Skip to content

Instantly share code, notes, and snippets.

Last active September 26, 2023 18:39
Star You must be signed in to star a gist
What would you like to do?
How to create an HTTPS certificate for localhost domains

How to create an HTTPS certificate for localhost domains

This focuses on generating the certificates for loading local virtual hosts hosted on your computer, for development only.

Do not use self-signed certificates in production ! For online certificates, use Let's Encrypt instead (tutorial).

Certificate authority (CA)

Generate RootCA.pem, RootCA.key & RootCA.crt:

openssl req -x509 -nodes -new -sha256 -days 1024 -newkey rsa:2048 -keyout RootCA.key -out RootCA.pem -subj "/C=US/CN=Example-Root-CA"
openssl x509 -outform pem -in RootCA.pem -out RootCA.crt

Note that Example-Root-CA is an example, you can customize the name.

Domain name certificate

Let's say you have two domains fake1.local and fake2.local that are hosted on your local machine for development (using the hosts file to point them to

First, create a file domains.ext that lists all your local domains:

keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
subjectAltName = @alt_names
DNS.1 = localhost
DNS.2 = fake1.local
DNS.3 = fake2.local

Generate localhost.key, localhost.csr, and localhost.crt:

openssl req -new -nodes -newkey rsa:2048 -keyout localhost.key -out localhost.csr -subj "/C=US/ST=YourState/L=YourCity/O=Example-Certificates/CN=localhost.local"
openssl x509 -req -sha256 -days 1024 -in localhost.csr -CA RootCA.pem -CAkey RootCA.key -CAcreateserial -extfile domains.ext -out localhost.crt

Note that the country / state / city / name in the first command can be customized.

You can now configure your webserver, for example with Apache:

SSLEngine on
SSLCertificateFile "C:/example/localhost.crt"
SSLCertificateKeyFile "C:/example/localhost.key"

Trust the local CA

At this point, the site would load with a warning about self-signed certificates. In order to get a green lock, your new local CA has to be added to the trusted Root Certificate Authorities.

Windows 10: Chrome, IE11 & Edge

Windows 10 recognizes .crt files, so you can right-click on RootCA.crt > Install to open the import dialog.

Make sure to select "Trusted Root Certification Authorities" and confirm.

You should now get a green lock in Chrome, IE11 and Edge.

Windows 10: Firefox

There are two ways to get the CA trusted in Firefox.

The simplest is to make Firefox use the Windows trusted Root CAs by going to about:config, and setting security.enterprise_roots.enabled to true.

The other way is to import the certificate by going to about:preferences#privacy > Certificats > Import > RootCA.pem > Confirm for websites.

Copy link

Need an easy solution:

You saved my day! Thanks!

Copy link

magi-web commented Jan 8, 2023

Thank you so much ! It works like a charm <3

Copy link

peppeg85 commented Feb 8, 2023

hello, if i need to add more hosts in the future, i have to update the domain.ext file and re-generate the certificates with the two instructions

openssl req -new -nodes -newkey rsa:2048 -keyout localhost.key -out localhost.csr -subj "/C=US/ST=YourState/L=YourCity/O=Example-Certificates/CN=localhost.local"
openssl x509 -req -sha256 -days 1024 -in localhost.csr -CA RootCA.pem -CAkey RootCA.key -CAcreateserial -extfile domains.ext -out localhost.crt

and another question: in the domain.ext file, the entries authorityKeyIdentifier=keyid,issuer how should be valorized?
thank you

Copy link

daxlai commented Feb 8, 2023 via email

Copy link

peppeg85 commented Feb 9, 2023

follow the guide, on windows you ave to add hosts inside the hosts


if you can't see it enable hidden files in the system explorer. then add entries like www.fake1.local (the entries inside the domains.ext file), do this with notepad++, it will ask you to save as administrator.

maybe you need to disconnect and reconnect windows.
if still doesn't work try to use CN=*.localhost.local for this instruction:

openssl req -new -nodes -newkey rsa:2048 -keyout localhost.key -out localhost.csr -subj "/C=US/ST=YourState/L=YourCity/O=Example-Certificates/CN=localhost.local"

then i use this with spring boot, so i had to convert the crt file to p12

Copy link

BraxtonI commented Feb 9, 2023 via email

Copy link

b-and-p commented Apr 14, 2023

Excellent information, thanks! I was struggling with Chrome and Wampserver for a week before I saw this. Worked like a charm!

Copy link

DragonOsman commented Jun 20, 2023

I want to do this for a MERN app I'm trying to develop and test locally that uses JWTs for authentication. Without HTTPS, the cookies would be ignored by the browser since I'd need to use secure cookies.

I think I successfully generated the .crt file using my .csr and .key files, but now when I try to visit https://localhost:3000 or https://localhost.local:3000 I get an error. What do I need to do from here?

Edit: I've installed the .crt file to the store (type of store left up to the wizard) and I've added "localhost" with port 3000 to my hosts, but it's still telling me that the site isn't secure when I try to visit it in MS Edge. Please help. Thanks.

Edit2: Okay, I've also added the cert file to the trusted store in mmc.exe but still doesn't work. I still get the error that the site isn't secure. What should I do?

Copy link

Wow awesome, thank you so much for your tutorial ! :)

Copy link

Thanks for your tutorial, it solve my problem!!

Copy link

thank you
it worked for after trying to many other options

Copy link

pixelfast commented Sep 18, 2023

So, SSL on localhost now works fine, and displays the Wampserver Homepage.

I now have Your Virtual Hosts listed as:


In my httpd-vhosts.conf file, the entry looks like this:

<VirtualHost *:8080> ServerName mortgagequest DocumentRoot "c:/mysites/azmortgage/new" <Directory "c:/mysites/azmortgage/new/"> Options +Indexes +Includes +FollowSymLinks +MultiViews AllowOverride All Require local </Directory> </VirtualHost>

My hosts file has this entry: mortgagequest
::1 mortgagequest

When I browse to https://mortgagequest I get the Wampserver Homepage.

What further steps do I need to take to enable SSL for the virtual host?

Thank you!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment