4get/lib/backend.php

198 lines
4.0 KiB
PHP

<?php
class backend{
public function __construct($scraper){
$this->scraper = $scraper;
}
/*
Proxy stuff
*/
public function get_ip(){
$this->requestid = apcu_inc("real_requests");
$pool = constant("config::PROXY_" . strtoupper($this->scraper));
if($pool === false){
// we don't want a proxy, fuck off!
return 'raw_ip::::';
}
// indent
$proxy_index_raw = apcu_inc("p." . $this->scraper);
$proxylist = file_get_contents("data/proxies/" . $pool . ".txt");
$proxylist = explode("\n", $proxylist);
// ignore empty or commented lines
$proxylist = array_filter($proxylist, function($entry){
$entry = ltrim($entry);
return strlen($entry) > 0 && substr($entry, 0, 1) != "#";
});
$proxylist = array_values($proxylist);
return $proxylist[$proxy_index_raw % count($proxylist)];
}
// this function is also called directly on nextpage
public function assign_proxy(&$curlproc, $ip){
// parse proxy line
[
$type,
$address,
$port,
$username,
$password
] = explode(":", $ip, 5);
switch($type){
case "raw_ip":
return;
break;
case "http":
case "https":
curl_setopt($curlproc, CURLOPT_PROXYTYPE, CURLPROXY_HTTP);
curl_setopt($curlproc, CURLOPT_PROXY, $type . "://" . $address . ":" . $port);
break;
case "socks4":
curl_setopt($curlproc, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
curl_setopt($curlproc, CURLOPT_PROXY, $address . ":" . $port);
break;
case "socks5":
curl_setopt($curlproc, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
curl_setopt($curlproc, CURLOPT_PROXY, $address . ":" . $port);
break;
case "socks4a":
curl_setopt($curlproc, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
curl_setopt($curlproc, CURLOPT_PROXY, $address . ":" . $port);
break;
case "socks5_hostname":
curl_setopt($curlproc, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
curl_setopt($curlproc, CURLOPT_PROXY, $address . ":" . $port);
break;
}
if($username != ""){
curl_setopt($curlproc, CURLOPT_PROXYUSERPWD, $username . ":" . $password);
}
}
/*
Next page stuff
*/
public function store($payload, $page, $proxy){
$page = $page[0];
$password = random_bytes(256); // 2048 bit
$salt = random_bytes(16);
$key = hash_pbkdf2("sha512", $password, $salt, 20000, 32, true);
$iv =
random_bytes(
openssl_cipher_iv_length("aes-256-gcm")
);
$tag = "";
$out = openssl_encrypt($payload, "aes-256-gcm", $key, OPENSSL_RAW_DATA, $iv, $tag, "", 16);
$key = apcu_inc("key", 1);
apcu_store(
$page . "." .
$this->scraper .
$this->requestid,
gzdeflate($proxy . "," . $salt.$iv.$out.$tag),
900 // cache information for 15 minutes blaze it
);
return
$this->scraper . $this->requestid . "." .
rtrim(strtr(base64_encode($password), '+/', '-_'), '=');
}
public function get($npt, $page){
$page = $page[0];
$explode = explode(".", $npt, 2);
if(count($explode) !== 2){
throw new Exception("Malformed nextPageToken!");
}
$apcu = $page . "." . $explode[0];
$key = $explode[1];
$payload = apcu_fetch($apcu);
if($payload === false){
throw new Exception("The nextPageToken is invalid or has expired!");
}
$key =
base64_decode(
str_pad(
strtr($key, '-_', '+/'),
strlen($key) % 4,
'=',
STR_PAD_RIGHT
)
);
$payload = gzinflate($payload);
// get proxy
[
$proxy,
$payload
] = explode(",", $payload, 2);
$key =
hash_pbkdf2(
"sha512",
$key,
substr($payload, 0, 16), // salt
20000,
32,
true
);
$ivlen = openssl_cipher_iv_length("aes-256-gcm");
$payload =
openssl_decrypt(
substr(
$payload,
16 + $ivlen,
-16
),
"aes-256-gcm",
$key,
OPENSSL_RAW_DATA,
substr($payload, 16, $ivlen),
substr($payload, -16)
);
if($payload === false){
throw new Exception("The nextPageToken is invalid or has expired!");
}
// remove the key after using
apcu_delete($apcu);
return [$payload, $proxy];
}
}