Alberto Bertogli fe00750e39 sts: Treat missing/empty "mx" list as invalid ...

The "mx" field is required, a policy without it is invalid, so add a
check for it.

See
https://mailarchive.ietf.org/arch/msg/uta/Omqo1Bw6rJbrTMl2Zo69IJr35Qo
for more background, in particular the following paragraph:

> The "mx" field is required, so if it is missing, the policy is invalid
> and should not be honored. (It doesn't make sense to honor the policy
> anyway, I would say, since a policy without allowed MXs is essentially a
> way of saying, "There should be TLS and the server identity should match
> the MX, whatever the MX is." I guess this prevents SSL stripping, but
> doesn't prevent DNS injection, so it's of relatively little value.)

2017-02-28 22:27:15 +00:00

..

sts_test.go

sts: Treat missing/empty "mx" list as invalid

2017-02-28 22:27:15 +00:00

sts.go

sts: Treat missing/empty "mx" list as invalid

2017-02-28 22:27:15 +00:00