fix(docker): let Provider Settings admit the host through the published port

Docker delivers the host's own browser to the container from the container
network's gateway, never from 127.0.0.1, so the loopback-only admission gate
answered every POWER UP request with 403 and no key could be saved. The README
and CHANGELOG claimed otherwise; both are corrected here.

- keySetupCore: GEV_KEY_SETUP_TRUSTED_PEERS, an exact-address list (no
  wildcards, prefixes or hostnames) admitted alongside loopback. Unset trusts
  nothing, and the sharing, Host, Origin, Content-Type and proxy-header checks
  all still apply to a listed address. Twelve assertions pin each refusal.
- scripts/docker-start.mjs: the container entry point, shaped after
  scripts/pinokio-start.mjs. It reads the default gateway from /proc/net/route,
  trusts exactly that address, and starts Vite. No gateway (--network none)
  trusts nothing. The pure helpers are unit-tested and a contract test pins the
  Dockerfile CMD and the loopback-only publish.
- Dockerfile: install git. `npm test` builds fixtures with `git init`, so the
  suite failed 71 tests inside the image and the README's claim that it runs in
  the container was wrong.
- SECURITY.md and .env.example document the setting and why it is safe only
  behind a 127.0.0.1 publish; README gains the Linux/NAS id note and .dockerignore
  drops macOS AppleDouble sidecars, both reported on the PR.

Verified in Docker on a clean build: saving a key from the panel writes the
bind-mounted .env (0600 in the container), it survives `compose down`/`up`, and
REMOVE comments it back out. A foreign Origin, a foreign Host, a proxy header
and a sibling container on the same network are each refused. `npm run doctor`,
`npm test` (5067 passed, 1 skipped, 0 failed) and `npm run build` are green
inside the container.

Reported-by: @jklaze
Co-Authored-By: Bogdan Petrut <[email protected]>
Co-Authored-By: Claude Opus 5 <[email protected]>

src/dockerLauncher.test.mjs

@@ -0,0 +1,81 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+import {
+  defaultGatewayFromRouteTable,
+  resolveAllowedHosts,
+  resolveTrustedPeers,
+} from '../scripts/docker-start.mjs';
+
+// The shape of /proc/net/route inside a bridge-networked container:
+// little-endian hex addresses, the default route first, an interface route
+// after.
+const BRIDGE_ROUTES = [
+  'Iface\tDestination\tGateway \tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU\tWindow\tIRTT',
+  'eth0\t00000000\t0100A8C0\t0003\t0\t0\t0\t00000000\t0\t0\t0',
+  'eth0\t0000A8C0\t00000000\t0001\t0\t0\t0\t00F0FFFF\t0\t0\t0',
+  '',
+].join('\n');
+
+test('the container gateway is decoded from the kernel routing table', () => {
+  assert.equal(defaultGatewayFromRouteTable(BRIDGE_ROUTES), '192.168.0.1', 'little-endian hex, default route only');
+  assert.equal(
+    defaultGatewayFromRouteTable(BRIDGE_ROUTES.replace('0100A8C0', '011FAC')),
+    null,
+    'a malformed gateway field is not an address',
+  );
+  assert.equal(
+    defaultGatewayFromRouteTable(BRIDGE_ROUTES.replace('\t0003\t', '\t0002\t')),
+    null,
+    'a default route that is not up is ignored',
+  );
+  assert.equal(
+    defaultGatewayFromRouteTable(BRIDGE_ROUTES.replace('0100A8C0', '00000000')),
+    null,
+    'a zero gateway is not an address',
+  );
+  assert.equal(
+    defaultGatewayFromRouteTable(
+      BRIDGE_ROUTES.split('\n').filter((line) => !line.includes('00000000\t0100A8C0')).join('\n'),
+    ),
+    null,
+    '--network none has no default route and must not invent one',
+  );
+  assert.equal(defaultGatewayFromRouteTable(''), null);
+  assert.equal(defaultGatewayFromRouteTable(undefined), null);
+});
+
+test('an operator list wins, and no gateway trusts nothing', () => {
+  assert.equal(resolveTrustedPeers({ env: {}, routeTable: BRIDGE_ROUTES }), '192.168.0.1');
+  assert.equal(resolveTrustedPeers({ env: { GEV_KEY_SETUP_TRUSTED_PEERS: ' 10.9.8.7 ' }, routeTable: BRIDGE_ROUTES }), '10.9.8.7');
+  assert.equal(
+    resolveTrustedPeers({ env: { GEV_KEY_SETUP_TRUSTED_PEERS: '  ' }, routeTable: BRIDGE_ROUTES }),
+    '192.168.0.1',
+    'a blank override falls through to the gateway',
+  );
+  assert.equal(resolveTrustedPeers({ env: {}, routeTable: '' }), '', 'loopback-only when there is no gateway');
+});
+
+test('the container answers the same host names as the native launcher', () => {
+  assert.deepEqual(resolveAllowedHosts({}), ['localhost', '127.0.0.1', '.local'], 'a wildcard bind never means "any Host header"');
+  assert.deepEqual(
+    resolveAllowedHosts({ GEV_ALLOWED_HOSTS: ' globe.lan , nas.internal ' }),
+    ['localhost', '127.0.0.1', '.local', 'globe.lan', 'nas.internal'],
+    'an operator can still add a LAN hostname',
+  );
+  assert.deepEqual(
+    resolveAllowedHosts({ GEV_ALLOWED_HOSTS: ' , localhost , ' }),
+    ['localhost', '127.0.0.1', '.local'],
+    'blank and duplicate entries change nothing',
+  );
+});
+
+test('the Docker install path keeps its loopback-only, launcher-owned contract', () => {
+  const dockerfile = readFileSync(new URL('../Dockerfile', import.meta.url), 'utf8');
+  assert.match(dockerfile, /^CMD \["node", "scripts\/docker-start\.mjs"\]$/m, 'the launcher is the container entry point');
+
+  const compose = readFileSync(new URL('../compose.yaml', import.meta.url), 'utf8');
+  assert.match(compose, /^\s+- "127\.0\.0\.1:4173:4173"$/m, 'the port is published on the host loopback only');
+  assert.doesNotMatch(compose, /GEV_KEY_SETUP_TRUSTED_PEERS/, 'trust is derived at launch, never hard-coded');
+  assert.doesNotMatch(compose, /network_mode/, 'the container keeps its own network namespace');
+});

src/keySetupCore.mjs

@@ -126,6 +126,29 @@ const LOCAL_HOSTNAMES = new Set(['localhost', '127.0.0.1', '::1', '[::1]']);
 /** Socket addresses that count as this machine. */
 const LOOPBACK_ADDRESSES = new Set(['127.0.0.1', '::1', '::ffff:127.0.0.1']);
 
+/**
+ * Whether a socket address is one the operator has explicitly declared to be
+ * this machine through GEV_KEY_SETUP_TRUSTED_PEERS: a comma-separated list of
+ * EXACT addresses, never wildcards, prefixes or hostnames. Unset trusts
+ * nothing, which is every launcher but one.
+ *
+ * The shipped use is the Docker launcher (scripts/docker-start.mjs). A port
+ * published on the host's loopback still reaches the container FROM the
+ * container network's gateway, never from 127.0.0.1, so the loopback check
+ * alone refuses the very machine running the server. Admitting that one
+ * address relaxes nothing else: the sharing, Host, Origin, Content-Type and
+ * proxy-header checks all still apply to it.
+ */
+function isTrustedPeerAddress(remoteAddress, env) {
+  const normalize = (value) =>
+    String(value || '').trim().toLowerCase().replace(/^::ffff:/, '');
+  const address = normalize(remoteAddress);
+  if (!address) return false;
+  return String(env?.GEV_KEY_SETUP_TRUSTED_PEERS || '')
+    .split(',')
+    .some((entry) => entry.trim() !== '' && normalize(entry) === address);
+}
+
 /** Parse an exact local request authority from a Host header. */
 function localAuthority(hostHeader, protocol) {
   const raw = String(hostHeader || '')
@@ -224,7 +247,9 @@ export function isSharingEnabled(env = {}) {
  *    outright — a credential-writing endpoint has no business existing on a
  *    shared instance, and tunnel traffic reaches the server FROM loopback, so
  *    the socket check below cannot carry that boundary alone;
- *  - loopback socket: refuses LAN peers when the server is bound wide;
+ *  - loopback socket: refuses LAN peers when the server is bound wide. The
+ *    only exception is an exact address listed in
+ *    GEV_KEY_SETUP_TRUSTED_PEERS, and every check below still applies to it;
  *  - local Host header: tunnel and DNS-rebinding traffic carries a foreign
  *    Host even when the socket says loopback;
  *  - exact same Origin on POST: a hostile web page can make a browser POST to
@@ -274,7 +299,10 @@ export function admitKeySetupRequest({
       error: 'Provider Settings is disabled while sharing is enabled',
     };
   }
-  if (!LOOPBACK_ADDRESSES.has(String(remoteAddress || ''))) {
+  if (
+    !LOOPBACK_ADDRESSES.has(String(remoteAddress || '')) &&
+    !isTrustedPeerAddress(remoteAddress, env)
+  ) {
     return {
       ok: false,
       status: 403,

src/keySetupCore.test.mjs

@@ -258,6 +258,23 @@ test('the admission gate refuses every non-local shape, one assertion per refusa
   assert.equal(admitKeySetupRequest({ ...local, env: { PINOKIO_SHARE_LOCAL: '1' } }).ok, false, 'LAN sharing disables the surface');
   // A LAN peer reaching a wide-bound server.
   assert.equal(admitKeySetupRequest({ ...local, remoteAddress: '192.168.1.20' }).ok, false, 'non-loopback socket refused');
+  // A container publishes its port on the host's loopback, yet the host's own
+  // browser still arrives from the container network's gateway. Only an exact
+  // address the operator listed admits it, and nothing else is relaxed.
+  const trusted = { GEV_KEY_SETUP_TRUSTED_PEERS: ' 10.0.0.9 , 172.29.73.1 ' };
+  const gateway = { ...local, remoteAddress: '172.29.73.1' };
+  assert.equal(admitKeySetupRequest(gateway).ok, false, 'container gateway refused without the opt-in');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: trusted }).ok, true, 'listed peer admitted');
+  assert.equal(admitKeySetupRequest({ ...gateway, remoteAddress: '::ffff:172.29.73.1', env: trusted }).ok, true, 'IPv4-mapped form of a listed peer admitted');
+  assert.equal(admitKeySetupRequest({ ...local, remoteAddress: '192.168.1.20', env: trusted }).ok, false, 'unlisted peer still refused');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: { GEV_KEY_SETUP_TRUSTED_PEERS: '*' } }).ok, false, 'wildcards are not addresses');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: { GEV_KEY_SETUP_TRUSTED_PEERS: '172.29.73.0/24' } }).ok, false, 'prefixes are not addresses');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: { GEV_KEY_SETUP_TRUSTED_PEERS: '' } }).ok, false, 'an empty list trusts nothing');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: { GEV_KEY_SETUP_TRUSTED_PEERS: ' , , ' } }).ok, false, 'blank entries trust nothing');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: { ...trusted, PINOKIO_SHARE_LOCAL: '1' } }).ok, false, 'sharing still disables the surface for a listed peer');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: trusted, hostHeader: 'abc.trycloudflare.com' }).ok, false, 'a listed peer still needs a local Host');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: trusted, origin: 'https://evil.example' }).ok, false, 'a listed peer still needs the exact Origin');
+  assert.equal(admitKeySetupRequest({ ...gateway, env: trusted, proxyHeaders: { 'x-forwarded-for': '203.0.113.5' } }).ok, false, 'a listed peer still refuses proxied requests');
   // Tunnel and DNS-rebinding traffic carries a foreign Host over a loopback socket.
   assert.equal(admitKeySetupRequest({ ...local, hostHeader: 'abc.trycloudflare.com' }).ok, false, 'foreign Host refused');
   assert.equal(admitKeySetupRequest({ ...local, hostHeader: 'workstation.local:4173' }).ok, false, 'non-localhost hostnames refused');