I'm new to ssl so forgive me.
I set up a site with ssl and all the online checks (eg. https://ssltools.websecurity.symantec.com/checker/views/certCheck.jsp) show that it is set up correctly and the site runs fine in the browser.
The site uses a payment gateway, this is where the problem is. When testing the payments, I found that the IPN wasn't being run. So I got support from from the payment gateway service provider and they sent back the reason that the IPN was not being run was because of this error
com.payjar.common.exception.TransactionProcessException: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
I've been reading up about it online and I've found a lot about keytool and truststore, but I'm not too sure how it all works and if it will even solve my problem as the IPN is stored on my server but it is not run on a browser but by the payment service provider. So will I need to use this keytool on my server or will they need to do something on their side(which is obviously not an option for them)?
Any help or guidance would be greatly appreciated on how I can solve this error.
My server is Ubuntu 14.04.1 running Apache 2.4.7. The ssl certificate is a CA signed certificate.