still missing things on google scraper

lib/nextpage.php

@@ -0,0 +1,106 @@
+<?php
+
+class nextpage{
+	
+	public function __construct($scraper){
+		
+		$this->scraper = $scraper;
+	}
+	
+	public function store($payload, $page){
+		
+		$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 . "." .
+			$this->scraper .
+			(string)($key),
+			gzdeflate($salt.$iv.$out.$tag),
+			420 // cache information for 7 minutes blaze it
+		);
+
+		return 
+			$this->scraper . $key . "." .
+			rtrim(strtr(base64_encode($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);
+		
+		$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;
+	}
+}