How to provide *.PFX in http_poller

I am trying to connect to my HTTPS service. My logstash conf. works fine for the HTTP call, but throws an exception during the secured call i.e. with HTTPS.

Error: "PKIX path building failed: sun.security.provider.c
ertpath.SunCertPathBuilderException: unable to find valid certification path to
requested target",

It is unable to grab my cert. I have a PFX file named "MyCert.pfx" protected with a password "c123456". Had a look into various articles but couldnt find a fix for this.

Can any one let me know how can i achieve this?

Any update on this please ?