Smallstep Certificate Manager is a commercial product that delivers a managed certificate authority (CA) capable of issuing private x.509 TLS or SSH certificates.
Certificate Manager builds on two open source projects, maintained by smallstep:
step-ca: a private online certificate authority for secure automated certificate management.
step: a general-purpose cryptography toolkit and the client-side counterpart to step-ca.
With Certificate Manager, you can create your own private CA to manage certificates on internal services, websites, infrastructure, people, or devices.
Install step, which will be used to manage access to, and get certificates from, an authority.
step 1 - create an Authority
Certificate Manager authorities are trusted services that manage certificate issuance and revocation.
In this tutorial, we will create a hosted authority, an online CA that authenticates and authorizes certificate requests and issues certificates.
Log into the smallstep dashboard, select the Certificate Manager tab, and click the "Add Authority" button.
Choose "Create a new hosted authority"
Give your Authority a name and subdomain value (the URL path you wish to use for your online CA).
Behind the scenes, Certificate Manager creates a new root and an online intermediate CA,
storing the private keys into Google's Cloud KMS.
On the Authority detail page, you will see the CA URL and Fingerprint;
you'll use these values to interact with your CA.
Certificate Manager also creates a default provisioner called 'authority-admin',
and a "super admin" account on that provisioner,
with your email address as the account name.
The super admin can manage admins and provisioners on your Authority.
step 2 - configure your client
Certificate Manager authorities are administered using the step command-line client.
To connect your local client with the hosted authority, you need to bootstrap into the PKI.
Run the following command, substituting the values from your Authority's properties:
$step ca bootstrap --ca-url [YOUR CA URL] --fingerprint [YOUR AUTHORITY FINGERPRINT]
(You can always find this command on the Quick Actions section on your authority page.)
This command will download the CA Root certificate and configure your local client to interact with the Authority.
step 3 - Create a test certificate
With an authority created and your local client configured,
you can create a test certificate by running the step ca certificate command.
Here is an example:
$step ca certificate myservice myservice.crt myservice.key --san myservice.internal.mycompany.net --not-after 24h
In this command, we are asking the CA to create a certificate with the following properties
myservice - The name on the certificate
myservice.crt - Store the certificate in a file with this name
myservice.key - Store the key in a file with this name
--san myservice.internal.mycompany.net - Add an additional SAN to the certificate with the specified value
--not-after 24h - Set the certificate to expire after 24 hours.
When you run this command, it will envoke the 'authority-admin' provisioner and start a single sign-on flow via the smallstep dashboard.
After a successful sign-in, the authority will issue the certificate.
You can inspect your certificate by running:
$step certificate inspect --short myservice.crt
It should look similar to this.
X.509v3 TLS Certificate (ECDSA P-256)[Serial: 2441...2018]
Issuer: provisioner test Intermediate CA
Provisioner: authority-admin [ID: 909d...8521]
Valid from: 2021-10-04T21:30:12Z
step 4 - renew a certificate
Certificate Manager makes renewing a certificate ahead of expiration easy.
Renewals are authenticated using your existing certificate, and produce an identical certificate with a new serial number and extended lifetime.
The private key is unchanged.
In its most primitive form, renewal is a simple single-command operation:
$step ca renew svc.crt svc.key
More than a dozen command-line flags make step ca renew flexible and easy to integrate into almost any operational environment.
You've now created an authority, issued a certificate, and renewed a certificate. These three actions are the foundation of your certificate management experience.