I'm using Amazon Load Balancer with SSL configuration. everything when fine except on Firefox that show the exception page. It looks not self to user.
This article suggest to put the Certificate Chain to the configuration section.
My SSL provider is Comodo (InstantSSL). They provide two files .crt and .ca-bundle only.
How can i generate the Certificate Chain?
You can cat the .crt and the .ca-bundle file together. That's what we wound up doing using a service called OpDemand, which is backed by AWS.
cat certfile.crt bundle.ca-bundle >> chain.crt
chain.crt should be the file you're looking for. Also, the order is important. The certificate.crt file has to be first.
Use Root.crt and Intermediate.crt content and arrange them in following order. you can create this file manually as well
-----BEGIN CERTIFICATE-----
<Root content>
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
<Intermediate content>
-----END CERTIFICATE-----
Comodo should provide you with the Certificate Chain. This is not something that you can generate yourself. A quick google looks like you should be able to download it from here: https://support.comodo.com/index.php?_m=downloads&_a=view&parentcategoryid=1
来源：https://stackoverflow.com/questions/13044451/how-to-generate-the-certificate-chain-for-aws-load-balancer