我正在开发一个注册和登录系统。通过谷歌搜索，幸运的是，我从一些贡献者那里得到了一些现成的代码。但是在尝试实现相同的功能时，我会收到警告消息。我在这里给出了两个代码片段。另外，我想在此处添加三条警告消息：
警告：session_start（）[function.session-start]：无法发送会话cookie - 已经发送的标头（输出从/home/dchcov5r/public_html/demo/application/includes/register.inc.php:1开始）在/home/dchcov5r/public_html/demo/application/functions.php第22行
警告：session_start（）[function.session-start]：无法发送会话缓存限制器 - 已发送的标头（输出从/home/dchcov5r/public_html/demo/application/includes/register.inc.php:1开始）在/home/dchcov5r/public_html/demo/application/functions.php第22行
警告：session_regenerate_id（）[function.session-regenerate-id]：无法重新生成会话ID - 已在第23行/home/dchcov5r/public_html/demo/application/functions.php中发送的标头
的functions.php
<?php
ob_start();
function sec_session_start() {
$session_name = 'sec_session_id'; // Set a custom session name
$secure = SECURE;
// This stops JavaScript being able to access the session id.
$httponly = true;
// Forces sessions to only use cookies.
if (ini_set('session.use_only_cookies', 1) === FALSE) {
header("Location: error.php?err=Could not initiate a safe session (ini_set)");
exit();
}
// Gets current cookies params.
$cookieParams = session_get_cookie_params();
session_set_cookie_params($cookieParams["lifetime"],
$cookieParams["path"],
$cookieParams["domain"],
$secure,
$httponly);
// Sets the session name to the one set above.
session_name($session_name);
session_start(); // Start the PHP session
session_regenerate_id(true); // regenerated the session, delete the old one.
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// database connection files
include '../lib/config.php';
include '../lib/opendb.php';
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function dLookUp($tablename,$fieldnamereq,$fieldnamegiven,$value){
$st_rs = mysql_query("select $fieldnamereq from $tablename where $fieldnamegiven='$value'") or die("dLookUp fetch error:".mysql_error());
if(mysql_num_rows($st_rs) == 1){
$data = mysql_fetch_array($st_rs);
echo $data[$fieldnamereq];
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function login($form_no, $password, $conn) {
// Using prepared statements means that SQL injection is not possible.
$stmt = mysql_query("SELECT sl_no, name, password, salt FROM application_form_i WHERE form_no = '$form_no' LIMIT 1") or die("Error Login :".mysql_error());
while($row = mysql_fetch_assoc($stmt)) {
// get variables from result.
$user_id = $row['sl_no'];
$db_password = $row['password'];
$salt = $row['salt'];
}
// hash the password with the unique salt.
$password = hash('sha512', $password . $salt);
if (mysql_num_rows($stmt) == 1) {
// If the user exists we check if the account is locked
// from too many login attempts
if (checkbrute($user_id, $conn) == true) {
// Account is locked
// Send an email to user saying their account is locked
return false;
} else {
// Check if the password in the database matches
// the password the user submitted.
if ($db_password == $password) {
// Password is correct!
// Get the user-agent string of the user.
$user_browser = $_SERVER['HTTP_USER_AGENT'];
// XSS protection as we might print this value
$user_id = preg_replace("/[^0-9]+/", "", $user_id);
$_SESSION['user_id'] = $user_id;
// XSS protection as we might print this value
$_SESSION['login_string'] = hash('sha512',$password . $user_browser);
// Login successful.
return true;
} else {
// Password is not correct
// We record this attempt in the database
$now = time();
mysql_query("INSERT INTO login_attempts(user_id, time) VALUES ('$user_id', '$now')");
return false;
}
}
} else {
// No user exists.
return false;
}
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function checkbrute($user_id, $conn) {
// Get timestamp of current time
$now = time();
// All login attempts are counted from the past 2 hours.
$valid_attempts = $now - (2 * 60 * 60);
$stmt = mysql_query("SELECT time FROM login_attempts WHERE user_id = $user_id AND time > '$valid_attempts'") or die("Error :".mysql_error());
// If there have been more than 5 failed logins
if (mysql_num_rows($stmt) > 5) {
return true;
} else {
return false;
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function login_check($conn) {
// Check if all session variables are set
if (isset($_SESSION['user_id'], $_SESSION['login_string'])) {
$user_id = $_SESSION['user_id'];
$login_string = $_SESSION['login_string'];
// Get the user-agent string of the user.
$user_browser = $_SERVER['HTTP_USER_AGENT'];
$stmt = mysql_query("SELECT password FROM application_form_i WHERE sl_no = $user_id LIMIT 1");
if (mysql_num_rows($stmt) == 1) {
while($row = mysql_fetch_assoc($stmt)){
// If the user exists get variables from result.
$password = $row['password'];
}
$login_check = hash('sha512', $password . $user_browser);
if ($login_check == $login_string) {
// Logged In!!!!
return true;
} else {
// Not logged in
return false;
}
} else {
// Not logged in
return false;
}
} else {
// Not logged in
return false;
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////
function esc_url($url) {
if ('' == $url) {
return $url;
}
$url = preg_replace('|[^a-z0-9-~+_.?#=!&;,/:%@$\|*\'()\\x80-\\xff]|i', '', $url);
$strip = array('%0d', '%0a', '%0D', '%0A');
$url = (string) $url;
$count = 1;
while ($count) {
$url = str_replace($strip, '', $url, $count);
}
$url = str_replace(';//', '://', $url);
$url = htmlentities($url);
$url = str_replace('&', '&', $url);
$url = str_replace("'", ''', $url);
if ($url[0] !== '/') {
// We're only interested in relative links from $_SERVER['PHP_SELF']
return '';
} else {
return $url;
}
}
?>
的login.php
<?php
include_once 'functions.php';
sec_session_start();
if (login_check($conn) == true) {
$logged = 'in';
header("Location: ./successpage.php?form_no=$form_no");
exit;
} else {
$logged = 'out';
}
?>
提前致谢。
答案 0 :(得分：0)
在使用会话变量之前，您需要使用session_start（）;开始会议。在调用session_start（）之前;如果有任何回音或打印，它可以显示错误＆＃34;标题已经发送＆＃34;。所以从一开始你就可以调用session_start（）;
为了安全起见，您可以这样打电话 if（！isset（$ _ SESSION））session_start（）;
你的代码中的和第4或第5行我看到$ secure = SECURE;我认为SECURE不是像＃34; SECURE＆＃34;或者它没有定义。请检查一下。感谢