feat: smime signed notification emails
What does this MR do?
Add a new optional ActionMailer interceptor that signs all outgoing emails with SMIME
- I checked this configuration working against a dummy gmail account with actual SMTP delivery in gdk; Gmail web and native Outlook on macOS were ok with the SMIME signing.
- We have identified that
letter_opener_webdoes not play nice with the signed emails, so they cannot currently be checked in development. Opened https://github.com/fgrehm/letter_opener_web/issues/96 to track this (check the attached screenshots in there).
- Per guidelines, this MR will require another Omnibus MR to add the new configuration options (I'd also say they need to be added to gdk? though this is not documented in https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/doc/settings/gitlab.yml.md)
Corresponding MR on omnibus for the new smime configuration params: omnibus-gitlab!3514 (merged)
Issue for adding new config parameters to k8s chart: https://gitlab.com/charts/gitlab/issues/1533
Issue for supporting eliptic curve keys: https://gitlab.com/gitlab-org/gitlab-ce/issues/66439
The development of this MR is sponsored by siemens (/cc @bufferoverflow).
Does this MR meet the acceptance criteria?
- Changelog entry
- Documentation created/updated or follow-up review issue created
- Code review guidelines
- Merge request performance guidelines
- Style guides
- Database guides n/a
- Separation of EE specific content n/a
Performance and testing
- Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
- Tested in all supported browsers n/a
If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:
Label as security and @ mention
- The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
- Security reports checked/validated by a reviewer from the AppSec team