const USER_STORE
const FILE_STORE
const ACL_LIST

func getFile(uname string, pwd string, fname string) bool {
    if authenticate(uname, pwd) == false {
        return false
    }

    if fileExists(fname) == false {
        return false
    }

    if authorization(uname, fname) == false {
        return false
    }

    return true
}

func authentication(uname string, pwd string) bool {

    val, ok := USER_STORE[uname]; ok {
        if val == hash(pwd + getSalt(uname)) {
            return true
        }
    }
    return false


func fileExists(fname string) bool {
    _, ok := FILE_STORE[fname]; ok {
        return true
    }
    return false
}

func authorization(uname string, fname string) bool {
    val, ok := ACL_LIST[uname]; ok {
        for _, file := range val {
            if file = fname {
                return true
            }
        }
    }
    return false
}