Invalid (wrong body hash) due to no line breaks about dkim

[carsonreinke]

I think you forgot the link. Mind attaching?

[JakeTheSnake3p0]

Oops! Here you go: https://www.osso.nl/blog/thunderbird-postfix-dkim-invalid-body-hash/

I've logged into my spamdrain account and they say there's a problem as well. "Computed body hash is different from the expected one"

[JakeTheSnake3p0]

The first header shown here is generated whenever I send emails from my email client (Thunderbird):

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
    d=whatever.com; s=default; h=Content-Type:MIME-Version:Date:
    Message-ID:Subject:From:To:Reply-To;
    bh=FVAhhJz6FzTfjyLzFYYUDyyNxa/NB6YNmUG8BROFscA=; b=0560610thBwMn0khOFFm5yFW2r
    /iNutZkbdGoLExrE0riCcoRjShKiIV5bRtumlHj69kp+XAi5RjmUtcVqYF1xhyizuifuSwqTwDh9V
    afCUX/FTCv8TxglpBErRpIoGUrJPAJUVO9j7OO66SCW1yYHbWSu6UDpDyp1c7xWN/Fh9CpeQXnDM6
    zI5QW7MwJbufPrXVQ1V010X1o447R6OSuVaMDi16u3G50u9RUGNLqZa+6cPJwEXx6QZ7hVt32LK1I
    QUDU34VjzyHFrTjmanT4Lp3NDr6PAF2BKK5LWm8XkHpEmHcu3yr9V4RfrYu07XLzJUjTM2n5lXOPs
    ux/aEJeA==;

However this is an example of one sent from my rails app:

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=whatever.com; q=dns/txt; s=default; t=1446495573; bh=v+Gie+4nzghZzpOSiQC08piKoNeY/n4Q11yNcr/BPCM=; h=date:from:to:message-id:subject:mime-version:content-type:content-transfer-encoding; b=011109VB+ZbHcdo0JM4USctVg83vJvG9QKWlgn/bI8jwtI1LXdHg5f22huIxTwOruuh+6nXsRkBR/SMzTDQ5z1FnFbuYD0JbEW47X6Qu0ItMseZwBnkVNKsfP0Qxt3LbmPHsWhM1Rg3ne78tLq4OLBrs0J+fLMk2tRAHJ1JRWakP2hG8pg6FPEWjWKi3da5555TjVC0zg1osvwF1+l/QoruPZ+hoawKajG1LNY/Dub7xlGzDrJqtjxtvO+h7Iutk30y0MaiP7I3782uOJ+pAuBSQQBM8TEdisjkllymBT4skhSt+W2LjNiQBxCZtIS6mhAAuBK48FnOtMtC5v6QHhQ==

I modified the string so don't worry about its validity, I only illustrate the fact that the one sent from my email client has new lines and the one sent via the rails app is all on one line.

[carsonreinke]

I see what you mean. A lot of the clients wrap the header too. Let me see what I can find.

On Nov 3, 2015, at 9:36 AM, Jake Mitchell [email protected] wrote:

The first header shown here is generated whenever I send emails from my email client (Thunderbird):

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
d=sprucewoodshores.com; s=default; h=Content-Type:MIME-Version:Date:
Message-ID:Subject:From:To:Reply-To;
bh=FVAhhJz6FzTfjyLzFYYUDyyNxa/NB6YNmUG8BROFscA=; b=0560610thBwMn0khOFFm5yFW2r
/iNutZkbdGoLExrE0riCcoRjShKiIV5bRtumlHj69kp+XAi5RjmUtcVqYF1xhyizuifuSwqTwDh9V
afCUX/FTCv8TxglpBErRpIoGUrJPAJUVO9j7OO66SCW1yYHbWSu6UDpDyp1c7xWN/Fh9CpeQXnDM6
zI5QW7MwJbufPrXVQ1V010X1o447R6OSuVaMDi16u3G50u9RUGNLqZa+6cPJwEXx6QZ7hVt32LK1I
QUDU34VjzyHFrTjmanT4Lp3NDr6PAF2BKK5LWm8XkHpEmHcu3yr9V4RfrYu07XLzJUjTM2n5lXOPs
ux/aEJeA==;
However this is an example of one sent from my rails app:

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sprucewoodshores.com; q=dns/txt; s=default; t=1446495573; bh=v+Gie+4nzghZzpOSiQC08piKoNeY/n4Q11yNcr/BPCM=; h=date:from:to:message-id:subject:mime-version:content-type:content-transfer-encoding; b=011109VB+ZbHcdo0JM4USctVg83vJvG9QKWlgn/bI8jwtI1LXdHg5f22huIxTwOruuh+6nXsRkBR/SMzTDQ5z1FnFbuYD0JbEW47X6Qu0ItMseZwBnkVNKsfP0Qxt3LbmPHsWhM1Rg3ne78tLq4OLBrs0J+fLMk2tRAHJ1JRWakP2hG8pg6FPEWjWKi3da5555TjVC0zg1osvwF1+l/QoruPZ+hoawKajG1LNY/Dub7xlGzDrJqtjxtvO+h7Iutk30y0MaiP7I3782uOJ+pAuBSQQBM8TEdisjkllymBT4skhSt+W2LjNiQBxCZtIS6mhAAuBK48FnOtMtC5v6QHhQ==
I modified the string so don't worry about its validity, I only illustrate the fact that the one sent from my email client has new lines and the one sent via the rails app is all on one line.

—
Reply to this email directly or view it on GitHub.

[carsonreinke]

Related Perl lib for the wrapping: http://search.cpan.org/~jaslong/Mail-DKIM/lib/Mail/DKIM/TextWrap.pm

[JakeTheSnake3p0]

I'm not sure that this Perl lib is what I need as I'm using RoR/ActionMailer to generate my emails. This gem hooks into ActionMailer during the delivery process which happens outside of the scope of my app.

I tried forking your repo and figuring out at what point the headers are generated but I can't make heads or tails of how things come together. The wrapping would need to be done somewhere in this gem.

[carsonreinke]

Sorry for not clarifying, I just noted that as a reference to the Perl library which wraps the DKIM header. A new feature would be have to be added to provide the wrapping.

If you are using the interceptor, the header is actually added here: https://github.com/jhawthorn/dkim/blob/master/lib/dkim/interceptor.rb#L18

[cg2v]

I have a partial implementation of this feature at https://github.com/cg2v/dkim/tree/interceptor_wrap_dkim_header

It has no new tests, and fails the Dkim::InterceptorTest#test_same_output_as_direct_usage because I implemented the change in mail/dkim_field.rb and the output no longer matches.

[carsonreinke]

@cg2v Definitely throw that over to a PR and lets get that going!!! The test failure is probably just because of assertion is against an unwrapped header.

[cg2v]

It doesn't assert against a fixed result that includes an unwrapped header, but against a call to Dkim.sign that generates one. If most people use Dkim.sign, then you need a solution that works there too. I didn't touch that part because the mixture of data and presentation in the Dkim::Header classes makes this harder.

[oz]

🆙 Hey!

I know that time is a finite and precious resource, but can I get someone to look at this PR some time, or maybe the issue is a won't fix ?