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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
<?php
class VideoStream
{
private $path = "";
private $stream = "";
private $start = -1;
private $end = -1;
private $size = 0;
function __construct($filePath)
{
$this->path = $filePath;
}
/**
* Decrypts a msg using sodium
*/
private function decrypt($msg) {
$key = "v6jM4s0hYqa52m8Bt5c1z7Celv6hFbnF";
$nonce = "mf5cOb6g19QRbX93bD6Fpj5d";
return sodium_crypto_secretbox_open($msg, $nonce, $key); // decr
}
/**
* Open stream
*/
private function open()
{
if (!($this->stream = fopen($this->path, 'rb'))) {
die('Could not open stream for reading');
}
}
/**
* Close curretly opened stream
*/
private function end()
{
fclose($this->stream);
exit;
}
/**
* Calculate the size of the decrypted video, based on $val,
* the size of the encrypted video.
* Works as long as the video has been encrypted by chunks of 1024 bytes
* (each chunck takes 16 bytes more when encrypted)
*/
private function clearSize($val)
{
$fullChuncksNb = floor($val/1040); // nb of chuncks of 1024 bytes (1024+16)
$lastChunckSize = $val - ($fullChuncksNb * 1040) - 16; // size of the last chunk (decrypted)
return $fullChuncksNb * 1024 + $lastChunckSize;
}
/**
* Set proper header to serve the video content
*/
private function setHeader()
{
ob_get_clean();
header("Content-Type: video/mp4");
header("Cache-Control: max-age=2592000, public");
header("Expires: ".gmdate('D, d M Y H:i:s', time()+2592000) . ' GMT');
header("Last-Modified: ".gmdate('D, d M Y H:i:s', @filemtime($this->path)) . ' GMT' );
$this->start = 0;
$this->size = $this->clearSize(filesize($this->path));
$this->cryptSize = filesize($this->path);
$this->end = $this->size - 1;
header("Accept-Ranges: bytes");
if (isset($_SERVER['HTTP_RANGE'])) {
$c_start = $this->start;
$c_end = $this->end;
list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
if (strpos($range, ',') !== false) {
header('HTTP/1.1 416 Requested Range Not Satisfiable');
header("Content-Range: bytes $this->start-$this->end/$this->size");
exit;
}
if ($range == '-') {
$c_start = $this->size - substr($range, 1);
}else{
$range = explode('-', $range);
$c_start = $range[0];
$c_end = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $c_end;
}
$c_end = ($c_end > $this->end) ? $this->end : $c_end;
if ($c_start > $c_end || $c_start > $this->size - 1 || $c_end >= $this->size) {
header('HTTP/1.1 416 Requested Range Not Satisfiable');
header("Content-Range: bytes $this->start-$this->end/$this->size");
exit;
}
$this->start = $c_start;
$this->end = $c_end;
$this->length = $this->end - $this->start + 1;
header('HTTP/1.1 206 Partial Content');
header("Content-Length: " . $this->length);
header("Content-Range: bytes $this->start-$this->end/".$this->size);
}
else
{
header("Content-Length: ". $this->size);
}
}
/**
* Perform the streaming of calculated range
*/
private function stream()
{
set_time_limit(0);
$bytesToRead = 1040;
// z_start = index of the chunck containing start
$z_start = $this->start;
$z_start /= 1024;
$z_start = floor($z_start);
// z_end = index of the chunck containing end
$z_end = $this->end;
$z_end /= 1024;
$z_end = floor($z_end);
// let's go at the beginning of the chunk containing z_start
fseek($this->stream, $z_start * $bytesToRead);
// read the chunk and decrypt it
$data = fread($this->stream, $bytesToRead); // size 1040
$data = $this->decrypt($data); // size 1024
// extracts the relevant bytes from this chunk
$len = ($z_end > $z_start) ? 1023 - ($this->start%1024) + 1 : $this->end - $this->start + 1;
$bytes = mb_substr($data, ($this->start%1024), $len, '8bit');
// keep record of how much bytes has been returned so far
$written = $len;
echo $bytes;
flush();
// i = pos of the cursor in the crypted stream (could be 1040, 2080, ...)
$i = ftell($this->stream);
while (!feof($this->stream) && $i < $this->cryptSize)
{
// if we are in last chunk of the crypted file (length < 1024)
if (($i + $bytesToRead) > $this->cryptSize - 1)
$bytesToRead = $this->cryptSize - $i;
// read and decrypt
$data = fread($this->stream, $bytesToRead);
$data = $this->decrypt($data);
// if I don't need all the bytes of this chunck
if ($written + 1024 > $this->length) {
$len = $this->length - $written;
$bytes2 = mb_substr($data, 0, $len, '8bit');
echo $bytes2;
flush();
return;
} else {
echo $data;
$written += 1024;
flush();
}
$i += 1040;
}
}
/**
* Start streaming video content
*/
function start()
{
$this->open();
$this->setHeader();
$this->stream();
$this->end();
}
}
$filePath = "file";
$stream = new VideoStream($filePath);
$stream->start();
?> |
