AWS S3 - How to create x-amz-server-side-encryption-customer-key and customer-key md5 for direct upload?

I'm trying to create these keys but I can not. Has anyone created in ruby? I tried different ways but none worked. Sorry but not sample code I have only form!

'AES256'},{'x-amz-server-side-encryption-customer-key' => 'error'},{'x-amz-server-side-encryption-customer-key-MD5' => 'md5-error'}] do %>