Anti Brute force Attacks

Opa.. fiz uma classe, para melhorar um pouco a segurança na questão de ataques brute force. Feita e testada no PHP4.

downloads:download(imagens)

Qualquer erro, por favor poste aqui.

class.php

<?php//==================================// Anti Brute Force Attacks//==================================class bruteforce{	var $ip; // =============================================	// Atualiza no DB (como banido)	// =============================================	function ban_bf($now){ $tries = $this->count_tries($this->ip);	// tentativas feitas pelo usuario $check = $this->select_bf($this->ip);	// checa se esta no BD settype($check, "boolean"); // define $check como boolean settype($tries, "int"); // define $tries como integer if ($tries == 3){ if ($check){ $query = mysql_query("UPDATE `bruteforce` SET `banned_until` = '".slashes($this->plus_min('5'))."' WHERE `bruteforce`.`ip` = '".slashes($this->ip)."'"); } }	} // =============================================	// Insere uma tentativa, se for a terceira bane	// =============================================	function insert_bf($user, $now){ $tries = $this->count_tries(); // tentativas feitas pelo usuario $check = $this->select_bf(); // checa se esta no BD settype($check, "boolean"); // define $check como boolean settype($tries, "int"); // define $tries como integer switch ($tries){ case "0": $query = mysql_query("INSERT INTO `bruteforce` (user, IP, ban, date) VALUES ('".slashes($user)."', '".slashes($this->ip)."', '1', '".server_date()."')"); break; case "1": $query = mysql_query("UPDATE `bruteforce` SET `ban` = '2', `date` = '".server_date()."' WHERE `bruteforce`.`ip` = '".slashes($this->ip)."'"); break; case "2": $query = mysql_query("UPDATE `bruteforce` SET `ban` = '3', `date` = '".server_date()."' WHERE `bruteforce`.`ip` = '".slashes($this->ip)."'"); $this->ban_bf($now); break; }	} // =============================================	// Conta quantas vezes errou login	// =============================================	function count_tries(){ $tries = $this->select_bf(); // checa se esta no BD settype($tries, "boolean"); // define $tries como boolean $query = mysql_query("SELECT `ban` FROM `bruteforce` WHERE `ip` = '".slashes($this->ip)."'"); $tries_num = @mysql_result($query,0); return $tries_num;	}	// =============================================	// Verifica se o usuario JÁ está no BD	// =============================================	function select_bf(){ $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ip` = '".slashes($this->ip)."'"); $rows = mysql_num_rows($query); if ($rows == 1){ return(true); } else { return(false); }	} // =============================================	// Adiciona minutos, ao horario em que foi banido	// =============================================	function plus_min($minutes){ $timestamp = mktime(date("H")-3, date("i")+$minutes, date("s"), date("m"), date("d"), date("Y")); return gmdate("Y-m-d H:i:s", $timestamp);	} // =============================================	// Verifica se o usuario está banido	// =============================================	function check_banned($type){	switch ($type){ case "all": $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ip` = '".slashes($this->ip)."' AND `ban` >= '1'"); $rows = mysql_num_rows($query); if ($rows == 1){ return(true); } else { return(false); }	break; case "tries": $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ip` = '".slashes($this->ip)."' AND `ban` != '3'"); $rows = mysql_num_rows($query); if ($rows == 1){ return(true); } else { return(false); }	break; case "ban": $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ip` = '".slashes($this->ip)."' AND `ban` = '3'"); $rows = mysql_num_rows($query); if ($rows == 1){ return(true); } else { return(false); }	break; }	} // ================================================	// Verifica se o IP da Session é = ao IP atual	// ================================================	function check_userip() {	if ($this->ip != $_SESSION['old_ip']){ $this->ip = $_SESSION['old_ip']; }	} // ================================================	// Verifica se já passou o tempo de espera	// ================================================	function bruteforce($ip){ $this->ip = $ip; // define o IP do usuario na session if (!isset($_SESSION['old_ip'])){ $_SESSION['old_ip'] = IP(); } $this->check_userip(); $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ban` = '3' AND `banned_until` <= '".server_date()."'"); while ($line = mysql_fetch_array($query)){ $usuario = $line["IP"]; $this->remove_bf($usuario); } $query = mysql_query("SELECT * FROM `bruteforce` WHERE `ban` != '3' AND DATE_ADD(date, INTERVAL 15 MINUTE) <= '".server_date()."'"); while ($row = mysql_fetch_array($query)){ $user = $row["IP"]; $this->remove_bf($user); }	} // ================================================	// Remove o Usuário do BD	// ================================================	function remove_bf($ip){ $query = mysql_query("DELETE FROM `bruteforce` WHERE `bruteforce`.`ip` = '".slashes($ip)."'"); }}/* * ************************ * Fim da Classe * ************************ */?>

// pega o horário do SERVIDOR, nao o do visitantefunction server_date(){ $timestamp = mktime(date("H")-3, date("i"), date("s"), date("m"), date("d"), date("Y")); return gmdate("Y-m-d H:i:s", $timestamp);}// Escapar Stringfunction slashes($string) {$string = (!get_magic_quotes_gpc()) ? mysql_escape_string($string) : $string;	return $string;}// IP do usuáriofunction IP() {if(isset($_SERVER['HTTP_X_FORWARDED_FOR']) && strpos($_SERVER['HTTP_X_FORWARDED_FOR'],',')) {$IP = explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);} elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {$IP = $_SERVER['HTTP_X_FORWARDED_FOR'];} else {$IP = $_SERVER['REMOTE_ADDR'];}return $IP; }// ANTI SQL INJECTIONfunction SQLInject($txt){ $inject=0;$badword = array(" select","select "," insert"," update","update "," delete","delete "," drop","drop "," destroy","destroy "); for($i=0;$i<sizeof($badword);$i++){ if(substr_count($txt,$badword[$i])!=0){ $inject=1; } }$charvalidos = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789ÁÀÃÂÇÉÈÊÍÌÓÒÔÕÚÙÜÑáàãâçéèêíìóòôõúùüñ!?@#$%&(){}[]:;,.-\/ "; for($i=0;$i<strlen($txt);$i++){ $char = substr($txt,$i,1); if(substr_count($charvalidos,$char)==0){ $inject=1; } } return($inject);}

CREATE TABLE bruteforce (action_id INT NOT NULL AUTO_INCREMENT ,user VARCHAR( 255 ) NOT NULL ,IP VARCHAR( 26 ) NOT NULL ,ban INT NOT NULL ,date DATETIME NOT NULL ,banned_until DATETIME NOT NULL ,PRIMARY KEY ( action_id ));
exemplo.php

<?phpsession_start();require_once("lib/class.php");require_once("lib/functions.php");if (isset($_SESSION["login"])){	echo("<center>".htmlentities("Você já está logado como")." <b>". $_SESSION['user'] ."</b>! Para logar-se com outro usúario, favor faça um logout!</b></center>");} else{$bf = new bruteforce(IP());$banned = $bf->check_banned('ban');if ($banned){$query = mysql_query("SELECT * FROM `bruteforce` WHERE `ip` = '".IP()."'");	while ($line = mysql_fetch_array($query)){	$banned_upto = substr($line["banned_until"], 10);	echo("<div align=\"center\">Você foi bloqueado por 5 minutos. <br /> Tente logar denovo às: <strong>".$banned_upto."</strong> de hoje</div>"); }} else {if (isset($_POST['act'])){$username = $_POST['user'];$passwd = $_POST['pass'];$image = (int)$_POST['image'];$imageverify = (int)$_POST['imageverify'];$key = '2a2cf8gk68gj67gf784kh69fo6';$time = time();$ip = $_SERVER['REMOTE_ADDR'];$rand = rand(0,10000);	if (empty($username) || empty($passwd) || empty($imageverify))	{ echo("<div align=\"center\">"); echo("<b>Por favor, preencha todos os campos!</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); return;	} if(SQLinject(STRTOLOWER($username)) || SQLinject(STRTOLOWER($passwd))) { echo("<div align=\"center\">"); echo("<b>Tentativa de Hack!</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); $bf->insert_bf($username, IP(), server_date()); return; }	if (strlen(trim($username)) < 4 || strlen(trim($username)) > 23)	{ echo("<div align=\"center\">"); echo("<b>".htmlentities("Seu nome de usuário deve conter entre 4 e 23 caractéres!")."</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); $bf->insert_bf($username, IP(), server_date()); return;	}	if (strlen(trim($passwd)) < 4 || strlen(trim($passwd)) > 23)	{ echo("<div align=\"center\">"); echo("<b>".htmlentities("Sua senha deve conter entre 4 e 23 caractéres!")."</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); $bf->insert_bf($username, IP(), server_date()); return;	}	if ($image != $imageverify) { echo("<div align=\"center\">"); echo("<b>".htmlentities("Verificação de Imagem Incorreta!")."</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); $bf->insert_bf($username, IP(), server_date()); return;	}	$passwd = md5($passwd);$query = mysql_query("SELECT `users`.`username`, `users`.`passwd` FROM `users` WHERE `users`.`username` = '".slashes($username)."' AND `users`.`passwd` = '".slashes($passwd)."'");$num = mysql_num_rows($query); if ($num == "0") { echo("<div align=\"center\">"); echo("<b>".htmlentities("Nome de Usuário/Senha não Existentes ou Incorretos!")."</b><br>"); echo("<a href=\"java script:self.history.go(-1)\">Voltar</a>"); echo("</div><br />"); $bf->insert_bf($username, IP(), server_date()); return;	}	$md5user = md5($_POST['user']);$md5pass = md5($_POST['pass']);$md5key = md5("2a2cf8gk68gj67gf784kh69fo6");$md5time = md5(time());$md5ip = md5($_SERVER['REMOTE_ADDR']);$md5rand = md5(rand(0,10000));$_SESSION['login'] = array("user" => $md5user, "key" => $md5key, "time" => $md5time, "ip" => $md5ip, "rand" => $md5rand);$_SESSION['user'] = serialize($username);echo("<meta http-equiv=\"refresh\" content=\"0; URL=default.php?link=home\">");} else {?><table align="center" width="300"> <tr> <td><fieldset width="300"><legend width="100" align="center"> <font color="#0066cc"><b> Autenticação</b></font></legend> <div align="center"><form name="login" method="post" action="exemplo.php"> <b>Usuário:</b> <br /> <input type="text" name="user" size="12" maxlength="24" class="input_text"><br /> <b>Senha:</b><br /> <input type="password" name="pass" size="12" maxlength="23"><br /><table style="margin: 5px" cellspacing="0" cellpadding="0" align="center"><?php//Verificacao de Imagem$randomnumone = rand("0", "9");$randomnumtwo = rand("0", "9");$randomnumthree = rand("0", "9");$randomnumfour = rand("0", "9");$randomnumfive = rand("0", "9");$randomnumsix = rand("0", "9");$total = $randomnumone." ".$randomnumtwo." ".$randomnumthree." ".$randomnumfour." ".$randomnumfive." ".$randomnumsix;$form = $randomnumone.$randomnumtwo.$randomnumthree.$randomnumfour.$randomnumfive.$randomnumsix;$exploded = explode(" ", $total);$one = 0;$two = 0;$three = 0;$four = 0;$five = 0;$six = 0;echo("<tr><td align=\"center\" colspan=\"6\" style=\"margin-top: 3px;\"><strong>".htmlentities("Verificação de Imagem")."</strong></td></tr>");while($exploded['0'] != $one){	$one++;}if($exploded['0'] == $one){	echo("<tr><td style=\"border-bottom: 2px #000000 solid; border-left: 2px #000000 solid; border-top: 2px #000000 solid;\"><img class=\"news\" src=\"../templates/images/autenticacao/{$one}.gif\"></td>");}while($exploded['1'] != $two){	$two++;}if($exploded['1'] == $two){	echo("<td style=\"border-bottom: 2px #000000 solid; border-top: 2px #000000 solid;\"><img src=\"../templates/images/autenticacao/{$two}.gif\"></td>");}while($exploded['2'] != $three){	$three++;}if($exploded['2'] == $three){	echo("<td style=\"border-bottom: 2px #000000 solid; border-top: 2px #000000 solid;\"><img src=\"../templates/images/autenticacao/{$three}.gif\"></td>");}while($exploded['3'] != $four){	$four++;}if($exploded['3'] == $four){	echo("<td style=\"border-bottom: 2px #000000 solid; border-top: 2px #000000 solid;\"><img src=\"../templates/images/autenticacao/{$four}.gif\"></td>");}while($exploded['4'] != $five){	$five++;}if($exploded['4'] == $five){	echo("<td style=\"border-bottom: 2px #000000 solid; border-top: 2px #000000 solid;\"><img src=\"../templates/images/autenticacao/{$five}.gif\"></td>");}while($exploded['5'] != $six){	$six++;}if($exploded['5'] == $six){	echo("<td style=\"border-right: 2px #000000 solid; border-bottom: 2px #000000 solid; border-top: 2px #000000 solid;\"><img src=\"../templates/images/autenticacao/{$six}.gif\"></td>");}?> </td> </tr> <input type="hidden" name="image" value="<?php echo $form; ?>" /> <tr> <td align="center" style="margin: 5px;" colspan="6"> <input style="margin: 3px;" type="text" maxlength="6" name="imageverify" /> </td> </tr></table> <input name="" type="reset" value="Limpar" /> <input name="act" type="submit" value="Enviar" /> <br /> </td></tr></table></form></div></fieldset> } }}?>