Daban-daban na aikin DNS tuni marubucin ya taɓa taɓa su akai-akai a adadin buga a matsayin wani ɓangare na blog. Har ila yau, babban abin da aka fi mayar da hankali a kai shi ne inganta tsaron wannan mahimmin sabis na Intanet.
Har zuwa kwanan nan, duk da bayyananniyar raunin zirga-zirgar zirga-zirgar DNS, wanda har yanzu, ga mafi yawan ɓangaren, ana watsa shi a bayyane, zuwa ayyukan ƙeta a ɓangaren masu samarwa da ke neman ƙara yawan kuɗin shiga ta hanyar shigar da talla a cikin abun ciki, hukumomin tsaro na gwamnati da ba da izini. da kuma kawai masu laifi, tsarin , duk da kasancewar fasaha daban-daban kamar DNSSEC/DANE, DNScrypt, DNS-over-TLS da DNS-over-HTTPS, sun tsaya cak. Kuma idan mafita na uwar garken, kuma wasu daga cikinsu sun wanzu na dogon lokaci, an san su sosai kuma suna samuwa, tallafin su daga software na abokin ciniki yana barin abubuwa da yawa da ake so.
Abin farin ciki, yanayin yana canzawa. Musamman, masu haɓaka mashahuriyar mai binciken Firefox game da shirye-shiryen kunna yanayin tallafi ta tsohuwa (DoH) sannu. Wannan yakamata ya taimaka kare zirga-zirgar DNS na mai amfani da WWW daga barazanar da ke sama, amma yana iya yuwuwar gabatar da sababbi.
1. Matsalolin DNS-over-HTTPS
A kallo na farko, farkon gabatarwar taro na DNS-over-HTTPS cikin software na Intanet yana haifar da amsa mai kyau kawai. Duk da haka, shaidan, kamar yadda suke faɗa, yana cikin cikakkun bayanai.
Matsala ta farko da ta iyakance iyakar amfani da DoH shine mayar da hankali ga zirga-zirgar yanar gizo kawai. Lallai, ka'idar HTTP da sigar HTTP/2 na yanzu, wacce DoH ta dogara akansa, sune tushen WWW. Amma Intanet ba yanar gizo ba ce kawai. Akwai mashahuran ayyuka da yawa, irin su imel, saƙonnin gaggawa daban-daban, tsarin canja wurin fayil, yawo multimedia, da sauransu, waɗanda basa amfani da HTTP. Don haka, duk da fahimtar yawancin DoH a matsayin panacea, ya zama mara amfani ba tare da ƙarin ƙoƙari (kuma wanda ba dole ba) ga wani abu banda fasahar bincike. Af, DNS-over-TLS yana kama da ɗan takara mafi cancanta don wannan rawar, wanda ke aiwatar da ƙaddamar da daidaitattun zirga-zirgar DNS a cikin amintacciyar ƙa'idar TLS.
Matsala ta biyu, wacce ke da yuwuwar ta fi ta farko mahimmanci, ita ce watsi da haƙiƙanin rarrabawar DNS ta hanyar ƙira don amfani da sabar DoH ɗaya da aka ƙayyade a cikin saitunan burauza. Musamman, Mozilla yana ba da shawarar amfani da sabis daga Cloudflare. Haka kuma wasu fitattun mutane a Intanet, musamman Google sun kaddamar da irin wannan sabis. Ya bayyana cewa aiwatar da DNS-over-HTTPS a cikin hanyar da aka gabatar da shi a halin yanzu yana ƙara dogaro ga masu amfani da ƙarshen akan manyan ayyuka. Ba asiri ba ne cewa bayanan da bincike na DNS queries iya bayar zai iya tattara ko da ƙarin bayanai game da shi, da kuma ƙara da daidaito da kuma dacewa.
A wannan batun, marubucin ya kasance kuma ya kasance mai goyon bayan aiwatar da taro ba na DNS-over-HTTPS ba, amma na DNS-over-TLS tare da DNSSEC / DANE a matsayin duniya, amintacce kuma ba ya dace da ci gaba da ƙaddamar da hanyoyin Intanet. don tabbatar da tsaro na zirga-zirgar DNS. Abin baƙin cikin shine, saboda dalilai masu ma'ana, mutum ba zai iya tsammanin saurin gabatar da tallafin taro don madadin DoH zuwa software na abokin ciniki ba, kuma har yanzu yanki ne na masu sha'awar fasahar tsaro.
Amma tun da yanzu muna da DoH, me zai hana mu yi amfani da shi bayan guje wa yuwuwar sa ido ta kamfanoni ta hanyar sabar su zuwa uwar garken DNS-over-HTTPS namu?
2. DNS-over-HTTPS yarjejeniya
Idan ka dubi ma'auni kwatanta ka'idar DNS-over-HTTPS, zaku iya ganin cewa, a zahiri, API ɗin gidan yanar gizo ne wanda ke ba ku damar ɓoye daidaitaccen kunshin DNS a cikin ka'idar HTTP/2. Ana aiwatar da wannan ta hanyar kanun labarai na HTTP na musamman, da kuma jujjuya tsarin binary na bayanan DNS da aka watsa (duba. da takardu masu zuwa) a cikin wani nau'i wanda ke ba ku damar watsawa da karɓar su, da kuma aiki tare da mahimman metadata.
Dangane da ma'auni, HTTP/2 kawai da amintaccen haɗin TLS ke tallafawa.
Ana iya aika buƙatar DNS ta amfani da daidaitattun hanyoyin GET da POST. A cikin shari'ar farko, ana canza buƙatar zuwa kirtani mai tushe64URL, kuma a cikin na biyu, ta jikin buƙatun POST a cikin nau'in binary. A wannan yanayin, ana amfani da nau'in bayanan MIME na musamman yayin buƙatun DNS da amsawa aikace-aikace/dns-saƙon.
root@eprove:~ # curl -H 'accept: application/dns-message' 'https://my.domaint/dns-query?dns=q80BAAABAAAAAAAAB2V4YW1wbGUDY29tAAABAAE' -v
* Trying 2001:100:200:300::400:443...
* TCP_NODELAY set
* Connected to eprove.net (2001:100:200:300::400) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /usr/local/share/certs/ca-root-nss.crt
CApath: none
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN, server accepted to use h2
* Server certificate:
* subject: CN=my.domain
* start date: Jul 22 00:07:13 2019 GMT
* expire date: Oct 20 00:07:13 2019 GMT
* subjectAltName: host "my.domain" matched cert's "my.domain"
* issuer: C=US; O=Let's Encrypt; CN=Let's Encrypt Authority X3
* SSL certificate verify ok.
* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Using Stream ID: 1 (easy handle 0x801441000)
> GET /dns-query?dns=q80BAAABAAAAAAAAB2V4YW1wbGUDY29tAAABAAE HTTP/2
> Host: eprove.net
> User-Agent: curl/7.65.3
> accept: application/dns-message
>
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* Connection state changed (MAX_CONCURRENT_STREAMS == 100)!
< HTTP/2 200
< server: h2o/2.3.0-beta2
< content-type: application/dns-message
< cache-control: max-age=86274
< date: Thu, 12 Sep 2019 13:07:25 GMT
< strict-transport-security: max-age=15768000; includeSubDomains; preload
< content-length: 45
<
Warning: Binary output can mess up your terminal. Use "--output -" to tell
Warning: curl to output it to your terminal anyway, or consider "--output
Warning: <FILE>" to save to a file.
* Failed writing body (0 != 45)
* stopped the pause stream!
* Connection #0 to host eprove.net left intactHar ila yau kula da take sarrafa cache: a cikin martani daga uwar garken gidan yanar gizo. A cikin siga max-shekaru ya ƙunshi ƙimar TTL don rikodin DNS ɗin da ake dawowa (ko mafi ƙarancin ƙimar idan ana dawo da saitin su).
Dangane da abin da ke sama, aikin uwar garken DoH ya ƙunshi matakai da yawa.
- Karɓi buƙatun HTTP. Idan wannan shine GET to yanke fakitin daga tushe64URL rufaffiyar.
- Aika wannan fakitin zuwa uwar garken DNS.
- Samu amsa daga uwar garken DNS
- Nemo mafi ƙarancin ƙimar TTL a cikin bayanan da aka karɓa.
- Koma amsa ga abokin ciniki ta HTTP.
3. Naku uwar garken DNS-over-HTTPS
Hanya mafi sauƙi, mafi sauri kuma mafi inganci don gudanar da uwar garken DNS-over-HTTPS naku shine amfani da sabar gidan yanar gizo ta HTTP/2 , wanda marubucin ya riga ya rubuta a takaice (duba "").
Wannan zaɓin yana goyan bayan gaskiyar cewa duk lambar uwar garken DoH ɗin ku za a iya aiwatar da shi gabaɗaya ta amfani da mai fassarar da aka haɗa cikin H2O kanta. . Baya ga daidaitattun ɗakunan karatu, don musayar bayanai tare da uwar garken DNS, kuna buƙatar ɗakin karatu na (mrbgem) Socket, wanda, da sa'a, an riga an haɗa shi cikin sigar haɓaka ta yanzu na H2O 2.3.0-beta2 a cikin tashar jiragen ruwa na FreeBSD. Koyaya, ba shi da wahala a ƙara shi zuwa kowane sigar da ta gabata ta cloning ma'ajiyar zuwa kasida /daps kafin hadawa.
root@beta:~ # uname -v
FreeBSD 12.0-RELEASE-p10 GENERIC
root@beta:~ # cd /usr/ports/www/h2o
root@beta:/usr/ports/www/h2o # make extract
===> License MIT BSD2CLAUSE accepted by the user
===> h2o-2.2.6 depends on file: /usr/local/sbin/pkg - found
===> Fetching all distfiles required by h2o-2.2.6 for building
===> Extracting for h2o-2.2.6.
=> SHA256 Checksum OK for h2o-h2o-v2.2.6_GH0.tar.gz.
===> h2o-2.2.6 depends on file: /usr/local/bin/ruby26 - found
root@beta:/usr/ports/www/h2o # cd work/h2o-2.2.6/deps/
root@beta:/usr/ports/www/h2o/work/h2o-2.2.6/deps # git clone https://github.com/iij/mruby-socket.git
Клонирование в «mruby-socket»…
remote: Enumerating objects: 385, done.
remote: Total 385 (delta 0), reused 0 (delta 0), pack-reused 385
Получение объектов: 100% (385/385), 98.02 KiB | 647.00 KiB/s, готово.
Определение изменений: 100% (208/208), готово.
root@beta:/usr/ports/www/h2o/work/h2o-2.2.6/deps # ll
total 181
drwxr-xr-x 9 root wheel 18 12 авг. 16:09 brotli/
drwxr-xr-x 2 root wheel 4 12 авг. 16:09 cloexec/
drwxr-xr-x 2 root wheel 5 12 авг. 16:09 golombset/
drwxr-xr-x 4 root wheel 35 12 авг. 16:09 klib/
drwxr-xr-x 2 root wheel 5 12 авг. 16:09 libgkc/
drwxr-xr-x 4 root wheel 26 12 авг. 16:09 libyrmcds/
drwxr-xr-x 13 root wheel 32 12 авг. 16:09 mruby/
drwxr-xr-x 5 root wheel 11 12 авг. 16:09 mruby-digest/
drwxr-xr-x 5 root wheel 10 12 авг. 16:09 mruby-dir/
drwxr-xr-x 5 root wheel 10 12 авг. 16:09 mruby-env/
drwxr-xr-x 4 root wheel 9 12 авг. 16:09 mruby-errno/
drwxr-xr-x 5 root wheel 14 12 авг. 16:09 mruby-file-stat/
drwxr-xr-x 5 root wheel 10 12 авг. 16:09 mruby-iijson/
drwxr-xr-x 5 root wheel 11 12 авг. 16:09 mruby-input-stream/
drwxr-xr-x 6 root wheel 11 12 авг. 16:09 mruby-io/
drwxr-xr-x 5 root wheel 10 12 авг. 16:09 mruby-onig-regexp/
drwxr-xr-x 4 root wheel 10 12 авг. 16:09 mruby-pack/
drwxr-xr-x 5 root wheel 10 12 авг. 16:09 mruby-require/
drwxr-xr-x 6 root wheel 10 12 сент. 16:10 mruby-socket/
drwxr-xr-x 2 root wheel 9 12 авг. 16:09 neverbleed/
drwxr-xr-x 2 root wheel 13 12 авг. 16:09 picohttpparser/
drwxr-xr-x 2 root wheel 4 12 авг. 16:09 picotest/
drwxr-xr-x 9 root wheel 16 12 авг. 16:09 picotls/
drwxr-xr-x 4 root wheel 8 12 авг. 16:09 ssl-conservatory/
drwxr-xr-x 8 root wheel 18 12 авг. 16:09 yaml/
drwxr-xr-x 2 root wheel 8 12 авг. 16:09 yoml/
root@beta:/usr/ports/www/h2o/work/h2o-2.2.6/deps # cd ../../..
root@beta:/usr/ports/www/h2o # make install clean
...Tsarin uwar garken gidan yanar gizo gabaɗaya daidai ne.
root@beta:/usr/ports/www/h2o # cd /usr/local/etc/h2o/
root@beta:/usr/local/etc/h2o # cat h2o.conf
# this sample config gives you a feel for how h2o can be used
# and a high-security configuration for TLS and HTTP headers
# see https://h2o.examp1e.net/ for detailed documentation
# and h2o --help for command-line options and settings
# v.20180207 (c)2018 by Max Kostikov http://kostikov.co e-mail: [email protected]
user: www
pid-file: /var/run/h2o.pid
access-log:
path: /var/log/h2o/h2o-access.log
format: "%h %v %l %u %t "%r" %s %b "%{Referer}i" "%{User-agent}i""
error-log: /var/log/h2o/h2o-error.log
expires: off
compress: on
file.dirlisting: off
file.send-compressed: on
file.index: [ 'index.html', 'index.php' ]
listen:
port: 80
listen:
port: 443
ssl:
cipher-suite: ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS
cipher-preference: server
dh-file: /etc/ssl/dhparams.pem
certificate-file: /usr/local/etc/letsencrypt/live/eprove.net/fullchain.pem
key-file: /usr/local/etc/letsencrypt/live/my.domain/privkey.pem
hosts:
"*.my.domain":
paths: &go_tls
"/":
redirect:
status: 301
url: https://my.domain/
"my.domain:80":
paths: *go_tls
"my.domain:443":
header.add: "Strict-Transport-Security: max-age=15768000; includeSubDomains; preload"
paths:
"/dns-query":
mruby.handler-file: /usr/local/etc/h2o/h2odoh.rbBanda kawai shine mai kula da URL /dns-tambaya wanda uwar garken DNS-over-HTTPS ɗin mu, wanda aka rubuta a cikin mruby kuma aka kira ta zaɓin mai kulawa, yana da alhakin gaske. mruby.handler-file.
root@beta:/usr/local/etc/h2o # cat h2odoh.rb
# H2O HTTP/2 web server as DNS-over-HTTP service
# v.20190908 (c)2018-2019 Max Kostikov https://kostikov.co e-mail: [email protected]
proc {|env|
if env['HTTP_ACCEPT'] == "application/dns-message"
case env['REQUEST_METHOD']
when "GET"
req = env['QUERY_STRING'].gsub(/^dns=/,'')
# base64URL decode
req = req.tr("-_", "+/")
if !req.end_with?("=") && req.length % 4 != 0
req = req.ljust((req.length + 3) & ~3, "=")
end
req = req.unpack1("m")
when "POST"
req = env['rack.input'].read
else
req = ""
end
if req.empty?
[400, { 'content-type' => 'text/plain' }, [ "Bad Request" ]]
else
# --- ask DNS server
sock = UDPSocket.new
sock.connect("localhost", 53)
sock.send(req, 0)
str = sock.recv(4096)
sock.close
# --- find lowest TTL in response
nans = str[6, 2].unpack1('n') # number of answers
if nans > 0 # no DNS failure
shift = 12
ttl = 0
while nans > 0
# process domain name compression
if str[shift].unpack1("C") < 192
shift = str.index("x00", shift) + 5
if ttl == 0 # skip question section
next
end
end
shift += 6
curttl = str[shift, 4].unpack1('N')
shift += str[shift + 4, 2].unpack1('n') + 6 # responce data size
if ttl == 0 or ttl > curttl
ttl = curttl
end
nans -= 1
end
cc = 'max-age=' + ttl.to_s
else
cc = 'no-cache'
end
[200, { 'content-type' => 'application/dns-message', 'content-length' => str.size, 'cache-control' => cc }, [ str ] ]
end
else
[415, { 'content-type' => 'text/plain' }, [ "Unsupported Media Type" ]]
end
}Lura cewa uwar garken caching na gida yana da alhakin sarrafa fakitin DNS, a wannan yanayin daga daidaitattun rarrabawar FreeBSD. Ta fuskar tsaro, wannan ita ce mafita mafi kyau. Koyaya, babu abin da zai hana ku maye gurbin Localhost zuwa wani adireshin DNS na daban wanda kuke son amfani da shi.
root@beta:/usr/local/etc/h2o # local-unbound verison
usage: local-unbound [options]
start unbound daemon DNS resolver.
-h this help
-c file config file to read instead of /var/unbound/unbound.conf
file format is described in unbound.conf(5).
-d do not fork into the background.
-p do not create a pidfile.
-v verbose (more times to increase verbosity)
Version 1.8.1
linked libs: mini-event internal (it uses select), OpenSSL 1.1.1a-freebsd 20 Nov 2018
linked modules: dns64 respip validator iterator
BSD licensed, see LICENSE in source package for details.
Report bugs to [email protected]
root@eprove:/usr/local/etc/h2o # sockstat -46 | grep unbound
unbound local-unbo 69749 3 udp6 ::1:53 *:*
unbound local-unbo 69749 4 tcp6 ::1:53 *:*
unbound local-unbo 69749 5 udp4 127.0.0.1:53 *:*
unbound local-unbo 69749 6 tcp4 127.0.0.1:53 *:*Abin da ya rage shi ne sake kunna H2O kuma ku ga abin da ya zo daga gare ta.
root@beta:/usr/local/etc/h2o # service h2o restart
Stopping h2o.
Waiting for PIDS: 69871.
Starting h2o.
start_server (pid:70532) starting now...4. Gwaji
Don haka, bari mu bincika sakamakon ta hanyar sake aika buƙatun gwaji da duba zirga-zirgar hanyar sadarwa ta amfani da mai amfani tppdump.
root@beta/usr/local/etc/h2o # curl -H 'accept: application/dns-message' 'https://my.domain/dns-query?dns=q80BAAABAAAAAAAAB2V4YW1wbGUDY29tAAABAAE'
Warning: Binary output can mess up your terminal. Use "--output -" to tell
Warning: curl to output it to your terminal anyway, or consider "--output
Warning: <FILE>" to save to a file.
...
root@beta:~ # tcpdump -n -i lo0 udp port 53 -xx -XX -vv
tcpdump: listening on lo0, link-type NULL (BSD loopback), capture size 262144 bytes
16:32:40.420831 IP (tos 0x0, ttl 64, id 37575, offset 0, flags [none], proto UDP (17), length 57, bad cksum 0 (->e9ea)!)
127.0.0.1.21070 > 127.0.0.1.53: [bad udp cksum 0xfe38 -> 0x33e3!] 43981+ A? example.com. (29)
0x0000: 0200 0000 4500 0039 92c7 0000 4011 0000 ....E..9....@...
0x0010: 7f00 0001 7f00 0001 524e 0035 0025 fe38 ........RN.5.%.8
0x0020: abcd 0100 0001 0000 0000 0000 0765 7861 .............exa
0x0030: 6d70 6c65 0363 6f6d 0000 0100 01 mple.com.....
16:32:40.796507 IP (tos 0x0, ttl 64, id 37590, offset 0, flags [none], proto UDP (17), length 73, bad cksum 0 (->e9cb)!)
127.0.0.1.53 > 127.0.0.1.21070: [bad udp cksum 0xfe48 -> 0x43fa!] 43981 q: A? example.com. 1/0/0 example.com. A 93.184.216.34 (45)
0x0000: 0200 0000 4500 0049 92d6 0000 4011 0000 ....E..I....@...
0x0010: 7f00 0001 7f00 0001 0035 524e 0035 fe48 .........5RN.5.H
0x0020: abcd 8180 0001 0001 0000 0000 0765 7861 .............exa
0x0030: 6d70 6c65 0363 6f6d 0000 0100 01c0 0c00 mple.com........
0x0040: 0100 0100 0151 8000 045d b8d8 22 .....Q...].."
^C
2 packets captured
23 packets received by filter
0 packets dropped by kernelFitowar yana nuna yadda buƙatar warware adireshin Misali.com Sabar DNS ta karɓi kuma ta yi nasarar sarrafa ta.
Yanzu abin da ya rage shine kunna uwar garken mu a cikin Firefox browser. Don yin wannan, kuna buƙatar canza saitunan da yawa akan shafukan daidaitawa game da: saiti.
Da fari dai, wannan shine adireshin API ɗin mu wanda mai bincike zai nemi bayanan DNS a ciki network.trr.uri. Hakanan ana ba da shawarar saka yankin IP daga wannan URL don ingantaccen ƙudurin IP ta amfani da mai binciken kansa ba tare da shiga cikin DNS ba network.trr.bootstrapAddress. Kuma a ƙarshe, siga kanta hanyar sadarwa.trr.mode ciki har da yin amfani da DoH. Saita ƙimar zuwa "3" zai tilasta mai binciken ya yi amfani da DNS-over-HTTPS na musamman don ƙudurin suna, yayin da mafi aminci da aminci "2" zai ba da fifiko ga DoH, yana barin daidaitaccen bincike na DNS azaman zaɓi na koma baya.
5. RABA!
Labarin ya taimaka? Sa'an nan don Allah kada ku ji kunya da tallafi da kuɗi ta hanyar fom ɗin gudummawa (a ƙasa).
source: www.habr.com