[arch-projects] [PATCH] valid_email :: check all sorts of stuff, as described by: http://www.linuxjournal.com/article/9585

[Lukas Fleischer]

The AUR has a separate development mailing list (aur-dev). I will
comment on your patch here but please send further patches to aur-dev.
Thanks!

On Mon, Mar 19, 2012 at 08:39:03PM +0100, BlackEagle wrote:
> Signed-off-by: BlackEagle <ike.devolder at gmail.com>
> ---
>  web/lib/aur.inc.php |   48 +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/web/lib/aur.inc.php b/web/lib/aur.inc.php
> index c662b80..9b604fe 100644
> --- a/web/lib/aur.inc.php
> +++ b/web/lib/aur.inc.php
> @@ -80,7 +80,53 @@ function check_sid($dbh=NULL) {
>  # verify that an email address looks like it is legitimate
>  #
>  function valid_email($addy) {
> -	return (filter_var($addy, FILTER_VALIDATE_EMAIL) !== false);
> +	$isValid = true;
> +	$atIndex = strrpos($addy, "@");
> +	if (is_bool($atIndex) && !$atIndex) {
> +		$isValid = false;
> +	} else {
> +		$domain = substr($addy, $atIndex+1);
> +		$local = substr($addy, 0, $atIndex);
> +		$localLen = strlen($local);
> +		$domainLen = strlen($domain);
> +		if ($localLen < 1 || $localLen > 64) {
> +			// local part length exceeded
> +			$isValid = false;
> +		} elseif ($domainLen < 1 || $domainLen > 255) {
> +			// domain part length exceeded
> +			$isValid = false;
> +		} elseif ($local[0] == '.' || $local[$localLen-1] == '.') {
> +			// local part starts or ends with '.'
> +			$isValid = false;
> +		} elseif (preg_match('/\\.\\./', $local)) {
> +			// local part has two consecutive dots
> +			$isValid = false;
> +		} elseif (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)) {
> +			// character not valid in domain part
> +			$isValid = false;
> +		} elseif (preg_match('/\\.\\./', $domain)) {
> +			// domain part has two consecutive dots
> +			$isValid = false;
> +		} elseif (
> +			!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
> +			str_replace("\\\\","",$local))
> +		) {
> +			// character not valid in local part unless
> +			// local part is quoted
> +			if (
> +				!preg_match('/^"(\\\\"|[^"])+"$/',
> +				str_replace("\\\\","",$local))
> +			) {
> +				$isValid = false;
> +			}
> +		}

Thanks for coding this up, but what's the rationale behind it? Doesn't
the FILTER_VALIDATE_EMAIL filter run most (all?) of these checks? I
don't think we should try to be more clever than filter_var() here...

> +
> +		if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A"))) {
> +			// domain not found in DNS
> +			$isValid = false;
> +		}

This makes more sense to me but again, I don't really think this is
useful/effective... Any spammers could just continue using random mail
addresses as long as they provide "valid" domains (e.g. they could just
use "$random_foo at archlinux.org"). If we really want to check mail
addresses for validity, we probably need to send verification mails.

> +	}
> +	return $isValid;
>  }
>  
>  # a new seed value for mt_srand()
> -- 
> 1.7.9.4