How to telnet via proxy authentication?
You could do what the browser does, i.e. connect to the proxy,
$ telnet proxy-server 3128
and talk to it. If there was no authentication, a simple GET
request (followed by two newlines (Enter)) with a full hostname and protocol, e.g.
GET http://www.google.com/ HTTP/1.1
should suffice. Since you need authentication, you need to provide your username and password base64-encoded in a Proxy-Authentication
header, e.g.
GET http://www.google.com/ HTTP/1.1
Proxy-Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ=
To create the base64 string, you could use echo -n username:password | openssl base64
You can use Proxychains for this.
First install proxychains, using the command:
$ apt-get install proxychains
Then configure your proxy settings in /etc/proxychains.conf
file.
Add at last, these lines for HTTP and HTTPS proxy.
http proxy-ip proxy-port username password
https proxy-ip proxy-port username password
Now you can do telnet by using the following command:
$ proxychains telnet www.google.com 80