HTTP using netcat
(redirected from Openssl.Cert)
nc(1), netcat, is the swiss-army knife of networking. It can be a valuable tool to help diagnose networking errors in your web server.
$ print "GET /index.html HTTP/1.1\r\nHostname: example.com\r\n\r\n" | nc example.com 80
You may get a few possible responses:
200 Response
A 200 response indicates that the request has succeeded and the web page is being served.
HTTP/1.1 200 OK Connection: keep-alive Content-Length: 14 Content-Type: text/html Date: Wed, 13 Nov 2024 02:21:41 GMT Last-Modified: Tue, 12 Nov 2024 06:15:19 GMT Server: OpenBSD httpd
302 Response
A 302 response indicates that the web page has been moved. This will occur if openhttpd is set to redirect to port 443:
HTTP/1.0 302 Found Date: Tue, 23 Feb 2024 14:01:28 GMT OpenBSD httpd Connection: close Content-Type: text/html Content-Length: 486 Location: https://www.example.com/index.html ...
This response normally tells your web browser to automatically redirect to the
new location, in this case, https://www.example.com/index.html
(which uses
TLS).
404 Response
HTTP/1.0 404 Not Found Date: Wed, 13 Nov 2024 02:24:22 GMT Server: OpenBSD httpd Connection: close Content-Type: text/html Content-Length: 494
This means the page cannot be found. Double check to see if the document is in
the correct path in /var/www/
.
500 Response
HTTP/1.0 500 Internal Server Error Date: Wed, 13 Nov 2024 02:53:59 GMT Server: OpenBSD httpd Connection: close Content-Type: text/html Content-Length: 518
This error indicates there is a problem with the web server. This can sometimes
be triggered by a CGI error, if the script cannot be run properly due to
misconfiguration, security restrictions, or improper file permissions. You may
want to check errors logs such as in /var/www/logs/
or your scripting
language's logs for further hints.
Save public certificate
To save the TLS public key in PEM format:
$ nc -c -Z certfile example.com 443
Replace example.com
.