Procedure

1. Enable access to the keytab file of HTTP/<SERVER_NAME>@realm principal by creating the service principal:

   # ipa service-add HTTP/<SERVER_NAME>

2. Retrieve the keytab for the principal stored in the /etc/gssproxy/http.keytab file:

   # ipa-getkeytab -s $(awk '/^server =/ {print $3}' /etc/ipa/default.conf) -k /etc/gssproxy/http.keytab -p HTTP/$(hostname -f)

   This step sets permissions to 400, thus only the root user has access to the keytab file. The apache user does not.

3. Create the /etc/gssproxy/80-httpd.conf file with the following content:

   [service/HTTP]
     mechs = krb5
     cred_store = keytab:/etc/gssproxy/http.keytab
     cred_store = ccache:/var/lib/gssproxy/clients/krb5cc_%U
     euid = apache

4. Restart and enable the gssproxy service:

   # systemctl restart gssproxy.service
   # systemctl enable gssproxy.service

Procedure

1. Configure the mod_auth_gssapi module to protect the /var/www/html/private/ directory:

   <Location /var/www/html/private>
     AuthType GSSAPI
     AuthName "GSSAPI Login"
     Require valid-user
   </Location>

2. Create the /etc/systemd/system/httpd.service file with the following content:

   .include /lib/systemd/system/httpd.service
   [Service]
   Environment=GSS_USE_PROXY=1

3. Reload the systemd configuration:

   # systemctl daemon-reload

4. Restart the httpd service:

   # systemctl restart httpd.service

Verification steps

1. Obtain a Kerberos ticket:

   # kinit

2. Open the URL to the protected directory in a browser.

Procedure

1. Install the mod_ssl package:

   # dnf install mod_ssl

2. Edit the /etc/httpd/conf.d/ssl.conf file and add the following settings to the <VirtualHost _default_:443> directive:

   1. Set the server name:

      ServerName example.com

      Important

      The server name must match the entry set in the Common Name field of the certificate.

   2. Optional: If the certificate contains additional host names in the Subject Alt Names (SAN) field, you can configure mod_ssl to provide TLS encryption also for these host names. To configure this, add the ServerAliases parameter with corresponding names:

      ServerAlias www.example.com server.example.com

   3. Set the paths to the private key, the server certificate, and the CA certificate:

      SSLCertificateKeyFile "/etc/pki/tls/private/example.com.key"
      SSLCertificateFile "/etc/pki/tls/certs/example.com.crt"
      SSLCACertificateFile "/etc/pki/tls/certs/ca.crt"

3. For security reasons, configure that only the root user can access the private key file:

   # chown root:root /etc/pki/tls/private/example.com.key
   # chmod 600 /etc/pki/tls/private/example.com.key

   Warning

   If the private key was accessed by unauthorized users, revoke the certificate, create a new private key, and request a new certificate. Otherwise, the TLS connection is no longer secure.

4. Open port 443 in the local firewall:

   # firewall-cmd --permanent --add-port=443/tcp
   # firewall-cmd --reload

5. Restart the httpd service:

   # systemctl restart httpd

   Note

   If you protected the private key file with a password, you must enter this password each time when the httpd service starts.

Procedure

1. Edit the /etc/httpd/conf/httpd.conf file, and add the following setting to the <VirtualHost> directive for which you want to set the TLS protocol version. For example, to enable only the TLSv1.3 protocol:

   SSLProtocol -All TLSv1.3

2. Restart the httpd service:

   # systemctl restart httpd

Verification steps

1. Use the following command to verify that the server supports TLSv1.3:

   # openssl s_client -connect example.com:443 -tls1_3

2. Use the following command to verify that the server does not support TLSv1.2:

   # openssl s_client -connect example.com:443 -tls1_2

   If the server does not support the protocol, the command returns an error:

   140111600609088:error:1409442E:SSL routines:ssl3_read_bytes:tlsv1 alert protocol version:ssl/record/rec_layer_s3.c:1543:SSL alert number 70

3. Optional: Repeat the command for other TLS protocol versions.

Procedure

1. Edit the /etc/httpd/conf/httpd.conf file, and add the SSLCipherSuite parameter to the <VirtualHost> directive for which you want to set the TLS ciphers:

   SSLCipherSuite "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH:!SHA1:!SHA256"

   This example enables only the EECDH+AESGCM, EDH+AESGCM, AES256+EECDH, and AES256+EDH ciphers and disables all ciphers which use the SHA1 and SHA256 message authentication code (MAC).

2. Restart the httpd service:

   # systemctl restart httpd

Verification steps

1. To display the list of ciphers the Apache HTTP Server supports:

   1. Install the nmap package:

      # yum install nmap

   2. Use the nmap utility to display the supported ciphers:

      # nmap --script ssl-enum-ciphers -p 443 example.com
      ...
      PORT    STATE SERVICE
      443/tcp open  https
      | ssl-enum-ciphers:
      |   TLSv1.2:
      |     ciphers:
      |       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
      |       TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (dh 2048) - A
      |       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
      ...

Procedure

1. Create a copy of the /etc/samba/smb.conf file:

   # cp /etc/samba/smb.conf /etc/samba/samba.conf.copy

2. Edit the copied file and make the desired changes.

3. Verify the configuration in the /etc/samba/samba.conf.copy file:

   # testparm -s /etc/samba/samba.conf.copy

   If testparm reports errors, fix them and run the command again.

4. Override the /etc/samba/smb.conf file with the new configuration:

   # mv /etc/samba/samba.conf.copy /etc/samba/smb.conf

5. Wait until the Samba services automatically reload their configuration or manually reload the configuration:

   # smbcontrol all reload-config

Procedure

1. Run the testparm utility as the root user:

   # testparm
   Load smb config files from /etc/samba/smb.conf
   rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
   Unknown parameter encountered: "log levell"
   Processing section "[example_share]"
   Loaded services file OK.
   ERROR: The idmap range for the domain * (tdb) overlaps with the range of DOMAIN (ad)!
   
   Server role: ROLE_DOMAIN_MEMBER
   
   Press enter to see a dump of your service definitions
   
   # Global parameters
   [global]
   	...
   
   [example_share]
   	...

   The previous example output reports a non-existent parameter and an incorrect ID mapping configuration.

2. If testparm reports incorrect parameters, values, or other errors in the configuration, fix the problem and run the utility again.

Procedure

1. Install the samba package:

   # yum install samba

2. Edit the /etc/samba/smb.conf file and set the following parameters:

   [global]
   	workgroup = Example-WG
   	netbios name = Server
   	security = user
   
   	log file = /var/log/samba/%m.log
   	log level = 1

   This configuration defines a standalone server named Server within the Example-WG work group. Additionally, this configuration enables logging on a minimal level (1) and log files will be stored in the /var/log/samba/ directory. Samba will expand the %m macro in the log file parameter to the NetBIOS name of connecting clients. This enables individual log files for each client.

3. Optionally, configure file or printer sharing. See:

   • Section 3.7, “Setting up a Samba file share that uses POSIX ACLs”
   • Section 3.9, “Setting up a share that uses Windows ACLs”
   • Section 3.15, “Setting up Samba as a print server”

4. Verify the /etc/samba/smb.conf file:

   # testparm

5. If you set up shares that require authentication, create the user accounts.

   For details, see Section 3.3.2, “Creating and enabling local user accounts”.

6. Open the required ports and reload the firewall configuration by using the firewall-cmd utility:

   # firewall-cmd --permanent --add-port={139/tcp,445/tcp}
   # firewall-cmd --reload

7. Enable and start the smb service:

   # systemctl enable --now smb

Procedure

1. Create the operating system account:

   # useradd -M -s /sbin/nologin example

   This command adds the example account without creating a home directory. If the account is only used to authenticate to Samba, assign the /sbin/nologin command as shell to prevent the account from logging in locally.

2. Set a password to the operating system account to enable it:

   # passwd example
   Enter new UNIX password: password
   Retype new UNIX password: password
   passwd: password updated successfully

   Samba does not use the password set on the operating system account to authenticate. However, you need to set a password to enable the account. If an account is disabled, Samba denies access if this user connects.

3. Add the user to the Samba database and set a password to the account:

   # smbpasswd -a example
   New SMB password: password
   Retype new SMB password: password
   Added user example.

   Use this password to authenticate when using this account to connect to a Samba share.

4. Enable the Samba account:

   # smbpasswd -e example
   Enabled user example.

Procedure

1. Edit the [global] section in the /etc/samba/smb.conf file:

   1. Add an ID mapping configuration for the default domain (*) if it does not exist. For example:

      idmap config * : backend = tdb
      idmap config * : range = 10000-999999

   2. Enable the ad ID mapping back end for the AD domain:

      idmap config DOMAIN : backend = ad

   3. Set the range of IDs that is assigned to users and groups in the AD domain. For example:

      idmap config DOMAIN : range = 2000000-2999999

      Important

      The range must not overlap with any other domain configuration on this server. Additionally, the range must be set big enough to include all IDs assigned in the future. For further details, see Section 3.4.1, “Planning Samba ID ranges”.

   4. Set that Samba uses the RFC 2307 schema when reading attributes from AD:

      idmap config DOMAIN : schema_mode = rfc2307

   5. To enable Samba to read the login shell and the path to the users home directory from the corresponding AD attribute, set:

      idmap config DOMAIN : unix_nss_info = yes

      Alternatively, you can set a uniform domain-wide home directory path and login shell that is applied to all users. For example:

      template shell = /bin/bash
      template homedir = /home/%U

   6. By default, Samba uses the primaryGroupID attribute of a user object as the user’s primary group on Linux. Alternatively, you can configure Samba to use the value set in the gidNumber attribute instead:

      idmap config DOMAIN : unix_primary_group = yes

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. Edit the [global] section in the /etc/samba/smb.conf file:

   1. Add an ID mapping configuration for the default domain (*) if it does not exist. For example:

      idmap config * : backend = tdb
      idmap config * : range = 10000-999999

   2. Enable the rid ID mapping back end for the domain:

      idmap config DOMAIN : backend = rid

   3. Set a range that is big enough to include all RIDs that will be assigned in the future. For example:

      idmap config DOMAIN : range = 2000000-2999999

      Samba ignores users and groups whose RIDs in this domain are not within the range.

      Important

      The range must not overlap with any other domain configuration on this server. For further details, see Section 3.4.1, “Planning Samba ID ranges”.

   4. Set a shell and home directory path that will be assigned to all mapped users. For example:

      template shell = /bin/bash
      template homedir = /home/%U

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Reload the Samba configuration:

   # smbcontrol all reload-config

   Additional resources

   • Section 3.4.2, “The * default domain”
   • For details about variable substitution, see the VARIABLE SUBSTITUTIONS section in the smb.conf(5) man page.
   • For details, how Samba calculates the local ID from a RID, see the idmap_rid(8) man page.

Procedure

1. Edit the [global] section in the /etc/samba/smb.conf file:

   1. Enable the autorid ID mapping back end for the * default domain:

      idmap config * : backend = autorid

   2. Set a range that is big enough to assign IDs for all existing and future objects. For example:

      idmap config * : range = 10000-999999

      Samba ignores users and groups whose calculated IDs in this domain are not within the range.

      Warning

      After you set the range and Samba starts using it, you can only increase the upper limit of the range. Any other change to the range can result in new ID assignments, and thus in losing file ownerships.

   3. Optionally, set a range size. For example:

      idmap config * : rangesize = 200000

      Samba assigns this number of continuous IDs for each domain’s object until all IDs from the range set in the idmap config * : range parameter are taken.

   4. Set a shell and home directory path that will be assigned to all mapped users. For example:

      template shell = /bin/bash
      template homedir = /home/%U

   5. Optionally, add additional ID mapping configuration for domains. If no configuration for an individual domain is available, Samba calculates the ID using the autorid back end settings in the previously configured * default domain.

      Important

      If you configure additional back ends for individual domains, the ranges for all ID mapping configuration must not overlap. For further details, see Section 3.4.1, “Planning Samba ID ranges”.

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. If your AD requires the deprecated RC4 encryption type for Kerberos authentication, enable support for these ciphers in RHEL:

   # update-crypto-policies --set DEFAULT:AD-SUPPORT

2. Install the following packages:

   # yum install realmd oddjob-mkhomedir oddjob samba-winbind-clients \ samba-winbind samba-common-tools samba-winbind-krb5-locator

3. To share directories or printers on the domain member, install the samba package:

   # yum install samba

4. Backup the existing /etc/samba/smb.conf Samba configuration file:

   # mv /etc/samba/smb.conf /etc/samba/smb.conf.bak

5. Join the domain. For example, to join a domain named ad.example.com:

   # realm join --membership-software=samba --client-software=winbind ad.example.com

   Using the previous command, the realm utility automatically:

   • Creates a /etc/samba/smb.conf file for a membership in the ad.example.com domain
   • Adds the winbind module for user and group lookups to the /etc/nsswitch.conf file
   • Updates the Pluggable Authentication Module (PAM) configuration files in the /etc/pam.d/ directory
   • Starts the winbind service and enables the service to start when the system boots
6. Optionally, set an alternative ID mapping back end or customized ID mapping settings in the /etc/samba/smb.conf file. For details, see Section 3.4, “Understanding and configuring Samba ID mapping”.

7. Verify that the winbind service is running:

   # systemctl status winbind
   ...
      Active: active (running) since Tue 2018-11-06 19:10:40 CET; 15s ago

   Important

   To enable Samba to query domain user and group information, the winbind service must be running before you start smb.

8. If you installed the samba package to share directories and printers, enable and start the smb service:

   # systemctl enable --now smb

9. Optionally, if you are authenticating local logins to Active Directory, enable the winbind_krb5_localauth plug-in. See Section 3.5.2, “Using the local authorization plug-in for MIT Kerberos”.

Verification steps

1. Display an AD user’s details, such as the AD administrator account in the AD domain:

   # getent passwd "AD\administrator"
   AD\administrator:*:10000:10000::/home/administrator@AD:/bin/bash

2. Query the members of the domain users group in the AD domain:

   # getent group "AD\Domain Users"
       AD\domain users:x:10000:user1,user2

3. Optionally, verify that you can use domain users and groups when you set permissions on files and directories. For example, to set the owner of the /srv/samba/example.txt file to AD\administrator and the group to AD\Domain Users:

   # chown "AD\administrator":"AD\Domain Users" /srv/samba/example.txt

4. Verify that Kerberos authentication works as expected:

   1. On the AD domain member, obtain a ticket for the administrator@AD.EXAMPLE.COM principal:

      # kinit administrator@AD.EXAMPLE.COM

   2. Display the cached Kerberos ticket:

      # klist
      Ticket cache: KCM:0
      Default principal: administrator@AD.EXAMPLE.COM
      
      Valid starting       Expires              Service principal
      01.11.2018 10:00:00  01.11.2018 20:00:00  krbtgt/AD.EXAMPLE.COM@AD.EXAMPLE.COM
              renew until 08.11.2018 05:00:00

5. Display the available domains:

   # wbinfo --all-domains
   BUILTIN
   SAMBA-SERVER
   AD

Procedure

1. Install the required packages:

   [root@ipaserver ~]# yum install ipa-server-trust-ad samba-client

2. Authenticate as the IdM administrative user:

   [root@ipaserver ~]# kinit admin

3. Run the ipa-adtrust-install utility:

   [root@ipaserver ~]# ipa-adtrust-install

   The DNS service records are created automatically if IdM was installed with an integrated DNS server.

   If you installed IdM without an integrated DNS server, ipa-adtrust-install prints a list of service records that you must manually add to DNS before you can continue.

4. The script prompts you that the /etc/samba/smb.conf already exists and will be rewritten:

   WARNING: The smb.conf already exists. Running ipa-adtrust-install will break your existing Samba configuration.
   
   Do you wish to continue? [no]: yes

5. The script prompts you to configure the slapi-nis plug-in, a compatibility plug-in that allows older Linux clients to work with trusted users:

   Do you want to enable support for trusted domains in Schema Compatibility plugin?
   This will allow clients older than SSSD 1.9 and non-Linux clients to work with trusted users.
   
   Enable trusted domains support in slapi-nis? [no]: yes

6. When prompted, enter the NetBIOS name for the IdM domain or press Enter to accept the name suggested:

   Trust is configured but no NetBIOS domain name found, setting it now.
   Enter the NetBIOS name for the IPA domain.
   Only up to 15 uppercase ASCII letters, digits and dashes are allowed.
   Example: EXAMPLE.
   
   NetBIOS domain name [IDM]:

7. You are prompted to run the SID generation task to create a SID for any existing users:

   Do you want to run the ipa-sidgen task? [no]: yes

   This is a resource-intensive task, so if you have a high number of users, you can run this at another time.

8. (Optional) By default, the Dynamic RPC port range is defined as 49152-65535 for Windows Server 2008 and later. If you need to define a different Dynamic RPC port range for your environment, configure Samba to use different ports and open those ports in your firewall settings. The following example sets the port range to 55000-65000.

   [root@ipaserver ~]# net conf setparm global 'rpc server dynamic port range' 55000-65000
   [root@ipaserver ~]# firewall-cmd --add-port=55000-65000/tcp
   [root@ipaserver ~]# firewall-cmd --runtime-to-permanent

9. Restart the ipa service:

   [root@ipaserver ~]# ipactl restart

10. Use the smbclient utility to verify that Samba responds to Kerberos authentication from the IdM side:

    [root@ipaserver ~]# smbclient -L server.idm.example.com -k
    lp_load_ex: changing to config backend registry
        Sharename       Type      Comment
        ---------       ----      -------
        IPC$            IPC       IPC Service (Samba 4.12.3)
    ...

Procedure

1. Open the Group Policy Management Console.
2. Right-click Default Domain Policy, and select Edit. The Group Policy Management Editor opens.
3. Navigate to Computer Configuration → Policies → Windows Settings → Security Settings → Local Policies → Security Options.
4. Double-click the Network security: Configure encryption types allowed for Kerberos policy.
5. Select AES256_HMAC_SHA1 and, optionally, Future encryption types.
6. Click OK.
7. Close the Group Policy Management Editor.
8. Repeat the steps for the Default Domain Controller Policy.

9. Wait until the Windows domain controllers (DC) applied the group policy automatically. Alternatively, to apply the GPO manually on a DC, enter the following command using an account that has administrator permissions:

   C:\> gpupdate /force /target:computer

Procedure

1. Install the ipa-client-samba package:

   [root@idm_client]# yum install ipa-client-samba

2. Use the ipa-client-samba utility to prepare the client and create an initial Samba configuration:

   [root@idm_client]# ipa-client-samba
   Searching for IPA server...
   IPA server: DNS discovery
   Chosen IPA master: idm_server.idm.example.com
   SMB principal to be created: cifs/idm_client.idm.example.com@IDM.EXAMPLE.COM
   NetBIOS name to be used: IDM_CLIENT
   Discovered domains to use:
   
    Domain name: idm.example.com
   NetBIOS name: IDM
            SID: S-1-5-21-525930803-952335037-206501584
       ID range: 212000000 - 212199999
   
    Domain name: ad.example.com
   NetBIOS name: AD
            SID: None
       ID range: 1918400000 - 1918599999
   
   Continue to configure the system with these values? [no]: yes
   Samba domain member is configured. Please check configuration at /etc/samba/smb.conf and start smb and winbind services

3. By default, ipa-client-samba automatically adds the [homes] section to the /etc/samba/smb.conf file that dynamically shares a user’s home directory when the user connects. If users do not have home directories on this server, or if you do not want to share them, remove the following lines from /etc/samba/smb.conf:

   [homes]
       read only = no

4. Share directories and printers. For details, see:

   • Section 3.7, “Setting up a Samba file share that uses POSIX ACLs”
   • Section 3.9, “Setting up a share that uses Windows ACLs”
   • Section 3.15, “Setting up Samba as a print server”

5. Open the ports required for a Samba client in the local firewall:

   [root@idm_client]# firewall-cmd --permanent --add-service=samba-client
   [root@idm_client]# firewall-cmd --reload

6. Enable and start the smb and winbind services:

   [root@idm_client]# systemctl enable --now smb winbind

1. Authenticate and obtain a Kerberos ticket-granting ticket:

   $ kinit example_user

2. List the shares on the Samba server using Kerberos authentication:

   $ smbclient -L idm_client.idm.example.com -k
   lp_load_ex: changing to config backend registry
   
       Sharename       Type      Comment
       ---------       ----      -------
       example         Disk
       IPC$            IPC       IPC Service (Samba 4.12.3)
   ...

Procedure

1. Authenticate using the host’s keytab:

   [root@idm_client]# kinit -k

2. Use the ipa idrange-find command to display both the base ID and the ID range size of the new domain. For example, the following command displays the values for the ad.example.com domain:

   [root@idm_client]# ipa idrange-find --name="AD.EXAMPLE.COM_id_range" --raw
   ---------------
   1 range matched
   ---------------
     cn: AD.EXAMPLE.COM_id_range
     ipabaseid: 1918400000
     ipaidrangesize: 200000
     ipabaserid: 0
     ipanttrusteddomainsid: S-1-5-21-968346183-862388825-1738313271
     iparangetype: ipa-ad-trust
   ----------------------------
   Number of entries returned 1
   ----------------------------

   You need the values from the ipabaseid and ipaidrangesize attributes in the next steps.

3. To calculate the highest usable ID, use the following formula:

   maximum_range = ipabaseid + ipaidrangesize - 1

   With the values from the previous step, the highest usable ID for the ad.example.com domain is 1918599999 (1918400000 + 200000 - 1).

4. Edit the /etc/samba/smb.conf file, and add the ID mapping configuration for the domain to the [global] section:

   idmap config AD : range = 1918400000 - 1918599999
   idmap config AD : backend = sss

   Specify the value from ipabaseid attribute as the lowest and the computed value from the previous step as the highest value of the range.

5. Restart the smb and winbind services:

   [root@idm_client]# systemctl restart smb winbind

Verification steps

1. Authenticate as a user from the new domain and obtain a Kerberos ticket-granting ticket:

   $ kinit example_user

2. List the shares on the Samba server using Kerberos authentication:

   $ smbclient -L idm_client.idm.example.com -k
   lp_load_ex: changing to config backend registry
   
       Sharename       Type      Comment
       ---------       ----      -------
       example         Disk
       IPC$            IPC       IPC Service (Samba 4.12.3)
   ...

Procedure

1. Create the folder if it does not exist. For example:

   # mkdir -p /srv/samba/example/

2. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:

   # semanage fcontext -a -t samba_share_t "/srv/samba/example(/.*)?"
   # restorecon -Rv /srv/samba/example/

3. Set file system ACLs on the directory. For details, see:

   • Section 3.7.2, “Setting standard Linux ACLs on a Samba share that uses POSIX ACLs”
   • Section 3.7.3, “Setting extended ACLs on a Samba share that uses POSIX ACLs”.

4. Add the example share to the /etc/samba/smb.conf file. For example, to add the share write-enabled:

   [example]
   	path = /srv/samba/example/
   	read only = no

   Note

   Regardless of the file system ACLs; if you do not set read only = no, Samba shares the directory in read-only mode.

5. Verify the /etc/samba/smb.conf file:

   # testparm

6. Open the required ports and reload the firewall configuration using the firewall-cmd utility:

   # firewall-cmd --permanent --add-service=samba
   # firewall-cmd --reload

7. Restart the smb service:

   # systemctl restart smb

Procedure

1. Enable the following parameter in the share’s section in the /etc/samba/smb.conf file to enable ACL inheritance of extended ACLs:

   inherit acls = yes

   For details, see the parameter description in the smb.conf(5) man page.

2. Restart the smb service:

   # systemctl restart smb

3. Set the ACLs on the directory. For example:

   Example 3.2. Setting Extended ACLs

   The following procedure sets read, write, and execute permissions for the Domain Admins group, read, and execute permissions for the Domain Users group, and deny access to everyone else on the /srv/samba/example/ directory:

   1. Disable auto-granting permissions to the primary group of user accounts:

      # setfacl -m group::--- /srv/samba/example/
      # setfacl -m default:group::--- /srv/samba/example/

      The primary group of the directory is additionally mapped to the dynamic CREATOR GROUP principal. When you use extended POSIX ACLs on a Samba share, this principal is automatically added and you cannot remove it.

   2. Set the permissions on the directory:

      1. Grant read, write, and execute permissions to the Domain Admins group:

         # setfacl -m group:"DOMAIN\Domain Admins":rwx /srv/samba/example/

      2. Grant read and execute permissions to the Domain Users group:

         # setfacl -m group:"DOMAIN\Domain Users":r-x /srv/samba/example/

      3. Set permissions for the other ACL entry to deny access to users that do not match the other ACL entries:

         # setfacl -R -m other::--- /srv/samba/example/

      These settings apply only to this directory. In Windows, these ACLs are mapped to the This folder only mode.

   3. To enable the permissions set in the previous step to be inherited by new file system objects created in this directory:

      # setfacl -m default:group:"DOMAIN\Domain Admins":rwx /srv/samba/example/
      # setfacl -m default:group:"DOMAIN\Domain Users":r-x /srv/samba/example/
      # setfacl -m default:other::--- /srv/samba/example/

      With these settings, the This folder only mode for the principals is now set to This folder, subfolders, and files.

   Samba maps the permissions set in the procedure to the following Windows ACLs:

   Principal	Access	Applies to
   Domain\Domain Admins	Full control	This folder, subfolders, and files
   Domain\Domain Users	Read & execute	This folder, subfolders, and files
   Everyone [a]	None	This folder, subfolders, and files
   owner (Unix User\owner) [b]	Full control	This folder only
   primary_group (Unix User\primary_group) [c]	None	This folder only
   CREATOR OWNER [d] [e]	Full control	Subfolders and files only
   CREATOR GROUP [e] [f]	None	Subfolders and files only
   [a] Samba maps the permissions for this principal from the other ACL entry. [b] Samba maps the owner of the directory to this entry. [c] Samba maps the primary group of the directory to this entry. [d] On new file system objects, the creator inherits automatically the permissions of this principal. [e] Configuring or removing these principals from the ACLs not supported on shares that use POSIX ACLs. [f] On new file system objects, the creator’s primary group inherits automatically the permissions of this principal.

Procedure

1. For example, to enable all members of the Domain Users group to access a share while access is denied for the user account, add the following parameters to the share’s configuration:

   valid users = +DOMAIN\"Domain Users"
   invalid users = DOMAIN\user

   The invalid users parameter has a higher priority than the valid users parameter. For example, if the user account is a member of the Domain Users group, access is denied to this account when you use the previous example.

2. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. Add the following parameters to the configuration of the share in the /etc/samba/smb.conf file:

   hosts allow = 127.0.0.1 192.0.2.0/24 client1.example.com
   hosts deny = client2.example.com

   The hosts deny parameter has a higher priority than hosts allow. For example, if client1.example.com resolves to an IP address that is listed in the hosts allow parameter, access for this host is denied.

2. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. For example, to grant the SeDiskOperatorPrivilege privilege to the DOMAIN\Domain Admins group:

   # net rpc rights grant "DOMAIN\Domain Admins" SeDiskOperatorPrivilege -U "DOMAIN\administrator"
   Enter DOMAIN\administrator's password:
   Successfully granted rights.

   Note

   In a domain environment, grant SeDiskOperatorPrivilege to a domain group. This enables you to centrally manage the privilege by updating a user’s group membership.

2. To list all users and groups having SeDiskOperatorPrivilege granted:

   # net rpc rights list privileges SeDiskOperatorPrivilege -U "DOMAIN\administrator"
   Enter administrator's password:
   SeDiskOperatorPrivilege:
     BUILTIN\Administrators
     DOMAIN\Domain Admins

Procedure

1. To enable it globally for all shares, add the following settings to the [global] section of the /etc/samba/smb.conf file:

   vfs objects = acl_xattr
   map acl inherit = yes
   store dos attributes = yes

   Alternatively, you can enable Windows ACL support for individual shares, by adding the same parameters to a share’s section instead.

2. Restart the smb service:

   # systemctl restart smb

Procedure

1. Create the folder if it does not exists. For example:

   # mkdir -p /srv/samba/example/

2. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:

   # semanage fcontext -a -t samba_share_t "/srv/samba/example(/.*)?"
   # restorecon -Rv /srv/samba/example/

3. Add the example share to the /etc/samba/smb.conf file. For example, to add the share write-enabled:

   [example]
   	path = /srv/samba/example/
   	read only = no

   Note

   Regardless of the file system ACLs; if you do not set read only = no, Samba shares the directory in read-only mode.

4. If you have not enabled Windows ACL support in the [global] section for all shares, add the following parameters to the [example] section to enable this feature for this share:

   vfs objects = acl_xattr
   map acl inherit = yes
   store dos attributes = yes

5. Verify the /etc/samba/smb.conf file:

   # testparm

6. Open the required ports and reload the firewall configuration using the firewall-cmd utility:

   # firewall-cmd --permanent --add-service=samba
   # firewall-cmd --reload

7. Restart the smb service:

   # systemctl restart smb

Procedure

1. Create the local example group, if it does not exist:

   # groupadd example

2. Prepare the directory for Samba to store the user share definitions and set its permissions properly. For example:

   1. Create the directory:

      # mkdir -p /var/lib/samba/usershares/

   2. Set write permissions for the example group:

      # chgrp example /var/lib/samba/usershares/
      # chmod 1770 /var/lib/samba/usershares/

   3. Set the sticky bit to prevent users to rename or delete files stored by other users in this directory.

3. Edit the /etc/samba/smb.conf file and add the following to the [global] section:

   1. Set the path to the directory you configured to store the user share definitions. For example:

      usershare path = /var/lib/samba/usershares/

   2. Set how many user shares Samba allows to be created on this server. For example:

      usershare max shares = 100

      If you use the default of 0 for the usershare max shares parameter, user shares are disabled.

   3. Optionally, set a list of absolute directory paths. For example, to configure that Samba only allows to share subdirectories of the /data and /srv directory to be shared, set:

      usershare prefix allow list = /data /srv

   For a list of further user share-related parameters you can set, see the USERSHARES section in the smb.conf(5) man page.

4. Verify the /etc/samba/smb.conf file:

   # testparm

5. Reload the Samba configuration:

   # smbcontrol all reload-config

   Users are now able to create user shares.

Procedure

1. To display all user shares created by any user:

   $ net usershare info -l
   [share_1]
   path=/srv/samba/
   comment=
   usershare_acl=Everyone:R,host_name\user:F,
   guest_ok=y
   ...

   To list only shares created by the user who runs the command, omit the -l parameter.

2. To display only the information about specific shares, pass the share name or wild cards to the command. For example, to display the information about shares whose name starts with share_:

   $ net usershare info -l share_*

Procedure

1. To list the shares created by any user:

   $ net usershare list -l
   share_1
   share_2
   ...

   To list only shares created by the user who runs the command, omit the -l parameter.

2. To list only specific shares, pass the share name or wild cards to the command. For example, to list only shares whose name starts with share_:

   $ net usershare list -l share_*

Procedure

1. Edit the /etc/samba/smb.conf file:

   1. If this is the first guest share you set up on this server:

      1. Set map to guest = Bad User in the [global] section:

         [global]
                 ...
                 map to guest = Bad User

         With this setting, Samba rejects login attempts that use an incorrect password unless the user name does not exist. If the specified user name does not exist and guest access is enabled on a share, Samba treats the connection as a guest log in.

      2. By default, Samba maps the guest account to the nobody account on Red Hat Enterprise Linux. Alternatively, you can set a different account. For example:

         [global]
                 ...
                 guest account = user_name

         The account set in this parameter must exist locally on the Samba server. For security reasons, Red Hat recommends using an account that does not have a valid shell assigned.

   2. Add the guest ok = yes setting to the [example] share section:

      [example]
              ...
              guest ok = yes

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. Edit the /etc/samba/smb.conf file, and enable the fruit and streams_xattr VFS modules in the [global] section:

   vfs objects = fruit streams_xattr

   Important

   You must enable the fruit module before enabling streams_xattr. The fruit module uses alternate data streams (ADS). For this reason, you must also enable the streams_xattr module.

2. Optionally, to provide macOS Time Machine support on a share, add the following setting to the share configuration in the /etc/samba/smb.conf file:

   fruit:time machine = yes

3. Verify the /etc/samba/smb.conf file:

   # testparm

4. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. Connect to the share:

   # smbclient -U "DOMAIN\user_name" //server_name/share_name

2. Change into the /example/ directory:

   smb: \> d /example/

3. List the files in the directory:

   smb: \example\> ls
     .                    D         0  Thu Nov 1 10:00:00 2018
     ..                   D         0  Thu Nov 1 10:00:00 2018
     example.txt          N   1048576  Thu Nov 1 10:00:00 2018
   
            9950208 blocks of size 1024. 8247144 blocks available

4. Download the example.txt file:

   smb: \example\> get example.txt
   getting file \directory\subdirectory\example.txt of size 1048576 as example.txt (511975,0 KiloBytes/sec) (average 170666,7 KiloBytes/sec)

5. Disconnect from the share:

   smb: \example\> exit

Procedure

1. Edit the [global] section in the /etc/samba/smb.conf file:

   1. Add the following parameters:

      rpc_server:spoolss = external
      rpc_daemon:spoolssd = fork

   2. Optionally, you can set the following parameters:

      Parameter	Default	Description
      spoolssd:prefork_min_children	5	Minimum number of child processes
      spoolssd:prefork_max_children	25	Maximum number of child processes
      spoolssd:prefork_spawn_rate	5	Samba forks the number of new child processes set in this parameter, up to the value set in spoolssd:prefork_max_children, if a new connection is established
      spoolssd:prefork_max_allowed_clients	100	Number of clients, a child process serves
      spoolssd:prefork_child_min_life	60	Minimum lifetime of a child process in seconds. 60 seconds is the minimum.

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Restart the smb service:

   # systemctl restart smb

   After you restarted the service, Samba automatically starts smbd child processes:

   # ps axf
   ...
   30903 smbd
   30912  \_ smbd
   30913      \_ smbd
   30914      \_ smbd
   30915      \_ smbd
   ...

Procedure

1. On the Samba server, set up CUPS and add the printer to the CUPS back end. For details about configuring printers in CUPS; see the documentation provided in the CUPS web console (https://print_server_host_name:631/help) on the print server.

   Note

   Samba can only forward the print jobs to CUPS if CUPS is installed locally on the Samba print server.

2. Edit the /etc/samba/smb.conf file:

   1. If you want to enable the spoolssd service, add the following parameters to the [global] section:

      rpc_server:spoolss = external
      rpc_daemon:spoolssd = fork

   2. To configure the printing back end, add the [printers] section:

      [printers]
              comment = All Printers
              path = /var/tmp/
              printable = yes
              create mask = 0600

      Important

      The [printers] share name is hard-coded and cannot be changed.

3. Verify the /etc/samba/smb.conf file:

   # testparm

4. Open the required ports and reload the firewall configuration using the firewall-cmd utility:

   # firewall-cmd --permanent --add-service=samba
   # firewall-cmd --reload

5. Restart the smb service:

   # systemctl restart smb

Procedure

1. Edit the /etc/samba/smb.conf file:

   1. In the [global] section, disable automatic printer sharing by setting:

      load printers = no

   2. Add a section for each printer you want to share. For example, to share the printer named example in the CUPS back end as Example-Printer in Samba, add the following section:

      [Example-Printer]
              path = /var/tmp/
              printable = yes
              printer name = example

      You do not need individual spool directories for each printer. You can set the same spool directory in the path parameter for the printer as you set in the [printers] section.

2. Verify the /etc/samba/smb.conf file:

   # testparm

3. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. For example, to grant the SePrintOperatorPrivilege privilege to the printadmin group:

   # net rpc rights grant "printadmin" SePrintOperatorPrivilege -U "DOMAIN\administrator"
   Enter DOMAIN\administrator's password:
   Successfully granted rights.

   Note

   In a domain environment, grant SePrintOperatorPrivilege to a domain group. This enables you to centrally manage the privilege by updating a user’s group membership.

2. To list all users and groups having SePrintOperatorPrivilege granted:

   # net rpc rights list privileges SePrintOperatorPrivilege -U "DOMAIN\administrator"
   Enter administrator's password:
   SePrintOperatorPrivilege:
     BUILTIN\Administrators
     DOMAIN\printadmin

Procedure

1. Add the [print$] section to the /etc/samba/smb.conf file:

   [print$]
           path = /var/lib/samba/drivers/
           read only = no
           write list = @printadmin
           force group = @printadmin
           create mask = 0664
           directory mask = 2775

   Using these settings:

   • Only members of the printadmin group can upload printer drivers to the share.
   • The group of new created files and directories will be set to printadmin.
   • The permissions of new files will be set to 664.
   • The permissions of new directories will be set to 2775.

2. To upload only 64-bit drivers for all printers, include this setting in the [global] section in the /etc/samba/smb.conf file:

   spoolss: architecture = Windows x64

   Without this setting, Windows only displays drivers for which you have uploaded at least the 32-bit version.

3. Verify the /etc/samba/smb.conf file:

   # testparm

4. Reload the Samba configuration

   # smbcontrol all reload-config

5. Create the printadmin group if it does not exists:

   # groupadd printadmin

6. Grant the SePrintOperatorPrivilege privilege to the printadmin group.

   # net rpc rights grant "printadmin" SePrintOperatorPrivilege -U "DOMAIN\administrator"
   Enter DOMAIN\administrator's password:
   Successfully granted rights.

7. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:

   # semanage fcontext -a -t samba_share_t "/var/lib/samba/drivers(/.*)?"
   # restorecon -Rv /var/lib/samba/drivers/

8. Set the permissions on the /var/lib/samba/drivers/ directory:

   • If you use POSIX ACLs, set:

     # chgrp -R "printadmin" /var/lib/samba/drivers/
     # chmod -R 2775 /var/lib/samba/drivers/

   • If you use Windows ACLs, set:

     Principal	Access	Apply to
     CREATOR OWNER	Full control	Subfolders and files only
     Authenticated Users	Read & execute, List folder contents, Read	This folder, subfolders, and files
     printadmin	Full control	This folder, subfolders, and files

     For details about setting ACLs on Windows, see the Windows documentation.

Procedure

1. Log into a Windows computer using an account that is allowed to edit group policies, such as the AD domain Administrator user.
2. Open the Group Policy Management Console.

3. Right-click to your AD domain and select Create a GPO in this domain, and Link it here.

   
4. Enter a name for the GPO, such as Legacy Printer Driver Policy and click OK. The new GPO will be displayed under the domain entry.
5. Right-click to the newly-created GPO and select Edit to open the Group Policy Management Editor.

6. Navigate to Computer Configuration → Policies → Administrative Templates → Printers.

   

7. On the right side of the window, double-click Point and Print Restriction to edit the policy:

   1. Enable the policy and set the following options:

      1. Select Users can only point and print to these servers and enter the fully-qualified domain name (FQDN) of the Samba print server to the field next to this option.

      2. In both check boxes under Security Prompts, select Do not show warning or elevation prompt.

         
   2. Click OK.

8. Double-click Package Point and Print - Approved servers to edit the policy:

   1. Enable the policy and click the Show button.

   2. Enter the FQDN of the Samba print server.

      
   3. Close both the Show Contents and the policy’s properties window by clicking OK.
9. Close the Group Policy Management Editor.
10. Close the Group Policy Management Console.

Procedure

1. Enable the FIPS mode on RHEL:

   # fips-mode-setup --enable

2. Reboot the server:

   # reboot

3. Use the testparm utility to verify the configuration:

   # testparm -s

   If the command displays any errors or incompatibilities, fix them to ensure that Samba works correctly.

Procedure

1. Remove the server max protocol parameter from the [global] section in the /etc/samba/smb.conf file.

2. Reload the Samba configuration

   # smbcontrol all reload-config

Procedure

1. Rename all files on the share to lowercase.

   Note

   Using the settings in this procedure, files with names other than in lowercase will no longer be displayed.

2. Set the following parameters in the share’s section:

   case sensitive = true
   default case = lower
   preserve case = no
   short preserve case = no

   For details about the parameters, see their descriptions in the smb.conf(5) man page.

3. Verify the /etc/samba/smb.conf file:

   # testparm

4. Reload the Samba configuration:

   # smbcontrol all reload-config

Procedure

1. Edit the /etc/samba/smb.conf file, add the server min protocol parameter, and set the parameter to the minimum SMB protocol version the server should support. For example, to set the minimum SMB protocol version to SMB3, add:

   server min protocol = SMB3

2. Restart the smb service:

   # systemctl restart smb

Procedure

1. Manually create the /etc/samba/smb.conf file with the following settings:

   • For an AD domain member:

     [global]
     workgroup = domain_name
     security = ads
     passdb backend = tdbsam
     realm = AD_REALM

   • For an NT4 domain member:

     [global]
     workgroup = domain_name
     security = user
     passdb backend = tdbsam

2. Add an ID mapping configuration for the * default domain and for the domain you want to join to the [global] section in the /etc/samba/smb.conf file.

3. Verify the /etc/samba/smb.conf file:

   # testparm

4. Join the domain as the domain administrator:

   • To join an AD domain:

     # net ads join -U "DOMAIN\administrator"

   • To join an NT4 domain:

     # net rpc join -U "DOMAIN\administrator"

5. Append the winbind source to the passwd and group database entry in the /etc/nsswitch.conf file:

   passwd:     files winbind
   group:      files winbind

6. Enable and start the winbind service:

   # systemctl enable --now winbind

7. Optionally, configure PAM using the authselect utility.

   For details, see the authselect(8) man page.

8. Optionally for AD environments, configure the Kerberos client.

   For details, see the documentation of your Kerberos client.

1. Add the account:

   # net user add user password -U "DOMAIN\administrator"
   User user added

2. Optionally, use the remote procedure call (RPC) shell to enable the account on the AD DC or NT4 PDC. For example:

   # net rpc shell -U DOMAIN\administrator -S DC_or_PDC_name
   Talking to domain DOMAIN (S-1-5-21-1424831554-512457234-5642315751)
   
   net rpc> user edit disabled user: no
   Set user's disabled flag from [yes] to [no]
   
   net rpc> exit

Procedure

1. If you run the command as a user, smbpasswd changes the Samba password of the user who run the command. For example:

   [user@server ~]$ smbpasswd
   New SMB password: password
   Retype new SMB password: password

2. If you run smbpasswd as the root user, you can use the utility, for example, to:

   • Create a new user:

     [root@server ~]# smbpasswd -a user_name
     New SMB password: password` Retype new SMB password: [command]password`
     Added user user_name.

     Note

     Before you can add a user to the Samba database, you must create the account in the local operating system. See the Adding a new user from the command line section in the Configuring basic system settings guide.

   • Enable a Samba user:

     [root@server ~]# smbpasswd -e user_name
     Enabled user user_name.

   • Disable a Samba user:

     [root@server ~]# smbpasswd -x user_name
     Disabled user ser_name

   • Delete a user:

     [root@server ~]# smbpasswd -x user_name
     Deleted user user_name.

Procedure

1. Disable NFSv3 by adding the following lines to the [nfsd] section of the /etc/nfs.conf configuration file:

   [nfsd]
   
   vers3=no

2. Optionally, disable listening for the RPCBIND, MOUNT, and NSM protocol calls, which are not necessary in the NFSv4-only case. Disable related services:

   # systemctl mask --now rpc-statd.service rpcbind.service rpcbind.socket

3. Restart the NFS server:

   # systemctl restart nfs-server

Procedure

1. Monitor the operations serviced from the server:

   # watch --differences \
           "nfsstat --server | egrep --after-context=1 read\|write\|layout"
   
   Every 2.0s: nfsstat --server | egrep --after-context=1 read\|write\|layout
   
   putrootfh    read         readdir      readlink     remove	 rename
   2         0% 0         0% 1         0% 0         0% 0         0% 0         0%
   --
   setcltidconf verify	  write        rellockowner bc_ctl	 bind_conn
   0         0% 0         0% 0         0% 0         0% 0         0% 0         0%
   --
   getdevlist   layoutcommit layoutget    layoutreturn secinfononam sequence
   0         0% 29        1% 49        1% 5         0% 0         0% 2435     86%

2. The client and server use pNFS SCSI operations when:

   • The layoutget, layoutreturn, and layoutcommit counters increment. This means that the server is serving layouts.
   • The server read and write counters do not increment. This means that the clients are performing I/O requests directly to the SCSI devices.

Procedure

1. List the per-mount operation counters:

   # cat /proc/self/mountstats \
         | awk /scsi_lun_0/,/^$/ \
         | egrep device\|READ\|WRITE\|LAYOUT
   
   device 192.168.122.73:/exports/scsi_lun_0 mounted on /mnt/rhel7/scsi_lun_0 with fstype nfs4 statvers=1.1
       nfsv4:  bm0=0xfdffbfff,bm1=0x40f9be3e,bm2=0x803,acl=0x3,sessions,pnfs=LAYOUT_SCSI
               READ: 0 0 0 0 0 0 0 0
              WRITE: 0 0 0 0 0 0 0 0
           READLINK: 0 0 0 0 0 0 0 0
            READDIR: 0 0 0 0 0 0 0 0
          LAYOUTGET: 49 49 0 11172 9604 2 19448 19454
       LAYOUTCOMMIT: 28 28 0 7776 4808 0 24719 24722
       LAYOUTRETURN: 0 0 0 0 0 0 0 0
        LAYOUTSTATS: 0 0 0 0 0 0 0 0

2. In the results:

   • The LAYOUT statistics indicate requests where the client and server use pNFS SCSI operations.
   • The READ and WRITE statistics indicate requests where the client and server fall back to NFS operations.