packaging: keep the signing certificate in a private folder and bound the Flatpak tarball

packaging/linux/flatpak-bundle.sh

@@ -47,6 +47,12 @@ done
 
 echo "==> SoundCraft $VERSION Flatpak bundle for $ARCH from $(basename "$TARBALL")"
 
+# The packaged app unpacks to tens of MB; an archive that lists far more would fill the build
+# host's disk before anything here could check it.
+MAX_UNPACKED_BYTES=$((2 * 1024 * 1024 * 1024))
+UNPACKED="$(tar -tzvf "$TARBALL" | awk '{ s += $3 } END { print s + 0 }')"
+[ "$UNPACKED" -le "$MAX_UNPACKED_BYTES" ] || { echo "error: $TARBALL unpacks to $UNPACKED bytes, more than $MAX_UNPACKED_BYTES" >&2; exit 1; }
+
 WORK="$CARGO_TARGET_DIR/flatpak-bundle"
 rm -rf "$WORK"
 mkdir -p "$WORK/stage"

packaging/macos/import-cert.sh

@@ -19,10 +19,13 @@ fi
 
 TMP="${RUNNER_TEMP:-${TMPDIR:-/tmp}}"
 KEYCHAIN="$TMP/soundcraft-signing.keychain-db"
-CERT="$TMP/soundcraft-signing.p12"
+# The decoded certificate goes in a folder of this run's own (mktemp creates it, owner-only):
+# a name another account could plant in the shared folder must not receive or redirect it.
+CERT_DIR="$(mktemp -d "$TMP/soundcraft-signing.XXXXXX")"
+CERT="$CERT_DIR/soundcraft-signing.p12"
 KC_PASS="${KEYCHAIN_PASSWORD:-$(openssl rand -hex 24)}"
 
-trap 'rm -f "$CERT"' EXIT
+trap 'rm -rf "$CERT_DIR"' EXIT
 printf '%s' "$APPLE_CERTIFICATE" | base64 --decode >"$CERT"
 security create-keychain -p "$KC_PASS" "$KEYCHAIN"
 security set-keychain-settings -lut 21600 "$KEYCHAIN"