使用 telnet, nc, openssl 浏览网站

LM-SHC-16507776:~ xiatian$ telnet www.tianxiaohui.com 80
Trying 156.236.115.130...
Connected to www.tianxiaohui.com.
Escape character is '^]'.

GET /about.html HTTP/1.1
Host: www.tianxiaohui.com

HTTP/1.1 400 Bad Request
Date: Sat, 02 Nov 2019 03:18:30 GMT
Server: Apache
Accept-Ranges: bytes
Connection: close
Content-Type: text/html

printf "GET /index.html HTTP/1.0\r\nHost: www.tianxiaohui.com\r\n\r\n" | nc www.tianxiaohui.com 80

使用 openssl 浏览 https 的
LM-SHC-16507776:~ xiatian$ openssl

OpenSSL> s_client -crlf -connect www.bing.com:443 -quiet

depth=2 C = IE, O = Baltimore, OU = CyberTrust, CN = Baltimore CyberTrust Root
verify return:1
depth=1 C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = Microsoft IT, CN = Microsoft IT TLS CA 2
verify return:1
depth=0 CN = www.bing.com
verify return:1

GET / HTTP/1.1
Host:www.bing.com

HTTP/1.1 302
Cache-Control: private
Content-Length: 137
Content-Type: text/html; charset=utf-8
Location: https://cn.bing.com/
Date: Sat, 02 Nov 2019 03:11:59 GMT

Object moved to https://cn.bing.com.

GET / HTTP/1.1
Host:cn.bing.com

HTTP/1.1 200 OK
Cache-Control: private, max-age=0
Content-Length: 114805