Merge pull request #116 from legionth/chunk-encoding

Decode chunked transfer encoding for incoming requests

Author: clue

src/ChunkedDecoder.php

@@ -0,0 +1,158 @@
+<?php
+namespace React\Http;
+
+use Evenement\EventEmitter;
+use React\Stream\ReadableStreamInterface;
+use React\Stream\WritableStreamInterface;
+use React\Stream\Util;
+use Exception;
+
+/** @internal */
+class ChunkedDecoder extends EventEmitter implements ReadableStreamInterface
+{
+    const CRLF = "\r\n";
+    const MAX_CHUNK_HEADER_SIZE = 1024;
+
+    private $closed = false;
+    private $input;
+    private $buffer = '';
+    private $chunkSize = 0;
+    private $transferredSize = 0;
+    private $headerCompleted = false;
+
+    public function __construct(ReadableStreamInterface $input)
+    {
+        $this->input = $input;
+
+        $this->input->on('data', array($this, 'handleData'));
+        $this->input->on('end', array($this, 'handleEnd'));
+        $this->input->on('error', array($this, 'handleError'));
+        $this->input->on('close', array($this, 'close'));
+    }
+
+    public function isReadable()
+    {
+        return !$this->closed && $this->input->isReadable();
+    }
+
+    public function pause()
+    {
+        $this->input->pause();
+    }
+
+    public function resume()
+    {
+        $this->input->resume();
+    }
+
+    public function pipe(WritableStreamInterface $dest, array $options = array())
+    {
+        Util::pipe($this, $dest, $options);
+
+        return $dest;
+    }
+
+    public function close()
+    {
+        if ($this->closed) {
+            return;
+        }
+
+        $this->buffer = '';
+
+        $this->closed = true;
+
+        $this->input->close();
+
+        $this->emit('close');
+        $this->removeAllListeners();
+    }
+
+    /** @internal */
+    public function handleEnd()
+    {
+        if (!$this->closed) {
+            $this->handleError(new \Exception('Unexpected end event'));
+        }
+    }
+
+    /** @internal */
+    public function handleError(\Exception $e)
+    {
+        $this->emit('error', array($e));
+        $this->close();
+    }
+
+    /** @internal */
+    public function handleData($data)
+    {
+        $this->buffer .= $data;
+
+        while ($this->buffer !== '') {
+            if (!$this->headerCompleted) {
+                $positionCrlf = strpos($this->buffer, static::CRLF);
+
+                if ($positionCrlf === false) {
+                    // Header shouldn't be bigger than 1024 bytes
+                    if (isset($this->buffer[static::MAX_CHUNK_HEADER_SIZE])) {
+                        $this->handleError(new \Exception('Chunk header size inclusive extension bigger than' . static::MAX_CHUNK_HEADER_SIZE. ' bytes'));
+                    }
+                    return;
+                }
+
+                $header = strtolower((string)substr($this->buffer, 0, $positionCrlf));
+                $hexValue = $header;
+
+                if (strpos($header, ';') !== false) {
+                    $array = explode(';', $header);
+                    $hexValue = $array[0];
+                }
+
+                $this->chunkSize = hexdec($hexValue);
+                if (dechex($this->chunkSize) !== $hexValue) {
+                    $this->handleError(new \Exception($hexValue . ' is not a valid hexadecimal number'));
+                    return;
+                }
+
+                $this->buffer = (string)substr($this->buffer, $positionCrlf + 2);
+                $this->headerCompleted = true;
+                if ($this->buffer === '') {
+                    return;
+                }
+            }
+
+            $chunk = (string)substr($this->buffer, 0, $this->chunkSize - $this->transferredSize);
+
+            if ($chunk !== '') {
+                $this->transferredSize += strlen($chunk);
+                $this->emit('data', array($chunk));
+                $this->buffer = (string)substr($this->buffer, strlen($chunk));
+            }
+
+            $positionCrlf = strpos($this->buffer, static::CRLF);
+
+            if ($positionCrlf === 0) {
+                if ($this->chunkSize === 0) {
+                    $this->emit('end');
+                    $this->close();
+                    return;
+                }
+                $this->chunkSize = 0;
+                $this->headerCompleted = false;
+                $this->transferredSize = 0;
+                $this->buffer = (string)substr($this->buffer, 2);
+            }
+
+            if ($positionCrlf !== 0 && $this->chunkSize === $this->transferredSize && strlen($this->buffer) > 2) {
+                // the first 2 characters are not CLRF, send error event
+                $this->handleError(new \Exception('Chunk does not end with a CLRF'));
+                return;
+            }
+
+            if ($positionCrlf !== 0 && strlen($this->buffer) < 2) {
+                // No CLRF found, wait for additional data which could be a CLRF
+                return;
+            }
+        }
+    }
+}

src/Server.php

@@ -90,7 +90,7 @@ public function handleConnection(ConnectionInterface $conn)
             $that->handleRequest($conn, $request);
 
             if ($bodyBuffer !== '') {
-                $request->emit('data', array($bodyBuffer));
+                $conn->emit('data', array($bodyBuffer));
             }
         });
 
@@ -130,6 +130,15 @@ public function handleRequest(ConnectionInterface $conn, Request $request)
             '[]'
         );
 
+        $stream = $conn;
+        if ($request->hasHeader('Transfer-Encoding')) {
+            $transferEncodingHeader = $request->getHeader('Transfer-Encoding');
+            // 'chunked' must always be the final value of 'Transfer-Encoding' according to: https://tools.ietf.org/html/rfc7230#section-3.3.1
+            if (strtolower(end($transferEncodingHeader)) === 'chunked') {
+                $stream = new ChunkedDecoder($conn);
+            }
+        }
+
         // forward pause/resume calls to underlying connection
         $request->on('pause', array($conn, 'pause'));
         $request->on('resume', array($conn, 'resume'));
@@ -141,10 +150,11 @@ public function handleRequest(ConnectionInterface $conn, Request $request)
         });
 
         // forward connection events to request
-        $conn->on('end', function () use ($request) {
+        $stream->on('end', function () use ($request) {
             $request->emit('end');
         });
-        $conn->on('data', function ($data) use ($request) {
+
+        $stream->on('data', function ($data) use ($request) {
             $request->emit('data', array($data));
         });