verify.php

<?
  // Cryptoblog Token-based Verifier Class
  // Copyleft by Elemential 2015
  // Licensed under LGPL 3.0
  
  require_once("config.php");
  
  class CryptoblogVerifier
  {
    private $prefix;
    private $con;
    
    public function __construct($prefix)
    {
      $this -> prefix = $prefix;
      $this -> con = CryptoblogConfig::getConnection();
    }
    
    public function verify($key,$token,$signature)
    {
      $query = sprintf(
        "SELECT time
        FROM %1\$sverifications
        WHERE token='%2\$s'",
        $this->prefix,
        $this -> con -> real_escape_string($token)
        );
      $result = $this -> con -> query($query);
      
      $valid = ! $result -> num_rows;
      
      if($valid)
      {
        $key_valid = openssl_verify($token, hex2bin($signature), $key, OPENSSL_ALGO_MD5);
        
        if($key_valid)
        {
          $query = sprintf(
            "INSERT INTO %1\$sverifications(token)
            VALUES (
              '%2\$s'
            )",
          $this->prefix,
          $this -> con -> real_escape_string($token));
          $result = $this -> con -> query($query);
        }
      }
      
      return $valid && $key_valid;
    }
  }
  
?>