1 // Copyright (c) 2012 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 "rlz/lib/machine_id.h"
6
7 #include "base/sha1.h"
8 #include "rlz/lib/assert.h"
9 #include "rlz/lib/crc8.h"
10 #include "rlz/lib/string_utils.h"
11
12 namespace rlz_lib {
13
GetMachineId(std::string * machine_id)14 bool GetMachineId(std::string* machine_id) {
15 if (!machine_id)
16 return false;
17
18 static std::string calculated_id;
19 static bool calculated = false;
20 if (calculated) {
21 *machine_id = calculated_id;
22 return true;
23 }
24
25 base::string16 sid_string;
26 int volume_id;
27 if (!GetRawMachineId(&sid_string, &volume_id))
28 return false;
29
30 if (!testing::GetMachineIdImpl(sid_string, volume_id, machine_id))
31 return false;
32
33 calculated = true;
34 calculated_id = *machine_id;
35 return true;
36 }
37
38 namespace testing {
39
GetMachineIdImpl(const base::string16 & sid_string,int volume_id,std::string * machine_id)40 bool GetMachineIdImpl(const base::string16& sid_string,
41 int volume_id,
42 std::string* machine_id) {
43 machine_id->clear();
44
45 // The ID should be the SID hash + the Hard Drive SNo. + checksum byte.
46 static const int kSizeWithoutChecksum = base::kSHA1Length + sizeof(int);
47 std::basic_string<unsigned char> id_binary(kSizeWithoutChecksum + 1, 0);
48
49 if (!sid_string.empty()) {
50 // In order to be compatible with the old version of RLZ, the hash of the
51 // SID must be done with all the original bytes from the unicode string.
52 // However, the chromebase SHA1 hash function takes only an std::string as
53 // input, so the unicode string needs to be converted to std::string
54 // "as is".
55 size_t byte_count = sid_string.size() * sizeof(base::string16::value_type);
56 const char* buffer = reinterpret_cast<const char*>(sid_string.c_str());
57 std::string sid_string_buffer(buffer, byte_count);
58
59 // Note that digest can have embedded nulls.
60 std::string digest(base::SHA1HashString(sid_string_buffer));
61 VERIFY(digest.size() == base::kSHA1Length);
62 std::copy(digest.begin(), digest.end(), id_binary.begin());
63 }
64
65 // Convert from int to binary (makes big-endian).
66 for (size_t i = 0; i < sizeof(int); i++) {
67 int shift_bits = 8 * (sizeof(int) - i - 1);
68 id_binary[base::kSHA1Length + i] = static_cast<unsigned char>(
69 (volume_id >> shift_bits) & 0xFF);
70 }
71
72 // Append the checksum byte.
73 if (!sid_string.empty() || (0 != volume_id))
74 rlz_lib::Crc8::Generate(id_binary.c_str(),
75 kSizeWithoutChecksum,
76 &id_binary[kSizeWithoutChecksum]);
77
78 return rlz_lib::BytesToString(
79 id_binary.c_str(), kSizeWithoutChecksum + 1, machine_id);
80 }
81
82 } // namespace testing
83
84 } // namespace rlz_lib
85