fix: binary files as part are corrupted when stripping carriage returns

src/Decode.php

@@ -22,6 +22,7 @@
 use const E_NOTICE;
 use const E_WARNING;
 use const ICONV_MIME_DECODE_CONTINUE_ON_ERROR;
+use const PREG_OFFSET_CAPTURE;
 
 class Decode
 {
@@ -37,36 +38,31 @@ class Decode
      */
     public static function splitMime($body, $boundary)
     {
-        // TODO: we're ignoring \r for now - is this function fast enough and is it safe to assume noone needs \r?
-        $body = str_replace("\r", '', $body);
-
-        $start = 0;
-        $res   = [];
+        $res = [];
         // find every mime part limiter and cut out the
         // string before it.
         // the part before the first boundary string is discarded:
-        $p = strpos($body, '--' . $boundary . "\n", $start);
-        if ($p === false) {
+        if (preg_match('/--' . $boundary . '(\r?\n)/', $body, $matches, PREG_OFFSET_CAPTURE) === 0) {
             // no parts found!
             return [];
         }
 
         // position after first boundary line
-        $start = $p + 3 + strlen($boundary);
+        $start     = $matches[0][1] + strlen($matches[0][0]);
+        $serverEOL = $matches[1][0];
 
-        while (($p = strpos($body, '--' . $boundary . "\n", $start)) !== false) {
-            $res[] = substr($body, $start, $p - $start);
-            $start = $p + 3 + strlen($boundary);
+        while (preg_match('/--' . $boundary . '\r?\n/', $body, $matches, PREG_OFFSET_CAPTURE, $start) === 1) {
+            $res[] = substr($body, $start, $matches[0][1] - $start - strlen($serverEOL));
+            $start = $matches[0][1] + strlen($matches[0][0]);
         }
 
         // no more parts, find end boundary
-        $p = strpos($body, '--' . $boundary . '--', $start);
-        if ($p === false) {
+        if (preg_match('/--' . $boundary . '--/', $body, $matches, PREG_OFFSET_CAPTURE, $start) !== 1) {
             throw new Exception\RuntimeException('Not a valid Mime Message: End Missing');
         }
 
         // the remaining part also needs to be parsed:
-        $res[] = substr($body, $start, $p - $start);
+        $res[] = substr($body, $start, $matches[0][1] - $start - strlen($serverEOL));
         return $res;
     }
 

test/MimeTest.php

@@ -246,7 +246,7 @@ public static function dataTestFromMessageDecode(): array
                 'Alle meine Entchen schwimmen in dem See, schwimmen in dem See, K=C3=B6pfche=
 n in das Wasser, Schw=C3=A4nzchen in die H=C3=B6h!',
             ],
-            ['foobar', 'base64', 'Zm9vYmFyCg=='],
+            ['foobar', 'base64', 'Zm9vYmFy'],
         ];
         // phpcs:enable
     }
@@ -257,15 +257,15 @@ public static function dataTestFromMessageDecode(): array
     public function testFromMessageDecode(string $input, string $encoding, string $result): void
     {
         $parts = Mime\Message::createFromMessage(
-            '--089e0141a1902f83ee04e0a07b7a' . "\r\n"
-            . 'Content-Type: text/plain; charset=UTF-8' . "\r\n"
-            . 'Content-Transfer-Encoding: ' . $encoding . "\r\n"
-            . "\r\n"
-            . $result . "\r\n"
+            '--089e0141a1902f83ee04e0a07b7a' . "\n"
+            . 'Content-Type: text/plain; charset=UTF-8' . "\n"
+            . 'Content-Transfer-Encoding: ' . $encoding . "\n"
+            . "\n"
+            . $result . "\n"
             . '--089e0141a1902f83ee04e0a07b7a--',
             '089e0141a1902f83ee04e0a07b7a'
         )->getParts();
-        $this->assertSame($input . "\n", $parts[0]->getRawContent());
+        $this->assertSame($input, $parts[0]->getRawContent());
     }
 
     /**

test/PartTest.php

@@ -205,4 +205,20 @@ public function testSetContentRaisesInvalidArgumentExceptionForInvalidContentTyp
         $this->expectException(Mime\Exception\InvalidArgumentException::class);
         $part->setContent($content);
     }
+
+    public function testBinaryPart()
+    {
+        $content      = file_get_contents(__DIR__ . '/TestAsset/laminas.png');
+        $inputMessage = new Mime\Message();
+        $inputMessage->addPart(new Mime\Part('Hello World'));
+        $inputMessage->addPart(new Mime\Part($content));
+
+        $outputMessage = Mime\Message::createFromMessage(
+            $inputMessage->generateMessage(),
+            $inputMessage->getMime()->boundary()
+        );
+        $parts         = $outputMessage->getParts();
+        $this->assertCount(2, $parts);
+        $this->assertEquals($content, $parts[1]->getContent());
+    }
 }