Error doing callout to a site with GoDaddy certificate

Question

When we try to send some data to an external web service (REST, POST, JSON), we get the next error:

System.CalloutException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

If we check the certificate, it's a valid "Go Daddy Secure Certificate Authority - G2".

Also, We have checked that this company is included as a valid Certificate Authority into Salesforce list (https://developer.salesforce.com/page/Outbound_Messaging_SSL_CA_Certificates#godaddy).

Answer 1

Posting the answer here so that it can help users facing similar error: Go to https://www.digicert.com/help/ put the and click on check server:

You will get the error below: SSL Certificate is not trusted

The certificate is not signed by a trusted authority (checking against Mozilla's root store). If you bought the certificate from a trusted authority, you probably just need to install one or more Intermediate certificates. Contact your certificate provider for assistance doing this for your server platform.

I understand you have used Go Daddy to sign the certificate, however, following is the only ones Salesforce supports By Godaddy:

godaddy godaddyclass2ca godaddyint

Kindly check to see the certificate Godaddy has provided - you can show them the 3 given above and ask them to confirm if the certificate given to you is one of them, if not - you need to get one with is salesforce supported.