第 6 章 配置 RHEL 主机以使用 AD 作为身份验证提供程序

流程

1. 在本地创建 AD_user 用户帐户而不为其分配密码：

   # useradd AD_user

2. 打开 /etc/nsswitch.conf 文件进行编辑，并确保该文件包含以下行：

   passwd:     sss files systemd
   group:      sss files systemd
   shadow:     files sss

3. 打开 /etc/krb5.conf 文件进行编辑，并确保该文件包含以下部分和项目：

   # To opt out of the system crypto-policies configuration of krb5, remove the
   # symlink at /etc/krb5.conf.d/crypto-policies which will not be recreated.
   includedir /etc/krb5.conf.d/
   
   [logging]
       default = FILE:/var/log/krb5libs.log
       kdc = FILE:/var/log/krb5kdc.log
       admin_server = FILE:/var/log/kadmind.log
   
   [libdefaults]
       dns_lookup_realm = false
       ticket_lifetime = 24h
       renew_lifetime = 7d
       forwardable = true
       rdns = false
       pkinit_anchors = /etc/pki/tls/certs/ca-bundle.crt
       spake_preauth_groups = edwards25519
       default_realm = EXAMPLE.COM
       default_ccache_name = KEYRING:persistent:%{uid}
   
   [realms]
    EXAMPLE.COM = {
        kdc = ad.example.com
        admin_server = ad.example.com
    }
   
   [domain_realm]
    .example.com = EXAMPLE.COM
    example.com = EXAMPLE.COM

4. 创建 /etc/sssd/sssd.conf 文件，并将以下部分和行插入到该文件中：

   [sssd]
       services = nss, pam
       domains = EXAMPLE.COM
   
   [domain/EXAMPLE.COM]
       id_provider = files
       auth_provider = krb5
       krb5_realm = EXAMPLE.COM
       krb5_server = ad.example.com

5. 更改 /etc/sssd/sssd.conf 文件的权限：

   # chmod 600 /etc/sssd/sssd.conf

6. 启动安全性系统服务守护进程（SSSD）：

   # systemctl start sssd

7. 启用 SSSD：

   # systemctl enable sssd

8. 打开 /etc/pam.d/system-auth 文件，修改该文件使其包含以下部分和行：

   # Generated by authselect on Wed May  8 08:55:04 2019
   # Do not modify this file manually.
   
   auth        required                                     pam_env.so
   auth        required                                     pam_faildelay.so delay=2000000
   auth        [default=1 ignore=ignore success=ok]         pam_succeed_if.so uid >= 1000 quiet
   auth        [default=1 ignore=ignore success=ok]         pam_localuser.so
   auth        sufficient                                   pam_unix.so nullok try_first_pass
   auth        requisite                                    pam_succeed_if.so uid >= 1000 quiet_success
   auth        sufficient                                   pam_sss.so forward_pass
   auth        required                                     pam_deny.so
   
   account     required                                     pam_unix.so
   account     sufficient                                   pam_localuser.so
   account     sufficient                                   pam_succeed_if.so uid < 1000 quiet
   account     [default=bad success=ok user_unknown=ignore] pam_sss.so
   account     required                                     pam_permit.so
   
   password    requisite                                    pam_pwquality.so try_first_pass local_users_only
   password    sufficient                                   pam_unix.so sha512 shadow nullok try_first_pass use_authtok
   password    sufficient                                   pam_sss.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     [success=1 default=ignore]                   pam_succeed_if.so service in crond quiet use_uid
   session     required                                     pam_unix.so
   session     optional                                     pam_sss.so

9. 将 /etc/pam.d/system-auth 文件的内容复制到 /etc/pam.d/password-auth 文件中。输入 yes 来确认覆盖文件的当前内容：

   # cp /etc/pam.d/system-auth /etc/pam.d/password-auth
   cp: overwrite '/etc/pam.d/password-auth'? yes

验证步骤

1. 为 AD_user 请求 Kerberos 票据 (TGT)。根据请求输入 AD_user 密码：

   # kinit AD_user
   Password for AD_user@EXAMPLE.COM:

2. 显示获得的 TGT：

   # klist
   Ticket cache: KEYRING:persistent:0:0
   Default principal: AD_user@EXAMPLE.COM
   
   Valid starting     Expires            Service principal
   11/02/20 04:16:38  11/02/20 14:16:38  krbtgt/EXAMPLE.COM@EXAMPLE.COM
   	renew until 18/02/20 04:16:34