Public domain
cd /usr/src
wget "http://www.isc.org/downloads/file/bind-9-9-5rc2/?version=tar.gz" -O bind-9-9-5rc2.tar.gz
su - install
cd /usr/src
tar xf bind-9-9-5rc2.tar.gz
cd bind-9.9.5
./configure --prefix=/opt/bind && make
make install DESTDIR=/usr/local/encap/bind-9.9.5
logout
cd /usr/local/encap/
epkg bind-9.9.5
mkdir /var/log/named/
mkdir /etc/bind
mkdir -p /var/bind/localhost/
cd /var/bind/
wget ftp://ftp.internic.net/domain/named.root
// Key generator : dnssec-keygen -r /dev/urandom -a hmac-md5 -b 128 -n HOST rndc-key
key "rndc-key" {
algorithm hmac-md5;
secret "XhWQPshdd/+APS2jDF9wOA==";
};
include "/etc/bind/rndc.key";
acl mynet {
172.16.10.0/24;
172.16.11.0/24;
};
controls { inet 127.0.0.1 port 953 allow { localhost; none; } keys { rndc-key; }; };
options {
directory "/var/bind/";
listen-on { 172.20.35.11; };
version "DNS Server";
recursive-clients 5000;
minimal-responses yes;
allow-transfer { none; };
allow-update { none; };
allow-query { localhost; mynet; none; };
allow-recursion { localhost; mynet; none; };
// listen-on-v6 { ::1; 2001:16c0:2:3545::3; };
// forward first;
// forward only;
// forwarders { 217.218.127.127; 8.8.8.8; };
};
logging {
channel default_log {
file "/var/log/named/named.log" versions 5 size 50M;
print-time yes;
print-severity yes;
print-category yes;
};
category default { default_log; };
category general { default_log; };
};
zone "." {
type hint;
file "named.root";
};
zone "localhost" {
type master;
file "localhost/localhost.fwd";
allow-update { none; };
};
zone "0.0.127.in-addr.arpa" IN {
type master;
file "localhost/localhost.rev";
allow-update { none; };
};
// zone "wikipedia.org" { type forward; forwarders { 8.8.8.8; }; };
// zone "google.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "gmail.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "gstatic.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "googleusercontent.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "googleaips.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "google-analytics.com" { type forward; forwarders { 127.0.0.1; }; };
// zone "dell.com" { type forward; forwarders { 127.0.0.1; }; };
$TTL 1D
$ORIGIN localhost.
@ SOA @ root (
1 ; Serial
3H ; Refresh
15M ; Retry
1W ; Expiry
1D ) ; Minimum
NS @
A 127.0.0.1
$TTL 1D
@ SOA localhost. root.localhost. (
1 ; Serial
3H ; Refresh
15M ; Retry
1W ; Expiry
1D ) ; Minimum
NS localhost.
1 PTR localhost.
#!/bin/bash
### BEGIN INIT INFO
# Provides: rc.bind
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start named at boot time
# Description: Enable service provided by bind name server.
### END INIT INFO
#
# BIND name server
#
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
DAEMON="named"
PID_FILE="/opt/bind/var/run/named/named.pid"
START="/opt/bind/sbin/named"
TIMEOUT="10"
BIND_OPTIONS="-4 -n 6 -c /etc/bind/named.conf"
RNDC="/opt/bind/sbin/rndc"
RDNC_OPTIONS="-k /etc/bind/rndc.key"
start()
{
echo "Starting $DAEMON : $START "
PROCESS=$(ps -A | egrep " ${DAEMON}$")
if [ "$PROCESS" == "" ]; then
if [ -e "$PID_FILE" ] ; then
rm "${PID_FILE}"
fi
$START ${BIND_OPTIONS}
ps -A | egrep " ${DAEMON}$"
echo
else
echo "$DAEMON is already running !!!"
fi
}
stop()
{
echo -n "Stopping $DAEMON "
$RNDC $RDNC_OPTIONS stop
sleep 1
for I in $(seq 1 $TIMEOUT); do
PROCESS=$(ps -A | egrep " ${DAEMON}$")
if [ "${PROCESS}" == "" ]; then
break
else
echo -n "${I} "
fi
sleep 1
done
echo
PROCESS=$(ps -A | egrep " ${DAEMON}$")
if [ "${PROCESS}" != "" ]; then
echo "Force killing ${DAEMON}..."
killall named
#2> /dev/null
fi
ps -A | egrep " ${DAEMON}$"
}
reload()
{
$RNDC $RDNC_OPTIONS reload
}
status()
{
$RNDC $RDNC_OPTIONS status
}
case "$1" in
'start')
start
;;
'stop')
stop
;;
'restart')
stop
sleep 1
start
;;
*)
echo "usage $0 start|stop|restart|reload|status"
;;
esac
; This file holds the information on root name servers needed to
; initialize cache of Internet domain name servers
; (e.g. reference this file in the "cache . <file>"
; configuration file of BIND domain name servers).
;
; This file is made available by InterNIC
; under anonymous FTP as
; file /domain/named.cache
; on server FTP.INTERNIC.NET
; -OR- RS.INTERNIC.NET
;
; last update: Jan 3, 2013
; related version of root zone: 2013010300
;
; formerly NS.INTERNIC.NET
;
. 3600000 IN NS A.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET. 3600000 A 198.41.0.4
A.ROOT-SERVERS.NET. 3600000 AAAA 2001:503:BA3E::2:30
;
; FORMERLY NS1.ISI.EDU
;
. 3600000 NS B.ROOT-SERVERS.NET.
B.ROOT-SERVERS.NET. 3600000 A 192.228.79.201
;
; FORMERLY C.PSI.NET
;
. 3600000 NS C.ROOT-SERVERS.NET.
C.ROOT-SERVERS.NET. 3600000 A 192.33.4.12
;
; FORMERLY TERP.UMD.EDU
;
. 3600000 NS D.ROOT-SERVERS.NET.
D.ROOT-SERVERS.NET. 3600000 A 199.7.91.13
D.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:2D::D
;
; FORMERLY NS.NASA.GOV
;
. 3600000 NS E.ROOT-SERVERS.NET.
E.ROOT-SERVERS.NET. 3600000 A 192.203.230.10
;
; FORMERLY NS.ISC.ORG
;
. 3600000 NS F.ROOT-SERVERS.NET.
F.ROOT-SERVERS.NET. 3600000 A 192.5.5.241
F.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:2F::F
;
; FORMERLY NS.NIC.DDN.MIL
;
. 3600000 NS G.ROOT-SERVERS.NET.
G.ROOT-SERVERS.NET. 3600000 A 192.112.36.4
;
; FORMERLY AOS.ARL.ARMY.MIL
;
. 3600000 NS H.ROOT-SERVERS.NET.
H.ROOT-SERVERS.NET. 3600000 A 128.63.2.53
H.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:1::803F:235
;
; FORMERLY NIC.NORDU.NET
;
. 3600000 NS I.ROOT-SERVERS.NET.
I.ROOT-SERVERS.NET. 3600000 A 192.36.148.17
I.ROOT-SERVERS.NET. 3600000 AAAA 2001:7FE::53
;
; OPERATED BY VERISIGN, INC.
;
. 3600000 NS J.ROOT-SERVERS.NET.
J.ROOT-SERVERS.NET. 3600000 A 192.58.128.30
J.ROOT-SERVERS.NET. 3600000 AAAA 2001:503:C27::2:30
;
; OPERATED BY RIPE NCC
;
. 3600000 NS K.ROOT-SERVERS.NET.
K.ROOT-SERVERS.NET. 3600000 A 193.0.14.129
K.ROOT-SERVERS.NET. 3600000 AAAA 2001:7FD::1
;
; OPERATED BY ICANN
;
. 3600000 NS L.ROOT-SERVERS.NET.
L.ROOT-SERVERS.NET. 3600000 A 199.7.83.42
L.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:3::42
;
; OPERATED BY WIDE
;
. 3600000 NS M.ROOT-SERVERS.NET.
M.ROOT-SERVERS.NET. 3600000 A 202.12.27.33
M.ROOT-SERVERS.NET. 3600000 AAAA 2001:DC3::35
; End of File
# PATH
PATH="/opt/bind/bin:/opt/bind/sbin:$PATH"
chmod +x /etc/bind/rc.bind
ln -sfn /etc/bind/rc.bind /etc/rc.d/rc.bind
/etc/rc.d/rc.bind start
cd /usr/src
wget --no-check-certificate "https://download.libsodium.org/libsodium/releases/libsodium-0.4.5.tar.gz"
FILE="libsodium-0.4.5.tar.gz"
SERVER="download.libsodium.org"
LOCAL="$(openssl dgst -sha256 $FILE | sed -e 's,.*= ,,')"
REMOTE="$(dig +short +dnssec TXT $FILE.$SERVER | head -n 1 |sed -e 's,",,g')"
echo $LOCAL; echo $REMOTE
[ "$LOCAL" != "$REMOTE" ] && echo "SHA256 digest not match ..."
su - install
cd /usr/src/
tar xf libsodium-0.4.5.tar.gz
cd libsodium-0.4.5
./configure --prefix=/usr && make
make install DESTDIR=/usr/local/encap/libsodium-0.4.5
logout
cd /usr/local/encap/
chown -R root:root libsodium-0.4.5/
epkg libsodium-0.4.5/
ldconfig
cd /usr/src/
wget "http://download.dnscrypt.org/dnscrypt-proxy/dnscrypt-proxy-1.3.3.tar.bz2"
FILE="dnscrypt-proxy-1.3.3.tar.bz2"
SERVER="download.dnscrypt.org"
LOCAL="$(openssl dgst -sha256 $FILE | sed -e 's,.*= ,,')"
REMOTE="$(dig +short +dnssec TXT $FILE.$SERVER | head -n 1 | sed -e 's,",,g')"
echo $LOCAL; echo $REMOTE
[ "$LOCAL" != "$REMOTE" ] && echo "SHA256 digest not match ..."
su - install
cd /usr/src/
tar xf dnscrypt-proxy-1.3.3.tar.bz2
cd dnscrypt-proxy-1.3.3
./configure --prefix=/usr && make
make install DESTDIR=/usr/local/encap/dnscrypt-proxy-1.3.3
cd /usr/local/encap/dnscrypt-proxy-1.3.3
mv usr/share/man/ usr/
logout
cd /usr/local/encap/
epkg dnscrypt-proxy-1.3.3/
/usr/sbin/dnscrypt-proxy --daemonize
/etc/rc.d/rc.bind restart
zone "google.com" { type forward; forwarders { 127.0.0.1; }; };
zone "gmail.com" { type forward; forwarders { 127.0.0.1; }; };
zone "gstatic.com" { type forward; forwarders { 127.0.0.1; }; };
zone "googleusercontent.com" { type forward; forwarders { 127.0.0.1; }; };
zone "googleaips.com" { type forward; forwarders { 127.0.0.1; }; };
zone "google-analytics.com" { type forward; forwarders { 127.0.0.1; }; };
zone "dell.com" { type forward; forwarders { 127.0.0.1; }; };
dnscrypt-proxy --daemonize \
--pidfile=/var/run/dnscrypt-proxy.pid \
--local-address=127.0.0.1:53 \
--logfile=/var/log/dnscrypt-proxy.log \
--max-active-requests=2500 \
--resolver-address=178.216.201.222:2053 \
--provider-name=2.dnscrypt-cert.soltysiak.com \
--provider-key="25C4:E188:2915:4697:8F9C:2BBD:B6A7:AFA4:01ED:A051:0508:5D53:03E7:1928:C066:8F21"
dnscrypt-proxy --daemonize \
--pidfile=/var/run/dnscrypt-proxy.pid \
--local-address=127.0.0.1:53 \
--logfile=/var/log/dnscrypt-proxy.log \
--max-active-requests=2500 \
--resolver-address=173.45.106.219:2050 \
--provider-name=2.dnscrypt-cert.rahanet.com \
--provider-key="0EB5:2BA4:54B8:A730:F100:9416:158C:715C:E4C2:0C18:7463:CF15:479A:A632:DB9C:4A3F"
#--user=<user name>
--resolver-port=<port> option. For example, OpenDNS servers reply to queries sent to ports 53, 443 and 5353.
The --tcp-only command-line switch forces this behavior. When an incoming query is received, the daemon immediately replies with a "response truncated" message, forcing the client to retry over TCP. The daemon then authenticates the query and forwards it over TCP to the resolver.
### Links
http://dnscrypt.org/
https://github.com/Cofyc/dnscrypt-wrapper
https://github.com/jedisct1/dnscrypt-proxy
https://github.com/jedisct1/libsodium
http://cr.yp.to/highspeed/coolnacl-20111201.pdf
http://dnscurve.org/
https://cloudns.com.au/
http://dnscrypt.eu/
http://dc1.soltysiak.com/
http://unbound.net/
https://calomel.org/unbound_dns.html
Client side:
### TECHNOTES
Implementation details
======================
Cryptographic library
---------------------
- The wheel hasn't been reinvented.
- The crypto code is provided by NaCl: http://nacl.cr.yp.to/ through
libsodium: https://github.com/jedisct1/libsodium
- Why NaCl? Unbloated, blazing fast, and less error-prone that other libraries.
See http://cr.yp.to/highspeed/coolnacl-20111201.pdf
- crypto_box_curve25519xsalsa20poly1305_*() for authenticating/encrypting
queries and replies, crypto_sign_ed25519_*() for signing certificates, and
crypto_stream_salsa20() as a PRNG.
See the NaCl documentation for details.
Event-notification library
--------------------------
- Uses libevent. Unbound's boilerplate is also excellent, but it hasn't been
packaged as a standalone library yet.
- Because it is totally awesome for writing portable software.
- Bundled with dnscrypt, for now, because it's a modified version (so
that evdns can cope with TXT records) and because some distributions
are still shipping dead old versions.
Certificates
------------
The following information has to be provided to the proxy:
- The provider name (defaults to 2.dnscrypt-cert.opendns.com.)
- The provider public key (defaults to the current one for OpenDNS).
- The resolver IP address (defaults to 208.67.220.220).
At startup and every 60 minute, the proxy directly connects to the specified
resolver IP address and issues a TXT query for the provider name. The
first component of the provider name indicates the latest protocol version,
or the version range, supported by the client. Right now, this should
be 2. Always.
One or more TXT records are returned, each containing a signed certificate.
The provider public key is only used to verify a certificate, never for
authenticating/encrypting queries.
Certificates have the following header:
- 4 byte magic header DNSC
- 2 byte major version
- 2 byte minor version
Followed by signed content (the signature adds 512 bits to the payload):
- server 256-bit public key
- 8 byte magic header to use for queries using this specific key
- 4 byte serial number
- 4 + 4 byte validity period (two timestamps)
This is the current structure of the second version of the protocol.
Don't assume anything about its length, it is very likely to change
after a version bump.
The proxy drops invalid certificates for the current date, and picks the one
with the highest serial number.
More than one certificate may be returned when keys rollovers or
function changes are performed.
Resolvers are never signing certificates themselves, they are just providing
pre-signed certificates.
Queries
-------
Queries and replies are basically using djb's dnscurve protocol:
http://www.dnscurve.org/
The proxy always generates a new, in-memory only key pair at startup.
Random padding is added to queries and replies, using a 64 byte block size.
Encrypted queries are prefixed with the following header structure:
- 8 byte magic header (provided by the chosen certificate)
- A 256 bit client public key
- A 96 bit client nonce (64 bit monotically increasing timestamp +
32 random bits)
- A 128 bit Poly1305-AES MAC
Replies are prefixed with the following header structure:
- 8 byte static magic header r6fnvWJ8
- A 192 bit nonce: the 96 bit client-supplied nonce + a 96 bit server
nonce extension.
- A 128 bit Poly1305-AES MAC.
The proxy immediately discards replies to queries made more than 10
second ago and replies that don't match the client-supplied nonce.
Miscellaneous
-------------
If you need extra monitoring/profiling, the proxy provides a bunch of
DTrace probes on OSX, as the dnscrypt-proxy provider.
See src/dnscrypt-proxy/probes_dnscrypt_proxy.d
The proxy doesn't cache replies. Neither does it perform any DNSSEC
validation yet.
This is better handled by a separate process or by linking libunbound.
The proxy does alter queries, though, in order to:
- immediately reply with a "reply truncated" message to a UDP query when
the --tcp-port switch has been turned on.
- add an empty OPT section in order to advertise a payload size unless
an EDNS section was already present or unless --payload-size with a
< 512 bytes size has been specified.
OSX Mountain Lion, OpenBSD/amd64 and Dragonfly BSD/amd64 are the primary
development platforms, but the code has been designed to be as
portable as possible, and patches to support other operating systems
and architectures are more than welcome.
### README.markdown
[](https://travis-ci.org/jedisct1/dnscrypt-proxy?branch=master)
[DNSCrypt](http://dnscrypt.org)
===============================
A tool for securing communications between a client and a DNS resolver.
Description
-----------
dnscrypt-proxy provides local service which can be used directly as
your local resolver or as a DNS forwarder, encrypting and
authenticating requests using the DNSCrypt protocol and passing them
to an upstream server, by default OpenDNS.
The DNSCrypt protocol uses high-speed high-security elliptic-curve
cryptography and is very similar to [DNSCurve](http://dnscurve.org/),
but focuses on securing communications between a client and its first-level
resolver.
While not providing end-to-end security, it protects the local
network, which is often the weakest point of the chain, against
man-in-the-middle attacks. It also provides some confidentiality to
DNS queries.
Current list of free, DNSCrypt-enabled resolvers
------------------------------------------------
* [OpenDNS](http://www.opendns.com)
- Server address: 208.67.220.220:443
- Provider name: 2.dnscrypt-cert.opendns.com
- Public key: B735:1140:206F:225D:3E2B:D822:D7FD:691E:A1C3:3CC8:D666:8D0C:BE04:BFAB:CA43:FB79
* [CloudNS](https://cloudns.com.au/) - No logs, DNSSEC
* Canberra, Australia
- Server address: 113.20.6.2:443 or gc2tzw6lbmeagrp3.onion:443
- Provider name: 2.dnscrypt-cert.cloudns.com.au
- Public key: 1971:7C1A:C550:6C09:F09B:ACB1:1AF7:C349:6425:2676:247F:B738:1C5A:243A:C1CC:89F4
* Sydney, Australia
- Server address: 113.20.8.17:443 or l65q62lf7wnfme7m.onion:443
- Provider name: 2.dnscrypt-cert-2.cloudns.com.au
- Public key: 67A4:323E:581F:79B9:BC54:825F:54FE:1025:8B4F:37EB:0D07:0BCE:4010:6195:D94F:E330
* [OpenNIC](http://www.opennicproject.org/) - No logs
* Japan
- Server address: 106.186.17.181:2053
- Provider name: 2.dnscrypt-cert.ns2.jp.dns.opennic.glue
- Public key: 8768:C3DB:F70A:FBC6:3B64:8630:8167:2FD4:EE6F:E175:ECFD:46C9:22FC:7674:A1AC:2E2A
* [DNSCrypt.eu](http://dnscrypt.eu/) - No logs, DNSSEC
* Holland
- Server address: 176.56.237.171:443
- Provider name: 2.dnscrypt-cert.dnscrypt.eu
- Public key: 67C0:0F2C:21C5:5481:45DD:7CB4:6A27:1AF2:EB96:9931:40A3:09B6:2B8D:1653:1185:9C66
* [Soltysiak.com](http://dc1.soltysiak.com/) - No logs, DNSSEC
* Poznan, Poland
- Server address: 178.216.201.222:2053
- Provider name: 2.dnscrypt-cert.soltysiak.com
- Public key: 25C4:E188:2915:4697:8F9C:2BBD:B6A7:AFA4:01ED:A051:0508:5D53:03E7:1928:C066:8F21
Download and integrity check
----------------------------
DNSCrypt can be downloaded here: [dnscrypt download](http://dnscrypt.org)
After having downloaded a file, compute its SHA256 digest. For example:
$ openssl dgst -sha256 dnscrypt-proxy-1.3.3.tar.bz2
Verify this digest against the expected one, that can be retrieved
using a simple DNS query:
$ drill -D TXT dnscrypt-proxy-1.3.3.tar.bz2.download.dnscrypt.org
or
$ dig +dnssec TXT dnscrypt-proxy-1.3.3.tar.bz2.download.dnscrypt.org
If the content of the TXT record doesn't match the SHA256 digest you
computed, please file a bug report on Github as soon as possible and
don't go any further.
Installation
------------
The daemon is known to work on recent versions of OSX, OpenBSD,
Bitrig, NetBSD, Dragonfly BSD, FreeBSD, Linux, iOS (requires a
jailbroken device), Android (requires a rooted device), Solaris
(SmartOS) and Windows (requires MingW).
Install [libsodium](https://github.com/jedisct1/libsodium).
On Linux, don't forget to run `ldconfig` if you installed it from
source.
On Fedora, RHEL and CentOS, you may need to add `/usr/local/lib` to
the paths the dynamic linker is going to look at. Before issuing
`ldconfig`, type:
# echo /usr/local/lib > /etc/ld.so.conf.d/usr_local_lib.conf
Now, download the latest dnscrypt-proxy version and extract it:
$ bunzip2 -cd dnscrypt-proxy-*.tar.bz2 | tar xvf -
$ cd dnscrypt-proxy-*
Compile and install it using the standard procedure:
$ ./configure && make -j2
# make install
Replace `-j2` with whatever number of CPU cores you want to use for the
compilation process.
The proxy will be installed as `/usr/local/sbin/dnscrypt-proxy` by default.
Command-line switches are documented in the `dnscrypt-proxy(8)` man page.
*Note:* gcc 3.4.6 (and probably other similar versions) is known to
produce broken code on Mips targets with the -Os optimization level.
Use a different level (-O and -O2 are fine) or upgrade the compiler.
Thanks to Adrian Kotelba for reporting this.
GUI for dnscrypt-proxy
----------------------
If you need a simple graphical user interface in order to start/stop
the proxy and change your DNS settings, check out the following
project:
- [DNSCrypt WinClient](https://github.com/FivfBx2dOQTC3gc8YS4yMNo0el/dnscrypt-winclient):
Easily enable/disable DNSCrypt on multiple adapters. Supports
different ports and protocols, IPv6, parental controls and the proxy
can act as a gateway service. Windows only, written in .NET. Designed
for OpenDNS and CloudNS.
Server-side proxy
-----------------
[DNSCrypt-Wrapper](https://github.com/Cofyc/dnscrypt-wrapper) is a
server-side dnscrypt proxy that works with any name resolver.
Usage
-----
Having a dedicated system user, with no privileges and with an empty
home directory, is highly recommended. For extra security, DNSCrypt
will chroot() to this user's home directory and drop root privileges
for this user's uid as soon as possible.
The easiest way to start the daemon is:
# dnscrypt-proxy --daemonize
The proxy will accept incoming requests on 127.0.0.1, tag them with an
authentication code, forward them to OpenDNS resolvers, and validate
each answer before passing it to the client.
Given such a setup, in order to actually start using DNSCrypt, you
need to update your `/etc/resolv.conf` file and replace your current
set of resolvers with:
nameserver 127.0.0.1
Other common command-line switches include:
* `--daemonize` in order to run the server as a background process.
* `--local-address=<ip>[:port]` in order to locally bind a different IP
address than 127.0.0.1
* `--logfile=<file>` in order to write log data to a dedicated file. By
default, logs are sent to stdout if the server is running in foreground,
and to syslog if it is running in background.
* `--loglevel=<level>` if you need less verbosity in log files.
* `--max-active-requests=<count>` to set the maximum number of active
requests. The default value is 250.
* `--pid-file=<file>` in order to store the PID number to a file.
* `--user=<user name>` in order to chroot()/drop privileges.
* `--test` in order to check that the server-side proxy is properly
configured and that a valid certificate can be used. This is useful
for monitoring your own dnscrypt proxy. See the man page for more
information.
DNSCrypt comes pre-configured for OpenDNS, although the
`--resolver-address=<ip>[:port]`,
`--provider-name=<certificate provider FQDN>`
and `--provider-key=<provider public key>` can be specified in
order to change the default settings.
Installation as a service (Windows only)
----------------------------------------
The proxy can be installed as a Windows service.
Copy the `dnscrypt-proxy.exe` file to any location, as well as the
`libsodium-4.dll` file. Both should be in the same location. If you
are using plugins depending on ldns, copy the ldns DLL as well. Then open a
terminal and type (eventually with the full path to `dnscrypt-proxy.exe`):
dnscrypt-proxy.exe --install
It will install a new service named `dnscrypt-proxy`.
After being stopped, the service can be removed with:
dnscrypt-proxy.exe --uninstall
Using DNSCrypt in combination with a DNS cache
----------------------------------------------
The DNSCrypt proxy is **not** a DNS cache. This means that incoming
queries will **not** be cached and every single query will require a
round-trip to the upstream resolver.
For optimal performance, the recommended way of running DNSCrypt is to
run it as a forwarder for a local DNS cache, like `unbound` or
`powerdns-recursor`.
Both can safely run on the same machine as long as they are listening
to different IP addresses (preferred) or different ports.
If your DNS cache is `unbound`, all you need is to edit the
`unbound.conf` file and add the following lines at the end of the `server`
section:
do-not-query-localhost: no
forward-zone:
name: "."
forward-addr: 127.0.0.1@40
The first line is not required if you are using different IP addresses
instead of different ports.
Then start `dnscrypt-proxy`, telling it to use a specific port (`40`, in
this example):
# dnscrypt-proxy --local-address=127.0.0.1:40 --daemonize
IPv6 support
------------
IPv6 is fully supported. IPv6 addresses with a port number should be
specified as [ip]:port
# dnscrypt-proxy --local-address='[::1]:40' --daemonize
Queries using nonstandard ports / over TCP
------------------------------------------
Some routers and firewalls can block outgoing DNS queries or
transparently redirect them to their own resolver. This especially
happens on public Wifi hotspots, such as coffee shops.
As a workaround, the port number can be changed using
the `--resolver-port=<port>` option. For example, OpenDNS servers
reply to queries sent to ports 53, 443 and 5353.
By default, dnscrypt-proxy sends outgoing queries to UDP port 443.
In addition, the DNSCrypt proxy can force outgoing queries to be
sent over TCP. For example, TCP port 443, which is commonly used for
communication over HTTPS, may not be filtered.
The `--tcp-only` command-line switch forces this behavior. When
an incoming query is received, the daemon immediately replies with a
"response truncated" message, forcing the client to retry over TCP.
The daemon then authenticates the query and forwards it over TCP
to the resolver.
`--tcp-only` is slower than UDP because multiple queries over a single
TCP connections aren't supported yet, and this workaround should
never be used except when bypassing a filter is actually required.
EDNS payload size
-----------------
DNS packets sent over UDP have been historically limited to 512 bytes,
which is usually fine for queries, but sometimes a bit short for
replies.
Most modern authoritative servers, resolvers and stub resolvers
support the Extension Mechanism for DNS (EDNS) that, among other
things, allows a client to specify how large a reply over UDP can be.
Unfortunately, this feature is disabled by default on a lot of
operating systems. It has to be explicitly enabled, for example by
adding `options edns0` to the `/etc/resolv.conf` file on most
Unix-like operating systems.
`dnscrypt-proxy` can transparently rewrite outgoing packets before
authenticating them, in order to add the EDNS0 mechanism. By
default, a conservative payload size of 1252 bytes is advertised.
This size can be made larger by starting the proxy with the
`--edns-payload-size=<bytes>` command-line switch. Values up to 4096
are usually safe.
A value below or equal to 512 will disable this mechanism, unless a
client sends a packet with an OPT section providing a payload size.
The `hostip` utility
--------------------
The DNSCrypt proxy ships with a simple tool named `hostip` that
resolves a name to IPv4 or IPv6 addresses.
This tool can be useful for starting some services before
`dnscrypt-proxy`.
Queries made by `hostip` are not authenticated.
BY: Pejman Moghadam
TAG: bind, dnscrypt
DATE: 2014-03-22 14:36:58