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4get/lib/curlproxy.php

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<?php
class proxy{
public const req_web = 0;
public const req_image = 1;
public function __construct($cache = true){
$this->cache = $cache;
}
public function do404(){
http_response_code(404);
header("Content-Type: image/png");
$handle = fopen("lib/img404.png", "r");
echo fread($handle, filesize("lib/img404.png"));
fclose($handle);
die();
return;
}
public function getabsoluteurl($path, $relative){
if($this->validateurl($path)){
return $path;
}
if(substr($path, 0, 2) == "//"){
return "https:" . $path;
}
$url = null;
$relative = parse_url($relative);
$url = $relative["scheme"] . "://";
if(
isset($relative["user"]) &&
isset($relative["pass"])
){
$url .= $relative["user"] . ":" . $relative["pass"] . "@";
}
$url .= $relative["host"];
if(isset($relative["path"])){
$relative["path"] = explode(
"/",
$relative["path"]
);
unset($relative["path"][count($relative["path"]) - 1]);
$relative["path"] = implode("/", $relative["path"]);
$url .= $relative["path"];
}
if(
strlen($path) !== 0 &&
$path[0] !== "/"
){
$url .= "/";
}
$url .= $path;
return $url;
}
public function validateurl($url){
$url_parts = parse_url($url);
// check if required parts are there
if(
!isset($url_parts["scheme"]) ||
!(
$url_parts["scheme"] == "http" ||
$url_parts["scheme"] == "https"
) ||
!isset($url_parts["host"])
){
return false;
}
$ip =
str_replace(
["[", "]"], // handle ipv6
"",
$url_parts["host"]
);
// if its not an IP
if(!filter_var($ip, FILTER_VALIDATE_IP)){
// resolve domain's IP
$ip = gethostbyname($url_parts["host"] . ".");
}
// check if its localhost
if(
filter_var(
$ip,
FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE
) === false
){
return false;
}
return true;
}
public function get($url, $reqtype = self::req_web, $acceptallcodes = false, $referer = null, $redirectcount = 0){
if($redirectcount === 5){
throw new Exception("Too many redirects");
}
if($url == "https://i.imgur.com/removed.png"){
throw new Exception("Encountered imgur 404");
}
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// sanitize URL
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if($this->validateurl($url) === false){
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throw new Exception("Invalid URL");
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}
$this->clientcache();
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_ENCODING, ""); // default encoding
curl_setopt($curl, CURLOPT_HEADER, 1);
switch($reqtype){
case self::req_web:
curl_setopt(
$curl,
CURLOPT_HTTPHEADER,
[
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"User-Agent: " . config::USER_AGENT,
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"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
"Accept-Language: en-US,en;q=0.5",
"Accept-Encoding: gzip, deflate",
"DNT: 1",
"Connection: keep-alive",
"Upgrade-Insecure-Requests: 1",
"Sec-Fetch-Dest: document",
"Sec-Fetch-Mode: navigate",
"Sec-Fetch-Site: none",
"Sec-Fetch-User: ?1"
]
);
break;
case self::req_image:
if($referer === null){
$referer = explode("/", $url, 4);
array_pop($referer);
$referer = implode("/", $referer);
}
curl_setopt(
$curl,
CURLOPT_HTTPHEADER,
[
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"User-Agent: " . config::USER_AGENT,
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"Accept: image/avif,image/webp,*/*",
"Accept-Language: en-US,en;q=0.5",
"Accept-Encoding: gzip, deflate",
"DNT: 1",
"Connection: keep-alive",
"Referer: {$referer}"
]
);
break;
}
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($curl, CURLOPT_TIMEOUT, 30);
// limit size of payloads
curl_setopt($curl, CURLOPT_BUFFERSIZE, 1024);
curl_setopt($curl, CURLOPT_NOPROGRESS, false);
curl_setopt(
$curl,
CURLOPT_PROGRESSFUNCTION,
function($downloadsize, $downloaded, $uploadsize, $uploaded
){
// if $downloaded exceeds 100MB, fuck off
return ($downloaded > 100000000) ? 1 : 0;
});
$body = curl_exec($curl);
if(curl_errno($curl)){
throw new Exception(curl_error($curl));
}
curl_close($curl);
$headers = [];
$http = null;
while(true){
$header = explode("\n", $body, 2);
$body = $header[1];
if($http === null){
// http/1.1 200 ok
$header = explode("/", $header[0], 2);
$header = explode(" ", $header[1], 3);
$http = [
"version" => (float)$header[0],
"code" => (int)$header[1]
];
continue;
}
if(trim($header[0]) == ""){
// reached end of headers
break;
}
$header = explode(":", $header[0], 2);
// malformed headers
if(count($header) !== 2){ continue; }
$headers[strtolower(trim($header[0]))] = trim($header[1]);
}
// check http code
if(
$http["code"] >= 300 &&
$http["code"] <= 309
){
// redirect
if(!isset($headers["location"])){
throw new Exception("Broken redirect");
}
$redirectcount++;
return $this->get($this->getabsoluteurl($headers["location"], $url), $reqtype, $acceptallcodes, $referer, $redirectcount);
}else{
if(
$acceptallcodes === false &&
$http["code"] > 300
){
throw new Exception("Remote server returned an error code! ({$http["code"]})");
}
}
// check if data is okay
switch($reqtype){
case self::req_image:
$format = false;
if(isset($headers["content-type"])){
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if(stripos($headers["content-type"], "text/html") !== false){
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throw new Exception("Server returned html");
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}
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if(
preg_match(
'/image\/([^ ]+)/i',
$headers["content-type"],
$match
)
){
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$format = strtolower($match[1]);
if(substr(strtolower($format), 0, 2) == "x-"){
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$format = substr($format, 2);
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}
}
}
return [
"http" => $http,
"format" => $format,
"headers" => $headers,
"body" => $body
];
break;
default:
return [
"http" => $http,
"headers" => $headers,
"body" => $body
];
break;
}
return;
}
public function stream_linear_image($url, $referer = null){
$this->stream($url, $referer, "image");
}
public function stream_linear_audio($url, $referer = null){
$this->stream($url, $referer, "audio");
}
private function stream($url, $referer, $format){
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$this->clientcache();
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$this->url = $url;
$this->format = $format;
// sanitize URL
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if($this->validateurl($url) === false){
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throw new Exception("Invalid URL");
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}
$curl = curl_init();
// set headers
if($referer === null){
$referer = explode("/", $url, 4);
array_pop($referer);
$referer = implode("/", $referer);
}
switch($format){
case "image":
curl_setopt(
$curl,
CURLOPT_HTTPHEADER,
[
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"User-Agent: " . config::USER_AGENT,
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"Accept: image/avif,image/webp,*/*",
"Accept-Language: en-US,en;q=0.5",
"Accept-Encoding: gzip, deflate, br",
"DNT: 1",
"Connection: keep-alive",
"Referer: {$referer}"
]
);
break;
case "audio":
curl_setopt(
$curl,
CURLOPT_HTTPHEADER,
[
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"User-Agent: " . config::USER_AGENT,
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"Accept: audio/webm,audio/ogg,audio/wav,audio/*;q=0.9,application/ogg;q=0.7,video/*;q=0.6,*/*;q=0.5",
"Accept-Language: en-US,en;q=0.5",
"Accept-Encoding: gzip, deflate, br",
"DNT: 1",
"Connection: keep-alive",
"Referer: {$referer}"
]
);
break;
}
// follow redirects
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($curl, CURLOPT_MAXREDIRS, 5);
curl_setopt($curl, CURLOPT_AUTOREFERER, 5);
// set url
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_ENCODING, ""); // default encoding
// timeout + disable ssl
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($curl, CURLOPT_TIMEOUT, 30);
curl_setopt(
$curl,
CURLOPT_WRITEFUNCTION,
function($c, $data){
if(curl_getinfo($c, CURLINFO_HTTP_CODE) !== 200){
throw new Exception("Serber returned a non-200 code");
}
echo $data;
return strlen($data);
}
);
$this->empty_header = false;
$this->cont = false;
$this->headers_tmp = [];
$this->headers = [];
curl_setopt(
$curl,
CURLOPT_HEADERFUNCTION,
function($c, $header){
$head = trim($header);
$len = strlen($head);
if($len === 0){
$this->empty_header = true;
$this->headers_tmp = [];
}else{
$this->empty_header = false;
$this->headers_tmp[] = $head;
}
foreach($this->headers_tmp as $h){
// parse headers
$h = explode(":", $h, 2);
if(count($h) !== 2){
if(curl_getinfo($c, CURLINFO_HTTP_CODE) !== 200){
// not HTTP 200, probably a redirect
$this->cont = false;
}else{
$this->cont = true;
}
// is HTTP 200, just ignore that line
continue;
}
$this->headers[strtolower(trim($h[0]))] = trim($h[1]);
}
if(
$this->cont &&
$this->empty_header
){
// get content type
if(isset($this->headers["content-type"])){
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$octet_check = stripos($this->headers["content-type"], "octet-stream");
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if(
stripos($this->headers["content-type"], $this->format) === false &&
$octet_check === false
){
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throw new Exception("Resource reported invalid Content-Type");
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}
}else{
throw new Exception("Resource is not an {$this->format} (no Content-Type)");
}
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$filetype = explode("/", $this->headers["content-type"]);
if(!isset($filetype[1])){
throw new Exception("Malformed Content-Type header");
}
if($octet_check !== false){
$filetype[1] = "jpeg";
}
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header("Content-Type: {$this->format}/{$filetype[1]}");
// give payload size
if(isset($this->headers["content-length"])){
header("Content-Length: {$this->headers["content-length"]}");
}
// give filename
$this->getfilenameheader($this->headers, $this->url, $filetype[1]);
}
return strlen($header);
}
);
curl_exec($curl);
if(curl_errno($curl)){
throw new Exception(curl_error($curl));
}
curl_close($curl);
}
public function getfilenameheader($headers, $url, $filetype = "jpg"){
// get filename from content-disposition header
if(isset($headers["content-disposition"])){
preg_match(
'/filename=([^;]+)/',
$headers["content-disposition"],
$filename
);
if(isset($filename[1])){
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header("Content-Disposition: filename=\"" . trim($filename[1], "\"'") . "." . $filetype . "\"");
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return;
}
}
// get filename from URL
$filename = parse_url($url, PHP_URL_PATH);
if($filename === null){
// everything failed! rename file to domain name
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header("Content-Disposition: filename=\"" . parse_url($url, PHP_URL_HOST) . "." . $filetype . "\"");
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return;
}
// remove extension from filename
$filename =
explode(
".",
basename($filename)
);
if(count($filename) > 1){
array_pop($filename);
}
$filename = implode(".", $filename);
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header("Content-Disposition: inline; filename=\"" . $filename . "." . $filetype . "\"");
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return;
}
public function getimageformat($payload, &$imagick){
$finfo = new finfo(FILEINFO_MIME_TYPE);
$format = $finfo->buffer($payload["body"]);
if($format === false){
if($payload["format"] === false){
header("X-Error: Could not parse format");
$this->favicon404();
}
$format = $payload["format"];
}else{
$format_tmp = explode("/", $format, 2);
if($format_tmp[0] == "image"){
$format_tmp = strtolower($format_tmp[1]);
if(substr($format_tmp, 0, 2) == "x-"){
$format_tmp = substr($format_tmp, 2);
}
$format = $format_tmp;
}
}
switch($format){
case "tiff": $format = "gif"; break;
case "vnd.microsoft.icon": $format = "ico"; break;
case "icon": $format = "ico"; break;
case "svg+xml": $format = "svg"; break;
}
$imagick = new Imagick();
if(
!in_array(
$format,
array_map("strtolower", $imagick->queryFormats())
)
){
// format could not be found, but imagemagick can
// sometimes detect it? shit's fucked
$format = false;
}
return $format;
}
public function clientcache(){
if($this->cache === false){
return;
}
header("Last-Modified: Thu, 01 Oct 1970 00:00:00 GMT");
$headers = getallheaders();
if(
isset($headers["If-Modified-Since"]) ||
isset($headers["If-Unmodified-Since"])
){
http_response_code(304); // 304: Not Modified
die();
}
}
}