Move CrxFile, FileReader, ExtensionResource to src/extensions.

extensions/common/id_util.cc

Index: extensions/common/id_util.cc
diff --git a/extensions/common/id_util.cc b/extensions/common/id_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5bdeba42aa48436259f0f815ceb700e588d538d3
--- /dev/null
+++ b/extensions/common/id_util.cc
@@ -0,0 +1,73 @@
+// Copyright (c) 2013 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 "extensions/common/id_util.h"
+
+#include "base/files/file_path.h"
+#include "base/string_number_conversions.h"
+#include "base/string_util.h"
+#include "crypto/sha2.h"
+
+namespace {
+
+// Converts a normal hexadecimal string into the alphabet used by extensions.
+// We use the characters 'a'-'p' instead of '0'-'f' to avoid ever having a
+// completely numeric host, since some software interprets that as an IP
+// address.
+static void ConvertHexadecimalToIDAlphabet(std::string* id) {
+  for (size_t i = 0; i < id->size(); ++i) {
+    int val;
+    if (base::HexStringToInt(base::StringPiece(id->begin() + i,
+                                               id->begin() + i + 1),
+                             &val)) {
+      (*id)[i] = val + 'a';
+    } else {
+      (*id)[i] = 'a';
+    }
+  }
+}
+
+}  // namespace
+
+namespace extensions {
+namespace id_util {
+
+// First 16 bytes of SHA256 hashed public key.
+const size_t kIdSize = 16;
+
+std::string GenerateId(const std::string& input) {
+  uint8 hash[kIdSize];
+  crypto::SHA256HashString(input, hash, sizeof(hash));
+  std::string output = StringToLowerASCII(base::HexEncode(hash, sizeof(hash)));
+  ConvertHexadecimalToIDAlphabet(&output);
+
+  return output;
+}
+
+std::string GenerateIdForPath(const base::FilePath& path) {
+  base::FilePath new_path = MaybeNormalizePath(path);
+  std::string path_bytes =
+      std::string(reinterpret_cast<const char*>(new_path.value().data()),
+                  new_path.value().size() * sizeof(base::FilePath::CharType));
+  return GenerateId(path_bytes);
+}
+
+base::FilePath MaybeNormalizePath(const base::FilePath& path) {
+#if defined(OS_WIN)
+  // Normalize any drive letter to upper-case. We do this for consistency with
+  // net_utils::FilePathToFileURL(), which does the same thing, to make string
+  // comparisons simpler.
+  base::FilePath::StringType path_str = path.value();
+  if (path_str.size() >= 2 && path_str[0] >= L'a' && path_str[0] <= L'z' &&
+      path_str[1] == ':')
+    path_str[0] += ('A' - 'a');
+
+  return base::FilePath(path_str);
+#else
+  return path;
+#endif
+}
+
+}  // namespace id_util
+}  // namespace extensions