ADR 0044's D49 (amended in building it): what reads and seals Learn's
content moves out of the Flutter packages, so Learn's agent, which runs
without Flutter, shares it rather than repeating the privacy rules.
packages/halkyon_content (new, pure Dart) takes from halkyon_app the
envelope and its cipher, SealedFile, UnlockedAccountKeys, shared
spaces' gateway with SharedKeys and KeyPins, FileCache and
FileServerGateway, with their fakes and tests; halkyon_app exports it,
so no app changes. Its rich_text.dart takes RichContent from
halkyon_editor, which exports it. newAccountKeys makes an agent's key
pair. halkyon_core takes DelayedDeletions and gains SyncRequests, what a
synced gateway asks of the sync, which SyncService implements.
apps/learn/halkyon_learn_core (new, pure Dart) takes Learn's privacy,
sync, payloads and the models, codecs, gateways and repositories of
studysets, cards, notes, tags and feedback, with what they reach of
files, learning paths, citations and study options; the app imports them
from there. A subject's icon, colour and name stay in the app
(SubjectLook); what only the app shows (progress, exam coverage, the
card browser, deletions' waits) stays too. Nothing changes for people
using the apps.
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 0044, D20: a row in a shared space counts as genuine when any
member this device pinned signed it, current or former, never by the
author column the row names.
- `ContentCipher.trustSigners`: content sealed with a key is checked
against the signing keys given for it, in place of the account's
alone; `FakeContentCipher` tells authors apart likewise.
- `KeyPins` keeps who it saw in each space (`sawIn`) and the signing
keys pinned for someone before a reset (`earlierSigning`), so what
they wrote stays readable; `signersIn` gives a space's signers.
`key_pins.json` holds both (`pins`, `spaces`); a file written by
step 3, on no released app, counts as none.
- `SharedKeys` pins the person's own keys too, records the members it
checks, and trusts the space's signers for each key it shares or
opens.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
A day's, night's and heart chunk's ID was a UUID of version 5 of the
person and the date, which the instance can hash for every date itself:
each ID told it which days the band was worn. halkyon_keys' keyedRowId
hashes the name under the account's X25519 secret key (BLAKE2b, a UUID of
version 8), the same on every device of the account and unreadable
without its keys; ContentCipher.rowId and TrainKeys.rowId hand it on.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Every account has a way in, so the apps make no anonymous account any
more. The start screen shows whenever nobody is signed in, a first
start included, and offers SimpleLogin, a password and GitHub for those
who have it, with no start without an account. An instance out of reach
is said so, with Try again, and one offering no way to create an account
too. An anonymous account's session left from before is deleted as the
app starts (D25), falling back to signing out on the device.
What only anonymous accounts needed goes: signing in anonymously, the
signed-out mark, adding GitHub to an account and switching to a GitHub
account from the Profile tab (with its Cancel, the only one), an
anonymous device's own keys, the warning that signing out deletes the
account, and the texts about keeping progress. Settings says on which
instance the account is signed in. Learn's publishing, reports and
suggestions and its learner count no longer ask whether the person has
an identity: everyone signed in has one.
The server still offers anonymous sign-in until the next commit, so
older apps keep working until v0.20.0 raises the minimum build.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
- `ContentKeys` opens the person's data keys (`content_key`) with their
account's keys on the device, an anonymous person's device keys made as
their data first opens; it makes a private studyset's key and the
personal key. Without the account's keys nothing opens and nothing new
is private (D8).
- `PayloadEnvelope` is the one place payloads are sealed and opened, each
for its table, row and column, so a payload moved to another row never
opens; one that doesn't open is `Locked`, never half-read.
- `Privacy` gives each gateway the key of the row's tree (its top-level
studyset's), and rewrites a tree under another key, or readable, in
place (`rekeyTree`).
- The studyset, card, note, learning path, path answer and PDF gateways
seal with their tree's key and open what they read: a new top-level
studyset is private where the device holds the keys, a new one inside a
tree takes its privacy, and one moved into another tree is rewritten
under that tree's key. Tags and settings are sealed with the personal
key; a tag or settings row that doesn't open here is left out, so
nothing folds or deletes it. A studyset whose key doesn't open shows as
locked (`Studyset.isLocked`); other rows that don't open read as blank.
- Every payload codec round-trips sealed, and refuses another row.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
`ContentCipher` makes a person's data keys, sealed to their account and
signed by it, opens them, and seals and opens a row's content with them for
the row it is stored in (`SodiumContentCipher`, on the isolate it is used
on, as rows are read and written one by one; `FakeContentCipher` for
tests). A sealed payload holds the signature, then the ciphertext.
`AccountCrypto.newDeviceKeys` makes the key pairs an anonymous person's
device encrypts their private studysets with (ADR 0017, point 9, not built
before); setting a password keeps them as the account's
(`keepingKeys` with a new phrase), so nothing they made private is lost.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
