crt2json prints a JSON formatted summary of an SSL certificate.
I made it because it was painful to use openssl to perform these tasks. I
chose JSON as the output format because it's relatively easy to read, and you
can pass it to other tools (like jq or gron) to easily extract the field
that you want.
go install github.com/superhuman/crt2json@latest
Usage: crt2json [-sni HOSTNAME] [ SERVER | FILENAME ]
Prints out a JSON summary of an SSL certificate.
If the argument exists on disk then the file is assumed to be a certificate file, otherwise
it is interpreted as a URL or a hostname to connect to.
-sni string
server name indication to instruct the server to return the correct certificate
Right now it only prints out the information I needed for my use-cases. It would be nice to support more use-cases.