@@ -0,0 +1,79 @@
+// @ts-check
+/// <reference path="types-dnscontrol.d.ts" />
+
+// Helpers
+
+/**
+ * @param {object} record
+ * @param {string[]} [record.alpn]
+ * @param {string[]} [record.ipv4hint]
+ * @param {string[]} [record.ipv6hint]
+ */
+function https(record) {
+  return Object.keys(record)
+    .map(function (key) {
+      return [key, record[key].join(',')].join('=')
+    })
+    .join(' ')
+}
+
+/**
+ * @param {string} target
+ */
+function ensureAbsolute(target) {
+  return target.endsWith('.') ? target : target + '.'
+}
+
+/**
+ * @param {string} target
+ * @param {string} prefix
+ */
+function prefix(target, prefix) {
+  return target === '@'
+    ? prefix
+    : prefix + '.' + target
+
+}
+
+/**
+ * @param {string} name
+ * @param {string} acmeTarget
+ */
+function acmeDelegate(name, acmeTarget) {
+  return CNAME(
+    name === '@' ? '_acme-challenge' : '_acme-challenge.' + name,
+    ensureAbsolute(acmeTarget),
+    TTL('15m'),
+  )
+}
+
+/**
+ * @param {string[]} sources
+ * @param {string} target
+ * @param {RecordModifier[]} [recordModifiers]
+ */
+function bulkCNAME(sources, target, recordModifiers) {
+  return sources.map(function (source) {
+    return CNAME.bind(CNAME, source, target).apply(CNAME, recordModifiers)
+  })
+}
+
+/**
+ * @param {string} domain
+ * @param {string} verification
+ * @param {string[]} [extras]
+ */
+function iCloudMail(domain, verification, extras) {
+  if (extras == null) {
+    extras = []
+  }
+  return [
+    MX('@', 10, 'mx01.mail.icloud.com.'),
+    MX('@', 10, 'mx02.mail.icloud.com.'),
+    TXT('@', 'apple-domain=' + verification),
+    SPF_BUILDER({
+      parts: ['v=spf1'].concat(extras).concat('include:icloud.com', '-all'),
+    }),
+    CNAME('sig1._domainkey', 'sig1.dkim.' + domain + '.at.icloudmailadmin.com.'),
+  ]
+}