* added check for Rspamd DKIM on startup
The newly added function `__rspamd__check_dkim_permissions` performs a
check on DKIM private key files. This is useful to prevent issues
like #3621 in the future. The function is deliberately kept simple and
may not catch every single misconfiguration in terms of permissions and
ownership, but it should be quite accurate.
Please note that the Rspamd setup does NOT change at all, and the checks
will not abort the setup in case they fail. A simple warning is emmited.
* add more documentation to Rspamd functions
* Apply suggestions from code review
* improve `__do_as_rspamd_user`
* rework check similar to review suggestion
see https://github.com/docker-mailserver/docker-mailserver/pull/3627#discussion_r1388697547
---------
Co-authored-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>
* outsource Rspamd ENVs into explicit helper
This will allow us to uniformly source the helper and get the values
from everywhere consistently. This is more than desirable since we will
be using these values not only for the Rspamd setup, but also for DKIM
management and during change-detection.
* integrate Rspamd into changedetection
We outsource one more function to reside in the helper script for Rspamd
so that we can call this function from the Rspamd setup and from the
changedetection functionality too.
* realize deprecation of old commands file for Rspamd
THIS IS A BREAKING CHANGE!
This change realizes the log message: "Using old file location now
(deprecated) - this will prevent startup in v13.0.0" Startup will now
fail.
* added '--force' option to Rspamd DKIM script
* use new helper to get ENVs for Rspamd in DKIM script
* remove the need for linking directories
This was unnecessary, as explained in
https://github.com/docker-mailserver/docker-mailserver/pull/3597#discussion_r1369413599
* Apply suggestions from code review
review by @polarathene
* apply more review feedback from @polarathene
- <https://github.com/docker-mailserver/docker-mailserver/pull/3599#discussion_r1370885519>
- <https://github.com/docker-mailserver/docker-mailserver/pull/3599#discussion_r1370904201>
* update documentation
---------
Co-authored-by: Brennan Kinney <5098581+polarathene@users.noreply.github.com>
Instead of using `etc/rspamd/override.d/dkim_signing.conf`, we will now
be using `/tmp/docker-mailserver/rspamd/override.d/dkim_signing.conf`.
The new location is persisted (and linked again during startup) and
hence better suited.
* chore: Adjust default DKIM size (`open-dkim`) from 4096-bit to 2048-bit
4096-bit is excessive in size for DKIM key. 2048-bit is plenty.
* chore: Additional revisions to `open-dkim` command help output
- The examples use `keysize 2048`, but as that's the new default it makes sense to change that.
- Other help text was also revised.
- Last example for domains did not need to demonstrate the other options. Changed example domains to more appropriate values.
* docs: Revise DKIM docs
Primarily for the change in default key size, but does revise some text to better communicate to the user.
- While the referenced RFC advises 512-bit to 2048-bit key size, we now explicitly discourage `512-bit` as it's not secure. `1024-bit` is still likely safe for most, but `2048-bit` is a good default for those not rotating their keys.
- Adjusted the domains example to match the new `setup config dkim domain` domains example.
- Tip for changing default key size changed to "info" with added clarity of lowering security or increasing it (excessively).
- Rspamd section is minor formatting changes, with the exception of clarifying the "main domain" for the mail accounts is assumed as the DMS FQDN with any subdomain (like `mail.`) stripped away. This is not great, but a legacy issue that needs to be addressed in future.
- `docs-rspamd-override-d` ref removed, and usage replaced with equivalent ref `docs-rspamd-config-dropin`, while `docs-rspamd-config-declarative` ref was not in use and also removed.
- Revised the `<selector>.txt` DNS formatting info section to better communicate with the reader. Additionally it had mixed usage of default `mail` and custom `dkim-rsa` selectors (_file content and output_).
* docs: Sync DKIM commands help messages and update DKIM docs for LDAP
- Adopt the help options format style from the `rspamd-dkim` into `open-dkim` command. And convert `./setup.sh` to `setup`. `selector` option has been implemented. for a while now.
- Update `rspamd-dkim` examples help output to align with `open-dkim` command examples.
- Give both DKIM command tools a consistent description. The two tools differ in support for the `domain` option (_implicit domain sourcing for default account provisioner, and support for multiple domains as input_).
- DKIM docs for LDAP domain support revised to better communicate when explicit domain config is necessary.
* tests: Adjust test-cases for `setup config dkim` change
`rspamd_dkim.bats`:
- Update assert for command help output.
- Don't bother creating a DKIM key at 512-bit size.
`setup_cli.bats`:
- Update assert for command help output of the `setup config dkim` (OpenDKIM) command.
* docs: Update DKIM section for large keys to newer RFC
The linked discussion from 2021 does mention this updated RFC over the original. That removes outdated advice about `512-bit` key length support.
The discussion link is still kept to reference a comment for the reader to better understand the security strength of 2048-bit RSA keys and why larger keys are not worthwhile, especially for DKIM.
* docs: Extract out common DKIM generation command from content tabs
Should be fine to be DRY here, not specific to `open-dkim` or `rspamd` generation/support. Previously rspamd lacked support of an equivalent command in DMS.
* docs: DKIM refactoring
- Shifted out the info admonition on key size advice out of the content tabs as it's now generic information.
- Indented the 4096-bit warning into this, which is less of a concern as the default for our DKIM generation tools is consistently 2048-bit now.
- Reworked the LDAP and Rspamd multi-domain advice. To avoid causing a bad diff, these sections haven't been moved/merged yet.
* docs: Revise DKIM docs
Advice for managing domains individually with LDAP and Rspamd extracted out of the content tabs. Default domain behaviour explained with extra info about OpenDKIM + FILE provisioner sourcing extra domains implicitly.
