CluPilotCloud/app/Services/Vpn/WireguardEndpointCheck.php

126 lines
5.3 KiB
PHP

<?php
namespace App\Services\Vpn;
use App\Support\ProvisioningSettings;
use Illuminate\Support\Str;
/**
* Whether the WireGuard hub endpoint an onboarding host is told to dial is
* even CAPABLE of being reached from outside this network.
*
* Deliberately makes no network call. A UDP port cannot be knocked on
* cleanly from the outside — there is no handshake to observe without a real
* peer, and this class runs on every readiness page load, not on demand. What
* IS decidable without touching the wire: whether the address configured is
* one a host on the internet could even attempt to reach. `10.10.90.185` and
* `203.0.113.11` (RFC 5737) both look "set" and are unreachable from any host
* outside this operator's own network or a documentation example generator —
* exactly the two shapes seen in this installation's configuration on
* 2026-07-30.
*/
final class WireguardEndpointCheck
{
/**
* IPv4 ranges FILTER_FLAG_NO_PRIV_RANGE|FILTER_FLAG_NO_RES_RANGE does NOT
* reject, checked one by one against this PHP build (`php -r
* 'var_dump(filter_var($ip, FILTER_VALIDATE_IP,
* FILTER_FLAG_NO_PRIV_RANGE|FILTER_FLAG_NO_RES_RANGE));'`) so the next
* reader does not have to repeat the research:
*
* Included below, because each is a shape a real installation can
* actually end up with:
* - 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24 (RFC 5737 "TEST-NET"):
* documentation/example addresses — seed data and copy-pasted examples
* land here. This was the original gap (Task 9 review).
* - 100.64.0.0/10 (RFC 6598, Carrier-Grade NAT): an ISP hands this out to
* a real customer connection; it is exactly as unreachable from the
* outside as RFC 1918, just not covered by NO_PRIV_RANGE. Confirmed
* passing filter_var's flags before this fix (fix-round finding).
* - 224.0.0.0/4 (multicast): not a shape a *mistake* produces, but never
* a single host's own reachable address either — no WireGuard peer's
* endpoint can legitimately be a multicast address, so it belongs in
* the same bucket as the others rather than being let through by
* omission.
*
* Already rejected by the filter_var flags above WITHOUT this list, so
* deliberately NOT duplicated here (verified empirically, not assumed):
* 0.0.0.0/8, 127.0.0.0/8 (loopback), 169.254.0.0/16 (link-local),
* 240.0.0.0/4 (reserved — this range also covers the 255.255.255.255
* broadcast address, confirmed separately).
*
* Deliberately left UNCHECKED, a considered omission and not an
* oversight: 192.0.0.0/24 (IETF protocol assignments), 192.88.99.0/24
* (deprecated 6to4 relay anycast), 198.18.0.0/15 (RFC 2544 benchmark
* testing). All three pass filter_var's flags today, but none of them is
* a shape an operator's real configuration plausibly lands in by
* accident or by a real provider's assignment — unlike the TEST-NET
* ranges (copy-pasted examples) and CGNAT (an ISP genuinely assigns it).
* Adding checks for ranges nobody will ever hit is effort spent on the
* task's shape, not its risk (R22).
*
* @var array<int, string>
*/
private const NON_PUBLIC_RANGES = [
'192.0.2.0/24', // TEST-NET-1 (RFC 5737)
'198.51.100.0/24', // TEST-NET-2 (RFC 5737)
'203.0.113.0/24', // TEST-NET-3 (RFC 5737)
'100.64.0.0/10', // Carrier-Grade NAT (RFC 6598)
'224.0.0.0/4', // Multicast
];
/** @return array<string, mixed> */
public function run(?string $endpoint = null): array
{
$endpoint ??= ProvisioningSettings::wgEndpoint();
if (blank($endpoint)) {
return ['ok' => false, 'reason' => 'missing'];
}
if (! str_contains($endpoint, ':')) {
return ['ok' => false, 'reason' => 'no_port'];
}
$host = Str::beforeLast($endpoint, ':');
// No valid IP means: a name. It can resolve publicly, and guessing
// here would be worse than letting it through — the check states what
// it knows, not what it suspects.
if (! filter_var($host, FILTER_VALIDATE_IP)) {
return ['ok' => true, 'reason' => 'hostname', 'address' => $host];
}
// NO_PRIV_RANGE covers RFC 1918, NO_RES_RANGE covers loopback and
// link-local among others — exactly the private address that stood
// at one host on 2026-07-30.
$public = filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE);
if ($public === false || $this->isKnownNonPublicRange($host)) {
return ['ok' => false, 'reason' => 'not_public', 'address' => $host];
}
return ['ok' => true, 'reason' => 'public', 'address' => $host];
}
private function isKnownNonPublicRange(string $ip): bool
{
if (! filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
return false;
}
$long = ip2long($ip);
foreach (self::NON_PUBLIC_RANGES as $cidr) {
[$subnet, $bits] = explode('/', $cidr);
$mask = -1 << (32 - (int) $bits);
if (($long & $mask) === (ip2long($subnet) & $mask)) {
return true;
}
}
return false;
}
}