ForceTLS: hash hostnames, handle subdomains, canonicalise.

net/base/dns_util.cc

+// 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.
+
+#include "net/base/dns_util.h"
+
+namespace net {
+
+// Based on DJB's public domain code.
+bool DNSDomainFromDot(const std::string& dotted, std::string* out) {
+  const char* buf = dotted.data();
+  unsigned n = dotted.size();
+  char label[63];
+  unsigned int labellen = 0; /* <= sizeof label */
+  char name[255];
+  unsigned int namelen = 0; /* <= sizeof name */
+  char ch;
+
+  for (;;) {
+    if (!n)
+      break;
+    ch = *buf++;
+    --n;
+    if (ch == '.') {
+      if (labellen) {
+        if (namelen + labellen + 1 > sizeof name)
+          return false;
+        name[namelen++] = labellen;
+        memcpy(name + namelen, label, labellen);
+        namelen += labellen;
+        labellen = 0;
+      }
+      continue;
+    }
+    if (labellen >= sizeof label)
+      return false;
+    label[labellen++] = ch;
+  }
+
+  if (labellen) {
+    if (namelen + labellen + 1 > sizeof name)
+      return false;
+    name[namelen++] = labellen;
+    memcpy(name + namelen, label, labellen);
+    namelen += labellen;
+    labellen = 0;
+  }
+
+  if (namelen + 1 > sizeof name)
+    return false;
+  name[namelen++] = 0;
+
+  *out = name;
+  return true;
+}
+
+bool IsSTD3ASCIIValidCharacter(char c) {
+  if (c <= 0x2c)
+    return false;
+  if (c >= 0x7b)
+    return false;
+  if (c >= 0x2e && c <= 0x2f)
+    return false;
+  if (c >= 0x3a && c <= 0x40)
+    return false;
+  if (c >= 0x5b && c <= 0x60)
+    return false;
+  return true;
+}
+
+}  // namespace net