+ $matches = [];
+ $contentLength = strlen($markdown);
+ $replacements = [];
+ preg_match_all('/!\[.*?]\(.*?(data:image\/.{1,6};base64,)/', $markdown, $matches, PREG_OFFSET_CAPTURE);
+
+ foreach ($matches[1] as $base64MatchPair) {
+ [$dataUri, $index] = $base64MatchPair;
+
+ for ($i = strlen($dataUri) + $index; $i < $contentLength; $i++) {
+ $char = $markdown[$i];
+ if ($char === ')' || $char === ' ' || $char === "\n" || $char === '"') {
+ break;
+ }
+ $dataUri .= $char;
+ }
+
+ $newUrl = $this->base64ImageUriToUploadedImageUrl($dataUri);
+ $replacements[] = [$dataUri, $newUrl];
+ }
+
+ foreach ($replacements as [$dataUri, $newUrl]) {
+ $markdown = str_replace($dataUri, $newUrl, $markdown);
+ }
+
+ return $markdown;
+ }
+
+ /**
+ * Parse the given base64 image URI and return the URL to the created image instance.
+ * Returns an empty string if the parsed URI is invalid or causes an error upon upload.
+ */
+ protected function base64ImageUriToUploadedImageUrl(string $uri): string
+ {
+ $imageRepo = app()->make(ImageRepo::class);
+ $imageInfo = $this->parseBase64ImageUri($uri);
+
+ // Validate extension and content
+ if (empty($imageInfo['data']) || !ImageService::isExtensionSupported($imageInfo['extension'])) {
+ return '';
+ }
+
+ // Validate that the content is not over our upload limit
+ $uploadLimitBytes = (config('app.upload_limit') * 1000000);
+ if (strlen($imageInfo['data']) > $uploadLimitBytes) {
+ return '';
+ }
+
+ // Save image from data with a random name
+ $imageName = 'embedded-image-' . Str::random(8) . '.' . $imageInfo['extension'];
+
+ try {
+ $image = $imageRepo->saveNewFromData($imageName, $imageInfo['data'], 'gallery', $this->page->id);
+ } catch (ImageUploadException $exception) {
+ return '';
+ }
+
+ return $image->url;
+ }
+
+ /**
+ * Parse a base64 image URI into the data and extension.
+ *
+ * @return array{extension: string, data: string}
+ */
+ protected function parseBase64ImageUri(string $uri): array
+ {
+ [$dataDefinition, $base64ImageData] = explode(',', $uri, 2);
+ $extension = strtolower(preg_split('/[\/;]/', $dataDefinition)[1] ?? '');
+
+ return [
+ 'extension' => $extension,
+ 'data' => base64_decode($base64ImageData) ?: '',
+ ];
projects / bookstack / blobdiff