mkcertchain is a utility for building a chain of intermediate certificates
for an SSL certificate.  It downloads the chain certificate from the URL
specified in the certificate's "CA Issuers" field, recurring until
encountering a root certificate that's trusted in all major browsers.
If multiple certificate chains are found, the shortest one is used.

Usage: mkcertchain [--ca-file=PATH] < CERTIFICATE

mkcertchain reads the certificate from standard in and outputs the
chain to standard out.

Use --ca-file to specify the path to the file containing root certificate
authorities trusted by browsers.  If unspecified, this option defaults
to ../share/mkcertchain/browser_roots.pem, relative to the directory
containing the mkcertchain program.

mkcertchain was developed by SSLMate <https://sslmate.com> and powers
the chain cert generator on <https://whatsmychaincert.com>.  SSLMate is
an SSL certificate management service that lets you buy SSL certificates
from the command line.