How to properly hash body and headers with PHP for dkim?

问题

I've gone through Eric Vyncke's PHP dkim script and copied how he was doing hashes for DKIM headers set in emails

$DKIM_bh = base64_encode(pack('H*', sha1($body)));

Would be used as so:

'bh='.$DKIM_bh.';'//...

However when I validate the email message it tells me that the hash doesn't match.

$headers .= 'DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/simple; q=dns/txt; bh=';//...

$body = 'Test PHP+SMTP authenticated email,3.';

bh='.base64_encode(pack('H*', sha1($body))).';';//...

I'm not sure what I'm missing? How do I properly hash the body and headers so I can set the DKIM values for the header properly?

回答1:

Here is example functions how to send emails with dkim and php mail() function:

https://github.com/breakermind/PHP-DKIM

Works on Gmail.com and multipart/mixed messages with attachments!

<?php
// Send simple email without DKIM SIgning
// YOUR E-MAIL
$name = 'Name Jony';
$sender = 'sdsdso@domain.pl';
$to = 'ffffu@gmail.com';
$subject = 'Simple html message with dkim';

$headers =
'MIME-Version: 1.0
From: "'.$name.'" <'.$sender.'>
Content-type: text/html; charset=utf8';

$message =
'<html>
    <header></header>
    <body>
        Hello, this a DKIM test e-mail
    </body>
</html>';

// NOW YOU WILL DO (after setting up the config file and your DNS records) :
// Make sure linefeeds are in CRLF format - it is essential for signing
$message = preg_replace('/(?<!\r)\n/', "\r\n", $message);
$headers = preg_replace('/(?<!\r)\n/', "\r\n", $headers);

require_once 'mail-signature.class.php';
require_once 'mail-signature.config.php';

$signature = new mail_signature(
    MAIL_RSA_PRIV,
    MAIL_RSA_PASSPHRASE,
    MAIL_DOMAIN,
    MAIL_SELECTOR
);
$signed_headers = $signature -> get_signed_headers($to, $subject, $message, $headers);

// Send email
ini_set('sendmail_from', $sender);
echo mail($to, $subject, $message, $signed_headers.$headers);
die();

来源：https://stackoverflow.com/questions/44809574/how-to-properly-hash-body-and-headers-with-php-for-dkim

标签

php

hash

dkim