[pmg-devel] [PATCH v2 pmg-{api, gui, docs} 0/4] fix #2437: Add TLS enforcment option for inbound domains

[Christoph Heiss <c.heiss@proxmox.com>]

TL;DR: Implements the approach as laid out by Stoiko in the Bugzilla
ticket [0].

A new API endpoint is added - /api2/json/config/tlsinbounddomains. This
is used to configure the newly introduced postfix map at
/etc/pmg/tls_inbound_domains, specifying sender domains which get the
`reject_plaintext_session` action [1] set, thus requiring TLS-encrypted
sessions on inbound connections.

On the GUI side, a new panel is added in Configuration -> Mail Proxy ->
TLS, where the domains for which this should be enforced can be specified.

Testing
-------
Tested this to the best of my knowledge, by adding some domains using
the UI and using `curl` to send some simple mails:

  echo '' | curl -skv smtp://<host> -T - \
    --mail-from foo@localhost.localdomain \
    --mail-rcpt bar@localhost.localdomain

.. where `localhost.localdomain` is on the new 'TLS Inbound Domains' list.
This will now fail with:

  450 4.7.1 Session encryption is required

When additionally adding the `--ssl-reqd` option to curl (instructing it
to require a TLS-encrypted session), the above command will succeed.

(Also tested it with a domain not on the list, checking that no
regressions are introduced.)

[0] https://bugzilla.proxmox.com/show_bug.cgi?id=2437
[1] http://www.postfix.org/postconf.5.html#reject_plaintext_session

v1: https://lists.proxmox.com/pipermail/pmg-devel/2023-March/002296.html

---
pmg-api:

Christoph Heiss (2):
      fix #2437: config: Add new tls_inbound_domains postfix map
      fix #2437: api: Add endpoint for managing tls_inbound_domains entries

 src/Makefile                      |   1 +
 src/PMG/API2/Config.pm            |   7 +++
 src/PMG/API2/InboundTLSDomains.pm | 127 ++++++++++++++++++++++++++++++++++++++
 src/PMG/Cluster.pm                |   1 +
 src/PMG/Config.pm                 |  56 +++++++++++++++++
 src/templates/main.cf.in          |   1 +
 6 files changed, 193 insertions(+)

pmg-gui:

Christoph Heiss (1):
      fix #2437: proxy: Add 'TLS Inbound Domains' panel

 js/MailProxyTLSInboundDomains.js | 93 ++++++++++++++++++++++++++++++++++++++++
 js/MailProxyTLSPanel.js          |  8 +++-
 js/Makefile                      |  1 +
 3 files changed, 101 insertions(+), 1 deletion(-)

pmg-docs:

Christoph Heiss (1):
      pmgconfig: Explain new TLS inbound domains configuration

 pmgconfig.adoc | 11 +++++++++++
 1 file changed, 11 insertions(+)
--
2.39.2