Mechiel Lukkien 8ca198882e
security fix: use correct domain for mta-sts, that of the email address
the original next-hop domain. not anything after resolving cname's, because
then it takes just a single injected dns cname record to lead us to an
unrelated server (that we would verify, but it's the wrong server).

also don't fallback to just strict tls when something is wrong. we must use the
policy to check if an mx host is allowed. the whole idea is that unsigned dns
records cannot be trusted.

i noticed this while implementing dane.
2023-10-14 22:30:43 +02:00
..