You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: smimea.go
    path of file: ./repos/gotosocial/vendor/github.com/miekg/dns
    
    the code of the file until where you have to start completion: package dns

import (
	"crypto/sha256"
	"crypto/x509"
	"
    
func SMIMEAName(email, domain string) (string, error) {
	hasher := sha256.New()
	hasher.Write([]byte(email))

	// RFC Section 3: "The local-part is hashed using the SHA2-256
	// algorithm with the hash truncated to 28 octets and
	// represented in its hexadecimal representation to become the
	// left-most label in the prepared domain name"
	return hex.EncodeToString(hasher.Sum(nil)[:28]) + "." + "_smimecert." + domain, nil
}