VAPID: the two values are the halves of one P-256 keypair, not independent
secrets — the browser verifies that a push is signed by the private key matching
the public key it subscribed with. The RANDOMIZED* generators mint each
placeholder on its own, so they produced two unrelated strings and web push could
never have worked. Generate the pair in mastodon_install_post_setup the way stoat
already does, encoded as Mastodon's webpush gem expects: unpadded URL-safe base64
of the 32-byte private scalar and the 65-byte uncompressed public point, sliced
out of the SEC1 DER. Verified by rebuilding the key from the emitted private half
and re-deriving the public point — openssl accepts it and the point matches.
Generated once and never rotated (rotation would invalidate every subscription),
but a pair of the wrong shape is replaced, so an install carrying the old
unrelated strings heals itself on next install — their public half is 42 chars
where a real point is 87.
Slots: CFG_<APP>_DB_PASSWORD -> CFG_<APP>_DB_PASSWORD_1 and likewise for
DB_ROOT_PASSWORD, across mastodon, owncloud, mattermost, matrix, nextcloud and
bookstack, so a database credential is always a numbered slot and a second one is
just _2. Renaming a key means reconciliation drops the old and adds the new
holding its placeholder, so an existing install regenerates unless the value is
carried over first — documented, including that the old file survives as
.<app>.config.bak.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>