Files
simtrace-analyser/frontend/sw.js
T
catarrh d21997764f Client-side SCP80 decryption: pure-JS 3DES/AES with user-supplied keys
Adds optional decryption of ciphered secured packets, entirely in the
browser — the key never leaves the frontend.

- decode.py: _decode_secured_packet exposes 'cipher_block' (the
  contiguous on-wire ciphered octets CNTR..end, ready for CBC) and
  raw kic/kid bytes for algorithm selection. Additive only.
- index.html: pure-JS DES/3DES core (FIPS 46-3 bit-array tables,
  parity ignored) + CBC; AES-CBC via native SubtleCrypto; both with
  zero IV per TS 102 225. decryptSecured() picks the algorithm from
  the KIc nibble (02 AES-CBC, 05 3DES-2K, 09 3DES-3K, 01 DES) with
  key-length validation.
- UI: ciphered packets show a key-hex input + Decrypt strip below the
  detail table; keys are memoized per key-set for the session in an
  in-memory OTA_KEYS map — never sent to the server, never persisted.
- Decrypted results cached by cipher_block (survive live-polling
  re-renders); plaintext rows rendered as CNTR/PCNTR/RC/Secured data
  (decrypted) alongside the ciphertext; wrong-key guard via the
  decrypted padding counter (PCNTR > remaining → "invalid padding").
- 3DES implementation validated byte-identical against openssl
  des-ede3-cbc (3-key, 2-key ×3 random vectors, single-key).

No CC verification (out of scope). Tests: +2 (cipher_block
contiguity, AES registry guard) — 350 total. Version 1.19.0,
SW cache simtrace-analyser-v27.
2026-08-24 21:12:24 +03:00

49 lines
1.4 KiB
JavaScript

const CACHE = 'simtrace-analyser-v27';
const PRECACHE = [
'index.html',
'manifest.json',
'icon-192.png',
'icon-512.png',
'favicon.png',
'sim-analyser.svg',
'sim-analyser-light.svg',
];
self.addEventListener('install', e => {
self.skipWaiting();
e.waitUntil(
caches.open(CACHE)
.then(cache => cache.addAll(PRECACHE))
.then(() => console.log('SW: precache done'))
.catch(err => console.error('SW: precache failed', err))
);
});
self.addEventListener('activate', e => {
e.waitUntil(
caches.keys()
.then(keys => Promise.all(
keys.filter(k => k !== CACHE).map(k => caches.delete(k))
))
.then(() => self.clients.claim())
.then(() => console.log('SW: activated, controlling clients'))
);
});
self.addEventListener('fetch', e => {
// Network-first: the local server is always up, so always serve fresh
// content and fall back to cache only when offline.
if (!e.request.url.startsWith('http')) return;
if (e.request.method !== 'GET') return;
e.respondWith(
fetch(e.request)
.then(r => {
const clone = r.clone();
caches.open(CACHE).then(c => c.put(e.request, clone)).catch(() => {});
return r;
})
.catch(() => caches.match(e.request))
);
});