* [FEATURE] SMTPS Support
- Added port_tls option to enable SMTPS, off by default.
* Remove configuration variable for SMTPS
Instead we enable SMTPS on port 465 only. The reason for this is so we don't require an additional configuration variable.
* Add SMTPS warning and updated docs
* Adjust SMTPS warning
- Adjust AUTH LOGIN functionality to be closer to AUTH PLAIN
- Removed: secure (notifier smtp conf) boolean string
- Added: disable_verify_cert (notifier smtp conf) boolean
- disables X509 validation of certificates
- Added: disable_require_tls (notifier smtp conf) boolean
- allows emails to be sent over plain text (for non-authenticated only)
- Added: trusted_cert (notifier smtp conf) string (path)
- allows specifying the path of a PEM format cert to add to trusted cert pool
- Make SMTP notifier return errors on connection over plain text
- Make SMTP notifier return errors on TLS connection with invalid certs
- Implemented various debug logging for the SMTP notifier
- Implemented explicit SMTP closes on errors (previously left con open)
- Split SMTPNotifier Send func to seperate funcs for:
- writing future test suites and startup checks more easily
- organization and readability
- Add details of changes to docs/security.yml
- Adjust config.yml's (template and test) for the changes
- Added a warning for users who attempt authentication on servers that don't allow STARTTLS (they are transmitted in plain text)
- Included a note when AUTH fails due to no supported mechanisms including the mechanisms supported (PLAIN and LOGIN)
- If the STARTTLS extension is advertised we automatically STARTTLS before authenticating or sending
- Uses the secure config key to determine if we should verify the cert. By default it does not verify the cert (should not break any configs)
- Attempt auth when the config has a SMTP password and the server supports the AUTH extension and either the PLAIN or LOGIN mechanism
- Check the mechanisms supported by the server and use PLAIN or LOGIN depending on which is supported
- Changed secure key to use boolean values instead of strings
- Arranged SMTP notifier properties/vars to be in the same order
- Log the steps for STARTTLS (debug only)
- Log the steps for AUTH (debug only)
