dnsovertls

To enable a secure dns communication by uing a proxy between client and dns server and sending the client dns queries to dns server through proxy using tls

Start docker in linux by issuing the below command

service docker start

TO start the container run

docker run -it -v <<file_path_to_the_project_folder>>:/dns ubuntu

Start two containers in seperate terminals and move to the dns folder in both the containers

cd dns

the project folder will be available in /dns path in the container In both the container run,

apt-get update && apt-get install python openssl nano net-tools

Consider the two container as container A and container B In A: run

apt-get install bind9 bind9utils bind9-doc

nano /etc/bind/named.conf.options

copy and paste the below cotents in the terminal after the command nano is entered:

options {
	directory "/var/cache/bind";

	// If there is a firewall between you and nameservers you want
	// to talk to, you may need to fix the firewall to allow multiple
	// ports to talk.  See http://www.kb.cert.org/vuls/id/800113

	// If your ISP provided one or more IP addresses for stable
	// nameservers, you probably want to use them as forwarders.  
	// Uncomment the following block, and insert the addresses replacing
	// the all-0's placeholder.

	 forwarders {
	        8.8.8.8;
                8.8.4.4;
	 };
         forward only;

	//========================================================================
	// If BIND logs error messages about the root key being expired,
	// you will need to update your keys.  See https://www.isc.org/bind-keys
	//========================================================================
	dnssec-validation auto;

	auth-nxdomain no;    # conform to RFC1035
	listen-on-v6 { any; };
};

After entering the above command save it using ctrl+x and enter y for yes and issue enter key to save it under the same file name.

Then issue the command as follows,

service bind9 start
nano /etc/resolv.conf

erase all the contents in the file and paste the below content:

nameserver 127.0.0.1

After entering the above content save it using ctrl+x and enter y for yes and issue enter key to save it under the same file name.

In container B, run the command as

nano dnsclient.py

go to line 20 and change the line as :

secure_socket.connect(('Container_B_ip_address',1000))

Get the ip address of the container by issuing the ifconfig command.

In container A, run the following command

python dnsServer.py

In container B,

python dnsclient.py

In the host terminal,

nano /etc/resolv.conf

erase all the contents in the file and paste the below content:

nameserver <<ip_address_of_container_A>>

to check whether the setup is working, issue the following command in host terminal

dig google.com

if dig is not found install it using

apt-get install dnsutils