December Adventure 2023

On 2023-12-01 I've learned about December Adventure. It's a very nice idea (esp. compared to Advent of Code, as I don't like competing).

My December Adventure will be working on Lacre, a Postfix mail filter encrypting incoming mail before it is written to recipient's inbox.

December 2nd

Lacre Webgate: Add identity table — I've finished introduction of identity database.
Lacre backend: Fix unencrypted delivery and key removal — I've re-read and merged my recent work on storing identities in a database.
Lacre backend: Enhance validation of keys with multiple email addresses — I've analysed the flow, and found that:
- we enforce keys with single email during key verification in Lacre Webgate (in public_html/include/gpg.php:76);
- to handle keys with multiple emails I'll need to rework GnuPG.confirm_key function.
I've learned a bit about asyncio Streams in Python by writing a little program. So far I seem to be doing something wrong.

I've implemented a tiny key-value store in Python using asyncio streams and email. It's an exercise before I approach something bigger but with similar semantics in Lacre backend.
Next, I've written something very similar based on http.server Python package.

I've added support for TTL to my tiny key-value store, learning how to use named tuples and delayed callbacks with asyncio.

I've fixed cron script that I've broken during refactoring. (I should rework its tests too.)
I've fixed identity removal.
I've added support for -r or –reload flag to import command, which deletes all keys before importing them from GnuPG's pubring.kbx.

I've written some Python decorators. I suspect reading decorators from the standard library could be enlightening.

Today I've skimmed some functools code and written another Python decorator. This one emits an auditing event before execution of the decorated function.

Fixed some minor error-reporting issues. Now when an expired key prevents Lacre from encrypting a message, a short error message is logged instead of a full trace-back.
Updated admin CLI documentation to include info about import command and its -r option.
Tagged 0.2 RC2.
Started working on Rust re-implementation of the Lacre admin's CLI tool. Started by trying to connect to sqlite.

Fixed misbehaviour when Lacre would bounce messages upon database exception. Now we let admin decide if they want cleartext to be delivered.

Experimented with clap, a Rust Command Line Argument Parser. Also learned about constants.

I had a little morning warm-up with Rust. Rust's compiler gives very helpful and detailed error messages!

I've added 3 new configuration parameters to Lacre's config file, controlling database connection pool. (Read more in Dealing with disconnects section of SQLAlchemy documentation.)

Learned more about enum Python module, then used it in Lacre.
Provided a configuration parameter in Lacre to choose optimistic or pessimistic handling of database connections.