On 4/22/21 5:39 AM, Wayne via Exim-users wrote: > On Thu, Apr 22, 2021 at 05:11:30AM +0800, Gedalya via Exim-users wrote:
>> On 4/22/21 4:39 AM, Wayne via Exim-users wrote:
>>> I'm still confused as it seems like EXIM should be signing based on just
>>> headers content and not message body content
>> What makes you say that? DKIM normally signs the header and the body.
>>
> Oh ok, thank you. I toally missed that as I was hung up looking at the
> docs for 'dkim_sign_headers' since it seems to only list headers. I made
> the incorrect assumption that only those headers were included in the
> signature calculation.
>
> Then I assume the body is being signed implicitly no matter what headers
> are selected?
>
> Yea, that's how it normally works, with exim and otherwise.
The need to enumerate specific headers included in signing comes from the fact that headers are added along the way, and thus when verifying some might not be included in the signature. The body is officially not supposed to be modified (yet sometimes it is, such as in mailing lists).
