screentinker/android/app
ScreenTinker 49ddd95c4e OTA: say which failure happened, and stop refusing readable APKs on API 28/29
Two changes, both aimed at the same dead end: a panel that will not update and a
message that cannot tell you why.

NAME THE FAILURE. "failed to download or failed signature verification" covers
SEVEN distinct branches — three of them download failures where verification never
runs at all. Every specific reason went to logcat, and an unprivileged app UID
cannot read logcat on Android 9, so in the field the message was unactionable: it
named a symptom shared by unrelated causes and pointed at the wrong half of the
code as often as the right one. Each branch now records what actually happened and
the operator sees it:

    "not installed — server returned HTTP 416 for the APK"
    "not installed — could not read signing certificates (archive=0, installed=1) on API 28"
    "not installed — APK is signed by a different key than the installed app"
    "not installed — download/install threw IOException: ENOSPC (downloaded 41232 bytes)"

The byte count rides along on verification failures so a truncated download is
distinguishable from a genuine key mismatch — the two look identical today.

FALLBACK ARCHIVE CERT READ. On API 28/29 the archive's signer comes from the
legacy GET_SIGNATURES path (#139: signingInfo is null for ARCHIVES below API 30).
When PackageManager returns nothing there, we refused a possibly-fine APK with no
way to tell that apart from a real mismatch. It now reads the v1 signature itself
via JarFile before giving up.

This does NOT weaken the check. JarFile with verify=true only populates
JarEntry.certificates after the covered bytes have been read and verified — the
read IS the verification — and the extracted cert is still compared against the
installed app's. An unsigned, tampered or differently-signed APK still fails, and
any error in the fallback returns empty, which still refuses the install.

Deliberately NOT done: disabling signature verification on Android 9. It would mean
those panels silently installing whatever the server hands them — on device-owner
hardware that is remote code execution, and the cheap Android 9 boxes are the ones
most likely on a customer's flat network. It also might not fix anything, since
three of the seven branches never reach verification.

Context: a panel on alpha failed four forced updates this evening while succeeding
at an unattended one, and four separate theories for it died on contact with
evidence. The reason this took an evening is that the device could not say what
went wrong. That is the actual bug being fixed here.
2026-08-13 19:35:11 -05:00
..
src OTA: say which failure happened, and stop refusing readable APKs on API 28/29 2026-08-13 19:35:11 -05:00
build.gradle.kts chore(release): v1.9.34-alpha10 2026-08-13 19:00:53 -05:00
proguard-rules.pro Initial open source release 2026-04-08 12:14:53 -05:00