1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "extensions/common/id_util.h"
7 #include "base/files/file_path.h"
8 #include "base/strings/string_number_conversions.h"
9 #include "base/strings/string_util.h"
10 #include "crypto/sha2.h"
14 // Converts a normal hexadecimal string into the alphabet used by extensions.
15 // We use the characters 'a'-'p' instead of '0'-'f' to avoid ever having a
16 // completely numeric host, since some software interprets that as an IP
18 static void ConvertHexadecimalToIDAlphabet(std::string* id) {
19 for (size_t i = 0; i < id->size(); ++i) {
21 if (base::HexStringToInt(base::StringPiece(id->begin() + i,
33 namespace extensions {
36 // First 16 bytes of SHA256 hashed public key.
37 const size_t kIdSize = 16;
39 std::string GenerateId(const std::string& input) {
41 crypto::SHA256HashString(input, hash, sizeof(hash));
42 std::string output = StringToLowerASCII(base::HexEncode(hash, sizeof(hash)));
43 ConvertHexadecimalToIDAlphabet(&output);
48 std::string GenerateIdForPath(const base::FilePath& path) {
49 base::FilePath new_path = MaybeNormalizePath(path);
50 std::string path_bytes =
51 std::string(reinterpret_cast<const char*>(new_path.value().data()),
52 new_path.value().size() * sizeof(base::FilePath::CharType));
53 return GenerateId(path_bytes);
56 base::FilePath MaybeNormalizePath(const base::FilePath& path) {
58 // Normalize any drive letter to upper-case. We do this for consistency with
59 // net_utils::FilePathToFileURL(), which does the same thing, to make string
60 // comparisons simpler.
61 base::FilePath::StringType path_str = path.value();
62 if (path_str.size() >= 2 && path_str[0] >= L'a' && path_str[0] <= L'z' &&
64 path_str[0] += ('A' - 'a');
66 return base::FilePath(path_str);
72 } // namespace id_util
73 } // namespace extensions