This migrates the key exchange curve group configuration into the OpenSSL
configuration format, which is the only path forward to configure these.
We now prefer a hybrid key exchange for TLS handshake and as a client
we'll send key shares for that and pure X25519, while keeping backwards-
compat for P256 and P384.
The statistics for my personal mail server over the last month show a
clear trend for X25519 key exchanges:
156 secp384r1
225 secp256r1
19541 x25519
When enabled the tlsrpt services will send out aggregated reports about
TLS connections the local Postfix made to interested parties, who set up
a `_smtp._tls` TXT record with a rua attribute.
Introduces mailserver.systemContact to specify an administrative contact
advertised in these automated reports.
Postfix with plain DANE only secures domains that configure DNSSEC and
publish TLSA records. With postfix-tlspol we support MTA-STS protected
connections and get caching for its policy results.
Finally, we use this as a stepping stone to build TLSRPT support on top.
In nixpkgs we expose `services.dovecot.hasNewUnitName` option that can be
safely inspected to understand that whether to use the `dovecot` systemd
service name instead of `dovecot2`.
I'm working on deprecating the top-level options, that configure main.cf
upstream in nixpkgs. With this change we stay ahead of the curve.
The `networks_style` option already defaults to `host` since Postfix 3.0,
so I dropped the setting.
```
$ postconf -d | grep networks_style
mynetworks_style = ${{$compatibility_level} <level {2} ? {subnet} : {host}}
````
- Groups settings between server and client
- Uses a range comparator for supported TLS versions
- Prune excluded primitives to what affects the supported TLS versions
It has been default enabled since Postfix 3.9 and can still be configured
from the NixOS option mentioned in the removal warning.
Removing the option makes our interface leaner.
Information is based on https://www.postfix.org/smtp-smuggling.html#long.
The sslCert and sslKey options are going away, because they do too much,
e.g. provision the keypair for client certificate authentication, which
is not at all what we want or need.
This migrates the security level for outgoing SMTP connections to
dane[1]. Either a server is configured for DANE or it now uses mandatory
unauthenticated TLS.
If DANE validation fails, the delivery will be tempfailed.
If DANE is invalid or unusable the connection will fall back to
unauthenticated mandatory TLS
This has been the default in various mail distributions:
- Mailcow since December 2016[2]
- mailinabox since July 2014[3]
[1] https://www.postfix.org/TLS_README.html#client_tls_dane
[2] 47a5166383
[3] e713af5f5a
OpenDKIM has not been updated in the last 7 years and failed to adopt
RFC8463, which introduces Ed25519-SHA256 signatures.
It has thereby held back the DKIM ecosystem, which relies on the DNS
system to publish its public keys. The DNS system in turn does not handle
large record sizes well (see RFC8301), which is why Ed25519 public keys
would be preferable, but I'm not sure the ecosystem has caught up, so we
stay on the conservative side with RSA for now.
Fixes: #203#210#279
Obsoletes: !162!338
Supersedes: !246
Allow configuring lookups for users and their mail addresses from an
LDAP directory. The LDAP username will be used as an accountname as
opposed to the email address used as the `loginName` for declarative
accounts. Mailbox for LDAP users will be stored below
`/var/vmail/ldap/<account>`.
Configuring domains is out of scope, since domains require further
configuration within the NixOS mailserver construct to set up all
related services accordingly.
Aliases can already be configured using `mailserver.forwards` but could
be supported using LDAP at a later point.
When a local account address is forwarded, the mails were not locally
kept. This was due to the way lookup tables were internally managed.
Instead of using lists to represent Postfix lookup tables, we now use
attribute sets: they can then be easily merged.
A regression test for
https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/issues/
has been added: it sets a forward on a local address and ensure an
email sent to this address is locally kept.
Fixes#205
The line type of this option make its concatenation cleaner: the user
doesn't have to manually add `\n` to its policydSPFExtraConfig value
when debug in set.
`services.postfix.extraConfig` is just a string while the
`services.postfix.config` option configures the same thing but with a
typed attrset instead which is easier to manipulate and override in Nix.
