Files
DodoSSH/docs/adr/0013-desktop-distribution-and-updates.md
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Give the seated user the TPM, so nobody has to join the tss group
ADR 0007 decision 4 refused this a commit ago, on the grounds that widening
access to the machine's TPM is a system-wide decision an application package
should not make for an administrator. That refusal is overturned here, and the
reasoning it is replaced with is narrower rather than louder — because the
refusal had treated "widen access" as one thing when it is two.

Adding a person to `tss` is what the refusal was really about, and it stays the
wrong answer: permanent, effective over SSH, applying whether or not they are at
the keyboard, and needing an administrator and a fresh login before the feature
appears at all.

Tagging /dev/tpmrm0 with `uaccess` is a different thing. It is systemd's own
mechanism for this exact question — the one /dev/dri, webcams, scanners and FIDO
keys already use — and logind grants the ACL to the user of the *active local
session*, then takes it back when that session ends. Not over SSH, not on an
inactive VT, not to daemons. The rule changes neither the mode nor the group, so
everything that worked before still works and the ACL is layered on top.

tpmrm and never tpm, which is what makes it defensible at all: /dev/tpm0 is the
raw device and is exclusive, where /dev/tpmrm0 is the kernel's resource manager,
which virtualises handles and isolates callers precisely so that more than one
unprivileged program can use the chip.

◆ THE COST IS A DENIAL OF SERVICE AND NOT A DISCLOSURE, AND IT IS WRITTEN DOWN.

TPM objects are protected by their own auth values, so this lets nobody read
anybody else's sealed data. What it allows is *failed* attempts — and a TPM
answers enough of those by locking out everyone, which is the same anti-hammering
this project relies on to make a four-digit PIN safe. On a machine that unlocks
its disk with the TPM at boot, somebody sitting at it can trip that and stop the
next boot from unlocking until it recovers.

An administrator who does not accept that masks the file:

    sudo ln -s /dev/null /etc/udev/rules.d/71-dodossh-tpm.rules

which is the standard override, survives upgrades, and puts DodoSSH back to
behaving as though the machine had no TPM. That is in the rule's own comments,
because the person who needs it is reading the file rather than the ADR.

Numbered 71 because 60-tpm-udev.rules is what creates the node's ownership and
73-seat-late.rules is what turns the tag into an ACL; verified in that order on
Fedora 44, along with `udevadm verify` accepting the file and the mask being
reported as "masked by previous entry". %post reloads and replays it against the
tpmrm subsystem, because a rule that waits for a reboot is a feature that does
not work on the day it is installed.

Both channels install the same path deliberately: this is about the machine's
TPM rather than about either build, the file is byte-identical from both, and
giving each its own copy would mean removing one package silently revoked the
other's access.

Phase 19 grew a check that the ACL exists for the local session and does *not*
exist for an SSH one, and another that masking the rule really does put the
machine back — then tells you to undo it before the checks that follow.

Also recorded, after it cost five confusing failures: swtpm serves exactly one
client, so a shell readiness probe sitting on the port makes the whole device-key
suite fail with "The TPM closed the connection" and nothing pointing at why.
2026-08-22 20:38:22 +02:00

481 lines
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Markdown

# ADR 0013 — Distributing the desktop client, and letting it replace itself
- Status: accepted
- Date: 2026-08-04
- Builds on: [ADR 0001](0001-e2ee-trust-model.md), [ADR 0011](0011-android-distribution.md)
- Settles: the desktop half of M4 packaging, which [ADR 0011](0011-android-distribution.md#consequences)
left open
## Context
[ADR 0011](0011-android-distribution.md) settled the phone and said explicitly what it was not settling:
"M4's desktop packaging inherits rule 2 and not the rest." This is that inheritance, plus the thing the
phone deliberately does not have.
The desktop head was not packaged at all. There were no tags, no `Version` property anywhere in the
repository, and therefore no version: every assembly reported the SDK's default `1.0.0`, and the API had
been serving that string to every client that asked it for `serverVersion`. There was no installer and no
way for anybody holding a copy to learn that a newer one existed.
That is tolerable while nobody has it. It stops being tolerable at the first release, and it stops in a
particular direction: this client holds the plaintext of a team's infrastructure credentials, by
construction (ADR 0001). For software like that, "the fix shipped and the user never got it" is a security
outcome. ADR 0011 named the cost of shipping outside a store — "no discovery, no automatic update" — and
accepted it for Android because the platform left no better option. The desktop leaves a better option, and
this ADR takes it.
The new thing an updater introduces is a capability that did not exist before: **something that can replace
the binary on a user's machine, without the user choosing each build.** ADR 0001 models the party who wants
the secrets as attacking the client rather than the crypto, and ADR 0011 turns that into a question of
custody — *which parties can ship one person a build?* An updater is a second answer to that question, so
it needs the same treatment as the signing key, and it is easy to get wrong because the dangerous part does
not look like a key.
## Decision
### 1. Velopack, per-user, under `%LOCALAPPDATA%`, with no administrator prompt
`docs/platform-flags.md` had already ruled out the platform-native option, and it is worth restating
because it is the kind of decision that gets reopened: **MSIX is not deprioritised, it is impossible
here.** A packaged application runs WebView2 in an AppContainer where loopback connections are blocked
without a `CheckNetIsolation` exemption, and the terminal data plane *is* a loopback WebSocket. MSIX would
not degrade the product, it would remove the terminal.
Velopack's path was checked against that and reintroduces nothing: `Setup.exe` is an ordinary Win32
executable that unpacks a directory and creates shortcuts, there is no package manifest and no package
identity, and the process therefore stays an ordinary desktop process. Manual check 16.4 is what would
notice if that ever changed, because it connects a real shell from the installed build.
### 2. The pack id is `DodoSSH.Desktop`, and it is irreversible
Velopack installs to `%LOCALAPPDATA%\<packId>` and **removes that entire directory on uninstall**.
`ClientPaths.DataDirectory` is `%LOCALAPPDATA%\DodoSSH`, and it holds `cache.db` with its `-wal` and `-shm`
companions, `settings.json`, and `device.key`.
So the obvious pack id would have installed the application on top of the user's encrypted cache, and
uninstalling would have deleted the device key and the outbox — the changes this machine has made and not
yet pushed, which `MainWindowViewModel.SignOutWarning` already describes to users as existing "nowhere else
in the world". The application refuses to delete that without a counted confirmation; an uninstaller would
have done it silently.
Velopack's own guidance is to keep persistent files in roaming `%APPDATA%`. **That guidance is declined**,
and `ClientPaths` already explains why: two machines writing one SQLite file through a file-sync client
corrupts it, and the outbox is per-machine by design. The install moves; the profile does not.
Like the Android package id, this is a one-way door — it is the identity an installed client matches an
update against, so changing it later orphans every existing install: still running, never updated, and
invisible to the new one.
### 3. The release is cut by a person, and the forge token never goes near CI
This is the paragraph that will be argued with, so it is the one written most carefully.
The tempting argument is that a Gitea write token is not a signing key, and so — unlike the Android
keystore ADR 0011 rule 1 keeps off runners — it could live in a CI secret and let a tag cut a release.
**It does not survive contact with what the token can do.** Velopack clients fetch from the configured
source over TLS and do not verify a package signature when they apply it. So anyone who can write a release
on this repository can publish an update that every installed client downloads and runs. That is precisely
the capability ADR 0011 rule 1 places on a machine which is not a runner, reached through a different door —
and a workflow secret is held by everyone who can change a workflow file, which for a repository with any
contributors is a wider set than it looks.
So: `scripts/release-windows.ps1`, run by a person on a Windows machine, in two phases. Phase one builds and
packs and stops. Phase two, a separate invocation, asks for the token and uploads. The split exists so that
what reaches users has been installed and started by a human first, and so that the credential is in memory
only for the minutes that need it.
A second, smaller reason was recorded here — that `vpk` stamps and embeds the `Setup.exe` and
`Update.exe` stubs with Windows tooling, and every job in `ci.yml` is `runs-on: [linux]` — on the
reasoning that somebody will fix one reason and believe they are done.
◆ **That second reason was not true, and the correction is worth more than the claim was.** `vpk`
cross-compiles when it is told to: the bracketed OS directive, `vpk [win] pack`, builds the setup stub,
the portable bundle and the `.nupkg` on Linux, and reports `Directive enabled for cross-compiling from
Linux (current os) to Windows` while doing it. Only signing needs Windows tooling, and rule 8 above is
why nothing is signed yet. Plain `vpk pack` on Linux targets Linux and rejects a Windows RID, which is
the shape of the mistake: the tool does not fail because it cannot, it fails because it was not asked.
The correction does not move this rule at all, and that is the point of separating the two. The reason
that stands was never mechanical, so a Linux runner that *can* pack changes nothing: what may not be on
a runner is the token, not the build.
What CI gains is the same thing the `android` job already does — it proves the artefact still builds and
still packages. On main and on tags the build job publishes `win-x64` and then packs it, so a restore
graph that resolves for `net10.0` and not for `net10.0/win-x64` fails there rather than under a person
midway through a release. Packaging is the more valuable half and adds a few seconds to a publish that
has already happened — measured at two to seven, against the minutes the publish itself takes: `vpk` verifies
that the main executable actually calls `VelopackApp.Build().Run()`, so the change that quietly produces
an application which never updates itself — compiling, tested, and invisible until a release goes
unreceived — fails in CI. The packages are written to `RUNNER_TEMP` and discarded, and are deliberately
not offered as workflow artefacts: an installer nobody has run should not sit somewhere that invites
passing it on.
CI does not call `scripts/release-windows.ps1` to do any of this, and should not. That script is the
person's procedure — it refuses a dirty tree, requires a tagged `HEAD`, fetches the previous release for
deltas, and prompts for the token — so running it on a runner would mean either weakening it with CI
switches or having CI satisfy conditions that only make sense at a desk. The workflow writes the same
`vpk` arguments out in shell, and the constants they share (pack id, title, authors, channel, icon) are
noted in both places as a contract with `VelopackUpdateChannel` and with every installed client.
### 4. The update check points at the project's forge, and the address is a constant
ADR 0011 rule 2 carries over unchanged, and its update clause carries with it: "If an update check is ever
added it points at the project's domain." Here that is `git.dodotech.cloud`, and it is a `const` in
`VelopackUpdateChannel` rather than a setting.
**The constant is the mechanism, not a convention.** A configurable feed address is exactly the knob that
would let an operator — or an edit to a plaintext `settings.json` — point the update path at the
deployment, and an operator who can answer "is there a newer version" can answer "no" forever, pinning a
chosen user to a build with a known hole while holding no key at all. Making it unsettable is that rule
expressed in a way nobody has to remember.
`ClientSettings` therefore stores whether to check, and nothing else: no address, no channel, no token. A
private release repository is incompatible with this design and that is worth knowing rather than
discovering, because the token would have to be readable before the vault is unlocked, and this file is the
one place that can be read then — which is the one place a token may not go.
◆ **It was discovered.** The paragraph above was written and the repository was private anyway, so every
check on every client asked an address that answers `404` — Gitea does not distinguish "not there" from
"not yours" — and both heads reported the running build as current. It had never once worked, on either
platform, and nothing anywhere said so. Two things came out of that and both are now written down rather
than assumed:
- **The feed repository must be readable with no credentials, and that is a deployment precondition** rather
than a property of the code. It is checkable in one line, which is the only reason it is worth stating:
`curl -so /dev/null -w '%{http_code}' https://git.dodotech.cloud/api/v1/repos/DodoTech-Public/DodoSSH` answers
`200` when the design holds and `404` when it does not. `/api/v1/version` answering `200` proves only that
the forge is reachable, which is what made this look like nothing was wrong.
- **An unreachable channel must be distinguishable from a current build.** `IUpdateChannel.CheckAsync` used
to document null as the honest answer for both, on the reasoning that the caller does the same thing
either way. That is true of the six-hourly pass and false of CHECK NOW, and it is what turned a total
outage into a reassuring sentence. It throws now, and `UpdateViewModel` keeps the distinction it always
had: silent on the timer, the exception's own message on the button.
### 5. `MinClientVersion` stays unread, and if it is ever read it may not fetch
`MetaResponse.MinClientVersion` has existed since M1, is served, is fetched on every sign-in, and is read
by nothing. Hanging the updater off it would have been natural and would have been wrong — and note the
shape of the error, because it is not "inherits an existing risk". Today the field controls nothing at all.
The moment an update check is conditioned on it, rule 2's sentence applies verbatim and the risk is
*created*.
The split to preserve:
- A deployment may say **"I will not serve a client this old"** and draw a remediation screen. That is the
deployment describing itself, which is legitimate and is what the field's own documentation asks for.
That screen may carry a sentence and a link to the project's release page.
- It may **not** carry a button that triggers a check or a download. A link is the user going somewhere; a
fetch is the operator's answer steering this process.
Under the design as built, an operator withholding or deflating the value achieves nothing — the check runs
on its own timer and never consults the deployment. Inflating it denies service to their own users, which
they can already do by turning the server off.
### 6. Self-contained, and not single-file
Self-contained because .NET 10 is recent enough that almost no machine has the runtime, and because the
usual objection — that runtime security patches then require an application update — is answered by the
feature this ADR is about. Velopack's deltas are per-file and the runtime files do not change between our
releases, so the runtime costs almost nothing per update; it is paid on first install.
Not single-file, for four independent reasons: `platform-flags.md` records that libsodium ships native
binaries per RID and complicates single-file publishing, and `libe_sqlite3`, `libSkiaSharp` and
`libHarfBuzzSharp` do the same; a bundle changes wholly on every build, so deltas stop working; Velopack is
a directory-based updater by design; and a self-extracting bundle puts the executable under a temp path
deep enough to hit the WebView2 long-path failure that same document records. Not trimmed — EF Core is not
trim-safe and `TreatWarningsAsErrors` turns every `IL2xxx` into a build break, so trimming is a project
rather than a flag.
**Native symbol files are excluded and ours are kept**, which is worth recording as a decision because the
numbers are so lopsided: `libSkiaSharp.pdb` and `libHarfBuzzSharp.pdb` are 100 MB of debug symbols for
third-party native code nobody here will step through, and all fifteen of our own managed PDBs together are
0.93 MB. Dropping the two took a publish from 227 MB to 127 MB. Keeping ours means an
`Exception.ToString()` carries file names and line numbers, which for a self-hosted product is the whole
diagnostic channel — the way a fault gets reported is a user pasting a stack into an issue.
### 7. One version, derived from the tag
MinVer, with `MinVerTagPrefix` of `v`, matching the tags CI already triggers on. The tag was already the
version of record for the API's container image; this makes it the version of record for everything,
including the client's own `AssemblyInformationalVersion`, which is what the preferences screen prints and
what Velopack compares.
MinVer's one sharp edge is that it answers plausibly rather than failing: a shallow clone with no tags
yields `0.0.0-alpha.0.N`. Here a wrong version is a client that never updates, so it is guarded twice —
`fetch-depth: 0` on every checkout, and a step that fails a tag build when the computed version and the tag
disagree.
The Windows application manifest's `assemblyIdentity` version is **deliberately** left at `1.0.0.0`. It is a
side-by-side activation field this application does not use and nothing reads; what a person sees comes from
the PE version resource, which MSBuild fills from `FileVersion`.
### 8. Unsigned for now, with a named trigger
Every installer will raise SmartScreen's "Windows protected your PC" until reputation accrues. The cost is
smaller and more precisely bounded than the reflex suggests, and the bound is worth knowing: Mark-of-the-Web
is applied by the *browser* that downloads `Setup.exe`, so the warning lands at first install only. In-app
updates are fetched by the application's own HTTP client and applied by `Update.exe` from a local file, and
never trip it. **One dialog per user per lifetime, not one per update.**
The trigger for buying an OV certificate on a hardware token is the first release the README invites a
stranger to install. ADR 0011 already describes Authenticode as the easy custody case — the key stays with
the developer — and the post-2023 requirement that it live on FIPS 140-2 Level 2 hardware enforces "offline,
never in CI" physically rather than by policy. `--signParams` is the single line in the release script that
changes.
**Azure Trusted Signing is not the quiet default and needs its own ADR.** It is cheaper and has no hardware
token, and it puts a compellable third party in the signing path — which is ADR 0011 rule 3's shape one
layer down, declined there for reasons that do not stop applying because the vendor changed.
**This rule is Windows-only, and macOS gets the opposite one.** See decision 10: there is no "unsigned for
now" available on that platform at any price, because Gatekeeper refuses rather than warns.
### 10. macOS is a second desktop platform on the same machinery, signed from the start
The macOS head is the same application, the same Velopack, and the same two-phase person-run release. Four
things differ, and each is forced rather than chosen.
**Signing is a precondition, not an improvement.** Decision 8's whole argument — one dialog per user per
lifetime, buy a certificate when a stranger is invited to install — has no macOS equivalent. An
un-notarized download is refused outright, so the Developer ID certificate and the notarization round trip
are the price of the package existing. `scripts/release-macos.sh` therefore refuses to run without the
signing identities, where the Windows script refuses nothing.
**The channels are `osx` and `osx-nightly`, and they are separate for decision 9's reason.** Four channels
now publish to one repository, and the only thing keeping a Mac from being offered a Windows package is
that it never reads that index. The macOS nightly channel is named and has no publisher: CI builds and
bundles the macOS head to prove it still builds, and uploads nothing, exactly as it does for the Windows
release channel.
**The pack id is shared with Windows, and on macOS it is visible.** vpk names the bundle after the pack id,
so `/Applications` holds `DodoSSH.Desktop.app`. Decision 2's reasoning applies with more force here rather
than less: a pack id of `DodoSSH` would put Velopack's install root on `~/Library/Application
Support/DodoSSH`, which is `ClientPaths.DataDirectory`, and an uninstall would take the user's un-synced
outbox with it. `CFBundleDisplayName` puts the product name back in front of a person; the directory keeps
the id.
**arm64 only, because the check is the scarce thing.** Velopack keys a channel to one architecture, and an
Intel package would be the only artefact in this repository reaching users without somebody having walked
Phase 18 against it. The engineering for a second channel is small and is described in the release script;
what is missing is an Intel Mac to verify on, and shipping blind is the thing this project's manual-check
discipline exists to refuse.
**And one thing that does not differ, which is worth saying because it is the expensive half.** The
capability to publish still lives on a person's machine and never in CI. Notarization does not change that:
Apple's ticket says this build came from this developer account, and says nothing about whether the build
should have been made. Velopack clients still apply what their feed serves. Rule 3 is untouched.
### 9. There is a second desktop channel, published by CI, and it is a second application
[ADR 0014](0014-android-updates.md) gave the phone a nightly channel and rule 3 above gives the desktop
none, which left the two heads with different answers to the same question — *how does somebody try what
is on main?* — for no reason other than the order the work happened in. This is the desktop's answer, and
it is the phone's arrangement with one difference that changes how much of it has to be built.
**Android gets the separation from the platform. Windows does not.** Two Android channels cannot replace
one another because the installer refuses a package signed by a different key; a mistake there is loud.
Velopack applies what its feed serves and verifies no signature, so on this head the separation is entirely
construction:
| | release | nightly |
| --- | --- | --- |
| pack id | `DodoSSH.Desktop` | `DodoSSH.Desktop.Nightly` |
| Velopack channel | `win` | `win-nightly` |
| feed | newest non-prerelease release | the rolling `nightly-desktop` prerelease |
| profile | `%LOCALAPPDATA%\DodoSSH` | `%LOCALAPPDATA%\DodoSSH.Nightly` |
| cut by | a person, from a `v*` tag | CI, on every push to main |
Four separations rather than one, because each closes a different door. The pack id decides the install
directory and what an installed client matches an update against, so it is what makes a nightly install
*beside* rather than *over*. The channel names the index file on the feed, so neither build ever reads the
other's — and the release channel additionally refuses prereleases, which is belt and braces in the one
direction that matters: an unsigned CI build must never reach a machine somebody is trusting with their
credentials. The profile is the one that is easy to skip and would hurt most: the cache schema is migrated
on every launch, before unlock, so a shared profile means a nightly quietly upgrading a database the
release build then opens.
**The prerelease flag is also how the two heads stay out of each other's way.** The phone's release channel
reads `releases/latest`, which skips prereleases. A desktop nightly published as a stable release would
become the newest release in this repository, and every phone on the release channel would start failing
its check against a release carrying no Android manifest. The nightly is published with `--pre` for its own
sake and for that one.
**What this costs, stated where somebody will read it before installing:** whoever can write a release on
this repository can put a build on every nightly desktop, because the client applies what the feed serves
without verifying a signature. That set includes CI and therefore everyone who can change a workflow file.
It is the same trade [ADR 0014](0014-android-updates.md) accepted for the phone's nightly, and it is
acceptable for the same reason and only that reason: this is not the channel anybody's real credentials are
on. Rule 3 is untouched — the release channel still has no job, no token and no runner.
**The version gets a floor, on this channel only.** MinVer answers `0.0.0-alpha.0.N` until the first `v*`
tag and `vpk` refuses to pack anything below `0.0.1`, so the nightly job lifts the patch digit and keeps
the prerelease height. It is applied through `MinVerVersionOverride`, which moves the assembly version too
— packing a number the assemblies disagree with would put one version in the installer and another on the
preferences screen, which is the screen somebody reads when asked which nightly they are running. Ordering
across the floor holds: heights rise within a floored version, and the first real tag moves past all of
them. The release script gets no floor and must not have one; there, `0.0.0` should be refused.
### 11. Linux is a third desktop platform, and it is a package rather than an updater
The Linux head existed and shipped as nothing: a checkout somebody built. `VelopackUpdateChannel` already
named the two platforms it serves rather than negating the one it does not, on the reasoning that "a future
AppImage should be an addition here rather than a thing that silently already half-happened". This is that
addition, and it is not an AppImage.
**The package is an RPM and nothing inside it replaces anything.** That is the decision, and everything
else follows from it. Velopack does have a Linux path, so the shape of decisions 1 through 9 could have been
repeated a third time — one more channel, one more index, one more client swapping its own files over. It
should not be, because this platform already has the mechanism that whole apparatus is a substitute for.
`dnf` is an updater the user already trusts, already audits and already controls, and it updates the
runtime's own dependencies besides. Adding a second one that answers to this project instead would be
building the capability decision 4 spends a page keeping unsettable, on the one platform where nobody had
to.
◆ **The first version of this rule said "there is no updater in it at all", and that went too far.** It
conflated two things the other two platforms happen to do together: *noticing* that a newer build exists,
and *installing* it. The second is what the argument above is about, and the first is not — a client that
checks a fixed address and tells you what it found has taken no capability from anybody. Written as a flat
refusal, the rule bought its safety by paying the cost in the paragraph below, and the cost was avoidable.
**So the split is: this client checks and fetches, and PackageKit installs.** `LinuxUpdateChannel` reads
the same rolling release the Windows nightly feed lives on, compares versions the way `rpm` compares them,
downloads the package, verifies its digest, and hands the file to PackageKit — which raises polkit and asks
the user, who may say no. `ApplyingEndsTheProcess` is false and nothing is torn down before the answer, which
is the phone's shape rather than the desktop's, and is already what `MainWindowViewModel` does with that
flag. Four things follow that are worth stating because each is a property the Velopack channels do not have
to think about:
- **The comparison is `rpmvercmp` and not SemVer.** Decision 7 made one version of record for the whole
repository, and this is the one place it is not the string that decides: `rpm` will accept or refuse the
install, so the client must compare the way `rpm` does or it can offer an update PackageKit then declines.
It is the same argument [ADR 0014](0014-android-updates.md) makes for comparing `versionCode`. The
manifest therefore carries both — the RPM version to compare and the SemVer to show a person — and the
installed side is read out of the rpm database rather than derived from the assembly, so the translation
`scripts/ci-linux-rpm.sh` performs exists in exactly one place.
- **The digest is checked, and it is not a signature.** Velopack verifies what it downloads and Android
refuses a package whose signature does not match the installed one. An RPM fetched over HTTPS and handed
to a package manager has neither, so the manifest names a SHA-256 and the client refuses anything else.
That catches a truncated download and a caching proxy and says nothing whatever about provenance, because
the same job writes the package and the manifest. Provenance here is decision 4's constant address.
- **`ONLY_TRUSTED` is cleared, deliberately.** The package is unsigned, so requiring PackageKit to trust it
would fail every update at the last step. Clearing the flag routes the request to polkit's
`package-install-untrusted` action, which asks for an administrator rather than proceeding quietly — the
user is told what they are agreeing to, which is the honest form of an unsigned package.
- **Nothing restarts.** Replacing files under a running process is ordinary on Linux and the old inodes stay
mapped, so the build keeps running until somebody closes it. That is the same courtesy decision 1's
consequences argue for on Windows, arrived at for free.
The honest cost that remains, recorded because it is the part that will be argued with: **discovery is still
worse here than on either other desktop, for anybody who declines the in-app check.** There is no package
repository to subscribe to, so `dnf upgrade` on its own will never bring a newer DodoSSH; the in-app check is
what stands in for one, and a user who turns it off on PREFERENCES → UPDATES has no other signal. A signed
repository is the fix, it is not built, and decision 11's last paragraph says what it would cost.
**CI publishes it, and only to the nightly channel.** Rule 3 is untouched and applies with its full force:
the token that writes a release is the capability to ship somebody a build, and it stays off runners. What
changes is nothing, because rule 9 already established a channel CI may publish to and this is a second
artefact on it. The release-shaped package is built on every `main` build and on every tag and uploaded
nowhere, exactly as the Windows and macOS packages are, which proves the `linux-x64` restore graph and the
packaging without putting an installer anybody has run in a place that invites passing it on.
Note what CI's check is and is not. `vpk` verifies that the main executable actually calls
`VelopackApp.Build().Run()` — a real assertion about the application, made for free by the packager. There
is no equivalent here, so `scripts/ci-linux-rpm.sh` makes its own: it asks the finished package what it
requires, what it provides, what files it holds and what modes they carry, and fails on each way a package
can build cleanly and then be uninstallable or unsafe. Two of those checks exist because the first realistic
payload tripped them — .NET's `libmscordbi.so` links `libmscordaccore.so`, which with bundled provides
excluded produces a dependency no host can satisfy; and `cp -a` off the wrong filesystem produced a
world-writable `/opt/DodoSSH`, which is a local privilege escalation against an application holding
plaintext credentials.
**The separations of rule 9 survive translation, and cost less here.** Two RPMs with different names owning
different paths cannot replace one another and `dnf` says so, where on Windows the same property had to be
built out of pack ids. The profile split is unchanged and still belongs to the build: `DodoChannel=nightly`
is what `ClientPaths` reads, and the packaging must not answer that question a second time.
**The device key store is settled separately and is not nothing.** The first version of this rule said this
platform had none and that the passphrase was asked for at every unlock. It has one:
[ADR 0007](0007-device-key-protection.md) decision 4 adds a TPM-sealed key released against a PIN the TPM
itself checks and counts failures against. It is weaker than Hello and Touch ID in a way that ADR names
precisely. Reaching the chip needs no group membership, because this package ships the udev rule that gives
the seated user an ACL on `/dev/tpmrm0` — a decision that ADR overturned from its own first answer, and
whose cost it states.
**What this platform does not have is a signature on the package**, which is not decision 8's "unsigned for
now": nothing on this platform
refuses or warns about an unsigned RPM, so there is no dialog to buy a certificate to remove. What stands in
for one is the same thing that stands in for it on the forge — TLS, and a project that publishes from one
address. An RPM repository would change that, because repository metadata is signed and a repository is a
thing users add once and then trust; that is the point at which a key becomes necessary rather than optional,
and it is the reason building one is a decision and not a chore.
**x86_64 only, for decision 10's reason and not a different one.** aarch64 is one argument to the publish
and one to the script. What is missing is somebody to run Phase 19 on such a machine, and this project does
not ship desktop builds nobody has run. The same sentence rules out claiming RHEL 9, which ships WebKitGTK's
4.0 API line under a soname the package deliberately does not accept: `dnf` refusing with *nothing provides
libwebkit2gtk-4.1.so.0* is a better answer than an install that draws a blank terminal.
## Consequences
**The desktop gets what ADR 0011 had to refuse the phone.** Discovery is still manual — somebody has to be
told where the release page is — but from the first install onward the client keeps itself current without
anybody deciding to go and look. That is the sharpest edge of the Android decision, blunted on the platform
where it could be.
**Nothing is ever installed while the application is running.** A fetched update waits for a restart the
user presses, or for the next launch they were going to do anyway. This is not caution for its own sake:
this application deliberately keeps shells running across a lock, and argues in `LockAsync` that a lock
which destroyed work would simply stop being used. A restart does end every shell, so it is a decision that
belongs to the person whose job is running in one — and the interface says so, in the same words the close
button already uses.
**The release is a manual step, and that will feel slow.** It is roughly ten minutes of a person's attention
per release, and the convenience being refused is the entire point of CI. Where the two collide the custody
argument wins, exactly as it does for the Android keystore.
**The forge grows by about 125 MB per release, forever.** Measured on the first real pack rather than
estimated: a 127 MB publish directory compresses to a 60 MB full `.nupkg` and a 64 MB `Setup.exe`, and both
are uploaded. Velopack needs the previous full package present to build a delta against, so pruning old
releases has a real cost — a client several versions behind falls back to a full download. A 64 MB asset is
also large enough to meet whatever body-size limit fronts `git.dodotech.cloud` (nginx's
`client_max_body_size` defaults to 1 MB), which is worth checking before the first upload rather than
discovering after ten minutes of transfer.
**Uninstalling leaves the vault cache behind, on purpose.** `%LOCALAPPDATA%\DodoSSH` survives, so a
reinstall finds an enrolled machine and asks for the passphrase — which is what somebody reinstalling wants.
The honest cost is that `device.key` is left too, and the account goes on listing a device that is no longer
installed. That is a wart rather than a hole: the blob is decryptable only by this machine's TPM, and Sign
Out is the button that withdraws the registration. An uninstall is not a sign-out and must not pretend to
be one.
**Contracts and client now share a version number.** `DodoSSH.Contracts` is packable, so a contracts-only
change ships as a client version bump. One number is the point; this is the price of it.
**The Android head's `versionName` now follows the same tag**, while its integer `versionCode` stays
hand-bumped, because Android needs a monotonic integer and SemVer does not provide one. Nothing else about
ADR 0011 changes.
## Rejected
- **MSIX.** Not a preference. It would break the terminal outright; see decision 1.
- **A CI job that cuts the release on a tag.** The convenience is the point of CI and the custody is the
point of ADR 0011; where they collide the custody wins. See decision 3, and note that a Windows runner
answers the mechanical objection while leaving the real one untouched.
- **A configurable update feed.** Named here because it is the change somebody will propose in good faith,
for a self-hosted product where making things configurable is usually right. It is the one setting that
would hand the operator the capability the whole trust model is about.
- **The deployment serving the installer.** Refused again, for the third ADR running, because it is
genuinely the nicest onboarding available and will be proposed again.
- **Conditioning updates on `MinClientVersion`.** See decision 5. It would create the attack rather than
inherit it.
- **A Velopack channel for Linux.** The mechanism exists — Velopack builds an AppImage — and repeating
decisions 1 through 9 a third time would have been the consistent-looking move. Declined in decision 11
because this is the one desktop platform that already has an updater the user controls, and a second one
answering to this project is the capability decision 4 exists to make unsettable.
- **Azure Trusted Signing**, for now, on custody grounds rather than on mechanics. See decision 8.
- **A hand-edited version property.** Considered seriously against MinVer, and it loses on the thing that
matters here: the tag is already the version of record for the container image, and two places to write
one number is a pair that can disagree. MinVer's silent-wrong-answer failure mode is real and is what the
two CI guards in decision 7 exist for.