Monday, June 26, 2023

Valid local self signed certs

While developing web sites/applications locally, to facilitate development, you often use a local host name, such as 127.0.0.1, localhost, site.local, example.test, or sub.company.local.  While you can access the site/application using normal HTTP, sometimes the application is configured for secure HTTP i.e. HTTPS or you always want to force HTTPS no matter the environment (dev/qa/prod).  


However, ‘made up’ local host names such as example.test, site.local, site.dev etc can not use an external ssl certificate, as they cannot be accessed remotely to verify authenticity by a certificate authority (CA).  So typically one would create a self signed certificate.  But over time, browsers have restricted the acceptance of self signed certificates, resulting in a less friendly or impossible developer workflow.  So the next step would be to add your own CA to your local environment, but that can be tedious and error prone. Luckily, there is a utility which greatly simplifies the process, for linux, macos, and even windows - mkcert


“Using certificates from real certificate authorities (CAs) for development can be dangerous or impossible (for hosts like example.test, localhost or 127.0.0.1), but self-signed certificates cause trust errors. Managing your own CA is the best solution, but usually involves arcane commands, specialized knowledge and manual steps.

mkcert automatically creates and installs a local CA in the system root store, and generates locally-trusted certificates. mkcert does not automatically configure servers to use the certificates, though, that's up to you.”

https://github.com/FiloSottile/mkcert


To creating a usable self signed ssl certificate using Windows, Nginx, and Laragon (a portable LAMP stack):


Download the latest mkcert for your OS (Windows in this case)

https://github.com/FiloSottile/mkcert/releases

mkcert-v1.4.1-windows-amd64.exe


Copy the file to a new dir

C:/laragon/bin/mkcert/

And rename to a generic mkcert.exe


Note, assuming you installed/extracted Laragon to C:/laragon


In a command window with Administrator Privileges (Run as Admin)

> cd C:\laragon\etc\ssl


Specify the destination of the CA cert

> mkdir C:\laragon\etc\ssl\mkcert


Set an temporary environment variable for mkcert to read

> setx CAROOT "C:\laragon\etc\ssl\mkcert"


By default, it would have be in you user directory

> C:\Users\<user>\AppData\Local\mkcert


Close the command window and re-open it so the environment variable can be read

In linux you might source ~/.bash_profile .. but windows


Test that the environment variable is indeed set

> cd C:\laragon\etc\ssl\

> echo %CAROOT%

C:\laragon\etc\ssl\mkcert


Create and install your local CA

> ..\..\bin\mkcert\mkcert -install


You will be shown a prompt warning you that you are doing what you want to do, add a local CA 


After reading, Click Yes


Note, by default the CA key will be named rootCA-key.pem and the CA cert will be named rootCA.pem. The names are hard coded in the project source main.go, if you want to compile the project.


You can view the CA via the Certificate Manager

Start Menu -> Run -> certmgr

Or

Laragon -> Menu -> Nginx -> Certificate Manager

Note, while Laragon does have its own CA which it can add, it does not seem to work with recent browser updates.


Click to Trusted Root Certification Authority -> Certificates

Scroll to find mkcert Computer\User@Computer


Note, you can delete it if you want by Right Clicking on and select Delete


Now generate the SSL certificate, which will be signed by the CA you just added


> cd C:\laragon\etc\ssl

> ..\..\bin\mkcert\mkcert site.local "*.site.local"

Would create the SSL key and cert in C:\laragon\etc\ssl as 

site.local+1-key.pem and site.local+1.pem 


Rename the files, or specify names when creating:


> ..\..\bin\mkcert\mkcert -key-file company.localhost.key -cert-file company.localhost.crt company.localhost *.company.localhost

Which would match

company.localhost

site1.company.localhost

site2.company.localhost


Or more generically


> ..\..\bin\mkcert\mkcert -key-file dev.localhost.key -cert-file dev.localhost.crt dev.localhost *.dev.localhost

Which would match

dev.localhost

site1.dev.localhost

site2.dev.localhost


Note, most browsers do not support wildcards 2 levels deep ie don't use just localhost or test


Note, Chrome redirects use of the .dev tld to HTTPS, as Google now owns the official .dev tld.  While using any domain name which you override in your /etc/hosts file should be ok, it is best to use a domain you actually own.  But if that is not practical, .test, .local, .localhost are the often provided alternatives.



Edit you Nginx or Apache config to add the SSL cert and key, and reload


Using the default website in Laragon as a working example 

C:\laragon\etc\nginx\sites-enabled\00-default.conf


    listen 8443;

    Server_name site1.dev.localhost;


    # Enable SSL

    ssl_certificate "C:/laragon/etc/ssl/dev.localhost.crt";

    ssl_certificate_key "C:/laragon/etc/ssl/dev.localhost.key";

    ssl_session_timeout 5m;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv3:+EXP;

    ssl_prefer_server_ciphers on;



Note, if you are using Skype, you may not be able to run a webserver on port 443, so choose another port, such as 8443.


Assuming you have added your local host name to /etc/hosts or 

C:\Windows\system32\drivers\etc\hosts 

127.0.0.1       site1.dev.localhost


Viewing https://site1.dev.localhost 

Should result in a valid SSL cert.



Enjoy your HTTPS, and develop away.



To install reinstall on a computer, or reinstall after deleting the mkcert CA


Copy the full Laragon dir, or the rootCA.pem at least

Set an temporary environment variable for mkcert to read

> setx CAROOT "C:\laragon\etc\ssl\mkcert"

Close the command window, re-open

Create and install your local CA

> ..\..\bin\mkcert\mkcert -install 




FireFox

Mkcert auto installs into chromium based browsers.

For FireFox, there are a few extra steps.


View where mkcert installed the CA certificate

> mkcert -CAROOT


in FireFox url, type in about:preferences#privacy

Filter options to ‘certificates’

click View Certificates -> Authorities -> Import

Select the rootCA.pem file, in the directory listed by the prior mkcert -CAROOT


The above used to be sufficient, for newer FireFox versions >= 112

There is an extra step to take

Within the certificate list, find the imported cert in the list; it will be in the middle listed under ‘mkcert’

Now click the Edit Trust button, and check ‘enable for websites’



Re-enjoy your HTTPS, and develop away.



-End of Document-

Thanks for reading