telnet accessing website with authentication

Question

I am trying to access httpbin.org with basic authentication. I must enter a username and a password. Using telnet in the command terminal(linux) I execute at least :

telnet httpbin.org 80 
HEAD /basic-auth/user/passwd HTTP/1.1

It gives a 401 status code (unauthorized).

I want to now somehow access it using a username and a password (in Base64, entered as username:password). In what way do I do this? I've tried (after 401 status code)

HEAD /username:password HTTP/1.1

(but this gives a 404 status code)

Answer 1

HTTP Basic Authentication uses base-64 encoding of the username and password together. For a username testuser and a password of hunter2, you would take the string testuser:hunter2 and base64-encode that. That will give you the string dGVzdHVzZXI6aHVudGVyMg==

How, you ask, do you get that encoding? Most POSIX systems have openssl installed, in which case you can use the output of echo -n "testuser:hunter2" | openssl base64 -base64. The -n is hyper-important, otherwise you'll also be including a newline in the encoding, which will give you an incorrect encoded string (as the password does not end with a newline character generally).

You can then transact via telnet thusly:

telnet hostname.example.com 80
GET / HTTP/1.1
Authorization: Basic dGVzdHVzZXI6aHVudGVyMg==