|
| 1 | +<?php |
| 2 | + |
| 3 | +declare(strict_types=1); |
| 4 | +/** |
| 5 | + * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors |
| 6 | + * SPDX-License-Identifier: AGPL-3.0-or-later |
| 7 | + */ |
| 8 | +namespace OC\Files; |
| 9 | + |
| 10 | +use OC\L10N\L10N; |
| 11 | +use OCP\Files\EmptyFileNameException; |
| 12 | +use OCP\Files\FileNameTooLongException; |
| 13 | +use OCP\Files\IFilenameValidator; |
| 14 | +use OCP\Files\InvalidCharacterInPathException; |
| 15 | +use OCP\Files\InvalidPathException; |
| 16 | +use OCP\Files\ReservedWordException; |
| 17 | +use OCP\IConfig; |
| 18 | +use OCP\L10N\IFactory; |
| 19 | +use Psr\Log\LoggerInterface; |
| 20 | + |
| 21 | +/** |
| 22 | + * @since 30.0.0 |
| 23 | + */ |
| 24 | +class FilenameValidator implements IFilenameValidator { |
| 25 | + |
| 26 | + private L10N $l10n; |
| 27 | + |
| 28 | + /** |
| 29 | + * @var list<string> |
| 30 | + */ |
| 31 | + private array $forbiddenNames = []; |
| 32 | + |
| 33 | + /** |
| 34 | + * @var list<string> |
| 35 | + */ |
| 36 | + private array $forbiddenCharacters = []; |
| 37 | + |
| 38 | + /** |
| 39 | + * @var list<string> |
| 40 | + */ |
| 41 | + private array $forbiddenExtensions = []; |
| 42 | + |
| 43 | + public function __construct( |
| 44 | + IFactory $l10nFactory, |
| 45 | + private IConfig $config, |
| 46 | + private LoggerInterface $logger, |
| 47 | + ) { |
| 48 | + $this->l10n = $l10nFactory->get('core'); |
| 49 | + } |
| 50 | + |
| 51 | + /** |
| 52 | + * Get a list of reserved filenames that must not be used |
| 53 | + * This list should be checked case-insensitive, all names are returned lowercase. |
| 54 | + * @return list<string> |
| 55 | + * @since 30.0.0 |
| 56 | + */ |
| 57 | + public function getForbiddenExtensions(): array { |
| 58 | + if (empty($this->forbiddenExtensions)) { |
| 59 | + $forbiddenExtensions = $this->config->getSystemValue('forbidden_filename_extensions', ['.filepart']); |
| 60 | + if (!is_array($forbiddenExtensions)) { |
| 61 | + $this->logger->error('Invalid system config value for "forbidden_filename_extensions" is ignored.'); |
| 62 | + $forbiddenExtensions = ['.filepart']; |
| 63 | + } |
| 64 | + |
| 65 | + // Always forbid .part files as they are used internally |
| 66 | + $forbiddenExtensions = array_merge($forbiddenExtensions, ['.part']); |
| 67 | + |
| 68 | + // The list is case insensitive so we provide it always lowercase |
| 69 | + $forbiddenExtensions = array_map('mb_strtolower', $forbiddenExtensions); |
| 70 | + $this->forbiddenExtensions = array_values($forbiddenExtensions); |
| 71 | + } |
| 72 | + return $this->forbiddenExtensions; |
| 73 | + } |
| 74 | + |
| 75 | + /** |
| 76 | + * Get a list of forbidden filename extensions that must not be used |
| 77 | + * This list should be checked case-insensitive, all names are returned lowercase. |
| 78 | + * @return list<string> |
| 79 | + * @since 30.0.0 |
| 80 | + */ |
| 81 | + public function getForbiddenFilenames(): array { |
| 82 | + if (empty($this->forbiddenNames)) { |
| 83 | + $forbiddenNames = $this->config->getSystemValue('forbidden_filenames', ['.htaccess']); |
| 84 | + if (!is_array($forbiddenNames)) { |
| 85 | + $this->logger->error('Invalid system config value for "forbidden_filenames" is ignored.'); |
| 86 | + $forbiddenNames = ['.htaccess']; |
| 87 | + } |
| 88 | + |
| 89 | + // Handle legacy config option |
| 90 | + // TODO: Drop with Nextcloud 34 |
| 91 | + $legacyForbiddenNames = $this->config->getSystemValue('blacklisted_files', []); |
| 92 | + if (!is_array($legacyForbiddenNames)) { |
| 93 | + $this->logger->error('Invalid system config value for "blacklisted_files" is ignored.'); |
| 94 | + $legacyForbiddenNames = []; |
| 95 | + } |
| 96 | + if (!empty($legacyForbiddenNames)) { |
| 97 | + $this->logger->warning('System config option "blacklisted_files" is deprecated and will be removed in Nextcloud 34, use "forbidden_filenames" instead.'); |
| 98 | + } |
| 99 | + $forbiddenNames = array_merge($legacyForbiddenNames, $forbiddenNames); |
| 100 | + |
| 101 | + // The list is case insensitive so we provide it always lowercase |
| 102 | + $forbiddenNames = array_map('mb_strtolower', $forbiddenNames); |
| 103 | + $this->forbiddenNames = array_values($forbiddenNames); |
| 104 | + } |
| 105 | + return $this->forbiddenNames; |
| 106 | + } |
| 107 | + |
| 108 | + /** |
| 109 | + * Get a list of characters forbidden in filenames |
| 110 | + * |
| 111 | + * Note: Characters in the range [0-31] are always forbidden, |
| 112 | + * even if not inside this list (see OCP\Files\Storage\IStorage::verifyPath). |
| 113 | + * |
| 114 | + * @return list<string> |
| 115 | + * @since 30.0.0 |
| 116 | + */ |
| 117 | + public function getForbiddenCharacters(): array { |
| 118 | + if (empty($this->forbiddenCharacters)) { |
| 119 | + // Get always forbidden characters |
| 120 | + $forbiddenCharacters = str_split(\OCP\Constants::FILENAME_INVALID_CHARS); |
| 121 | + if ($forbiddenCharacters === false) { |
| 122 | + $forbiddenCharacters = []; |
| 123 | + } |
| 124 | + |
| 125 | + // Get admin defined invalid characters |
| 126 | + $additionalChars = $this->config->getSystemValue('forbidden_chars', []); |
| 127 | + if (!is_array($additionalChars)) { |
| 128 | + $this->logger->error('Invalid system config value for "forbidden_chars" is ignored.'); |
| 129 | + $additionalChars = []; |
| 130 | + } |
| 131 | + $forbiddenCharacters = array_merge($forbiddenCharacters, $additionalChars); |
| 132 | + |
| 133 | + // Handle legacy config option |
| 134 | + // TODO: Drop with Nextcloud 34 |
| 135 | + $legacyForbiddenCharacters = $this->config->getSystemValue('forbidden_chars', []); |
| 136 | + if (!is_array($legacyForbiddenCharacters)) { |
| 137 | + $this->logger->error('Invalid system config value for "forbidden_chars" is ignored.'); |
| 138 | + $legacyForbiddenCharacters = []; |
| 139 | + } |
| 140 | + if (!empty($legacyForbiddenCharacters)) { |
| 141 | + $this->logger->warning('System config option "forbidden_chars" is deprecated and will be removed in Nextcloud 34, use "forbidden_filename_characters" instead.'); |
| 142 | + } |
| 143 | + $forbiddenCharacters = array_merge($legacyForbiddenCharacters, $forbiddenCharacters); |
| 144 | + |
| 145 | + $this->forbiddenCharacters = array_values($forbiddenCharacters); |
| 146 | + } |
| 147 | + return $this->forbiddenCharacters; |
| 148 | + } |
| 149 | + |
| 150 | + /** |
| 151 | + * @inheritdoc |
| 152 | + */ |
| 153 | + public function isFilenameValid(string $filename): bool { |
| 154 | + try { |
| 155 | + $this->validateFilename($filename); |
| 156 | + } catch (\OCP\Files\InvalidPathException) { |
| 157 | + return false; |
| 158 | + } |
| 159 | + return true; |
| 160 | + } |
| 161 | + |
| 162 | + /** |
| 163 | + * @inheritdoc |
| 164 | + */ |
| 165 | + public function validateFilename(string $filename): void { |
| 166 | + // Ensure we are working on the filename |
| 167 | + $filename = \OC\Files\Filesystem::normalizePath($filename); |
| 168 | + $filename = basename($filename); |
| 169 | + |
| 170 | + $trimmed = trim($filename); |
| 171 | + if ($trimmed === '') { |
| 172 | + throw new EmptyFileNameException(); |
| 173 | + } |
| 174 | + |
| 175 | + // the special directories . and .. would cause never ending recursion |
| 176 | + if ($trimmed === '.' || $trimmed === '..') { |
| 177 | + throw new ReservedWordException(); |
| 178 | + } |
| 179 | + |
| 180 | + // 255 characters is the limit on common file systems (ext/xfs) |
| 181 | + // oc_filecache has a 250 char length limit for the filename |
| 182 | + if (isset($fileName[250])) { |
| 183 | + throw new FileNameTooLongException(); |
| 184 | + } |
| 185 | + |
| 186 | + if ($this->isForbidden($filename)) { |
| 187 | + throw new ReservedWordException(); |
| 188 | + } |
| 189 | + |
| 190 | + $this->checkForbiddenExtension($filename); |
| 191 | + |
| 192 | + $this->checkForbiddenCharacters($filename); |
| 193 | + } |
| 194 | + |
| 195 | + /** |
| 196 | + * Check if the filename is forbidden |
| 197 | + * @param string $filename |
| 198 | + * @return bool True if invalid name, False otherwise |
| 199 | + */ |
| 200 | + public function isForbidden(string $filename): bool { |
| 201 | + $filename = mb_strtolower($filename); |
| 202 | + |
| 203 | + if ($filename === '') { |
| 204 | + return false; |
| 205 | + } |
| 206 | + |
| 207 | + // The name part without extension |
| 208 | + $basename = substr($filename, 0, strpos($filename, '.', 1) ?: null); |
| 209 | + // Check for forbidden filenames |
| 210 | + $forbiddenNames = $this->getForbiddenFilenames(); |
| 211 | + if (in_array($basename, $forbiddenNames)) { |
| 212 | + return true; |
| 213 | + } |
| 214 | + |
| 215 | + // Filename is not forbidden |
| 216 | + return false; |
| 217 | + } |
| 218 | + |
| 219 | + /** |
| 220 | + * Check if a filename contains any of the forbidden characters |
| 221 | + * @param string $filename |
| 222 | + * @throws InvalidCharacterInPathException |
| 223 | + */ |
| 224 | + protected function checkForbiddenCharacters(string $filename): void { |
| 225 | + $sanitizedFileName = filter_var($filename, FILTER_UNSAFE_RAW, FILTER_FLAG_STRIP_LOW); |
| 226 | + if ($sanitizedFileName !== $filename) { |
| 227 | + throw new InvalidCharacterInPathException(); |
| 228 | + } |
| 229 | + |
| 230 | + foreach ($this->getForbiddenCharacters() as $char) { |
| 231 | + if (str_contains($filename, $char)) { |
| 232 | + throw new InvalidCharacterInPathException($char); |
| 233 | + } |
| 234 | + } |
| 235 | + } |
| 236 | + |
| 237 | + /** |
| 238 | + * Check if a filename has a forbidden filename extension |
| 239 | + * @param string $filename The filename to validate |
| 240 | + * @throws InvalidPathException |
| 241 | + */ |
| 242 | + protected function checkForbiddenExtension(string $filename): void { |
| 243 | + $filename = mb_strtolower($filename); |
| 244 | + // Check for forbidden filename exten<sions |
| 245 | + $forbiddenExtensions = $this->getForbiddenExtensions(); |
| 246 | + foreach ($forbiddenExtensions as $extension) { |
| 247 | + if (str_ends_with($filename, $extension)) { |
| 248 | + throw new InvalidPathException($this->l10n->t('Invalid filename extension "%1$s"', [$extension])); |
| 249 | + } |
| 250 | + } |
| 251 | + } |
| 252 | +}; |
0 commit comments