SEC_ERROR_REUSED_ISSUER_AND_SERIAL in Firefox

[andfinally]

Thanks for this useful tool! I ran into an issue with the serial number in Firefox, using it on a nginx Docker container. If you

• Generate a certificate and set your server to use it.
• Visit the site in Firefox.
• Add a security exception in Firefox, when it detects the self-signed certificate.
• Later generate a new certificate.
• Visit the site again.

Firefox will refuse to show the page, and show the SEC_ERROR_REUSED_ISSUER_AND_SERIAL error. This is because it has a record of the original certificate with the same serial number.

There's a workaround - open the cert9.db database in your Firefox profile folder in a SQLite client and delete the entry for the certificate, or even delete the whole database, and restart Firefox. But it would probably avoid this problem if your cert generation used a different serial number each time.