nokogiri ssl issue

README.md

nokogiri tls issues

Without https or the www
Forced redirect to https://www

lunix@boran]  -> curl -I http://nokogiri.org/
HTTP/1.1 301 Moved Permanently
Server: GitHub.com
Content-Type: text/html
Location: https://www.nokogiri.org/
X-GitHub-Request-Id: B568:08C6:429D1EE:4AEA28A:5C32BE57
Content-Length: 178
Accept-Ranges: bytes
Date: Mon, 07 Jan 2019 02:50:03 GMT
Via: 1.1 varnish
Age: 3
Connection: keep-alive
X-Served-By: cache-syd18925-SYD
X-Cache: HIT
X-Cache-Hits: 1
X-Timer: S1546829403.014666,VS0,VE0
Vary: Accept-Encoding
X-Fastly-Request-ID: 8502660efe388ac663e4112f7371ff04b86601a9

With https but no www

lunix@boran]  -> curl -I https://nokogiri.org/
curl: (51) SSL: certificate subject name (www.github.com) does not match target host name 'nokogiri.org'

Has a github.com ssl cert which fails as it does not match.
Let's try again ignoring ssl errors

lunix@boran]  -> curl -k -I https://nokogiri.org/

HTTP/1.1 301 Moved Permanently
Server: GitHub.com
Content-Type: text/html
Location: https://www.nokogiri.org/
X-GitHub-Request-Id: AAEA:08C3:2ED288D:349EC01:5C32BC84
Content-Length: 178
Accept-Ranges: bytes
Date: Mon, 07 Jan 2019 02:45:43 GMT
Via: 1.1 varnish
Age: 210
Connection: keep-alive
X-Served-By: cache-syd18930-SYD
X-Cache: HIT
X-Cache-Hits: 1
X-Timer: S1546829144.939001,VS0,VE1
Vary: Accept-Encoding
X-Fastly-Request-ID: ae1d0f0d50679a999b69766cae216e95a1231ecf

We see that it wants to 301 us over to https://www.nokogiri.org/

Github Support instructs you to use A records for the domain apex pointing to the following IP's, unless you have the ability to do ANAME or ALIAS record types.

lunix@boran]  -> dig +noall +answer  nokogiri.org 
nokogiri.org.		300	IN	A	185.199.110.153
nokogiri.org.		300	IN	A	185.199.108.153
nokogiri.org.		300	IN	A	185.199.109.153
nokogiri.org.		300	IN	A	185.199.111.153
[~]
lunix@boran]  -> curl -I -H "Host: www.nokogiri.org" https://185.199.108.153
curl: (51) SSL: certificate subject name (www.github.com) does not match target host name '185.199.108.153'
[~]
lunix@boran]  -> curl -I -H "Host: www.nokogiri.org" https://185.199.110.153
curl: (51) SSL: certificate subject name (www.github.com) does not match target host name '185.199.110.153'
[~]
lunix@boran]  -> curl -I -H "Host: www.nokogiri.org" https://185.199.109.153
curl: (51) SSL: certificate subject name (www.github.com) does not match target host name '185.199.109.153'
[~]
lunix@boran]  -> curl -I -H "Host: www.nokogiri.org" https://185.199.111.153
curl: (51) SSL: certificate subject name (www.github.com) does not match target host name '185.199.111.153'

Conclusion

The domain apex nokogiri.org responds with ssl cert for github.com