Extensions: Move id_util functions to crx_file component.

Consolidates id_util functions of extension/app/component ids in the crx_file component.

It belongs there because these types of ids are not exclusive to extensions, but rather, for anything that comes in a crx file.

BUG=371463
TBR=blundell@chromium.org

Review URL: https://codereview.chromium.org/481433005

Cr-Commit-Position: refs/heads/master@{#290971}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290971 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 88 insertions, 0 deletions

diff --git a/components/crx_file/id_util.cc b/components/crx_file/id_util.cc
new file mode 100644
index 0000000..ef271ad
--- /dev/null
+++ b/components/crx_file/id_util.cc
@@ -0,0 +1,88 @@
+// Copyright 2014 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 "components/crx_file/id_util.h"
+
+#include "base/files/file_path.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/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 crx_file {
+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 =
+      base::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] == L':')
+    path_str[0] = towupper(path_str[0]);
+
+  return base::FilePath(path_str);
+#else
+  return path;
+#endif
+}
+
+bool IdIsValid(const std::string& id) {
+  // Verify that the id is legal.
+  if (id.size() != (crx_file::id_util::kIdSize * 2))
+    return false;
+
+  // We only support lowercase IDs, because IDs can be used as URL components
+  // (where GURL will lowercase it).
+  std::string temp = base::StringToLowerASCII(id);
+  for (size_t i = 0; i < temp.size(); i++)
+    if (temp[i] < 'a' || temp[i] > 'p')
+      return false;
+
+  return true;
+}
+
+}  // namespace id_util
+}  // namespace crx_file