php 邮件验证

2017-04-05 tech php 6 mins 1 图 2345 字

起因是昨天看到有人twitter上吐槽网站遇到注册机：

一般拿来说，对于初级的注册机，可以在页面上添加一些字段作为session验证。也可以做一个IP统计窗口，同一个IP注册时限不得低于10s，IP连续注册超过N个识别为恶意IP然后封禁。

还有一个简单的办法，就是做邮箱有效性判断。当然也可以将这几个办法结合起来。这里我贴一个github上的邮箱有效性判断的代码。来源已经不记得在哪了Orz

function emailValidate($email)
{
    $isValid = true;
    $atIndex = strrpos($email, "@");
    if (is_bool($atIndex) && !$atIndex) {
        $isValid = false;
    } else {
        $domain = substr($email, $atIndex + 1);
        $local = substr($email, 0, $atIndex);
        $localLen = strlen($local);
        $domainLen = strlen($domain);
        if ($localLen < 1 || $localLen > 64) {
            // local part length exceeded
            info('local part length exceeded:' . $localLen);
            $isValid = false;
        } else if ($domainLen < 1 || $domainLen > 255) {
            // domain part length exceeded
            info('domain part length exceeded:' . $domainLen);
            $isValid = false;
        } else if ($local[0] == '.' || $local[$localLen - 1] == '.') {
            // local part starts or ends with '.'
            info('local part starts or ends with .:' . $localLen);
            $isValid = false;
        } else if (preg_match('/\\.\\./', $local)) {
            // local part has two consecutive dots
            info('local part has two consecutive dots:' . $local);
            $isValid = false;
        } else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)) {
            // character not valid in domain part
            info('character not valid in domain part:' . $domain);
            $isValid = false;
        } else if (preg_match('/\\.\\./', $domain)) {
            // domain part has two consecutive dots
            info('domain part has two consecutive dots:' . $domain);
            $isValid = false;
        } else if (!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\", "", $local))) {
            // character not valid in local part unless
            // local part is quoted
            if (!preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\", "", $local))) {
                info('character not valid in local part: ' . $local);
                $isValid = false;
            }
        }
        if ($isValid && !(checkdnsrr($domain, "MX") || checkdnsrr($domain, "A"))) {
            // domain not found in DNS
            $isValid = false;
        }
    }
    return $isValid;
}