing_smart_cards/pam_configuration_files
password required       pam_cracklib.so retry=3
password sufficient     pam_unix.so nullok use_authtok md5 shadow
password required       pam_deny.so

As you see, I didn't change the core content, I only did few changes. See that "the order change the result". In the @common-auth@ file the line pam_krb5.so comes first, but if you put it so, all domain users will log on in ftp. So, put that is required the pam_winbind.so ONLY the GROUPNAME that you want. After, it search in the pam_krb5.so. It's an AND operator.

Important: if you delete pam_permit.so line, I don't know why, but it won't work.

Try this and good luck!

pam_winbind: unknown option require_membership_of

1 Answers1