SimpleLogin takes only https redirect addresses, each registered exactly,
so the instance's SimpleLogin app registers one page on the register's
web server, /simplelogin-callback, which sends the browser on to the app
that began the sign-in: a 303 to the desktop's loopback (127.0.0.1, a port
per app) or the phone's scheme, chosen by the marker the state begins with
(`<app>-<platform>.<rest>`, the rest 1 to 512 characters of base64url),
from a fixed table, so it sends nobody anywhere else. It forwards the code
or SimpleLogin's error (`deny`) with the state and nothing else, refuses
anything malformed, repeated or not a GET with a page that repeats nothing
it was given, and keeps and logs nothing (no-store, no referrer). It is
built ahead of the sign-in itself so development can sign in through
learn.halkyon.eu's page, which the development app registers too.
Android's assetlinks.json for Halkyon Learn signed with the release key
is answered by the Caddyfile on learn.halkyon.eu alone: the one domain the
project's builds name, and the server knows no app's key. A root test
holds its fingerprint to tool/release/android-certificate.sha256. The
app's intent filter comes with the sign-in; iOS's association waits for
an Apple team ID.
The profile page's language choice and look move to common/web_page.dart,
shared by both pages.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Tizian 「ティツィアーン」
8d6785f5c6