1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
// Copyright 2015 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/cdm/browser/widevine_drm_delegate_android.h"
#include "base/logging.h"
#include "base/numerics/safe_conversions.h"
namespace cdm {
namespace {
uint32_t ReadUint32(const uint8_t* data) {
uint32_t value = 0;
for (int i = 0; i < 4; ++i)
value = (value << 8) | data[i];
return value;
}
uint64_t ReadUint64(const uint8_t* data) {
uint64_t value = 0;
for (int i = 0; i < 8; ++i)
value = (value << 8) | data[i];
return value;
}
// The structure of an ISO CENC Protection System Specific Header (PSSH) box is
// as follows. (See ISO/IEC FDIS 23001-7:2011(E).)
// Note: ISO boxes use big-endian values.
//
// PSSH {
// uint32_t Size
// uint32_t Type
// uint64_t LargeSize # Field is only present if value(Size) == 1.
// uint32_t VersionAndFlags
// uint8_t[16] SystemId
// uint32_t DataSize
// uint8_t[DataSize] Data
// }
const int kBoxHeaderSize = 8; // Box's header contains Size and Type.
const int kBoxLargeSizeSize = 8;
const int kPsshVersionFlagSize = 4;
const int kPsshSystemIdSize = 16;
const int kPsshDataSizeSize = 4;
const uint32_t kTencType = 0x74656e63;
const uint32_t kPsshType = 0x70737368;
const uint8_t kWidevineUuid[16] = {
0xED, 0xEF, 0x8B, 0xA9, 0x79, 0xD6, 0x4A, 0xCE,
0xA3, 0xC8, 0x27, 0xDC, 0xD5, 0x1D, 0x21, 0xED };
// Tries to find a PSSH box with the Widevine UUID, parses the
// "Data" of the box and put it in |pssh_data|. Returns true if such a box is
// found and successfully parsed. Returns false otherwise.
// Notes:
// 1, If multiple PSSH boxes are found,the "Data" of the first matching PSSH box
// will be set in |pssh_data|.
// 2, Only PSSH and TENC boxes are allowed in |data|. TENC boxes are skipped.
bool GetPsshData(const std::vector<uint8_t>& data,
std::vector<uint8_t>* pssh_data) {
int bytes_left = base::checked_cast<int>(data.size());
const uint8_t* cur = &data[0];
const uint8_t* data_end = cur + bytes_left;
while (bytes_left > 0) {
const uint8_t* box_head = cur;
if (bytes_left < kBoxHeaderSize)
return false;
uint64_t box_size = ReadUint32(cur);
uint32_t type = ReadUint32(cur + 4);
cur += kBoxHeaderSize;
bytes_left -= kBoxHeaderSize;
if (box_size == 1) { // LargeSize is present.
if (bytes_left < kBoxLargeSizeSize)
return false;
box_size = ReadUint64(cur);
cur += kBoxLargeSizeSize;
bytes_left -= kBoxLargeSizeSize;
} else if (box_size == 0) {
box_size = bytes_left + kBoxHeaderSize;
}
const uint8_t* box_end = box_head + box_size;
if (data_end < box_end)
return false;
if (type == kTencType) {
// Skip 'tenc' box.
cur = box_end;
bytes_left = data_end - cur;
continue;
} else if (type != kPsshType) {
return false;
}
const int kPsshBoxMinimumSize =
kPsshVersionFlagSize + kPsshSystemIdSize + kPsshDataSizeSize;
if (box_end < cur + kPsshBoxMinimumSize)
return false;
uint32_t version_and_flags = ReadUint32(cur);
cur += kPsshVersionFlagSize;
bytes_left -= kPsshVersionFlagSize;
if (version_and_flags != 0)
return false;
DCHECK_GE(bytes_left, kPsshSystemIdSize);
if (!std::equal(kWidevineUuid,
kWidevineUuid + sizeof(kWidevineUuid), cur)) {
cur = box_end;
bytes_left = data_end - cur;
continue;
}
cur += kPsshSystemIdSize;
bytes_left -= kPsshSystemIdSize;
uint32_t data_size = ReadUint32(cur);
cur += kPsshDataSizeSize;
bytes_left -= kPsshDataSizeSize;
if (box_end < cur + data_size)
return false;
pssh_data->assign(cur, cur + data_size);
return true;
}
return false;
}
}
WidevineDrmDelegateAndroid::WidevineDrmDelegateAndroid() {
}
WidevineDrmDelegateAndroid::~WidevineDrmDelegateAndroid() {
}
const std::vector<uint8_t> WidevineDrmDelegateAndroid::GetUUID() const {
return std::vector<uint8_t>(kWidevineUuid,
kWidevineUuid + arraysize(kWidevineUuid));
}
bool WidevineDrmDelegateAndroid::OnCreateSession(
const media::EmeInitDataType init_data_type,
const std::vector<uint8_t>& init_data,
std::vector<uint8_t>* init_data_out,
std::vector<std::string>* /* optional_parameters_out */) {
if (init_data_type != media::EmeInitDataType::CENC)
return true;
// Widevine MediaDrm plugin only accepts the "data" part of the PSSH box as
// the init data when using MP4 container.
return GetPsshData(init_data, init_data_out);
}
} // namespace cdm
|
