Support for inspecting or extracting RFC9399 logotypes

[tashian]

The new BIMI standard is used for email logo verification in Gmail. It uses RFC9399 (OID 1.3.6.1.5.5.7.1.12) to embed an SVG in the certificate. Here's an example PEM from LinkedIn.

Herman suggested we could use Kitty to display the embedded image, or spin up a local web server to display it.

Or, maybe the easiest first step is to recognize the OID and allow users to export the image from the certificate.