The short reading's H1: open(2) takes its mode among variable arguments,
which Apple's Arm passes on the stack, so bound with three fixed ones it
read the mode from whatever the stack held: a phrase or recovery codes
saved on an Apple silicon Mac could be readable by everyone. It is bound
as variadic now (VarArgs), and every file written is made 0600 through its
descriptor (fchmod), checked.
M1: macOS's sandbox lets an app reach the file the person chose and
nothing beside it, so the file made beside it was refused and nothing
could be saved; Learn's sandbox allowed reading chosen files alone, so its
exports never saved on macOS either. There, writePrivately now writes the
chosen file itself (decided by the developer on 21 Oct): opened without
following a link or waiting on a pipe and without truncating, refused with
nothing written unless fstat finds a file of the own user's, then made
0600 and emptied. Both apps' entitlements grant reading and writing the
files the person chooses. Linux keeps the new file renamed over it.
The reading's nits: the buffer is wiped whatever happens, an interrupted
call is made again (EINTR), the file made beside a chosen one is named
apart from it so a name as long as a folder takes still saves, the folder
is flushed after the rename, and Linux reads a file's type and owner with
statx, alike on every architecture, where __lxstat's version differed
(riscv64's was wrong). The test of another user's file is skipped as root.
The in-place path is tested on Linux; none of it has run on a Mac.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
The reading of the full reading's fixes noted that macOS and Windows can
keep a window out of screen captures, which SecretScreen didn't ask.
PlatformScreenGuard now asks the app's window on Android, macOS and
Windows (asksOn), and both apps' runners answer app.halkyon/screen_guard,
counting what shows: macOS's MainFlutterWindow sets sharingType = .none,
Windows' FlutterWindow WDA_EXCLUDEFROMCAPTURE (Windows 10 2004 on;
before, WDA_MONITOR, black in captures). Neither runner was built here
(Linux): to be tried on each system.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
ADR 0017, step 3: halkyon_app's side, which Learn and Todo take.
- The account's cryptography on the device (`SodiumAccountCrypto`):
halkyon_keys and SRP's client half, each step on an isolate of its
own. sodium hands out results as views of native memory its
finalizers free once the isolate that made them ends, so everything
crossing back is copied first: a view read freed memory and crashed
the process.
- `PasswordGateway` on the module's endpoints (steps without a session
through a client holding none; an authenticator set up with a session
granted but not yet the device's), and `PasswordRepository` running
the flows: signing in (M2 checked, the keys opened before anything is
trusted), signing up, a password for someone signed in, an account
never finished, the authenticators, recovery codes, changing the
password, a new recovery phrase, and getting back in.
- The unlocked keys in the system's keyring per instance and person
(`SecureAccountKeyStore`), gone once another person signs in or
nobody, and with the instance's removal.
- The screens: the start screen's Sign in and Create an account (and
when GitHub sign-in ends), the sign-in sheet (codes, recovery codes,
an account never finished, a lost authenticator), the account's setup
(the recovery phrase shown once, three random words typed back before
anything reaches the instance; the authenticator's QR code, drawn
with pub.dev's qr; the recovery codes), getting back in, and the
account section (`AccountSecuritySection`).
- `FileSaver` moves from Learn into halkyon_app, for the phrase and the
codes in Todo too; `AppDependencies` names it and `passwords`.
- halkyon_keys rebuilds account keys from the secret keys a device kept;
the key proof's message is in halkyon_base_client, checked against
the register's.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Todo's app is halkyon_app's instance and session gates with Todo's
frame ("Todo" under "Halkyon", its icon, its own sentences) and an
instance check accepting only `todo`; TodoDependencies on an instance,
an empty TodoPerson per person, nothing kept or synced yet. A person
sees an empty home and their account: whose it is on which instance,
switching account, signing out and deleting it (each asking first where
it deletes), and About with the source of what the instance runs and
the licence list. Texts in British English and German. App ID
app.halkyon.todo on every platform, GitHub's callback scheme registered
on Android, no web build.
Its icon is Lucide's list-checks (lucide-static 1.50.0) in the brand's
blues on white: tool/app_icons.py draws its strokes with Pillow and
writes every platform's launcher icon; Lucide's ISC notice joins the
licence list.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Its server, client and app as `serverpod create` made them, with the
switch to server-side sessions that was waiting uncommitted, as files:
its one commit holds the scaffold alone.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
