74 lines
3.4 KiB
Plaintext
74 lines
3.4 KiB
Plaintext
MBOX-Line: From barryleiba at computer.org Sat Mar 14 07:25:21 2015
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To: imap-protocol@u.washington.edu
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From: Barry Leiba <barryleiba@computer.org>
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Date: Fri Jun 8 12:34:54 2018
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Subject: [Imap-protocol] DKIM signatures on this list
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In-Reply-To: <alpine.LSU.2.20.1503131631020.2099@linux-0rhy>
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References: <20150313211600.25485.qmail@ary.lan>
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<alpine.LSU.2.20.1503131631020.2099@linux-0rhy>
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Message-ID: <CAC4RtVA-D1_yvYb8LOsN+ed7J=SyGNp3qEvgTsW=Gxst4xCw1A@mail.gmail.com>
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The problem with your "you" thesis is that you're attributing things
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to the signature that are not meant by DKIM signatures. There is no
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sensible comparison to be made between a purported signature by your
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boss that asserts that she authorized you to spend money... and what a
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DKIM signature asserts. As John says, it's critical to fully
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understand what DKIM signatures do and don't do, and not to use them
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for things beyond what they're intended for.
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Barry
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On Fri, Mar 13, 2015 at 6:49 PM, Eduardo Chappa <echappa@gmx.com> wrote:
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> On Fri, 13 Mar 2015, John Levine wrote:
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>
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>>>> The point of a signature is to have a way of verification of the message
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>>>> as sent and received. If "you" received a message from your boss saying "I
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>>>> approve that you spend ten thousand dollars in the company party" and the
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>>>> signature of such message would not validate, that would certainly not be a
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>>>> situation where "you" would say "the correct thing to do is to ignore it."
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>>
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>>
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>> RFC 6376 is quite clear about what you do with an invalid DKIM signature
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>> -- you ignore it, as though the signature wasn't there at all. We
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>> deliberately wrote it that way.
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>
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>
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> The question is who is "you" in the sentence above. If you mean to say that
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> "you" is the client implementor, well, there is no much that can be done to
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> recover from such error. It is hard to try to recover, so "ignoring it" is
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> sensible.
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>
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> However, the comment that originated this conversation was not a comment
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> about the implementation of a RFC, it was about a user point of view, so
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> while the comment you made may be sensible to implementors, I do not see it
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> as such for users, and that is the context of what I saw.I read originally
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> was not meant to say (in my opinion) that the list was
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>
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>> It's fine to treat mail with valid signatures differently from mail
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>> without valid signatures, but it's not fine to treat mail with an invalid
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>> signature differently from mail with no signature. That's why you shouldn't
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>> depend on lists to strip the signatures they break.
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>>
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>> I would have hoped that people interested enough in mail software to be on
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>> this list would go to the effort to read and understand the specs they
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>> implement.
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>
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>
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> In generic terms I understand you. But the RFC is just that, and it is for
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> implementors, not for users. I do not think that you can tell me, as a user,
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> that it is "fine" when a signature does not validate, because I care to
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> receive what was sent and I do not have any algorithmic way to know what the
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> original message was. I know there is no much that can be done to fix it as
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> an implementor, so in that sense, I should ignore the failure, but that is
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> not what makes a user feels warm and fuzzy about the message they just
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> received and fails to validate.
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>
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> --
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> Eduardo
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>
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> _______________________________________________
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> Imap-protocol mailing list
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> Imap-protocol@u.washington.edu
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> http://mailman13.u.washington.edu/mailman/listinfo/imap-protocol
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