原理在于生成一个随机字符串放在session里。提交表单后来验证这个字符串。可以做到防止他人自己写form来欺骗提交,重复提交或者双击提交。
Token.php
/*
* Created on 2013-3-25
*
* To change the template for this generated file go to
* Window - Preferences - PHPeclipse - PHP - Code Templates
*/
function getToken($len = 32, $md5 = true) {
# Seed random number generator
# Only needed for PHP versions prior to 4.2
mt_srand((double) microtime() * 1000000);
# Array of characters, adjust as desired
$chars = array (
"Q",
"@",
"8",
"y",
"%",
"^",
"5",
"Z",
"(",
"G",
"_",
"O",
"`",
"S",
"-",
"N",
"<",
"D",
"{",
"}",
"[",
"]",
"h",
";",
"W",
".",
"/",
"|",
":",
"1",
"E",
"L",
"4",
"&",
"6",
"7",
"#",
"9",
"a",
"A",
"b",
"B",
"~",
"C",
"d",
">",
"e",
"2",
"f",
"P",
"g",
")",
"?",
"H",
"i",
"X",
"U",
"J",
"k",
"r",
"l",
"3",
"t",
"M",
"n",
"=",
"o",
"+",
"p",
"F",
"q",
"!",
"K",
"R",
"s",
"c",
"m",
"T",
"v",
"j",
"u",
"V",
"w",
",",
"x",
"I",
"$",
"Y",
"z",
"*"
);
# Array indice friendly number of chars;
$numChars = count($chars) - 1;
$token = "";
# Create random token at the specified length
for ($i = 0; $i < $len; $i++)
$token .= $chars[mt_rand(0, $numChars)];
# Should token be run through md5?
if ($md5) {
# Number of 32 char chunks
$chunks = ceil(strlen($token) / 32);
$md5token = "";
# Run each chunk through md5
for ($i = 1; $i <= $chunks; $i++)
$md5token .= md5(substr($token, $i * 32 - 32, 32));
# Trim the token
$token = substr($md5token, 0, $len);
}
return $token;
}
?>
form.php
include_once("token.php");
$token = getToken();
session_start();
$_SESSION["token"] = $token;
?>
action.php
session_start();
if($_POST["token"] == $_SESSION["token"]){
unset($_SESSION["token"]);
echo "这是一个正常的提交请求";
}else{
echo "这是一个非法的提交请求";
}
?>
[php表单增加token验证码]PHP表单增加token验证,防止站外及重复提交
http://m.bbyears.com/wangyetexiao/78587.html
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