The instance's half of Halkyon's ADR 0044, step 5 (D37 to D40).
An invitation by mail (sharedSpace.inviteByEmail) goes out through the
register (send-space-invitation), naming who invites by their handle
and nothing of what is shared, with a link to /join/<token>. The
instance keeps only the address's keyed hash, as for sign-in, and the
SHA-256 of the token. Whoever opens it joins with a code mailed to that
address (EmailCodePurpose.joinSpace, proven through the register,
prove-address-code), so a forwarded mail admits nobody else; a code
proving another address is refused. It lapses after 14 days, and the
hourly pruning forgets it; inviting the address again replaces it.
A space's own link (setJoinLink, the Owner's) admits whoever opens it
as a Viewer (joinByLink) while it is on; switched off and on, it gets a
new token. Its token is kept as it is, so that whoever may invite copies
the link again (joinLink). The page at /join/<token>, in English and
German, says who invites and as whom; preview tells the app the same.
A membership someone else made is new to its member until they mark it
seen (isNew, addedBy; mine names who shared it), for the Inbox.
halkyon_app learns the two new refusals (handleNeeded, otherAddress),
which Learn reports as not allowed until its screens offer these ways
in. The ADR records D37 to D40 and how the instance's half is built.
The migration, the same in the module and in each server including it
(Learn, Meditate, Todo, Train):
ALTER TABLE "shared_space" ADD COLUMN "joinToken" text;
CREATE UNIQUE INDEX "shared_space_join_token_idx"
ON "shared_space" ("joinToken");
CREATE TABLE "shared_space_email_invitation" (…), with its unique
indexes on the space and address hash, and on the token's hash,
and its foreign key to "shared_space" ON DELETE CASCADE;
ALTER TABLE "shared_space_member" ADD COLUMN "addedBy" uuid;
ALTER TABLE "shared_space_member"
ADD COLUMN "isNew" boolean NOT NULL DEFAULT false;
Every space gets no token, and the unique index allows any number of
nulls; every membership gets no one who added it and isn't new, so
nothing already shared shows in an Inbox. The new table starts empty.
None of it rewrites a table, and the server before the switch names its
own columns, so it keeps working.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Two of the fourth reading's lows:
- A signed-in proof whose call to the register failed
(RegisterUnavailableException, a member's call timing out after the
register checked it) stays counted against the session, rather than
taken back: a guess never goes uncounted.
- A sign-up code also gives an existing account with that address its
first password, which its mail now says in the subject too ("create an
account or give it a password").
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 fourth reading's first finding: password.set took a session alone,
so whoever took one made a GitHub-only account, or an address account
without a password, theirs for good (their address or password, their
authenticator; GitHub then refused the owner).
- An account with an address proves it anew: a code mailed to that
address for this (EmailCodePurpose.firstPassword, its own mail), never
the session alone, a code asked for anything else, or another address.
- An account that signs in with GitHub alone does it within 10 minutes of
a GitHub sign-in (the session's method and creation time, where the
session lives; members tell the register), refused signInAgain before
any code is used; the address it adds is proved as before.
- Anonymous people still become identified with a code to the address
they add.
The app mails the code to the person's own address (asking for it where
the device doesn't know it), offers a password right after a GitHub
sign-in (D2's "at their next sign-in") before the person's app, and asks
for a GitHub sign-in anew when the instance refuses an older one, keeping
the code typed.
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 notification shows a mail's subject alone, and the subject said only
"K7QX-M2PD is your Halkyon Learn code" whatever the code would do (the
third reading). The subject now says it: to create an account, finish
setting it up, switch off the authenticator, reset or delete the account.
The sign-up mail also says that the code gives a password to an account
that has the address and none yet, as signing up does.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
Codes by mail were tied to nothing but their address (the re-review's
seventh finding): a hostile instance could answer that a setup never
finished, have the person type a code into it, relay it to start the real
instance's account reset, and 72 hours later relay a second to finish it
with its own password and keys; the mail said "to sign in" whatever the
code was for. A code is now asked for a purpose (signUp, finishSetup,
authenticatorReset, accountReset, deletion), only that purpose takes it (any
other is refused as no longer valid, leaving the code as it was), and its
mail says what it would do ("to reset your account on learn.halkyon.eu: a
new password and new keys, and what was encrypted with the old ones is
lost") and to type it only in the app on that instance, nowhere else. The
app asks for each code with the purpose of its step.
Migration (module, Learn's and Todo's servers, Learn's device schema):
ALTER TABLE "email_code_request" ADD COLUMN "purpose" text; nullable,
so the requests of the last 15 minutes before it stay, taken by nothing
and forgotten within the hour.
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 register's side of signing in with an address, a password that never
leaves the device (SRP-6a) and a code from an authenticator (ADR 0017),
with members forwarding every step through AccountRegister:
- password.set: salt, Argon2id's costs, SRP's verifier, the public keys
and the private keys wrapped twice, all made on the device; with the
address a mailed code proves, an anonymous person becomes identified
under their ID. It signs in once an authenticator is confirmed.
- passwordSignIn.begin and complete: SRP's two steps with a TOTP or
recovery code. An address nobody has is answered from a decoy key as
an account would be; every wrong credential is refused alike.
- authenticator: secrets sealed under totpKey (XChaCha20-Poly1305, bound
to their row), each code accepted once, ten recovery codes with the
first, the last one kept.
- accountRecovery: a lost authenticator reset 72 hours after the
password and a mailed code or the recovery phrase ask, a lost password
set anew with the phrase's signature, or the account reset with new
keys 72 hours after a mailed code asks; a mail at each start, a
sign-in calling it off.
- An account with a password no longer signs in by a mailed code or
GitHub; no new GitHub account is linked where passwords are offered,
and from GITHUB_SIGN_IN_ENDS GitHub signs nobody in and its IDs go.
Five tables, added by the module's migration; deletePerson deletes
their rows.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
What every Halkyon server has, taken from Halkyon Learn's: anonymous,
GitHub and email-code sign-in with their endpoints, an account's ways
in and its deletion, the pruning of abandoned anonymous people, of
sign-up attempts and of expired codes, and the instance's basics (the
sign-in ways offered, the source link, the minimum app build, where
people's data and its backups are). Endpoints sit under the nickname
`base`. A host configures it in one place before its pod starts: its
name for the mails, its source link, its minimum build, and hooks that
delete its own data with a person.
The tables keep Learn's names, columns and indexes, so a host moving
onto the module migrates nothing but version rows. Server package under
the SSPL, client under the AGPL, as Learn's are.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
