Naive guide to generating development certificates2019-06-10
The easy way: mkcert.
Recently I was working on an Ansible role to provision Nginx with TLS already configured and enabled, however to test it effectively, I needed to have valid certificates installed in the testing container. This was my brief foray into OpenSSL.
Before we can set up a CA and start signing certificates, there are a few requirements. We need a place to store the certificates, we need some configuration, and we need a database for CA lookups. Fortunately, that is all readily available.
Create a directory somewhere on your machine where you'd like your certificates to be stored:
mkdir -p ~/.local/share/certs cd ~/.local/share/certs
Add in your OpenSSL configuration, here's the config I used to generate my certicates for the Ansible role:
When generating a signed certificate with
openssl ca, OpenSSL will try to update a database file which, depending on your configuration, might be
Create a Certificate Authority
First generate a key:
openssl genrsa -out ca.key 2048
Then create a certificate signed with that key:
openssl req -new -x509 -key ca.key -out ca.crt
Note that the key and certificate filenames are important here. They should match the names in your configuration file.
To avoid prompts when generating the certificate, an extra
-subj argument can be passed:
openssl req -new -x509 -key ca.key -out ca.crt -subj "/C=ZA/ST=Western Cape/L=Cape Town/O=Bush Co/OU=Tech/CN=my-domain.dev"
The fields passed to the subject argument correspond with:
[C] Country Name (2 letter code) The two-letter country code where your company is legally located. [ST] State or Province Name (full name) The state/province where your company is legally located. [L] Locality Name (e.g., city) The city where your company is legally located. [O] Organization Name (e.g., company) Your company's legally registered name (e.g., YourCompany, Inc.). [OU] Organizational Unit Name (e.g., section) The name of your department within the organization. (You can leave this option blank; simply press Enter.) [CN] Common Name (e.g., server FQDN) The fully-qualified domain name (FQDN) (e.g., www.example.com).
Generate your certificate
Create your site key:
openssl genrsa -out localhost.key 2048
Generate a signing request:
openssl req -new -key localhost.key -out localhost.csr -subj "/C=ZA/ST=Western Cape/L=Cape Town/O=Bush Co/OU=Tech/CN=localhost"
And finally, sign the key and generate your certificate:
openssl ca -config openssl.cnf -in localhost.csr -out localhost.cer -create_serial -batch
Using the certificates
Install your CA on Firefox
In Firefox, navigate to Preferences -> Privacy & Security -> Certificates. Click "View Certificates" and under "Authorities" click Import and import your
In your vhosts file for your site:
ssl_certificate_path: "/etc/path/to/your/localhost.cer" ssl_certificate_key_path: "/etc/path/to/your/localhost.key"
In my case, I was using Molecule which runs tests against a Docker container. I needed to make a call to my test site over TLS and verify the response:
curl --cacert /etc/path/to/my/ca.crt -I -H "Host: test.dev" https://localhost HTTP/2 200 date: Mon, 10 Jun 2019 20:22:57 GMT expires: Wed, 10 Jul 2019 20:22:57 GMT server: nginx x-xss-protection: 0 x-frame-options: SAMEORIGIN ...