我正在尝试将登录表单添加到我的免费mathhelp站点，但每当我在索引页面中包含该表单时，它都隐藏了该站点的其余部分。以下是Codex-m所有信用的源代码：
<?php
session_start();
//require user configuration and database connection parameters
require('config.php');
if (($_SESSION['logged_in'])==TRUE) {
//valid user has logged-in to the website
//Check for unauthorized use of user sessions
$iprecreate= $_SERVER['REMOTE_ADDR'];
$useragentrecreate=$_SERVER["HTTP_USER_AGENT"];
$signaturerecreate=$_SESSION['signature'];
//Extract original salt from authorized signature
$saltrecreate = substr($signaturerecreate, 0, $length_salt);
//Extract original hash from authorized signature
$originalhash = substr($signaturerecreate, $length_salt, 40);
//Re-create the hash based on the user IP and user agent
//then check if it is authorized or not
$hashrecreate= sha1($saltrecreate.$iprecreate.$useragentrecreate);
if (!($hashrecreate==$originalhash)) {
//Signature submitted by the user does not matched with the
//authorized signature
//This is unauthorized access
//Block it
header(sprintf("Location: %s", $forbidden_url));
exit;
}
//Session Lifetime control for inactivity
//Credits: http://stackoverflow.com/questions/520237/how-do-i-expire-a-php-session-after-30-minutes
if ((isset($_SESSION['LAST_ACTIVITY']) && (time() - $_SESSION['LAST_ACTIVITY'] > $sessiontimeout))) {
session_destroy();
session_unset();
//redirect the user back to login page for re-authentication
$redirectback=$domain.'securelogin/';
header(sprintf("Location: %s", $redirectback));
}
$_SESSION['LAST_ACTIVITY'] = time();
}
//Pre-define validation
$validationresults=TRUE;
$registered=TRUE;
$recaptchavalidation=TRUE;
//Trapped brute force attackers and give them more hard work by providing a captcha-protected page
$iptocheck= $_SERVER['REMOTE_ADDR'];
$iptocheck= mysql_real_escape_string($iptocheck);
if ($fetch = mysql_fetch_array( mysql_query("SELECT `loggedip` FROM `ipcheck` WHERE `loggedip`='$iptocheck'"))) {
//Already has some IP address records in the database
//Get the total failed login attempts associated with this IP address
$resultx = mysql_query("SELECT `failedattempts` FROM `ipcheck` WHERE `loggedip`='$iptocheck'");
$rowx = mysql_fetch_array($resultx);
$loginattempts_total = $rowx['failedattempts'];
If ($loginattempts_total>$maxfailedattempt) {
//too many failed attempts allowed, redirect and give 403 forbidden.
header(sprintf("Location: %s", $forbidden_url));
exit;
}
}
//Check if a user has logged-in
if (!isset($_SESSION['logged_in'])) {
$_SESSION['logged_in'] = FALSE;
}
//Check if the form is submitted
if ((isset($_POST["pass"])) && (isset($_POST["user"])) && ($_SESSION['LAST_ACTIVITY']==FALSE)) {
//Username and password has been submitted by the user
//Receive and sanitize the submitted information
function sanitize($data){
$data=trim($data);
$data=htmlspecialchars($data);
$data=mysql_real_escape_string($data);
return $data;
}
$user=sanitize($_POST["user"]);
$pass= sanitize($_POST["pass"]);
//validate username
if (!($fetch = mysql_fetch_array( mysql_query("SELECT `username` FROM `authentication` WHERE `username`='$user'")))) {
//no records of username in database
//user is not yet registered
$registered=FALSE;
}
if ($registered==TRUE) {
//Grab login attempts from MySQL database for a corresponding username
$result1 = mysql_query("SELECT `loginattempt` FROM `authentication` WHERE `username`='$user'");
$row = mysql_fetch_array($result1);
$loginattempts_username = $row['loginattempt'];
}
if(($loginattempts_username>2) || ($registered==FALSE) || ($loginattempts_total>2)) {
//Require those user with login attempts failed records to
//submit captcha and validate recaptcha
require_once('recaptchalib.php');
$resp = recaptcha_check_answer ($privatekey, $_SERVER["REMOTE_ADDR"], $_POST["recaptcha_challenge_field"], $_POST["recaptcha_response_field"]);
if (!$resp->is_valid) {
//captcha validation fails
$recaptchavalidation=FALSE;
} else {
$recaptchavalidation=TRUE;
}
}
//Get correct hashed password based on given username stored in MySQL database
if ($registered==TRUE) {
//username is registered in database, now get the hashed password
$result = mysql_query("SELECT `password` FROM `authentication` WHERE `username`='$user'");
$row = mysql_fetch_array($result);
$correctpassword = $row['password'];
$salt = substr($correctpassword, 0, 64);
$correcthash = substr($correctpassword, 64, 64);
$userhash = hash("sha256", $salt . $pass);
}
if ((!($userhash == $correcthash)) || ($registered==FALSE) || ($recaptchavalidation==FALSE)) {
//user login validation fails
$validationresults=FALSE;
//log login failed attempts to database
if ($registered==TRUE) {
$loginattempts_username= $loginattempts_username + 1;
$loginattempts_username=intval($loginattempts_username);
//update login attempt records
mysql_query("UPDATE `authentication` SET `loginattempt` = '$loginattempts_username' WHERE `username` = '$user'");
//Possible brute force attacker is targeting registered usernames
//check if has some IP address records
if (!($fetch = mysql_fetch_array( mysql_query("SELECT `loggedip` FROM `ipcheck` WHERE `loggedip`='$iptocheck'")))) {
//no records
//insert failed attempts
$loginattempts_total=1;
$loginattempts_total=intval($loginattempts_total);
mysql_query("INSERT INTO `ipcheck` (`loggedip`, `failedattempts`) VALUES ('$iptocheck', '$loginattempts_total')");
} else {
//has some records, increment attempts
$loginattempts_total= $loginattempts_total + 1;
mysql_query("UPDATE `ipcheck` SET `failedattempts` = '$loginattempts_total' WHERE `loggedip` = '$iptocheck'");
}
}
//Possible brute force attacker is targeting randomly
if ($registered==FALSE) {
if (!($fetch = mysql_fetch_array( mysql_query("SELECT `loggedip` FROM `ipcheck` WHERE `loggedip`='$iptocheck'")))) {
//no records
//insert failed attempts
$loginattempts_total=1;
$loginattempts_total=intval($loginattempts_total);
mysql_query("INSERT INTO `ipcheck` (`loggedip`, `failedattempts`) VALUES ('$iptocheck', '$loginattempts_total')");
} else {
//has some records, increment attempts
$loginattempts_total= $loginattempts_total + 1;
mysql_query("UPDATE `ipcheck` SET `failedattempts` = '$loginattempts_total' WHERE `loggedip` = '$iptocheck'");
}
}
} else {
//user successfully authenticates with the provided username and password
//Reset login attempts for a specific username to 0 as well as the ip address
$loginattempts_username=0;
$loginattempts_total=0;
$loginattempts_username=intval($loginattempts_username);
$loginattempts_total=intval($loginattempts_total);
mysql_query("UPDATE `authentication` SET `loginattempt` = '$loginattempts_username' WHERE `username` = '$user'");
mysql_query("UPDATE `ipcheck` SET `failedattempts` = '$loginattempts_total' WHERE `loggedip` = '$iptocheck'");
//Generate unique signature of the user based on IP address
//and the browser then append it to session
//This will be used to authenticate the user session
//To make sure it belongs to an authorized user and not to anyone else.
//generate random salt
function genRandomString() {
//credits: http://bit.ly/a9rDYd
$length = 50;
$characters = "0123456789abcdef";
for ($p = 0; $p < $length ; $p++) {
$string .= $characters[mt_rand(0, strlen($characters))];
}
return $string;
}
$random=genRandomString();
$salt_ip= substr($random, 0, $length_salt);
//hash the ip address, user-agent and the salt
$useragent=$_SERVER["HTTP_USER_AGENT"];
$hash_user= sha1($salt_ip.$iptocheck.$useragent);
//concatenate the salt and the hash to form a signature
$signature= $salt_ip.$hash_user;
//Regenerate session id prior to setting any session variable
//to mitigate session fixation attacks
session_regenerate_id();
//Finally store user unique signature in the session
//and set logged_in to TRUE as well as start activity time
$_SESSION['signature'] = $signature;
$_SESSION['logged_in'] = TRUE;
$_SESSION['LAST_ACTIVITY'] = time();
}
}
if (!$_SESSION['logged_in']):
?>
<!-- START OF LOGIN FORM -->
<form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="POST">
Username: <input type="text" class="<?php if ($validationresults==FALSE) echo "invalid"; ?>" id="user" name="user">
Password: <input name="pass" type="password" class="<?php if ($validationresults==FALSE) echo "invalid"; ?>" id="pass" >
<?php if (($loginattempts_username > 5) || ($registered==FALSE) || ($loginattempts_total> 5)) { ?>
Type the captcha below:
<?php
require_once('recaptchalib.php');
echo recaptcha_get_html($publickey);
?>
<?php } ?>
<?php if ($validationresults==FALSE) echo '<font color="red">Please enter valid username, password or captcha (if required).</font>'; ?>
<input type="submit" value="Login">
</form>
<!-- END OF LOGIN FORM -->
<a href="register.php">Register</a>.
<?php
exit();
endif;
?>
它看起来像什么：http://i.imgur.com/bReQl.jpg，它应该是什么样的：http://imgur.com/I0BsE.jpg（这只是在用户登录之后。在用户登录登录之前它应该是这样的在顶部）基本上它嵌入后嵌入登录下的所有代码 提前感谢您的帮助
答案 0 :(得分：2)
第三行到最后一行的exit();调用导致页面在该点之后停止打印。删除该行以解决您的问题。
