Alin,

> > What I really want is a  "dkim=strict; handling=deny" SSP record.
> > Problem is dkim-milter-2.4.2 fails to verify subdomains signed with
> > one of domain's selector and I believe is due to the lack of
> > "[EMAIL PROTECTED]" tag in DKIM-Signature header.

Keep in mind that signatures where the From domain does not
exactly match the domain in 'i' tag are considered third-party
signatures. This is not to say that they would not validate,
but these are not author's signatures (originator signatures).

> I've analyzed the code and conclude that dkim_policy() is to blame. More
> precisely, a signature is valid only if signer domain == the domain part
> of the sender address. I think it should also accept a signature if both
> the following conditions are satisfied:
>   - dkim->dkim_domain is a subdomain of sig->sig_domain
>   - SSP entry of the sig->sig_domain doesn't have t=s

When From is [EMAIL PROTECTED], the following holds (assuming absence
of 's' flag in a public key):

-  [EMAIL PROTECTED] d=example.com  => first party signature
- ([EMAIL PROTECTED])    d=example.com  => third party signature

So even if a DKIM signer offers a choice to sign [EMAIL PROTECTED]
as d=example.com (with a default [EMAIL PROTECTED]), this produces
a third party signature to recipient and should cause a SSP lookup.
Such signature could still have value to recipient though (e.g. for
whitelisting).

  Mark

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