ForceTLS: hash hostnames, handle subdomains, canonicalise.

net/base/dns_util.h

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_BASE_DNS_UTIL_H_
+#define NET_BASE_DNS_UTIL_H_
+
+#include <string>
+
+namespace net {
+
+// DNSDomainFromDot - convert a domain string to DNS format. From DJB's
+// public domain DNS library.
+//
+//   dotted: a string in dotted form: "www.google.com"
+//   out: a result in DNS form: "\x03www\x06google\x03com\x00"
+bool DNSDomainFromDot(const std::string& dotted, std::string* out);
+
+// Returns true iff the given character is in the set of valid DNS label
+// characters as given in RFC 3490, 4.1, 3(a)
+bool IsSTD3ASCIIValidCharacter(char c);
+
+}  // namespace net
+
+#endif  // NET_BASE_DNS_UTIL_H_