-
-
Notifications
You must be signed in to change notification settings - Fork 4.7k
Expand file tree
/
Copy pathDnsPinMiddleware.php
More file actions
154 lines (124 loc) · 3.93 KB
/
DnsPinMiddleware.php
File metadata and controls
154 lines (124 loc) · 3.93 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
<?php
declare(strict_types=1);
/**
* SPDX-FileCopyrightText: 2021 Nextcloud GmbH and Nextcloud contributors
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
namespace OC\Http\Client;
use OC\Diagnostics\TLogSlowOperation;
use OC\Net\IpAddressClassifier;
use OCP\Http\Client\LocalServerException;
use Psr\Http\Message\RequestInterface;
use Psr\Log\LoggerInterface;
class DnsPinMiddleware {
use TLogSlowOperation;
public function __construct(
private NegativeDnsCache $negativeDnsCache,
private IpAddressClassifier $ipAddressClassifier,
private LoggerInterface $logger,
) {
}
/**
* Fetch soa record for a target
*/
private function soaRecord(string $target): ?array {
$labels = explode('.', $target);
$top = count($labels) >= 2 ? array_pop($labels) : '';
$second = array_pop($labels);
$hostname = $second . '.' . $top;
$responses = $this->dnsGetRecord($hostname, DNS_SOA);
if ($responses === false || count($responses) === 0) {
return null;
}
return reset($responses);
}
private function dnsResolve(string $target, int $recursionCount) : array {
if ($recursionCount >= 10) {
return [];
}
$recursionCount++;
$targetIps = [];
$soaDnsEntry = $this->soaRecord($target);
$dnsNegativeTtl = $soaDnsEntry['minimum-ttl'] ?? null;
$canHaveCnameRecord = true;
$dnsTypes = \defined('AF_INET6') || @inet_pton('::1')
? [DNS_A, DNS_AAAA, DNS_CNAME]
: [DNS_A, DNS_CNAME];
foreach ($dnsTypes as $dnsType) {
if ($canHaveCnameRecord === false && $dnsType === DNS_CNAME) {
continue;
}
if ($this->negativeDnsCache->isNegativeCached($target, $dnsType)) {
continue;
}
$dnsResponses = $this->dnsGetRecord($target, $dnsType);
if ($dnsResponses !== false && count($dnsResponses) > 0) {
foreach ($dnsResponses as $dnsResponse) {
if (isset($dnsResponse['ip'])) {
$targetIps[] = $dnsResponse['ip'];
$canHaveCnameRecord = false;
} elseif (isset($dnsResponse['ipv6'])) {
$targetIps[] = $dnsResponse['ipv6'];
$canHaveCnameRecord = false;
} elseif (isset($dnsResponse['target']) && $canHaveCnameRecord) {
$targetIps = array_merge($targetIps, $this->dnsResolve($dnsResponse['target'], $recursionCount));
}
}
} elseif ($dnsNegativeTtl !== null) {
$this->negativeDnsCache->setNegativeCacheForDnsType($target, $dnsType, $dnsNegativeTtl);
}
}
return $targetIps;
}
/**
* Wrapper for dns_get_record
*/
protected function dnsGetRecord(string $hostname, int $type): array|false {
return $this->monitorAndLog(
$this->logger,
'dns_get_record',
fn () => \dns_get_record($hostname, $type),
);
}
public function addDnsPinning(): callable {
return function (callable $handler) {
return function (
RequestInterface $request,
array $options,
) use ($handler) {
if ($options['nextcloud']['allow_local_address'] === true) {
return $handler($request, $options);
}
$hostName = $request->getUri()->getHost();
$port = $request->getUri()->getPort();
$ports = [
'80',
'443',
];
if ($port !== null) {
$ports[] = (string)$port;
}
$targetIps = $this->dnsResolve(idn_to_utf8($hostName), 0);
if (empty($targetIps)) {
throw new LocalServerException('No DNS record found for ' . $hostName);
}
$curlResolves = [];
foreach ($ports as $port) {
$curlResolves["$hostName:$port"] = [];
foreach ($targetIps as $ip) {
if ($this->ipAddressClassifier->isLocalAddress($ip)) {
// TODO: continue with all non-local IPs?
throw new LocalServerException('Host "' . $ip . '" (' . $hostName . ':' . $port . ') violates local access rules');
}
$curlResolves["$hostName:$port"][] = $ip;
}
}
// Coalesce the per-host:port ips back into a comma separated list
foreach ($curlResolves as $hostport => $ips) {
$options['curl'][CURLOPT_RESOLVE][] = "$hostport:" . implode(',', $ips);
}
return $handler($request, $options);
};
};
}
}