Tillaabo-tilaabo ah oo hagitaan ah si aad u dejiso BIND DNS server-ka deegaanka chroot ee Koofiyada Cas (RHEL/CentOS) 7

Turjumaada maqaalka loo diyaariyey ardayda koorsada "Linux Security". Xiisaynaya horumarinta jihadan? Daawo duubista baahinta baahinta fasalka master-ka ee Ivan Piskunov "Amniga Linux marka loo eego Windows iyo MacOS"

Tillaabo-tilaabo ah oo hagitaan ah si aad u dejiso BIND DNS server-ka deegaanka chroot ee Koofiyada Cas (RHEL/CentOS) 7

Maqaalkan, waxaan ku dhex mari doonaa tillaabooyinka lagu dejinayo server-ka DNS ee RHEL 7 ama CentOS 7. Waxaan u isticmaalay Red Hat Enterprise Linux 7.4 bandhigga. Hadafkayagu waa in aanu samayno hal rikoodh A iyo hal rikoodh oo PTR ah oo ah meelaha hore iyo kuwa kale ee raadinta, siday u kala horreeyaan.

Marka hore, ku rakib xirmooyinka rpm lagama maarmaanka ah ee server-ka DNS.

FIIRO GAAR AH: RHEL waa inaad haysataa RHN firfircoon, ama waad awoodaa samee kayd khadka tooska ah ee maxaliga ah, kaas oo maamulaha xirmada "yum" uu ku rakibi karo xirmooyinka rpm lagama maarmaanka ah iyo ku-tiirsanaanta.

# yum install bind bind-chroot caching-nameserver

Dejintayda:

# hostname
golinuxhub-client.example
Мой IP-адрес 192.168.1.7
# ip address | egrep 'inet.*enp0s3'
    inet 192.168.1.7/24 brd 192.168.1.255 scope global dynamic enp0s3

Maadaama aan isticmaaleyno chroot, waxaan u baahanahay inaan joojino adeegga.

# systemctl stop named
# systemctl disable named

Ka dib koobi faylasha loo baahan yahay galka chroot.
FIIRO GAAR AH. Isticmaal dood -p koox ahaan cp si loo ilaaliyo xuquuqda iyo mulkiilayaasha.

[root@golinuxhub-client ~]# cp -rpvf /usr/share/doc/bind-9.9.4/sample/etc/*  /var/named/chroot/etc/
‘/usr/share/doc/bind-9.9.4/sample/etc/named.conf’ -> ‘/var/named/chroot/etc/named.conf’
‘/usr/share/doc/bind-9.9.4/sample/etc/named.rfc1912.zones’ -> ‘/var/named/chroot/etc/named.rfc1912.zones’

Dabadeed koobiyi faylasha la xidhiidha aagga meel cusub.

[root@golinuxhub-client ~]# cp -rpvf /usr/share/doc/bind-9.9.4/sample/var/named/* /var/named/chroot/var/named/
‘/usr/share/doc/bind-9.9.4/sample/var/named/data’ -> ‘/var/named/chroot/var/named/data’
‘/usr/share/doc/bind-9.9.4/sample/var/named/my.external.zone.db’ -> ‘/var/named/chroot/var/named/my.external.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/my.internal.zone.db’ -> ‘/var/named/chroot/var/named/my.internal.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.ca’ -> ‘/var/named/chroot/var/named/named.ca’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.empty’ -> ‘/var/named/chroot/var/named/named.empty’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.localhost’ -> ‘/var/named/chroot/var/named/named.localhost’
‘/usr/share/doc/bind-9.9.4/sample/var/named/named.loopback’ -> ‘/var/named/chroot/var/named/named.loopback’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves’ -> ‘/var/named/chroot/var/named/slaves’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves/my.ddns.internal.zone.db’ -> ‘/var/named/chroot/var/named/slaves/my.ddns.internal.zone.db’
‘/usr/share/doc/bind-9.9.4/sample/var/named/slaves/my.slave.internal.zone.db’ -> ‘/var/named/chroot/var/named/slaves/my.slave.internal.zone.db’
```bash
Теперь давайте посмотрим на основной файл конфигурации.
```bash
# cd /var/named/chroot/etc/

Nadiifi waxa ku jira magacaabay.conf oo dheji kuwan soo socda.

[root@golinuxhub-client etc]# vim named.conf
options {
        listen-on port 53 { 127.0.0.1; any; };
#       listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { localhost; any; };
        allow-query-cache { localhost; any; };
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

view my_resolver {
        match-clients      { localhost; any; };
        recursion yes;
        include "/etc/named.rfc1912.zones";
};

Aagga macluumaadka gaarka ah waa in lagu daraa /var/named/chroot/etc/named.rfc1912.zones. Ku dar qoraalada hoos. Faylka example.zone waa faylka aaga hore ee raadinta, iyo tusaale.rzone - gadaashii aagga roga.

FIIRO GAAR AH: Aagga dib u eegisku wuxuu ka kooban yahay 1.168.192 sababtoo ah ciwaanka IP-gaygu waa 192.168.1.7

zone "example" IN {
        type master;
        file "example.zone";
        allow-update { none; };
};

zone "1.168.192.in-addr.arpa" IN {
        type master;
        file "example.rzone";
        allow-update { none; };
};

Faylasha la xidhiidha aagagga waxay yaalliin halkan:

# cd /var/named/chroot/var/named/

Marka xigta, waxaan u abuuri doonaa faylal hore iyo gadaal. Magacyada faylka waxay la mid noqon doonaan kuwa sare ee faylka magaceedu.rfc1912.soone. Waxaan horey u haysanay dhowr qaab oo aan isticmaali karno.

# cp -p named.localhost  example.zone
# cp -p named.loopback example.rzone

Sida aad arki karto, oggolaanshaha hadda ee dhammaan faylasha iyo hagayaasha ayaa iska leh xidid.

[root@golinuxhub-client named]# ll
total 32
drwxr-xr-x. 2 root root    6 May 22  2017 data
-rw-r--r--. 1 root root  168 May 22  2017 example.rzone
-rw-r--r--. 1 root root  152 May 22  2017 example.zone
-rw-r--r--. 1 root root   56 May 22  2017 my.external.zone.db
-rw-r--r--. 1 root root   56 May 22  2017 my.internal.zone.db
-rw-r--r--. 1 root root 2281 May 22  2017 named.ca
-rw-r--r--. 1 root root  152 May 22  2017 named.empty
-rw-r--r--. 1 root root  152 May 22  2017 named.localhost
-rw-r--r--. 1 root root  168 May 22  2017 named.loopback
drwxr-xr-x. 2 root root   71 Feb 12 21:02 slaves

Beddel oggolaanshaha dhammaan faylasha si aad u muujiso isticmaaluhu inuu yahay mulkiilaha xidid iyo kooxda magacaabay.

# chown root:named *

Laakiin xogta mulkiiluhu waa inuu ahaado magac: magacaabay.

# chown -R  named:named data
# ls -l
total 32
drwxr-xr-x. 2 named named    6 May 22  2017 data
-rw-r--r--. 1 root  named  168 May 22  2017 example.rzone
-rw-r--r--. 1 root  named  152 May 22  2017 example.zone
-rw-r--r--. 1 root  named   56 May 22  2017 my.external.zone.db
-rw-r--r--. 1 root  named   56 May 22  2017 my.internal.zone.db
-rw-r--r--. 1 root  named 2281 May 22  2017 named.ca
-rw-r--r--. 1 root  named  152 May 22  2017 named.empty
-rw-r--r--. 1 root  named  152 May 22  2017 named.localhost
-rw-r--r--. 1 root  named  168 May 22  2017 named.loopback
drwxr-xr-x. 2 root  named   71 Feb 12 21:02 slaves

Ku dar macluumaadka soo socda faylkaaga aaga hore. Halkan waxaan ku abuureynaa rikoor A loogu talagalay localhost (golinuxhub-client) iyo mid kale oo loogu talagalay server-ka (golinuxhub-server).

# vim example.zone
$TTL 1D
@       IN SOA  example. root (
                                        1       ; serial
                                        3H      ; refresh
                                        15M     ; retry
                                        1W      ; expire
                                        1D )    ; minimum

                IN NS           example.

                        IN A 192.168.1.7
golinuxhub-server       IN A 192.168.1.5
golinuxhub-client       IN A 192.169.1.7

Marka xigta, ku dar waxa ku jira faylka aaga roga. Halkan waxaan ku abuureynaa rikoorka PTR ee golinuxhub-macmiilka iyo golinuxhub-server.

# vim example.rzone
$TTL 1D
@       IN SOA  example. root.example. (
                                        1997022700      ; serial
                                        28800           ; refresh
                                        14400           ; retry
                                        3600000         ; expire
                                        86400  )        ; minimum

        IN NS   example.
5       IN PTR  golinuxhub-server.example.
7       IN PTR  golinuxhub-client.example.

Kahor intaanan bilaabin adeegga magac-Croot, aynu eegno habaynta faylka aagga.

[root@golinuxhub-client named]# named-checkzone golinuxhub-client.example example.zone
zone golinuxhub-client.example/IN: loaded serial 1
OK

[root@golinuxhub-client named]# named-checkzone golinuxhub-client.example example.rzone
zone golinuxhub-client.example/IN: loaded serial 1997022700
OK

Wax walba waxay u muuqdaan kuwo wanaagsan. Hadda hubi faylka qaabeynta adoo isticmaalaya amarka soo socda.

[root@golinuxhub-client named]# named-checkconf -t /var/named/chroot/ /etc/named.conf

Markaa, wax walba si guul leh ayaa loo dhameeyay.

[root@golinuxhub-client named]# echo $?
0

FIIRO GAAR AH: Waxaan haystaa SELinux qaab ogolaansho ah

# getenforce
Permissive

Wax walba waxay u muuqdaan kuwo wanaagsan, markaa waa waqtigii la bilaabi lahaa adeeggayaga magac-Croot .

[root@golinuxhub-client named]# systemctl restart named-chroot

[root@golinuxhub-client named]# systemctl status named-chroot
● named-chroot.service - Berkeley Internet Name Domain (DNS)
   Loaded: loaded (/usr/lib/systemd/system/named-chroot.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2018-02-12 21:53:23 IST; 19s ago
  Process: 5236 ExecStop=/bin/sh -c /usr/sbin/rndc stop > /dev/null 2>&1 || /bin/kill -TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 5327 ExecStart=/usr/sbin/named -u named -c ${NAMEDCONF} -t /var/named/chroot $OPTIONS (code=exited, status=0/SUCCESS)
  Process: 5325 ExecStartPre=/bin/bash -c if [ ! "$DISABLE_ZONE_CHECKING" == "yes" ]; then /usr/sbin/named-checkconf -t /var/named/chroot -z "$NAMEDCONF"; else echo "Checking of zone files is disabled"; fi (code=exited, status=0/SUCCESS)
 Main PID: 5330 (named)
   CGroup: /system.slice/named-chroot.service
           └─5330 /usr/sbin/named -u named -c /etc/named.conf -t /var/named/chroot

Feb 12 21:53:23 golinuxhub-client.example named[5330]: managed-keys-zone/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 0.in-addr.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.0.0.127.in-addr.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.168.192.in-addr.arpa/IN/my_resolver: loaded serial 1997022700
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone example/IN/my_resolver: loaded serial 1
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone localhost/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: zone localhost.localdomain/IN/my_resolver: loaded serial 0
Feb 12 21:53:23 golinuxhub-client.example named[5330]: all zones loaded
Feb 12 21:53:23 golinuxhub-client.example named[5330]: running
```bash
Убедитесь, что resolv.conf содержит ваш IP-адрес, чтобы он мог работать в качестве DNS-сервера.
```bash
# cat /etc/resolv.conf
search example
nameserver 192.168.1.7
```bash
Давайте проверим наш DNS-сервер для обратной зоны, используя dig.
```bash
[root@golinuxhub-client named]# dig -x 192.168.1.5

; <<>> DiG 9.9.4-RedHat-9.9.4-50.el7 <<>> -x 192.168.1.5
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40331
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;5.1.168.192.in-addr.arpa.      IN      PTR

;; ANSWER SECTION:
5.1.168.192.in-addr.arpa. 86400 IN      PTR     golinuxhub-server.example.

;; AUTHORITY SECTION:
1.168.192.in-addr.arpa. 86400   IN      NS      example.

;; ADDITIONAL SECTION:
example.                86400   IN      A       192.168.1.7

;; Query time: 1 msec
;; SERVER: 192.168.1.7#53(192.168.1.7)
;; WHEN: Mon Feb 12 22:13:17 IST 2018
;; MSG SIZE  rcvd: 122

Sida aad arki karto, waxaan ka helnay jawaab celin togan (JAWAAB) codsigeena (QUERY).

[root@golinuxhub-client named]# dig -x 192.168.1.7

; <<>> DiG 9.9.4-RedHat-9.9.4-50.el7 <<>> -x 192.168.1.7
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55804
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;7.1.168.192.in-addr.arpa.      IN      PTR

;; ANSWER SECTION:
7.1.168.192.in-addr.arpa. 86400 IN      PTR     golinuxhub-client.example.

;; AUTHORITY SECTION:
1.168.192.in-addr.arpa. 86400   IN      NS      example.

;; ADDITIONAL SECTION:
example.                86400   IN      A       192.168.1.7

;; Query time: 1 msec
;; SERVER: 192.168.1.7#53(192.168.1.7)
;; WHEN: Mon Feb 12 22:12:54 IST 2018
;; MSG SIZE  rcvd: 122

Waxaan u hubin karnaa aagga tooska ah si la mid ah.

[root@golinuxhub-client named]# nslookup golinuxhub-client.example
Server:         192.168.1.7
Address:        192.168.1.7#53

Name:   golinuxhub-client.example
Address: 192.169.1.7

[root@golinuxhub-client named]# nslookup golinuxhub-server.example
Server:         192.168.1.7
Address:        192.168.1.7#53

Name:   golinuxhub-server.example
Address: 192.168.1.5

Maqaalkani waxoogaa waa duugoobay sida RHEL 7 uma baahnid inaad nuqul ka sameysid faylalka qaabeynta isku xidhka chroot. Tababarka Tallaabo-tallaabo ah: Ku habeyn Server-ka DNS addoo isticmaalaya bind chroot (CentOS/RHEL 7).

Source: www.habr.com

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