Client Authentication:Fedora

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Revision as of 21:24, 11 January 2015 by Relayer (talk | contribs) (Correction)
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Warning.png Warning:
This is based upon limited testing and a small number of users.


Client Configuration

Introduction

The following is Fedora 21 (F21) - standard gnome edition desktop configuration for SME Server 9 authentication using Samba and Winbind. It allows login via the standard Fedora login screen. Also suitable for Fedora 19 and 20 (F19 and F20) for SME Server 8 - note that the Firewall and SELinux Administration GUI's may be slightly different.

Install Fedora

  • Download the Fedora .iso and install. During the install process change the hostname to something of your choice and your domain name.
<HOSTNAME>.<yourdomain>.<yourtld>
  Tip:
Make sure you set the <HOSTNAME> to something less than 15 characters.

The hostname can be set during the Installation Summary section of the install procedure by selecting Network & Hostname.

When creating a user account, give a non SME Server user such as 'administrator' as this first user effectively becomes a local user for Gnome login. Root is not allowed to login at the Gnome GDM prompt. You can login as this user, open the Terminal (cli) and 'su' to root to carry out most of the authentication setup later.


  • When the install has finished, remove the media and reboot.
  • Complete the install, login and apply all updates. Logout and Restart.
  Note:
There may be a lot of updates, it is recommended to apply them all but ensure the security fixes are applied as a minimum.


Additional Packages

  • Open the Terminal and use "su" to log in as root user.
  • Use "yum" at the Terminal to install the additional packages.
  • If you prefer to use a graphical package manager then install the "Yum Extender" from the Software" package.
  • The following shows how to install using yum at the Terminal, the package names are the same if you use the gui. Note: Firewall-config is already installed on F19 & F20.
sudo yum install \
pam_mount policycoreutils-gui authconfig-gtk \
samba samba-winbind samba-winbind-clients \
system-config-samba firewall-config

Package Removal

  • Remove the following package (F21 only)
yum remove sssd-libwbclient

Firewall Modifications

  • Search for and open “Firewall” and tick
samba
samba-client

as trusted services. Do not forget to select “Permanent” in the configuration drop down box first otherwise the changes will apply to the current session only.

SELinux Administration

  • Search for and open “SELinux Management” - note that the screen which opens is titled “SELinux Administration” (not Management)
  • On the "Status" menu select the "System Default Enforcing Mode" to "Disabled".

Samba Modifications

At the Terminal and still as root user, run the following two commands. 

systemctl enable smb.service
systemctl start smb.service
  • Search for and open “Authentication”. This will open the Authentication Configuration dialogue.
  Tip:
Do not press the “Join Domain” button until you have completed the changes to all of the Authentication Configuration dialogue boxes as detailed below.


  • On the Identity & Authentication tab select Winbind as the User Account Database.
  • Complete the dialogue box as follows:
Winbind Domain			- this is the Windows Workgroup name for your SME Server
Security Model			- set this to domain
Winbind Domain Controllers	- this is the IP Address of your SME Server
Template shell			- set this to /bin/bash
Allow offline login		- tick
  • On the Advanced Options tab
Enable local access control			- tick
Password hashing Algorithm			- MD5
Create home directories on first login	        - tick
  • Password options tab.
No configuration changes changes on this tab are necessary
  • Change back to the Identity & Authentication tab.
  • Click on “Join Domain” button and save changes when prompted. Enter 'admin' as the Domain Administrator and then enter your SME Server 'admin' password. Click “OK”, then click “Apply” on the Identity & Authentication tab.
  • Open the Terminal and 'su' to root if not already done.
  • Open and edit /etc/samba/smb.conf. Under [global] there will be a section commented as having been generated by authconfig. Check this section is as below, some lines may not exist and may need to be added.
Replace <WORKGROUP> below with the 'Windows Workgroup' name of your SME Server.
Replace <ip of sme server> below with the ip address of your SME Server.
[global] 
#--authconfig--start-line-- 

# Generated by authconfig on 2013/08/10 15:16:23 
# DO NOT EDIT THIS SECTION (delimited by --start-line--/--end-line--) 
# Any modification may be deleted or altered by authconfig in future 

workgroup = <WORKGROUP> 
#  password server = <ip of sme server>		(not required – leave as is but comment out) 
security = domain 
idmap config * : backend = tdb 			(add this line)
idmap config * : range = 16777216-33554431            (leave whatever range is set by default)
idmap config DOMAIN : backend = rid 		      (add his line)
idmap config DOMAIN : range = 10000-49999 	      (add this line)
idmap config DOMAIN : base_rid = 1000                 (add this line)
template shell = /bin/bash
# kerberos method = secrets only                      (comment out if this line exists)
winbind use default domain = yes 			(change this from false)
winbind offline logon = true 
wins server = <ip of sme server>			(add all of the following lines)
name resolve order = wins host lmhosts bcast 
socket options = TCP_NODELAY 
template homedir = /home/%D/%U 
winbind enum users = yes 
winbind enum groups = yes 
winbind cache time = 10 
obey pam restrictions = yes 
pam password change = yes 
hostname lookups = yes 

 #--authconfig--end-line--


  Note:
If you run the 'Authentication' tool again your amendments will be lost


  • To check validation of smb.conf, run
testparm
  • The 'Join Domain' above should also have worked so to list users, groups and available shares respectively from the SME server, test with
wbinfo -u
wbinfo -g
smbtree
If it doesn't appear to have worked then run
net rpc join -D <WORKGROUP> -U admin
Enter the admin password for the SME server when prompted and you should get a message,
Joined domain <WORKGROUP>

Authentication Modifications

  Warning:
Altering the pam system authentication files can seriously effect your ability to login in to the system. Take a backup of the /etc/pam.d directory and /etc/nsswitch.conf. Have a live DVD available to give access and re-apply the backup files if you make a mistake and/or get locked out


  • Open, check and edit as necessary /etc/nsswitch.conf. On F21 the following 4 lines will require amendment, on F19 and F20 only line 4 should require amendment. Close and Save.
passwd:  files winbind				
shadow: files winbind
group: files winbind
hosts: files dns wins			(ensure the order is correct – put wins at the end)
  • Open and edit the /etc/pam.d/system-auth file, and amend as below:
#%PAM-1.0 
# This file is auto-generated. 
# User changes will be destroyed the next time authconfig is run. 
auth        required      pam_env.so 
auth        sufficient    pam_fprintd.so 
auth        sufficient    pam_unix.so nullok try_first_pass 
auth        requisite     pam_succeed_if.so uid >= 1000 quiet_success 
auth        sufficient    pam_winbind.so cached_login use_first_pass 
auth	  optional      pam_mount.so enable_pam_password 
auth        required      pam_deny.so 

account     required      pam_access.so 
account     required      pam_unix.so broken_shadow 
account     sufficient    pam_localuser.so 
account     sufficient    pam_succeed_if.so uid < 1000 quiet 
account     [default=bad success=ok user_unknown=ignore] pam_winbind.so cached_login 
account     required      pam_permit.so 

password    requisite     pam_pwquality.so try_first_pass retry=3 type= 
password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtok 
password    sufficient    pam_winbind.so use_authtok 
password    required      pam_deny.so 

session     optional      pam_keyinit.so revoke 
session     required      pam_limits.so 
-session     optional      pam_systemd.so 
session     optional      pam_mkhomedir.so 
session     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid 
session     required      pam_unix.so 
session     optional      pam_winbind.so cached_login 
session	    optional	  pam_mount.so enable_pam_password
  Note:
The following two lines were added to the system-auth file:

auth optional pam_mount.so enable_pam_password

session optional pam_mount.so enable_pam_password


  • Open and edit the /etc/pam.d/password-auth file, and amend as below:
#%PAM-1.0 
# This file is auto-generated. 
# User changes will be destroyed the next time authconfig is run. 
auth        required      pam_env.so 
auth        sufficient    pam_unix.so nullok try_first_pass 
auth        requisite     pam_succeed_if.so uid >= 1000 quiet_success 
auth        sufficient    pam_winbind.so cached_login use_first_pass 
auth        optional      pam_mount.so enable_pam_password 
auth        required      pam_deny.so 

account     required      pam_access.so 
account     required      pam_unix.so broken_shadow 
account     sufficient    pam_localuser.so 
account     sufficient    pam_succeed_if.so uid < 1000 quiet 
account     [default=bad success=ok user_unknown=ignore] pam_winbind.so cached_login 
account     required      pam_permit.so 

password    requisite     pam_pwquality.so try_first_pass retry=3 type= 
password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtok 
password    sufficient    pam_winbind.so use_authtok 
password    required      pam_deny.so 

session     optional      pam_keyinit.so revoke 
session     required      pam_limits.so 
-session     optional      pam_systemd.so 
session     optional      pam_mkhomedir.so 
session     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid 
session     required      pam_unix.so 
session     optional      pam_winbind.so cached_login 
session	    optional	  pam_mount.so enable_pam_password
  Note:
The following two lines were added to the password-auth file:

auth optional pam_mount.so enable_pam_password

session optional pam_mount.so enable_pam_password


  • Open and edit the /etc/pam.d/gdm-password file, and amend as below:
auth     [success=done ignore=ignore default=bad] pam_selinux_permit.so 
auth        substack      password-auth 
auth        optional      pam_gnome_keyring.so 
auth       optional       pam_mount.so 
auth        include       postlogin 

account     required      pam_nologin.so 
account     include       password-auth 

password    include       password-auth 

session     required      pam_selinux.so close 
session     required      pam_loginuid.so 
session     optional      pam_console.so 
-session    optional    pam_ck_connector.so 
session     required      pam_selinux.so open 
session     optional      pam_keyinit.so force revoke 
session     required      pam_namespace.so 
session     include       password-auth 
session     optional      pam_gnome_keyring.so auto_start 
session     include       postlogin 
session	    optional	  pam_mount.so
  Note:
The following two lines were added to the gdm-password file:

auth optional pam_mount.so

session optional pam_mount.so


Automount User Home Directories at Login

  • Create a new group in SME Server with a Group Name of “nethome” and a Description of “nethome-group”. Add all SME Server users to this group, or at least all SME Server users who will be using the SME Server to authenticate a Fedora client workstation.
  Note:
The names “nethome” and “nethome-group” can, of course be anything you like, these are just my example for the purpose of this HowTo. They are, however, a sensible choice as we are going to use a mount point called “nethome” but again this mount point name can be anything you want.


  • Open and edit /etc/security/pam_mount.conf.xml file. Find the 'Volume Definitions' section. Add a volume line below the header
<!-- Volume Definitions --> 
<volume sgrp="nethome-group" fstype="cifs" server="<SMESERVER>" path="homes" mountpoint="~/nethome" options="nosuid,nodev" />
  • Replace <SMESERVER> above with the samba name of your SME Server. This will mount the users 'home' directory from SME Server into a directory called 'nethome' in their local home directory.

Automount Using smserver-tw-loginscript

The Smeserver-tw-logonscript package provides a convenient and flexible alternative to managing mounts for user home directories and i-bay directories.

Instead of the hardcoded lines as described above it auto generates a small user specific script when the user logs in and then links the pam_mount to this user script.

Automount Ibays at Login

  • Edit /etc/security/pam_mount.conf.xml and add a line below the header
<!-- Volume Definitions --> 
<volume sgrp="<GROUPNAME>" fstype="cifs" server="<SMESERVER>" path="<IBAYNAME>" mountpoint="~/<IBAYNAME>" options="user=%(DOMAIN_USER),setuids,acl" />
  • Replace <SMESERVER> with the samba name of your SME server, <IBAYNAME> with the ibay name, <GROUPNAME> with the description of the ibay owner group. The description can be recovered with
wbinfo -g
  Note:
The sgrp param is optional. If used, ibay will be mounted only if %(DOMAIN_USER) is a member of ibay's owner group


Login and Test

  • Exit the Terminal cli
  • Logout, and Restart Fedora.
  • Login as a valid SME server user on your system, just giving username and password. No need for DOMAIN\user as samba configured above to use the default Windows Workgroup
  • Authentication against SME Server should proceed and the user log in. A home directory on the local machine should be created as /home/DOMAIN/user, and a sub directory to that called 'nethome' mounted to the users home directory on the SME server.

Password Changes

User password changes made through the web browser (www.yourdomain.xxx/user-password) are implemented correctly. The new password also being recognised when logging in away from the SME Server network i.e. off-line cached login, particularly useful for business laptops.

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