problem with telnet HTTP/1.1 400 Bad Request

Question

I was trying to do this:

Telnet into a Web server and send a multiline request message. Include in the request message the If-modified-since: header line to force a response message with the 304 Not Modified status code.

so I did steps below

telnet example.com 80

and then

GET /index.html HTTP/1.1
Host: example.com

and two enter. and I got some information. I added

If-modified-since: Thu, 17 Oct 2019 06:18:26 GMT

but still no 304 not modified.

this is what I get after GEt and Host

and

HTTP/1.0 501 Not Implemented
Content-Type: text/html
Content-Length: 357
Connection: close
Date: Fri, 30 Apr 2021 16:10:33 GMT
Server: ECSF (dcb/7F80)

@Exampleperson I'm really confused, after GET and Host it gives me some information and some code and when I enter if modified again some code and "connection lost". — negar, Apr 30 '21 at 15:25
@Exampleperson it's hidden in cmd that's exactly what I wrote above. am I doing anything wrong?? — negar, Apr 30 '21 at 15:52
@Exampleperson so how should I find a website with this error?:) — negar, Apr 30 '21 at 17:08
what? I cannot understand what you mean. Why should you find a website with this error? And what error? This whole 200 instead of 304 is not an error. — Example person, Apr 30 '21 at 17:09
@Exampleperson cause I have to use telnet and get 304 Not Modified status code from some website. — negar, Apr 30 '21 at 17:36

score 1 · Answer 1 · edited Oct 09 '22 at 21:19

1

HTTP/1.1 needs the Host header. Your request should be:

GET /index.html HTTP/1.1
Host: hostname.tld

Edit

So if you are connecting to example.com:

GET /index.html HTTP/1.1
Host: example.com

edited Oct 09 '22 at 21:19

halfer

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answered Apr 30 '21 at 14:35

Example person

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host name should be the address of the site? still I don't get 304 not modified:( – negar Apr 30 '21 at 14:57
@negar, it should be the domain name of the site. Including the subdomains. Example: So, it would be www.google.com if you are connected to www.google.com, and google.com if you are connected to google.com. – Example person Apr 30 '21 at 14:59
@negar show your full HTTP request. You can ofcourse hide any private info while showing it – Example person Apr 30 '21 at 15:00
could you give me an example, please? – negar Apr 30 '21 at 15:04
@negar see my answer now – Example person Apr 30 '21 at 15:08
@negar, what is your If-Modified-Since header content? – Example person Apr 30 '21 at 15:13

problem with telnet HTTP/1.1 400 Bad Request

1 Answers1

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