Danny Guo | 郭亚东

How to Get a Free S/MIME Certificate

  ·  428 words  ·  ~3 minutes to read

I recently needed a S/MIME certificate to fulfill someone’s security requirement. If you’re willing to pay, Sectigo seems like a good, affordable option. I didn’t actually need to use mine for email, so I looked for a free option.

I first checked out Let’s Encrypt, but they don’t issue S/MIME certificates. I also found instructions for generating self-signed certificates, but I needed mine to come from an external certificate authority.

Actalis was the only free provider that I could find. You can request a certificate from them using this form, and the certificate lasts for one year. Actalis does generate the private key, so that may be unacceptable depending on your situation.

I had never heard of Actalis before, so I did some due diligence and found them on the Adobe Approved Trust List and on Google’s list of CA certificates that are trusted by Gmail for S/MIME.

How It Works

First you submit your email address to get a verification code. You’ll get an email like:

Dear customer, in order to proceed with the issuance of the certificate you have to confirm the validity of the specified e-mail address.

Please enter the following verification code in the “Verification Code” field:

<code>

and than continue with the other steps in the request page.

The certificate will not be issued in the absence of this operation.

Thank you for choosing our services.

Best regards.

Actalis S.p.A.

After you submit the code, Actalis will display a password that you should save. They’ll also send you a second email like:

Dear Customer,

attached to this email you will find the S/MIME certificate you have requested.

Please note that to install and use the certificate, you must provide the password that was shown at the end of the procedure.

To manage the certificate status (suspend / reactivate or revoke) you can login to the following website:

https://extrassl.actalis.it/portal/

Using the following credentials:

User Code: <email address> (to be included in the Tax Code field)

Private Personal Code (CRP): <code>

Thank you for choosing our services.

Best regards.

Actalis S.p.A.

The email will have an attached ZIP file containing a PKCS #12 file with a name like PKCS12_Credential_<email address>.pfx.

You can extract the public certificate using OpenSSL. This command should prompt you for the password that the Actalis website provided.

openssl pkcs12 -in PKCS12_Credential_<email address>.pfx -nokeys -out certificate.pem

certificate.pem will contain the certificate chain: your public certificate, an intermediate certificate, and the Actalis root certificate.

Run this command to extract the private key as private-key.pem.

openssl pkcs12 -in PKCS12_Credential_<email address>.pfx -nocerts -nodes -out private-key.pem

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