Q:

I want to set azure server side encryption to file present in azure blob container

The problem is I want to set azure server side encryption to file which is present in azure blob container but i do not found any way to set server side encryption.  

A:

So there are 2 sides to this:

Azure Storage is encrypted by default at rest
You can use Azure Storage Service Encryption to encrypt data. You can use REST API\powershell\cli\SDK to do that.

Notice that you would need to rewrite your existing data on the storage to the storage to encrypt it.

