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. 4 5 #include "extensions/common/id_util.h" 6 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" 11 12 namespace { 13 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 17 // address. ConvertHexadecimalToIDAlphabet(std::string * id)18static void ConvertHexadecimalToIDAlphabet(std::string* id) { 19 for (size_t i = 0; i < id->size(); ++i) { 20 int val; 21 if (base::HexStringToInt(base::StringPiece(id->begin() + i, 22 id->begin() + i + 1), 23 &val)) { 24 (*id)[i] = val + 'a'; 25 } else { 26 (*id)[i] = 'a'; 27 } 28 } 29 } 30 31 } // namespace 32 33 namespace extensions { 34 namespace id_util { 35 36 // First 16 bytes of SHA256 hashed public key. 37 const size_t kIdSize = 16; 38 GenerateId(const std::string & input)39std::string GenerateId(const std::string& input) { 40 uint8 hash[kIdSize]; 41 crypto::SHA256HashString(input, hash, sizeof(hash)); 42 std::string output = StringToLowerASCII(base::HexEncode(hash, sizeof(hash))); 43 ConvertHexadecimalToIDAlphabet(&output); 44 45 return output; 46 } 47 GenerateIdForPath(const base::FilePath & path)48std::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); 54 } 55 MaybeNormalizePath(const base::FilePath & path)56base::FilePath MaybeNormalizePath(const base::FilePath& path) { 57 #if defined(OS_WIN) 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' && 63 path_str[1] == ':') 64 path_str[0] += ('A' - 'a'); 65 66 return base::FilePath(path_str); 67 #else 68 return path; 69 #endif 70 } 71 72 } // namespace id_util 73 } // namespace extensions 74