Generate random code golang

code.go

import "crypto/rand"

func generateRandomSecret(size int) string {
	alphanum := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefbgijklmnopqrstuvwxyz0123456789"
	var bytes = make([]byte, size)
	rand.Read(bytes)
	for i, b := range bytes {
		bytes[i] = alphanum[b%byte(len(alphanum))]
	}
	return string(bytes)
}