Server does not respond to manual request - http

Question

I'm trying to connect to api.poloniex.com on port 443 (SSL). They are using a WebSocket/Wamp server on that port which is pushing data. I've already tried to connect with Autobahn|JS and it works.
Before the data transmission begins, a Http-Upgrade-Request is sent to the server, which indicates that the client wants to switch from http to websocket. Then the server normally responds with 101 - Switching protocols.
Using the Autobahn|JS library, the request looks like this:
Request:
GET / HTTP/1.1
Host: api.poloniex.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Sec-WebSocket-Version: 13
Origin: ...
Sec-WebSocket-Protocol: wamp.2.json
Sec-WebSocket-Extensions: permessage-deflate
Sec-WebSocket-Key: 0n4ibEwIyTMDMhKoxXt+Cg==
Cookie: ......
Connection: keep-alive, Upgrade
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket
Response:
HTTP/1.1 101 Switching Protocols
Server: Crossbar/0.10.4
X-Powered-By: AutobahnPython/0.10.4
Upgrade: WebSocket
Connection: Upgrade
Sec-WebSocket-Protocol: wamp.2.json
Sec-WebSocket-Accept: dbaqDVdVW+xtbCa2V0yjtb7yXqI=
I tried to manually send the Request-Header. I used openssl s_client -connect api.poloniex.com:443 to connect with SSL-encryption. Then I sent a slightly modified header (I removed Origin and Cookie):
GET / HTTP/1.1
Host: api.poloniex.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Sec-WebSocket-Version: 13
Sec-WebSocket-Protocol: wamp.2.json
Sec-WebSocket-Extensions: permessage-deflate
Sec-WebSocket-Key: czW+w3Z+3yZCKVGx6DQ1Rg==
Connection: keep-alive, Upgrade
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket
But then, the server does not answer. It does not even close the connection, just nothin happens at all. I've also tried to leave the Cookie and Origin fields in, but that does also not work.
Edit: Sending the message this way does also not work:
GET / HTTP/1.1\r\nHost: api.poloniex.com\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\nAccept-Language: de,en-US;q=0.7,en;q=0.3\r\nAccept-Encoding: gzip, deflate\r\nSec-WebSocket-Version: 13\r\nSec-WebSocket-Protocol: wamp.2.json\r\nSec-WebSocket-Extensions: permessage-deflate\r\nSec-WebSocket-Key: czW+w3Z+3yZCKVGx6DQ1Rg==\r\nConnection: keep-alive, Upgrade\r\nPragma: no-cache\r\nCache-Control: no-cache\r\nUpgrade: websocket\r\n\r\n

Answer 1

HTTP requests have a line end of \r\n but often single \n will be accepted. But what you probably missed is the final empty line which is the end of header marker. Thus the server still waits for the end of the header.