Multi-Hoster-Upload/lib/diagnostics-agent.js
Administrator 8d757a99dd fix(diagnostics): harden read-only agent — grep ReDoS, prototype-chain whitelist bypass, redaction gaps
Intensive end-to-end testing (a live gateway-MCP <-> agent integration harness +
an adversarial redaction/abuse probe + an independent security audit) surfaced
three real issues in the shipped read-only diagnostic agent. All run in lib/**,
which is packaged in the app.

1. grep ReDoS froze the Electron main process. read_log compiled the
   client-supplied grep into `new RegExp(grep, 'i')` and ran it synchronously over
   the log tail IN the main process. A catastrophic pattern (e.g. "(a+)+$" against
   a long line) hangs the whole app — empirically confirmed (8s timeout, killed).
   JS regex is synchronous and uncancellable, so grep is now a case-insensitive
   literal substring filter with "|" alternation ("error|timeout|502"). Provably
   linear-time; covers the real diagnostic need.

2. Prototype-chain whitelist bypass. The op table was a plain object literal, so
   handle("constructor" | "toString" | "valueOf", ...) resolved an inherited
   Object.prototype function, passed the `typeof fn === 'function'` guard and
   returned {ok:true}. Harmless functions today, but a whitelist-integrity hole.
   Now guarded with a string check + Object.prototype.hasOwnProperty.

3. Redaction defense-in-depth gaps. redactLogText now also scrubs: basic-auth URL
   passwords (scheme://user:pass@host), Authorization: Basic, JWTs (eyJ...x.y.z),
   and bare/JSON session= values. Mostly theoretical in today's readable logs
   (secret-bearing bodies go to the excluded doodstream-debug.log; other hosters
   throw static strings) but matters as the verbose-logging surface grows.

Verified: 383 app tests (incl. new regression tests for all three), the live
gateway-MCP integration harness (all 14 tools, zero leaks, error paths), the
adversarial probe (14/14+ secret shapes scrubbed, ReDoS 1ms, lockout, malformed
args), e2e gate, lint 0 errors. Only residual: a standalone high-entropy blob with
zero key/Bearer/URL context — inherent to any denylist, acknowledged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-19 18:40:57 +02:00

33 lines
1.2 KiB
JavaScript

function createAgent(collectors) {
const OPS = {
get_system_info: (a) => collectors.getSystemInfo(a),
server_health: (a) => collectors.serverHealth(a),
get_config_redacted: (a) => collectors.getConfigRedacted(a),
list_logs: () => collectors.listLogs(),
read_log: (a) => collectors.readLog(a),
tail_log: (a) => collectors.readLog(a),
get_app_events: (a) => collectors.getAppEvents(a),
list_errors: (a) => collectors.listErrors(a),
get_queue_state: (a) => collectors.getQueueState(a),
get_history: (a) => collectors.getHistory(a),
get_rotation_state: () => collectors.getRotationState(),
get_health: () => collectors.getHealth()
};
function handle(op, args) {
const fn = (typeof op === 'string' && Object.prototype.hasOwnProperty.call(OPS, op)) ? OPS[op] : null;
if (typeof fn !== 'function') return { ok: false, error: `unknown or non-readonly op: ${op}` };
try {
const data = fn(args || {});
if (data && data.ok === false) return data;
return { ok: true, data };
} catch (e) {
return { ok: false, error: String((e && e.message) || e) };
}
}
return { handle, ops: Object.keys(OPS) };
}
module.exports = { createAgent };