localhost SSL with puma

ssl_puma.sh

# 1) Create your private key (any password will do, we remove it below)

$ cd ~/.ssh
$ openssl genrsa -des3 -out server.orig.key 2048


# 2) Remove the password

$ openssl rsa -in server.orig.key -out server.key


# 3) Generate the csr (Certificate signing request) (Details are important!)

$ openssl req -new -key server.key -out server.csr

# IMPORTANT
# MUST have localhost.ssl as the common name to keep browsers happy 
# (has to do with non internal domain names ... which sadly can be
# avoided with a domain name with a "." in the middle of it somewhere)

Country Name (2 letter code) [AU]:
...
Common Name: localhost.ssl 
...


# 4) Generate self signed ssl certificate 

$ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

# 5) Finally Add localhost.ssl to your hosts file

$ echo "127.0.0.1 localhost.ssl" | sudo tee -a /private/etc/hosts

# 6) Boot puma

$ puma -b 'ssl://127.0.0.1:3000?key=/Users/tadas/.ssh/server.key&cert=/Users/tadas/.ssh/server.crt'

# 7) Add server.crt as trusted !!SYSTEM!! (not login) cert in the mac osx keychain
# Open keychain tool, drag .crt file to system, and trust everything.

# Notes:
# 1) Https traffic and http traffic can't be served from the same process. If you want 
#    both you need to start two instances on different ports.
#
#

In order to run with Rails (version 7),

bin/rails s -u puma -b 'ssl://127.0.0.1:3000?key=server.key&cert=server.crt&verify_mode=peer&ca=server.crt'

There is a fantastic tool called mkcert which eliminates most of the pain of generating self signed certs and installing them as trusted certs on your machine - https://github.com/FiloSottile/mkcert. Way easier than trying wrangle OpenSSL commands and APIs.

I would like to recommend this approach as well.

I am no SSL guru, so I had a long battle trying to get local SSL to work a my new computer (it works fine on my older one). At some point I even had subjectively non-deterministic results where my SSL would work for a minute or two and then stop working with no apparent change in anything.

Using the mkcert on my macOS computer via homebrew solved the problem very quickly and easily.