Postman client certificate add with IPV6 not working - ssl

While Using postman for accessing my application , My client certificate is not working with IPV6 as host section of certificate is trimmed and not store my full IP address. While I am working with IPV4 its working fine.

Related

ERR_SSL_PROTOCOL_ERROR using a reserved IP address on Digital Ocean

So I have a digital ocean droplet running apache with an SSL certificate provided by LetsEncrpt. When I use the Inet address of the server everything works as expected. I have now added a reserved IP address to the droplet however when trying to access that via HTTPS is get the Generic ERR_SSL_PROTOCOL_ERROR running through a tester it appears to indicate no SSL protocols are support.
The reversed IP address does indeed route to the server, I can SSH over it for example.
Im using UFW which is configure to allow any on 443.
Any insight/advice would be greatly received.

Is it possible for HTTPS server to provide different SSL certificate based on HTTP headers?

I am trying to connect to a service over HTTPS, and currently the connection fails due to certificate mismatch with the hostname. I am receiving different certificate host name depending on whether I connect using hostname or IP address. The hostname does resolve to exact same IP address, but it consistently keeps giving different certificate for the IP address when using curl. Using python requests module, it always gives me the certificate I get with curl and IP address (which is unfortunately the wrong one).
Any explanations what might be going on here?

Use my external IP address with HTTPS to forward to my localmachine

I'm doing some development and want to point a remote webhook I have to a server I have on my localmachine. I was able to create a SSL certificate on my machine, and from my own machine I can access https://localhost:3000 and it accepts HTTPS.
I forwarded port 3000 on my router to my localmachine, and it works if I use my external IP address with http, but not with http.
e.g: http://my-external-ip-address:3000 works https://my-external-ip-address:3000 does not work.
What do I need to do to have https on my external IP address work?
Make sure that the caller can work with self-signed certificates (which looks like what's you have). Alternatively, check a SSH tunnel service such as ngrok.com (free).

HTTPS client - certificate

I write raw HTTPS client in C - a program that takes domain name, resolves it to IP address (via DNS), connects to the IP address on port 443 (SSL), performs SSL handshake and then sends HTTP request via the SSL socket.
To try this program I have a domain hosted on a webserver. I installed Let's encrypt certificate for the domain.
I found out that there are many domain names sharing the same IP address as my domain. So when I connect to the IP address on port 443 to perform SSL handshake who ensures that mydomain's SSL certificate will be sent from the server to the client and not another certificate belonging to other domain name sharing the same IP address?
There exists a TLS extension called Server Name Indication (SNI) which is widely used (and is e.g. require for http/2 clients). You can find the formal specification of this extension in RFC 6066.
Using SNI, a client can send a desired hostname in its Hello request which allows the server to select a matching key/certificate combination for this connection.

Why reverse lookup is not done to validate ssl cert against IP?

I have a ssl cert generated for "host1.domain.com". This host has 4 NIC configured. 192.168.1.10, 192.168.1.11, 192.168.1.12 and 192.168.1.13 are the IPs. Now, if I try to browse through IP, it gives cert mismatch and works fine with hostname as expected. Why doesn't it do a lookup to validate the certificate against ip?