Dnscrypt-proxy

出自 Arch Linux 中文维基

本文內容或本節內容已經過期。

原因: 請提供模板的第一個位置參數以概括原因。 (在Talk:Dnscrypt-proxy討論)

dnscrypt-proxy 可以加密和認證用戶和 DNS 解析伺服器之間的數據傳輸,支持 DNS over HTTPSDNSCrypt,可以避免中間人攻擊和竊聽。dnscrypt-proxy 兼容 DNSSEC

安裝[編輯 | 編輯原始碼]

安裝 軟件包 dnscrypt-proxy

配置[編輯 | 編輯原始碼]

啟動[編輯 | 編輯原始碼]

服務有兩種啟動方式,但是只能二選一:

  • 啟用 .service
注意: 必須指定 listen_addresses (即在配置文件中寫好 listen_addresses = ['127.0.0.1:53', '[::1]:53'])
  • 啟用 .socket
注意: 必須留空 listen_addresses (即 listen_addresses = [ ]),systemd 會自己配置好 socket

選擇解析伺服器[編輯 | 編輯原始碼]

By leaving server_names commented out in the configuration file /etc/dnscrypt-proxy/dnscrypt-proxy.toml, dnscrypt-proxy will choose the fastest server from the sources already configured under [sources] [1]. The lists will be downloaded, verified, and automatically updated. [2]. Thus, configuring a specific set of servers is optional.

To manually set which server is used, edit /etc/dnscrypt-proxy/dnscrypt-proxy.toml and uncomment the server_names variable, selecting one or more of the servers. For example, to use Cloudflare's servers:

server_names = ['cloudflare', 'cloudflare-ipv6']

A full list of resolvers is located at the upstream page or Github. If dnscrypt-proxy has run successfully on the system before, /var/cache/dnscrypt-proxy/public-resolvers.md will also contain a list. Look at the description for servers note which validate DNSSEC, do not log, and are uncensored. These requirements can be configured globally with the require_dnssec, require_nolog, require_nofilter options.

禁用其他佔用53端口的服務[編輯 | 編輯原始碼]

提示:如果使用 #Unbound 提供本地 DNS 緩存,請跳過這一節,因為 unbound 默認監聽 53。

查看佔用 53 端口的服務:

 $ ss -lp 'sport = :domain'

如果輸出除了表頭還有其他內容,你就需要禁用佔用53端口的那些服務,比如 systemd-resolved.service 和其他網絡管理器包含的類似服務。把它們全部幹掉,直到上面的命令的輸出只剩這個樣子:

 Netid               State                 Recv-Q                Send-Q                     Local Address:Port                                   Peer Address:Port

修改 resolv.conf[編輯 | 編輯原始碼]

這篇文章的某些內容需要擴充。

原因: Explain what the options mean. (在 Talk:Dnscrypt-proxy 中討論)

修改 resolv.conf,把現有的nameserver全部清掉,添一行指向 localhost 的地址(一般是 127.0.0.1)的nameserver;並增添一行 options [3]。示例如下:

nameserver ::1
nameserver 127.0.0.1
options edns0 single-request-reopen

其他程序可能會修改 resolv.conf,詳見:resolv.conf#Overwriting of /etc/resolv.conf

啟動 systemd 服務[編輯 | 編輯原始碼]

根據上面你選擇的配置start/enable dnscrypt-proxy.service 或者 dnscrypt-proxy.socket

技巧[編輯 | 編輯原始碼]

本地 DNS 緩存配置[編輯 | 編輯原始碼]

提示:dnscrypt can cache entries without relying on another program. This feature is enabled by default with the line cache = true in your dnscrypt configuration file

It is recommended to run DNSCrypt as a forwarder for a local DNS cache if not using dnscrypt's cache feature; otherwise, every single query will make a round-trip to the upstream resolver. Any local DNS caching program should work. In addition to setting up dnscrypt-proxy, you must setup your local DNS cache program.

修改端口[編輯 | 編輯原始碼]

In order to forward queries from a local DNS cache, dnscrypt-proxy should listen on a port different from the default 53, since the DNS cache itself needs to listen on 53 and query dnscrypt-proxy on a different port. Port number 53000 is used as an example in this section. In this example, the port number is larger than 1024 so dnscrypt-proxy is not required to be run by root.

There are two methods for changing the default port:

Socket method

Edit dnscrypt-proxy.socket with the following contents:

[Socket]
ListenStream=
ListenDatagram=
ListenStream=127.0.0.1:53000
ListenDatagram=127.0.0.1:53000

When queries are forwarded from the local DNS cache to 53000, dnscrypt-proxy.socket will start dnscrypt-proxy.service.

Service method

Edit the listen_addresses option in /etc/dnscrypt-proxy/dnscrypt-proxy.toml with the following:

listen_addresses = ['127.0.0.1:53000', '[::1]:53000']

本地 DNS 緩存配置舉例[編輯 | 編輯原始碼]

The following configurations should work with dnscrypt-proxy and assume that it is listening on port 53000.

Unbound[編輯 | 編輯原始碼]

Configure Unbound to your liking (in particular, see Unbound#Local DNS server) and add the following lines to the end of the server section in /etc/unbound/unbound.conf:

  do-not-query-localhost: no
forward-zone:
  name: "."
  forward-addr: 127.0.0.1@53000
提示:If you are setting up a server, add interface: 0.0.0.0@53 and access-control: your-network/subnet-mask allow inside the server: section so that the other computers can connect to the server. A client must be configured with nameserver address-of-your-server in /etc/resolv.conf.

Restart unbound.service to apply the changes.

dnsmasq[編輯 | 編輯原始碼]

Configure dnsmasq as a local DNS cache. The basic configuration to work with DNSCrypt:

/etc/dnsmasq.conf
no-resolv
server=127.0.0.1#53000
listen-address=127.0.0.1

If you configured DNSCrypt to use a resolver with enabled DNSSEC validation, make sure to enable it also in dnsmasq:

/etc/dnsmasq.conf
proxy-dnssec

Restart dnsmasq.service to apply the changes.

pdnsd[編輯 | 編輯原始碼]

Install pdnsd. A basic configuration to work with DNSCrypt is:

/etc/pdnsd.conf
global {
    perm_cache = 1024;
    cache_dir = "/var/cache/pdnsd";
    run_as = "pdnsd";
    server_ip = 127.0.0.1;
    status_ctl = on;
    query_method = udp_tcp;
    min_ttl = 15m;       # Retain cached entries at least 15 minutes.
    max_ttl = 1w;        # One week.
    timeout = 10;        # Global timeout option (10 seconds).
    neg_domain_pol = on;
    udpbufsize = 1024;   # Upper limit on the size of UDP messages.
}

server {
    label = "dnscrypt-proxy";
    ip = 127.0.0.1;
    port = 53000;
    timeout = 4;
    proxy_only = on;
}

source {
    owner = localhost;
    file = "/etc/hosts";
}

Restart pdnsd.service to apply the changes.

沙盒隔離[編輯 | 編輯原始碼]

Edit dnscrypt-proxy.service to include the following lines:

[Service]
CapabilityBoundingSet=CAP_IPC_LOCK CAP_SETGID CAP_SETUID CAP_NET_BIND_SERVICE
ProtectSystem=strict
ProtectHome=true
ProtectKernelTunables=true
ProtectKernelModules=true
ProtectControlGroups=true
PrivateTmp=true
PrivateDevices=true
MemoryDenyWriteExecute=true
NoNewPrivileges=true
RestrictRealtime=true
RestrictAddressFamilies=AF_INET AF_INET6
SystemCallArchitectures=native
SystemCallFilter=~@clock @cpu-emulation @debug @keyring @ipc @module @mount @obsolete @raw-io

See systemd.exec(5) and Systemd#Sandboxing application environments for more information. Additionally see upstream comments.

啟用 EDNS0[編輯 | 編輯原始碼]

這篇文章的某些內容需要擴充。

原因: Name the advantages/motivation for enabling this. (在 Talk:Dnscrypt-proxy 中討論)

Extension Mechanisms for DNS that, among other things, allows a client to specify how large a reply over UDP can be.

Add the following line to your /etc/resolv.conf:

options edns0

本文內容或本節內容已經過期。

原因: dnscrypt-proxy2 uses different config file. (在Talk:Dnscrypt-proxy討論)

You may also wish to append the following to /etc/dnscrypt-proxy.conf:

EDNSPayloadSize <bytes>

Where <bytes> is a number, the default size being 1252, with values up to 4096 bytes being purportedly safe. A value below or equal to 512 bytes will disable this mechanism, unless a client sends a packet with an OPT section providing a payload size.

測試 EDNS0[編輯 | 編輯原始碼]

Make use of the DNS Reply Size Test Server, use the drill command line tool to issue a TXT query for the name rs.dns-oarc.net:

$ drill rs.dns-oarc.net TXT

With EDNS0 supported, the "answer section" of the output should look similar to this:

rst.x3827.rs.dns-oarc.net.
rst.x4049.x3827.rs.dns-oarc.net.
rst.x4055.x4049.x3827.rs.dns-oarc.net.
"2a00:d880:3:1::a6c1:2e89 DNS reply size limit is at least 4055 bytes"
"2a00:d880:3:1::a6c1:2e89 sent EDNS buffer size 4096"