ceftests: Add HSTS redirect test (see issue #3336, see issue #3348)

tests/shared/common/string_util.cc

@@ -0,0 +1,34 @@
+// Copyright (c) 2022 The Chromium Embedded Framework 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 "tests/shared/common/string_util.h"
+
+#include <algorithm>
+
+namespace client {
+
+std::string AsciiStrToLower(const std::string& str) {
+  std::string lowerStr = str;
+  std::transform(lowerStr.begin(), lowerStr.end(), lowerStr.begin(), ::tolower);
+  return lowerStr;
+}
+
+std::string AsciiStrReplace(const std::string& str,
+                            const std::string& from,
+                            const std::string& to) {
+  std::string result = str;
+  std::string::size_type pos = 0;
+  std::string::size_type from_len = from.length();
+  std::string::size_type to_len = to.length();
+  do {
+    pos = result.find(from, pos);
+    if (pos != std::string::npos) {
+      result.replace(pos, from_len, to);
+      pos += to_len;
+    }
+  } while (pos != std::string::npos);
+  return result;
+}
+
+}  // namespace client