135 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			PHP
		
	
	
	
			
		
		
	
	
			135 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			PHP
		
	
	
	
| <?php
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| 
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| namespace BookStack\Http;
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| 
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| use BookStack\Util\WebSafeMimeSniffer;
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| use Illuminate\Http\Request;
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| 
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| /**
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|  * Helper wrapper for range-based stream response handling.
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|  * Much of this used symfony/http-foundation as a reference during build.
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|  * URL: https://github.com/symfony/http-foundation/blob/v6.0.20/BinaryFileResponse.php
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|  * License: MIT license, Copyright (c) Fabien Potencier.
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|  */
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| class RangeSupportedStream
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| {
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|     protected string $sniffContent = '';
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|     protected array $responseHeaders = [];
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|     protected int $responseStatus = 200;
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| 
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|     protected int $responseLength = 0;
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|     protected int $responseOffset = 0;
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| 
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|     public function __construct(
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|         protected $stream,
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|         protected int $fileSize,
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|         Request $request,
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|     ) {
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|         $this->responseLength = $this->fileSize;
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|         $this->parseRequest($request);
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|     }
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| 
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|     /**
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|      * Sniff a mime type from the stream.
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|      */
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|     public function sniffMime(): string
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|     {
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|         $offset = min(2000, $this->fileSize);
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|         $this->sniffContent = fread($this->stream, $offset);
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| 
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|         return (new WebSafeMimeSniffer())->sniff($this->sniffContent);
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|     }
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| 
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|     /**
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|      * Output the current stream to stdout before closing out the stream.
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|      */
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|     public function outputAndClose(): void
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|     {
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|         // End & flush the output buffer, if we're in one, otherwise we still use memory.
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|         // Output buffer may or may not exist depending on PHP `output_buffering` setting.
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|         // Ignore in testing since output buffers are used to gather a response.
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|         if (!empty(ob_get_status()) && !app()->runningUnitTests()) {
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|             ob_end_clean();
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|         }
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| 
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|         $outStream = fopen('php://output', 'w');
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|         $sniffLength = strlen($this->sniffContent);
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|         $bytesToWrite = $this->responseLength;
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| 
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|         if ($sniffLength > 0 && $this->responseOffset < $sniffLength) {
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|             $sniffEnd = min($sniffLength, $bytesToWrite + $this->responseOffset);
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|             $sniffOutLength = $sniffEnd - $this->responseOffset;
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|             $sniffOutput = substr($this->sniffContent, $this->responseOffset, $sniffOutLength);
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|             fwrite($outStream, $sniffOutput);
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|             $bytesToWrite -= $sniffOutLength;
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|         } else if ($this->responseOffset !== 0) {
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|             fseek($this->stream, $this->responseOffset);
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|         }
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| 
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|         stream_copy_to_stream($this->stream, $outStream, $bytesToWrite);
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| 
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|         fclose($this->stream);
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|         fclose($outStream);
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|     }
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| 
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|     public function getResponseHeaders(): array
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|     {
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|         return $this->responseHeaders;
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|     }
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| 
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|     public function getResponseStatus(): int
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|     {
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|         return $this->responseStatus;
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|     }
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| 
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|     protected function parseRequest(Request $request): void
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|     {
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|         $this->responseHeaders['Accept-Ranges'] = $request->isMethodSafe() ? 'bytes' : 'none';
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| 
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|         $range = $this->getRangeFromRequest($request);
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|         if ($range) {
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|             [$start, $end] = $range;
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|             if ($start < 0 || $start > $end) {
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|                 $this->responseStatus = 416;
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|                 $this->responseHeaders['Content-Range'] = sprintf('bytes */%s', $this->fileSize);
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|             } elseif ($end - $start < $this->fileSize - 1) {
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|                 $this->responseLength = $end < $this->fileSize ? $end - $start + 1 : -1;
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|                 $this->responseOffset = $start;
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|                 $this->responseStatus = 206;
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|                 $this->responseHeaders['Content-Range'] = sprintf('bytes %s-%s/%s', $start, $end, $this->fileSize);
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|                 $this->responseHeaders['Content-Length'] = $end - $start + 1;
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|             }
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|         }
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| 
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|         if ($request->isMethod('HEAD')) {
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|             $this->responseLength = 0;
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|         }
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|     }
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| 
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|     protected function getRangeFromRequest(Request $request): ?array
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|     {
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|         $range = $request->headers->get('Range');
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|         if (!$range || !$request->isMethod('GET') || !str_starts_with($range, 'bytes=')) {
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|             return null;
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|         }
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| 
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|         if ($request->headers->has('If-Range')) {
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|             return null;
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|         }
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| 
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|         [$start, $end] = explode('-', substr($range, 6), 2) + [0];
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| 
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|         $end = ('' === $end) ? $this->fileSize - 1 : (int) $end;
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| 
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|         if ('' === $start) {
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|             $start = $this->fileSize - $end;
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|             $end = $this->fileSize - 1;
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|         } else {
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|             $start = (int) $start;
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|         }
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| 
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|         $end = min($end, $this->fileSize - 1);
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|         return [$start, $end];
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|     }
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| }
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