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refactor: RemoteFileFetcher aus MediaImporter herausgelöst (URL-Prüfung, Weiterleitungen, Download)

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Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
This commit is contained in:
Jan-Niclas Loosen
2026-10-19 18:00:41 +02:00
co-authored by Claude Sonnet 5.5
parent bba5a618ed
commit 172a703903
3 changed files with 264 additions and 76 deletions
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src/Integrations/Media/MediaImporter.php
+11 -76
View File
@@ -11,18 +11,15 @@ use LIT\MCP\Limits;
use LIT\MCP\Log;
use Throwable;
use WP_Error;
use WpOrg\Requests\Exception as RequestsException;
defined('ABSPATH') || exit;
/**
* Imports files into the media library (spec §6.3, §10).
*
* - URL: only http(s), checked with wp_http_validate_url() and the plugin's own range check
* (PublicAddress, independent of the core version) before any request and on every redirect,
* fetched with wp_safe_remote_get() (core re-validates redirects too), streamed into a temp file
* and cut off one byte above the upload limit. Network failures reach the client only as one
* generic message (no refused/timeout/status oracle, security audit M3); details go to the log.
* - URL: downloaded by RemoteFileFetcher (public http(s) only, redirects checked, streamed into a
* temp file and cut off one byte above the upload limit). Network failures reach the client only
* as one generic message (no refused/timeout/status oracle, security audit M3); details go to the log.
* - Base64: decoded strictly; the size is checked against Limits::inlineBytes() (upload limit,
* at most 10 MB – the whole file sits in memory) before anything is decoded or written.
* - Type: whitelist (filter lit_mcp_upload_mimes) intersected with what WordPress allows the
@@ -48,28 +45,20 @@ class MediaImporter
'mp3' => 'audio/mpeg',
];
private const TIMEOUT = 30;
private const ALT_KEY = '_wp_attachment_image_alt';
private const REDIRECT_HOOK = 'requests-requests.before_redirect';
/** @var Closure(string): list<string> Host name => IPv4 addresses. */
private Closure $resolve;
private RemoteFileFetcher $fetcher;
/** @param (Closure(string): list<string>)|null $resolve DNS lookup; null = the real one. */
public function __construct(private Limits $limits, ?Closure $resolve = null)
{
$this->resolve = $resolve ?? PublicAddress::dnsResolver();
$this->fetcher = new RemoteFileFetcher($resolve);
}
/** @param array{title?: string, alt?: string, post_id?: int} $meta */
public function fromUrl(string $url, ?string $filename, array $meta): int|WP_Error
{
$scheme = strtolower((string) wp_parse_url($url, PHP_URL_SCHEME));
if (
! in_array($scheme, ['http', 'https'], true)
|| ! wp_http_validate_url($url)
|| ! $this->isPublicUrl($url)
) {
if (! $this->fetcher->allows($url)) {
return Errors::invalidInput(
'Die URL ist nicht erlaubt.',
['url' => 'nur öffentlich erreichbare http(s)-Adressen'],
@@ -134,42 +123,9 @@ class MediaImporter
/** @return array<string, mixed>|WP_Error The response (body streamed into $tmp). */
private function download(string $url, string $tmp): array|WP_Error
{
// IPv4 only, for this request only: wp_http_validate_url() checks the IPv4 address
// (gethostbyname), so an AAAA record must not lead cURL to an unchecked IPv6 target.
$ipv4 = static function ($handle): void {
if (defined('CURLOPT_IPRESOLVE') && defined('CURL_IPRESOLVE_V4')) {
// phpcs:ignore WordPress.WP.AlternativeFunctions.curl_curl_setopt -- http_api_curl hands us the handle.
curl_setopt($handle, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
}
};
// Every redirect target gets the plugin's own range check too; Requests turns the
// exception into a failed request (WP_Http returns a WP_Error).
$redirect = function ($location): void {
if (! $this->isPublicUrl((string) $location)) {
throw new RequestsException('Redirect to a non-public address refused', 'lit_mcp_redirect');
}
};
add_action('http_api_curl', $ipv4);
add_action(self::REDIRECT_HOOK, $redirect);
try {
$response = wp_safe_remote_get($url, [
'timeout' => self::TIMEOUT,
'stream' => true,
'filename' => $tmp,
'limit_response_size' => $this->limits->uploadBytes() + 1,
]);
} finally {
remove_action('http_api_curl', $ipv4);
remove_action(self::REDIRECT_HOOK, $redirect);
}
if ($response instanceof WP_Error) {
return $this->downloadFailed($url, $response->get_error_message());
}
$status = (int) wp_remote_retrieve_response_code($response);
if ($status !== 200) {
return $this->downloadFailed($url, sprintf('HTTP status %d', $status));
$response = $this->fetcher->fetch($url, $tmp, $this->limits->uploadBytes(), 'media import');
if ($response === null) {
return $this->downloadFailed();
}
$length = (string) wp_remote_retrieve_header($response, 'content-length');
@@ -361,30 +317,9 @@ class MediaImporter
}
}
/** Host (name or IP literal) of $url resolves to public addresses only (PublicAddress). */
private function isPublicUrl(string $url): bool
/** One message for every network failure (security audit M3); RemoteFileFetcher logged the reason. */
private function downloadFailed(): WP_Error
{
return PublicAddress::hostIsPublic((string) wp_parse_url($url, PHP_URL_HOST), $this->resolve);
}
/** Scheme, host, port and path of $url – no credentials, query string or fragment in the log. */
private static function loggableUrl(string $url): string
{
$parts = wp_parse_url($url);
if (! is_array($parts)) {
return '(ungültige URL)';
}
$port = isset($parts['port']) ? ':' . (int) $parts['port'] : '';
return sprintf('%s://%s%s%s', $parts['scheme'] ?? '', $parts['host'] ?? '', $port, $parts['path'] ?? '');
}
/** One message for every network failure (security audit M3); the reason is logged only. */
private function downloadFailed(string $url, string $reason): WP_Error
{
Log::failure('media import from ' . self::loggableUrl($url), $reason);
return Errors::invalidInput(
'Die Datei konnte nicht geladen werden.',
['url' => 'nicht abrufbar'],
src/Integrations/Media/RemoteFileFetcher.php
+120
View File
@@ -0,0 +1,120 @@
<?php
declare(strict_types=1);
namespace LIT\MCP\Integrations\Media;
use Closure;
use LIT\MCP\Log;
use WP_Error;
use WpOrg\Requests\Exception as RequestsException;
defined('ABSPATH') || exit;
/**
* Downloads a file from a public http(s) URL into a temp file (spec §6.3, §10) – shared by the media import and
* the font upload. Only http(s), checked with wp_http_validate_url() and the plugin's own range check
* (PublicAddress, independent of the core version) before any request and on every redirect, fetched with
* wp_safe_remote_get() over IPv4 only (core re-validates redirects too), streamed into the temp file and cut off
* one byte above $maxBytes. A failure reaches the caller only as null (no refused/timeout/status oracle, security
* audit M3); the reason goes to the log. Not final so abilities can be tested with a fake.
*/
class RemoteFileFetcher
{
private const TIMEOUT = 30;
private const REDIRECT_HOOK = 'requests-requests.before_redirect';
/** @var Closure(string): list<string> Host name => IPv4 addresses. */
private Closure $resolve;
/** @param (Closure(string): list<string>)|null $resolve DNS lookup; null = the real one. */
public function __construct(?Closure $resolve = null)
{
$this->resolve = $resolve ?? PublicAddress::dnsResolver();
}
/** Whether $url may be fetched at all: http(s), accepted by core, host with public addresses only. */
public function allows(string $url): bool
{
$scheme = strtolower((string) wp_parse_url($url, PHP_URL_SCHEME));
return in_array($scheme, ['http', 'https'], true) && wp_http_validate_url($url) && $this->isPublicUrl($url);
}
/**
* Streams $url into $tmp; the caller checks allows() first and the size of $tmp afterwards (a body above
* $maxBytes is cut off at $maxBytes + 1 bytes).
*
* @param string $context Names the download in the failure log, e.g. "media import".
* @return array<string, mixed>|null The response (headers, status), null when the download failed.
*/
public function fetch(string $url, string $tmp, int $maxBytes, string $context): ?array
{
// IPv4 only, for this request only: wp_http_validate_url() checks the IPv4 address
// (gethostbyname), so an AAAA record must not lead cURL to an unchecked IPv6 target.
$ipv4 = static function ($handle): void {
if (defined('CURLOPT_IPRESOLVE') && defined('CURL_IPRESOLVE_V4')) {
// phpcs:ignore WordPress.WP.AlternativeFunctions.curl_curl_setopt -- http_api_curl hands us the handle.
curl_setopt($handle, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
}
};
// Every redirect target gets the plugin's own range check too; Requests turns the
// exception into a failed request (WP_Http returns a WP_Error).
$redirect = function ($location): void {
if (! $this->isPublicUrl((string) $location)) {
throw new RequestsException('Redirect to a non-public address refused', 'lit_mcp_redirect');
}
};
add_action('http_api_curl', $ipv4);
add_action(self::REDIRECT_HOOK, $redirect);
try {
$response = wp_safe_remote_get($url, [
'timeout' => self::TIMEOUT,
'stream' => true,
'filename' => $tmp,
'limit_response_size' => $maxBytes + 1,
]);
} finally {
remove_action('http_api_curl', $ipv4);
remove_action(self::REDIRECT_HOOK, $redirect);
}
if ($response instanceof WP_Error) {
return $this->failed($context, $url, $response->get_error_message());
}
$status = (int) wp_remote_retrieve_response_code($response);
if ($status !== 200) {
return $this->failed($context, $url, sprintf('HTTP status %d', $status));
}
return $response;
}
/** Host (name or IP literal) of $url resolves to public addresses only (PublicAddress). */
private function isPublicUrl(string $url): bool
{
return PublicAddress::hostIsPublic((string) wp_parse_url($url, PHP_URL_HOST), $this->resolve);
}
/** The reason goes to the log only (security audit M3). */
private function failed(string $context, string $url, string $reason): ?array
{
Log::failure($context . ' from ' . self::loggableUrl($url), $reason);
return null;
}
/** Scheme, host, port and path of $url – no credentials, query string or fragment in the log. */
private static function loggableUrl(string $url): string
{
$parts = wp_parse_url($url);
if (! is_array($parts)) {
return '(ungültige URL)';
}
$port = isset($parts['port']) ? ':' . (int) $parts['port'] : '';
return sprintf('%s://%s%s%s', $parts['scheme'] ?? '', $parts['host'] ?? '', $port, $parts['path'] ?? '');
}
}
tests/Unit/Integrations/Media/RemoteFileFetcherTest.php
+133
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@@ -0,0 +1,133 @@
<?php
declare(strict_types=1);
namespace LIT\MCP\Tests\Unit\Integrations\Media;
use Brain\Monkey\Actions;
use Brain\Monkey\Functions;
use LIT\MCP\Integrations\Media\RemoteFileFetcher;
use LIT\MCP\Tests\Unit\TestCase;
use Mockery;
use WP_Error;
/**
* The URL guard and the download shared by the media import and the font upload. MediaImporterTest keeps covering
* the same guard through fromUrl(); this test pins the parts a second caller relies on: the size limit as
* parameter, null instead of an error message, the log context.
*/
final class RemoteFileFetcherTest extends TestCase
{
private string $tmp = '';
/** error_log() is a PHP internal and cannot be stubbed; it is redirected to this file. */
private string $errorLog = '';
private string|false $previousErrorLog = false;
protected function setUp(): void
{
parent::setUp();
$this->tmp = (string) tempnam(sys_get_temp_dir(), 'lit-fetch');
$this->errorLog = (string) tempnam(sys_get_temp_dir(), 'lit-mcp-log');
$this->previousErrorLog = ini_set('error_log', $this->errorLog);
Functions\when('wp_parse_url')->alias('parse_url');
Functions\when('wp_http_validate_url')->returnArg();
Functions\when('wp_remote_retrieve_response_code')->alias(static fn (array $r): int => $r['response']['code']);
}
protected function tearDown(): void
{
ini_set('error_log', (string) $this->previousErrorLog);
foreach ([$this->tmp, $this->errorLog] as $file) {
if (is_file($file)) {
unlink($file);
}
}
parent::tearDown();
}
/** @param list<string> $addresses What every host name resolves to (no DNS in unit tests). */
private function fetcher(array $addresses = ['93.184.216.34']): RemoteFileFetcher
{
return new RemoteFileFetcher(static fn (string $host): array => $addresses);
}
public function testOnlyPublicHttpUrlsAreAllowed(): void
{
self::assertTrue($this->fetcher()->allows('https://fonts.example.com/inter.woff2'));
self::assertTrue($this->fetcher()->allows('HTTP://fonts.example.com/inter.woff2'));
self::assertFalse($this->fetcher()->allows('ftp://fonts.example.com/inter.woff2'));
self::assertFalse($this->fetcher()->allows('file:///etc/passwd'));
self::assertFalse($this->fetcher()->allows('http://169.254.169.254/latest/meta-data/'));
self::assertFalse($this->fetcher(['10.0.0.5'])->allows('https://intern.example.com/x.woff2'));
self::assertFalse($this->fetcher([])->allows('https://nirgends.example.com/x.woff2'));
Functions\when('wp_http_validate_url')->justReturn(false);
self::assertFalse($this->fetcher()->allows('https://fonts.example.com/inter.woff2'));
}
public function testTheBodyIsStreamedIntoTheTempFileAndCutOffOneByteAboveTheLimit(): void
{
Functions\expect('wp_safe_remote_get')->once()->with(
'https://fonts.example.com/inter.woff2',
Mockery::on(function (array $args): bool {
file_put_contents($args['filename'], 'wOF2DATA');
return $args['filename'] === $this->tmp && $args['stream'] === true && $args['timeout'] === 30
&& $args['limit_response_size'] === 2048 + 1;
})
)->andReturn(['response' => ['code' => 200], 'headers' => ['content-type' => 'font/woff2']]);
$response = $this->fetcher()->fetch('https://fonts.example.com/inter.woff2', $this->tmp, 2048, 'font upload');
self::assertSame(['code' => 200], $response['response'] ?? null);
self::assertSame('wOF2DATA', file_get_contents($this->tmp));
}
public function testAFailedRequestIsNullAndOnlyTheLogNamesTheReasonAndTheContext(): void
{
Functions\when('wp_safe_remote_get')->justReturn(new WP_Error('http_request_failed', 'Connection refused'));
$response = $this->fetcher()->fetch(
'https://nutzer:geheim@fonts.example.com:8443/inter.woff2?token=abc',
$this->tmp,
2048,
'font upload'
);
$log = (string) file_get_contents($this->errorLog);
self::assertNull($response);
self::assertStringContainsString('font upload from https://fonts.example.com:8443/inter.woff2', $log);
self::assertStringContainsString('Connection refused', $log);
self::assertStringNotContainsString('geheim', $log);
self::assertStringNotContainsString('token=abc', $log);
}
public function testAnHttpErrorStatusIsNull(): void
{
Functions\when('wp_safe_remote_get')->justReturn(['response' => ['code' => 404], 'headers' => []]);
self::assertNull($this->fetcher()->fetch('https://fonts.example.com/fehlt.woff2', $this->tmp, 2048, 'x'));
self::assertStringContainsString('HTTP status 404', (string) file_get_contents($this->errorLog));
}
public function testTheIpv4AndRedirectHooksLiveOnlyDuringTheRequest(): void
{
$listener = null;
Actions\expectAdded('http_api_curl')->once();
Actions\expectAdded('requests-requests.before_redirect')->once()
->whenHappen(static function (callable $callback) use (&$listener): void {
$listener = $callback;
});
Functions\when('wp_safe_remote_get')->justReturn(['response' => ['code' => 200], 'headers' => []]);
$this->fetcher()->fetch('https://fonts.example.com/inter.woff2', $this->tmp, 2048, 'x');
self::assertFalse(has_action('http_api_curl'));
self::assertFalse(has_action('requests-requests.before_redirect'));
self::assertIsCallable($listener);
$listener('https://cdn.example.com/inter.woff2'); // public: no exception
$this->expectException(\WpOrg\Requests\Exception::class);
$listener('http://127.0.0.1/inter.woff2');
}
}