Allow mail to be sent without starttls() and login creds if desired

[MaverikMoody]

Proposed changes

Addresses some of the limitations outlined in the README for the SMTP output.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update

Checklist

• Lint and unit tests pass locally with my changes (if applicable)
• I have run pre-commit (pre-commit in the repo)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Linked to the relevant github issue or github discussion

[thinkst-daniel]

Hi @MaverikMoody, thanks, this is a valid change.

Although I think we could possibly get away with a slightly simpler implementation, where we simply check if smtp_username and smtp_password are set instead. i.e. something like:

if smtp_username is not None or smtp_password is not None:
    server.starttls()
    server.login(smtp_username, smtp_password)

What do you think?

[MaverikMoody]

Thanks for taking a look at this, I agree that something simpler here is totally fine and I've updated the PR to reflect your suggestion. I know some projects prefer to have explicit switches required for anything that could be deemed an insecure transmission of data, so I thought I would err on the side of caution here. Let me know if you'd like any additional changes.

[thinkst-daniel]

Thanks for making the tweak @MaverikMoody

[MaverikMoody]

Thanks again for the review, are we waiting on anything else for getting this merged?

[thinkst-daniel]

Thanks @MaverikMoody, I just wanted to double-check that it works as expected on my set up. Does it work as expected on yours?

The change is working as expected:

SMTP creds set:
➜  canarytokens-docker git:(master) ✗ docker exec -it c97965588723 bash
root@c97965588723:/srv# c97965588723
bash: c97965588723: command not found
root@c97965588723:/srv# poetry run python
Python 3.9.20 (main, Oct 19 2024, 03:58:16)
[GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from canarytokens.settings import SwitchboardSettings
>>> switchboard_settings = SwitchboardSettings()
>>> smtp_username = switchboard_settings.SMTP_USERNAME
>>> smtp_password = switchboard_settings.SMTP_PASSWORD
>>> print(smtp_username)
test
>>> print(smtp_password)
logmein
>>> if smtp_username is not None and smtp_password is not None:
...      print("do smtp auth, etc")
... else:
...      print("dont do smtp auth, just send it!")
...
do smtp auth, etc
>>>

SMTP creds not set:
root@aefaf15aca7d:/srv# poetry run python
Python 3.9.20 (main, Oct 19 2024, 03:58:16)
[GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from canarytokens.settings import SwitchboardSettings
>>> switchboard_settings = SwitchboardSettings()
>>> smtp_username = switchboard_settings.SMTP_USERNAME
>>> smtp_password = switchboard_settings.SMTP_PASSWORD
>>> print(smtp_username)
None
>>> print(smtp_password)
None
>>> if smtp_username is not None and smtp_password is not None:
...      print("do smtp auth, etc")
... else:
...      print("dont do smtp auth, just send it!")
...
dont do smtp auth, just send it!
>>>