Multipart-Message Boundaries are empty

[DasTobbel]

Describe the bug
Got an Email, where a parsed header contains a malformed header, so that somehow the getBoundary() method is called twice and returns the correct boundary in the first run, but a empty one in the second
src/Structure.php:99:

    public function getBoundary(){
        $tmp = $this->header->find("/boundary\=\"(.*)\"/");
        \Log::debug(print_r(["getBoundary" => $tmp], true));
        return tmp;
    }
[...]
    public function find_parts(){
        if($this->type === IMAP::MESSAGE_TYPE_MULTIPART) {
            if (($boundary = $this->getBoundary()) === null)  {
                throw new MessageContentFetchingException("no content found", 0);
            }
          
            $boundaries = [
                $boundary
            ];
            \Log::debug(print_r(["boundaries" => $boundaries], true));
            if (preg_match("/boundary\=\"(.*)\"/", $this->raw, $match) == 1) {
                if(is_array($match[1])){
                    foreach($match[1] as $matched){
                        $boundaries[] = $matched;
                    }
                }else{
                    if(!empty($match[1])) {
                        $boundaries[] = $match[1];
                    }
                }
            }
            \Log::debug(print_r(["boundaries #2" => $boundaries], true));
            $raw_parts = explode( $boundaries[0], str_replace($boundaries, $boundaries[0], $this->raw) );
            $parts = [];
[...]

Log:
[2020-10-13 13:51:30] production.DEBUG: Array( [getBoundary()] => _009_VI1PR05MB57270B55FFCF7840254D7E6F95040VI1PR05MB5727eurp_ )
[2020-10-13 13:51:30] production.DEBUG: Array( [boundaries] => Array( [0] => _009_VI1PR05MB57270B55FFCF7840254D7E6F95040VI1PR05MB5727eurp_ ))
[2020-10-13 13:51:30] production.DEBUG: Array( [boundaries #2] => Array ([0] => _009_VI1PR05MB57270B55FFCF7840254D7E6F95040VI1PR05MB5727eurp_ , [1] => _000_VI1PR05MB57270B55FFCF7840254D7E6F95040VI1PR05MB5727eurp_ ))
[2020-10-13 13:51:30] production.DEBUG: Array( [getBoundary()] => null ) 
[2020-10-13 13:51:30] production.DEBUG: Array( [boundaries] => Array([0] => null ))
[2020-10-13 13:51:30] production.DEBUG: Array( [boundaries #2] => Array([0] => null ))

To Reproduce
Steps to reproduce the behavior:
Create an email where a the Header have a definition like this

Content-Language: de-DE

Content-Type: multipart/related;

	boundary="_009_VI1PR05MB57270B55FFCF7840254D7E6F95040VI1PR05MB5727eurp_";

	type="multipart/alternative"

MIME-Version: 1.0

Try to recive the said mail
Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop / Server (please complete the following information):

• OS: ubuntu 20
• PHP: 7.4
• Version 2.1.11

Additional context
Another smaller Issue was that some boundary params were set without any qoute (") markers, could be fixed with an alternation on the regex = boundary\=\"?(.*)\"?

[DasTobbel]

So i worked some time on this, i think i kinda got a fix, pull request incoming - but after my fix i get the mail as an attachment - still investigating

[DasTobbel]

Need to take a look into the Attachement Handling - i don't know why the text mail body gets handles as an attachment on my side (could be just me, need to validate)

[Webklex]

Sry didn't mean to close it..

[Webklex]

You probably mean \Webklex\PHPIMAP\Message::fetchPart() @ line 461:

$this->fetchAttachment($part);

If I remember correctly it's there because many plain text attachments don't have the required disposition and therefor get interpreted as part of the text body. But I see the problem - do you have any suggestion for a better handling?

[DasTobbel]

My best guess:
Maybe look for a filename -> If it has a filename its an attachment - if not, its a text body.
Not sure if this is any good tho...
Message.php

    private function fetchPart(Part $part) {
        if ($part->type == IMAP::MESSAGE_TYPE_TEXT && ($part->ifdisposition == 0 || (empty($part->disposition) || !in_array(strtolower($part->disposition), ['attachment', 'inline'])) ) ) {
            if (strtolower($part->subtype) == "plain" || strtolower($part->subtype) == "csv") {
                [...]
                if (isset($part->name) and !is_empty($part->name))
                    $this->fetchAttachment($part);
                } elseif (isset($part->filename) and !is_empty($part->filename))
                    $this->fetchAttachment($part);
                } else {
                    $this->bodies['text'] = $content;
                }
            } elseif {
            [..]

[DasTobbel]

Hi @Webklex,
had a email where the the Part::parseSubtype() had an array as response of $this->header->get("content-type"); if that's the case it will fetch that part as an Attachment.

To Reproduce
Steps to reproduce the behavior:
Create an email where a part has a definition of the content-type like this

--limiter
Content-Type: text/plain; 
    charset=utf-8;
Content-transfer-encoding: quoted-printable

that is my text
--limiter--

somewhat similar to #24

suggestion 1

    private function parseSubtype(){
        $content_type = $this->header->get("content-type");
        // If its an array the mime needs to be in the first array, because it's in the same line as "content-type"
        $content_type = (is_array($content_type)) ? $content_type[0] : $content_type;
        if (($pos = strpos($content_type, "/")) !== false){
            $this->subtype = substr($content_type, $pos + 1);
        }
    }

or
suggestion 2 (somewhat fail proof but unnecessary i think)

    private function parseSubtype(){
        $content_type = $this->header->get("content-type");
        if (is_array($content_type)) {
            foreach ($content_type as $part){
                if ((strpos($part, "/")) !== false){
                    $content_type = $part;
                    break;
                }
            }
        }
        if (($pos = strpos($content_type, "/")) !== false){
            $this->subtype = substr($content_type, $pos + 1);
        }
    }