Parse X509 certificates to get the subdomains in it.

When downloading X509 certificates you might want to parse out all the (sub)domains included in the certificate. This small tool allows you to give the path to the .der certificate and get the (sub)domains and IP addresses back.

Usage

ruby certs.rb ./spec/samples/alt_names_cert.der 127.0.0.1

Output

127.0.0.1,cs-stage-home02.qwilt.com
127.0.0.1,cs-stage-home02.op.qwilt.com