# I am the Watcher. I am your guide through this vast new twtiverse.
# 
# Usage:
#     https://watcher.sour.is/api/plain/users              View list of users and latest twt date.
#     https://watcher.sour.is/api/plain/twt                View all twts.
#     https://watcher.sour.is/api/plain/mentions?uri=:uri  View all mentions for uri.
#     https://watcher.sour.is/api/plain/conv/:hash         View all twts for a conversation subject.
# 
# Options:
#     uri     Filter to show a specific users twts.
#     offset  Start index for quey.
#     limit   Count of items to return (going back in time).
# 
# twt range = 1 5
# self = https://watcher.sour.is/conv/dtiseua
here is my progress so far: https://github.com/eapl-gemugami/twtxt-direct-message-php
The encryption part seems to work, if I decrypt it the message with OpenSSL.
I think it can help you for some key parts not well explained in OpenSSL documentation.

@andros reading your spec I wrote a few notes here: https://github.com/eapl-gemugami/twtxt-direct-message-php/blob/main/direct_message_spec.md

@arne I haven't check your repo yet, although you are using sodium, right?
@eapl.me Nope, I switched to the openssl library in PHP. But our rubberducking 🦆 seems to be working. Your find https://crypto.stackexchange.com/a/79855 for the IV generation may be the breakthrough ...
@eapl.me @andros Eureka! It works! https://github.com/upputter/testing-twtxt-dm
PBKDF2_KEY_SIZE = 48 was the turning point! My dirty little crypt.class.php can en- and decrypt, accoridng to the OpenSSL standard and options used in https://twtxt.dev/exts/direct-message.html
@arne Amazing!!! 😋
@arne Amazing!!! 😋