Four Kotlin files appeared in both apps. Diffed with the product names
normalised, EnrollmentScanActivity was 31 lines each differing in six --
all of them comments -- and PinnedCert was 58 against 59 with identical
TrustManager logic. That is the same evidence that moved the Rust half.
Two parameters, both per-app, and they fail differently. A wrong URI
scheme means a scanned QR is ignored, which is visible at once. A wrong
Keystore alias means the app cannot unseal the token it already stored,
so an enrolled phone reads as not enrolled and nothing says why -- so
both existing values are recorded in the README rather than left to be
rediscovered.
The certificate alias went the other way and became a constant: it names
an entry in a KeyStore that exists only in memory for the length of one
lazy block, so nothing ever reads it back and having two of them said
nothing.
The drift was in both directions, as the evidence predicted: ai-app had
gained localNetworkAllowed -- which matters because Android 17's
ACCESS_LOCAL_NETWORK denial is invisible at the socket, and without it a
blocked app and an unreachable server produce the same timeout -- and had
moved to the KTX `edit` block. dev-updater had neither, and gets both.
No Compose, deliberately. Nothing here draws anything; the screens are
each app's own because that is where the two products actually differ.
The PinnedCaCertificate generator did not move, and the README says why:
all three things it varies are per-app, so sharing it means a composite
build neither project has. Its one historical bug is already fixed
identically in both copies.
Review from ai-app's session, acted on.
**A test that asserted nothing.** `a_missing_tunnel_explains_itself`
returned early whenever `wg0` was up -- which it is on this VM and on the
host, so it passed everywhere and never once checked the message. The same
shape of test that let the file-permissions bug survive three codebases.
`netif` now splits the lookup from the decision: `wg_address_among` and
`addresses_among` take the interfaces, so the failure is reachable by
handing in an empty list rather than by hoping the machine has no tunnel.
Four tests where there were two, including that an IPv6-only `wg0` is not
an answer.
**Two modules the docs promised and the crate did not have.** `certs`,
which is the piece where being written twice is worst -- a trust anchor
built two ways can be built differently two ways, and the difference
reaches a phone as an opaque handshake failure. And `format`, the RON
house rules, which were byte-identical in both projects and so the
clearest thing in the evidence table. `product` names the certificate and
is the whole of what is per-project; the test decodes the DER and looks
for it there rather than trusting what was passed in.
**The README title still said wg-server-app**, three commits after
everything else was renamed.
Two judgement calls promoted from silent to written down, both of which
would otherwise be inherited rather than chosen: `WG_INTERFACE` is a
constant because *these* projects have one tunnel, which is the first
thing a third user should expect to change; and `local_addresses` puts
the emulator's host alias in every certificate, a SAN for an address the
machine does not own.
And a review heuristic the day kept proving: when you find a rule stated,
grep for its siblings. Three bugs today were the correct rule already
written down and applied to one member of a set.
`wg-link` was not merely vague. `wg` and `ip link` are both real network
tools, so it reads as something that manages a WireGuard interface --
misleading rather than ambiguous. `app` rules that reading out, and says
which two ends the link is between.
The repository is still called wg-server-app until it is renamed on
gitea; the crate leads.
Three copies, one bug, and the correct reasoning already written down in
a comment three functions above the code that needed it. That is an
argument about review rather than about duplication, and it is more
persuasive than any of the similarity percentages above it.
dev-updater serves APKs to a phone and ai-app runs model sessions for
one. Above the waterline they share nothing. Underneath they are the
same program: bound to wg0 so they are not on the LAN, presenting a
certificate from a CA the app pins, answering only requests carrying a
token enrolled by scanning a QR off the terminal, keeping state in
owner-only files outside the repo.
Three modules, each extracted only after diffing the two copies and
finding nothing between them but a product name and a type parameter.
netif fails closed when the tunnel is down. enroll generates, stores and
compares the token, and prints the QR, with the URI scheme as the one
per-project part. private owns the file modes, taken from ai-app's
version because it had already factored out what dev-updater still has
inline in two places.
Nothing is removed from either project. This is a proposal with a
working core, and the README carries the measured evidence -- the
enrollment scanner activity differs by its package line and nothing
else, the RON format module is byte-identical, and the two copies have
each drifted into holding an improvement the other lacks, which is the
cost being paid today.
iris