Files
roundcubemail/program/lib/Roundcube/rcube_message.php
Mathias Schneider bdbfbd9074 Support early MIME types for S/MIME encrypted messages (#9973)
Co-authored-by: Mathias Schneider <thiesje@web.de>
2025-09-21 10:14:24 +02:00

1374 lines
50 KiB
PHP

<?php
/*
+-----------------------------------------------------------------------+
| This file is part of the Roundcube Webmail client |
| |
| Copyright (C) The Roundcube Dev Team |
| |
| Licensed under the GNU General Public License version 3 or |
| any later version with exceptions for skins & plugins. |
| See the README file for a full license statement. |
| |
| PURPOSE: |
| Logical representation of a mail message with all its data |
| and related functions |
+-----------------------------------------------------------------------+
| Author: Thomas Bruederli <roundcube@gmail.com> |
+-----------------------------------------------------------------------+
*/
/**
* Logical representation of a mail message with all its data
* and related functions
*/
class rcube_message
{
/**
* Instance of framework class.
*
* @var rcube
*/
protected $app;
/**
* Instance of storage class
*
* @var rcube_storage
*/
protected $storage;
/**
* Instance of mime class
*
* @var rcube_mime
*/
protected $mime;
protected $opt = [];
protected $parse_alternative = false;
protected $got_html_part = false;
protected $tnef_decode = false;
/**
* This holds a list of Content-IDs and Content-Locations by which parts of
* this message are referenced (e.g. in HTML parts).
*
* @var array
*/
protected $replacement_references = [];
public $uid;
public $folder;
public $headers;
public $sender;
public $context;
public $body;
public $subject = '';
public $is_safe = false;
public $pgp_mime = false;
public $encrypted_part;
/** @var array<rcube_message_part> */
public $parts = [];
/** @var array<rcube_message_part> */
public $mime_parts = [];
/** @var array<rcube_message_part> */
public $attachments = [];
public const BODY_MAX_SIZE = 1048576; // 1MB
/**
* __construct
*
* Provide a uid, and parse message structure.
*
* @param string $uid the message UID
* @param string $folder Folder name
* @param bool $is_safe Security flag
*/
public function __construct($uid, $folder = null, $is_safe = false)
{
// decode combined UID-folder identifier
if (preg_match('/^[0-9.]+-.+/', $uid)) {
[$uid, $folder] = explode('-', $uid, 2);
}
$context = null;
if (preg_match('/^([0-9]+)\.([0-9.]+)$/', $uid, $matches)) {
$uid = $matches[1];
$context = $matches[2];
}
$this->uid = $uid;
$this->context = $context;
$this->app = rcube::get_instance();
$this->storage = $this->app->get_storage();
$this->folder = is_string($folder) && strlen($folder) ? $folder : $this->storage->get_folder();
// Set current folder
$this->storage->set_folder($this->folder);
$this->storage->set_options(['all_headers' => true]);
$this->headers = $this->storage->get_message($uid);
if (!$this->headers) {
return;
}
$this->tnef_decode = (bool) $this->app->config->get('tnef_decode', true);
$this->set_safe($is_safe || !empty($_SESSION['safe_messages'][$this->folder . ':' . $uid]));
$this->opt = [
'safe' => $this->is_safe,
'prefer_html' => $this->app->config->get('prefer_html'),
'get_url' => $this->app->url([
'action' => 'get',
'mbox' => $this->folder,
'uid' => $uid,
],
false, false, true
),
];
$this->mime = new rcube_mime($this->headers->charset);
$this->subject = str_replace("\n", '', (string) $this->headers->get('subject'));
$from = $this->mime->decode_address_list($this->headers->from, 1);
$this->sender = current($from);
if (!empty($this->headers->structure)) {
$this->get_mime_numbers($this->headers->structure);
$this->parse_structure($this->headers->structure);
} elseif ($this->context === null) {
$this->body = $this->storage->get_body($uid);
}
// notify plugins and let them analyze this structured message object
$this->app->plugins->exec_hook('message_load', ['object' => $this]);
}
/**
* Return a (decoded) message header
*
* @param string $name Header name
* @param bool $raw Don't mime-decode the value
*
* @return string|null Header value
*/
public function get_header($name, $raw = false)
{
if (empty($this->headers)) {
return null;
}
return $this->headers->get($name, !$raw);
}
/**
* Set is_safe var and session data
*
* @param bool $safe enable/disable
*/
public function set_safe($safe = true)
{
$_SESSION['safe_messages'][$this->folder . ':' . $this->uid] = $this->is_safe = $safe;
}
/**
* Compose a valid URL for getting a message part
*
* @param string $mime_id Part MIME-ID
* @param mixed $embed Mimetype class for parts to be embedded
*
* @return string|false URL or false if part does not exist
*/
public function get_part_url($mime_id, $embed = false)
{
if (!empty($this->mime_parts[$mime_id])) {
return $this->opt['get_url'] . '&_part=' . $mime_id
. ($embed ? '&_embed=1&_mimeclass=' . $embed : '');
}
return false;
}
/**
* Get content of a specific part of this message
*
* @param string $mime_id Part MIME-ID
* @param resource $fp File pointer to save the message part
* @param bool $skip_charset_conv Disables charset conversion
* @param int $max_bytes Only read this number of bytes
* @param bool $formatted Enables formatting of text/* parts bodies
*
* @return string|bool Part content, False on error
*
* @deprecated
*/
public function get_part_content($mime_id, $fp = null, $skip_charset_conv = false, $max_bytes = 0, $formatted = true)
{
$part = $this->mime_parts[$mime_id] ?? null;
if ($part) {
// stored in message structure (winmail/inline-uuencode)
if (!empty($part->body) || $part->encoding == 'stream') {
if ($fp) {
fwrite($fp, $part->body);
}
return $fp ? true : $part->body;
}
// get from IMAP
$this->storage->set_folder($this->folder);
return $this->storage->get_message_part($this->uid, $mime_id, $part,
null, $fp, $skip_charset_conv, $max_bytes, $formatted);
}
return false;
}
/**
* Get content of a specific part of this message
*
* @param string $mime_id Part ID
* @param bool $formatted Enables formatting of text/* parts bodies
* @param int $max_bytes Only return/read this number of bytes
* @param mixed $mode NULL to return a string, -1 to print body
* or file pointer to save the body into
*
* @return string|bool Part content or operation status, False on error
*/
public function get_part_body($mime_id, $formatted = false, $max_bytes = 0, $mode = null)
{
if (empty($this->mime_parts[$mime_id])) {
return false;
}
$part = $this->mime_parts[$mime_id];
// allow plugins to modify part body
$plugin = $this->app->plugins->exec_hook('message_part_body',
['object' => $this, 'part' => $part]);
// only text parts can be formatted
$formatted = $formatted && $part->ctype_primary == 'text';
// part body not fetched yet... save in memory if it's small enough
if ($part->body === null && is_numeric($mime_id) && $part->size < self::BODY_MAX_SIZE) {
$this->storage->set_folder($this->folder);
// Warning: body here should be always unformatted
$body = $this->storage->get_message_part($this->uid, $mime_id, $part, null, null, true, 0, false);
if ($body === false) {
return false;
}
$part->body = $body;
}
$charset = !empty($this->headers) ? $this->headers->charset : null;
// body stored in message structure (winmail/inline-uuencode)
if (is_string($part->body) || $part->encoding == 'stream') {
$body = $part->body;
if ($formatted) {
$body = self::format_part_body($body, $part, $charset);
}
if ($max_bytes && strlen($body) > $max_bytes) {
$body = substr($body, 0, $max_bytes);
}
if (is_resource($mode)) {
fwrite($mode, $body);
@rewind($mode);
return true;
}
if ($mode === -1) {
echo $body;
return true;
}
return $body;
}
// get the body from IMAP
$this->storage->set_folder($this->folder);
$body = $this->storage->get_message_part($this->uid, $mime_id, $part,
$mode === -1, is_resource($mode) ? $mode : null,
!($mode && $formatted), $max_bytes, $mode && $formatted);
if (is_resource($mode)) {
@rewind($mode);
return $body !== false;
}
if (!$mode && is_string($body) && $formatted) {
$body = self::format_part_body($body, $part, $charset);
}
return $body;
}
/**
* Format text message part for display
*
* @param string $body Part body
* @param rcube_message_part $part Part object
* @param string $default_charset Fallback charset if part charset is not specified
*
* @return string Formatted body
*/
public static function format_part_body($body, $part, $default_charset = null)
{
// remove useless characters
$body = preg_replace('/[\t\r\0\x0B]+\n/', "\n", $body);
// remove NULL characters if any (#1486189)
if (str_contains($body, "\x00")) {
$body = str_replace("\x00", '', $body);
}
// detect charset...
if (empty($part->charset) || strtoupper($part->charset) == 'US-ASCII') {
// try to extract charset information from HTML meta tag (#1488125)
if ($part->ctype_secondary == 'html' && preg_match('/<meta[^>]+charset=([a-z0-9-_]+)/i', $body, $m)) {
$part->charset = strtoupper($m[1]);
} elseif ($default_charset) {
$part->charset = $default_charset;
} else {
$rcube = rcube::get_instance();
$part->charset = $rcube->config->get('default_charset', RCUBE_CHARSET);
}
}
// ..convert charset encoding
$body = rcube_charset::convert($body, $part->charset);
return $body;
}
/**
* Determine if the message contains a HTML part. This must to be
* a real part not an attachment (or its part)
*
* @param bool $check_convertible Enables checking for text/enriched or markdown parts, too
* @param rcube_message_part|null &$ref Reference to the part if found
*
* @return bool True if a HTML is available, False if not
*/
public function has_html_part($check_convertible = false, &$ref = null)
{
// check all message parts
foreach ($this->mime_parts as $part) {
if ($part->mimetype == 'text/html' || ($check_convertible && ($part->mimetype == 'text/enriched' || $part->mimetype === 'text/markdown' || $part->mimetype === 'text/x-markdown'))) {
// Skip if part is an attachment, don't use is_attachment() here
if ($part->filename) {
continue;
}
if (!$part->size) {
continue;
}
if (!$this->check_context($part)) {
continue;
}
// The HTML body part extracted from a winmail.dat attachment part
if (str_starts_with($part->mime_id, 'winmail.')) {
$ref = $part;
return true;
}
$level = explode('.', $part->mime_id);
$depth = count($level);
$last = '';
// Check if the part does not belong to a message/rfc822 part
// @phpstan-ignore-next-line
while (array_pop($level) !== null) {
if (!count($level)) {
break;
}
$parent = $this->mime_parts[implode('.', $level)];
if (!$this->check_context($parent)) {
break;
}
if ($parent->mimetype == 'message/rfc822') {
continue 2;
}
}
$ref = $part;
return true;
}
}
return false;
}
/**
* Determine if the message contains a text/plain part. This must to be
* a real part not an attachment (or its part)
*
* @param ?rcube_message_part &$ref Reference to the part if found
*
* @return bool True if a plain text part is available, False if not
*/
public function has_text_part(&$ref = null)
{
// check all message parts
foreach ($this->mime_parts as $part) {
if ($part->mimetype == 'text/plain') {
// Skip if part is an attachment, don't use is_attachment() here
if (!empty($part->filename)) {
continue;
}
if (empty($part->size)) {
continue;
}
if (!$this->check_context($part)) {
continue;
}
$level = explode('.', $part->mime_id);
// Check if the part does not belong to a message/rfc822 part
// @phpstan-ignore-next-line
while (array_pop($level) !== null) {
if (!count($level)) {
break;
}
$parent = $this->mime_parts[implode('.', $level)];
if (!$this->check_context($parent)) {
break;
}
if ($parent->mimetype == 'message/rfc822') {
continue 2;
}
}
$ref = $part;
return true;
}
}
return false;
}
/**
* Return the first HTML part of this message
*
* @param rcube_message_part &$part Reference to the part if found
* @param bool $check_convertible Enables checking for text/enriched or markdown parts, too
*
* @return string|null HTML message part content
*/
public function first_html_part(&$part = null, $check_convertible = false)
{
if ($this->has_html_part($check_convertible, $part)) {
$body = $this->get_part_body($part->mime_id, true);
if ($part->mimetype == 'text/enriched') {
$body = rcube_enriched::to_html($body);
} elseif ($part->mimetype == 'text/markdown' || $part->mimetype == 'text/x-markdown') {
$body = rcube_markdown::to_html($body);
}
return $body;
}
return null;
}
/**
* Return the first text part of this message.
* If there's no text/plain part but $strict=true and text/html part
* exists, it will be returned in text/plain format.
*
* @param rcube_message_part &$part Reference to the part if found
* @param bool $strict Check only text/plain parts
*
* @return string|null Plain text message/part content
*/
public function first_text_part(&$part = null, $strict = false)
{
// no message structure, return complete body
if (empty($this->parts)) {
return $this->body;
}
if ($this->has_text_part($part)) {
return $this->get_part_body($part->mime_id, true);
}
if (!$strict && ($body = $this->first_html_part($part, true))) {
// create instance of html2text class
$h2t = new rcube_html2text($body);
return $h2t->get_text();
}
return null;
}
/**
* Return message parts in current context
*
* @return array<rcube_message_part> Message parts
*/
public function mime_parts()
{
if ($this->context === null) {
return $this->mime_parts;
}
$parts = [];
foreach ($this->mime_parts as $part_id => $part) {
if ($this->check_context($part)) {
$parts[$part_id] = $part;
}
}
return $parts;
}
/**
* Checks if part of the message is an attachment (or part of it)
*
* @param rcube_message_part $part Message part
*
* @return bool True if the part is an attachment part
*/
public function is_attachment($part)
{
foreach ($this->attachments as $att_part) {
if ($att_part->mime_id === $part->mime_id) {
return true;
}
// check if the part is a subpart of another attachment part (message/rfc822)
if ($att_part->mimetype == 'message/rfc822') {
if (in_array($part, (array) $att_part->parts)) {
return true;
}
}
}
return false;
}
private function parse_html_for_replacement_references(rcube_message_part $part): array
{
// Check if the part is actually referenced in a text/html-part sibling
// (i.e. that is part of the same `$part`).
$html_parts = $this->find_html_parts($part);
if (empty($html_parts)) {
return [];
}
// Note: There might be more than one HTML part, thus we use a callback
// and concatenate the results.
$html_content = implode('', array_map(function ($html_part) { return $this->get_part_body($html_part->mime_id); }, $html_parts));
$referenced_content_identifiers = [];
$replacements = [];
// TODO: recursion.
// TODO: only get replacements from siblings
foreach ($this->mime_parts as $mime_part) {
$replacements = array_merge($replacements, array_keys($mime_part->replaces));
}
foreach ($replacements as $content_identifier) {
// Is the Content-Id or Content-Location used?
// TODO: match Content-Location more strictly. E.g. "image.jpg" is a
// valid value here, too, which can easily be matched wrongly
// currently.
if (str_contains($html_content, $content_identifier)) {
$referenced_content_identifiers[] = preg_replace('/^cid:/', '', $content_identifier);
}
}
return $referenced_content_identifiers;
}
/**
* Get a cached list of replacement references, which are collected during
* parsing from Content-Id and Content-Location headers of mime-parts.
*/
protected function get_replacement_references(rcube_message_part $part): array
{
if (!isset($this->replacement_references[$part->mime_id])) {
$this->replacement_references[$part->mime_id] = $this->parse_html_for_replacement_references($part);
}
return $this->replacement_references[$part->mime_id];
}
/**
* Checks if a given message part is referred to from another message part.
* Usually this happens if an HTML-part includes images to show inline, but
* technically there can be other cases, too.
* In any case, an attachment that is *not* referred to, shall be shown to
* the users (either in/after the message body or as downloadable file).
*
* @param rcube_message_part $part Message part
*
* @return bool True if the part is an attachment part
*/
public function is_referred_attachment(rcube_message_part $part): bool
{
// This code is intentionally verbose to keep it comprehensible.
$references = $this->get_replacement_references($part);
// Filter out attachments that are referenced by their Content-ID in
// another mime-part.
if (!empty($part->content_id) && in_array($part->content_id, $references)) {
return true;
}
// Filter out attachments that are referenced by their Content-Location
// in another mime-part.
if (!empty($part->content_location) && in_array($part->content_location, $references)) {
return true;
}
return false;
}
/**
* In a multipart/encrypted encrypted message,
* find the encrypted message payload part.
*
* @return rcube_message_part|null
*/
public function get_multipart_encrypted_part()
{
foreach ($this->mime_parts as $mime_id => $mpart) {
if ($mpart->mimetype == 'multipart/encrypted') {
$this->pgp_mime = true;
}
if ($this->pgp_mime && ($mpart->mimetype == 'application/octet-stream'
|| (!empty($mpart->filename) && $mpart->filename != 'version.txt'))
) {
$this->encrypted_part = $mime_id;
return $mpart;
}
}
return null;
}
/**
* Read the message structure returned by the IMAP server
* and build flat lists of content parts and attachments
*
* @param rcube_message_part $structure Message structure node
* @param bool $recursive True when called recursively
*/
private function parse_structure($structure, $recursive = false)
{
// real content-type of message/rfc822 part
if ($structure->mimetype == 'message/rfc822' && !empty($structure->real_mimetype)) {
$mimetype = $structure->real_mimetype;
// parse headers from message/rfc822 part
if (!isset($structure->headers['subject']) && !isset($structure->headers['from'])) {
$part_body = $this->get_part_body($structure->mime_id, false, 32768);
if (str_contains($part_body, "\r\n\r\n")) {
[$headers] = explode("\r\n\r\n", $part_body, 2);
}
$structure->headers = rcube_mime::parse_headers($headers);
if ($this->context === $structure->mime_id) {
$this->headers = rcube_message_header::from_array($structure->headers);
}
// For small text messages we can optimize, so an additional FETCH is not needed
if ($structure->size < 32768) {
$decoder = new rcube_mime_decode();
$decoded = $decoder->decode($part_body);
// Non-multipart message
if (isset($decoded->body) && count($structure->parts) == 1) {
$structure->parts[0]->body = $decoded->body;
}
// Multipart message
else {
foreach ($decoded->parts as $idx => $p) {
if (array_key_exists($idx, $structure->parts)) {
$structure->parts[$idx]->body = $p->body;
}
}
}
}
}
} else {
$mimetype = $structure->mimetype;
}
// show message headers
if (
$recursive
&& (
isset($structure->headers['subject'])
|| !empty($structure->headers['from'])
|| !empty($structure->headers['to'])
)
) {
$c = new rcube_message_part();
$c->type = 'headers';
$c->headers = $structure->headers;
$this->add_part($c);
}
// Allow plugins to handle message parts
$plugin = $this->app->plugins->exec_hook('message_part_structure', [
'object' => $this,
'structure' => $structure,
'mimetype' => $mimetype,
'recursive' => $recursive,
]);
if ($plugin['abort']) {
return;
}
/** @var rcube_message_part $structure */
$structure = $plugin['structure'];
$mimetype = $plugin['mimetype'];
$recursive = $plugin['recursive'];
[$message_ctype_primary, $message_ctype_secondary] = explode('/', $mimetype);
// print body if message doesn't have multiple parts
if ($message_ctype_primary == 'text' && !$recursive) {
// parts with unsupported type add to attachments list
if (!in_array($message_ctype_secondary, ['plain', 'html', 'enriched', 'markdown', 'x-markdown'])) {
$this->add_attachment($structure);
return;
}
$structure->type = 'content';
$this->add_part($structure);
// Parse simple (plain text) message body
if ($message_ctype_secondary == 'plain') {
foreach ((array) $this->uu_decode($structure) as $uupart) {
$this->mime_parts[$uupart->mime_id] = $uupart;
$this->add_attachment($uupart);
}
}
}
// the same for pgp signed messages
elseif ($mimetype == 'application/pgp' && !$recursive) {
$structure->type = 'content';
$this->add_part($structure);
}
// message contains (more than one!) alternative parts
elseif ($mimetype == 'multipart/alternative' && count($structure->parts) > 1) {
// get html/plaintext parts, other add to attachments list
foreach ($structure->parts as $p => $sub_part) {
$sub_mimetype = $sub_part->mimetype;
$is_multipart = preg_match('/^multipart\/(related|relative|mixed|alternative)/', $sub_mimetype);
// skip empty text parts
if (!$sub_part->size && !$is_multipart) {
continue;
}
// We've encountered (malformed) messages with more than
// one text/plain or text/html part here. There's no way to choose
// which one is better, so we'll display first of them and add
// others as attachments (#1489358)
// check if sub part is
if ($is_multipart) {
$related_part = $p;
} elseif ($sub_mimetype == 'text/plain' && !isset($plain_part)) {
$plain_part = $p;
} elseif ($sub_mimetype == 'text/html' && !isset($html_part)) {
$html_part = $p;
$this->got_html_part = true;
} elseif ($sub_mimetype == 'text/enriched' && !isset($enriched_part)) {
$enriched_part = $p;
} elseif (($sub_mimetype === 'text/markdown' || $sub_mimetype === 'text/x-markdown') && !isset($markdown_part)) {
$markdown_part = $p;
} else {
// add unsupported/unrecognized parts to attachments list
$this->add_attachment($sub_part);
}
}
// parse related part (alternative part could be in here)
if (isset($related_part) && !$this->parse_alternative) {
$this->parse_alternative = true;
$this->parse_structure($structure->parts[$related_part], true);
$this->parse_alternative = false;
// if plain part was found, we should unset it if html is preferred
if (!empty($this->opt['prefer_html']) && count($this->parts)) {
$plain_part = null;
}
}
// choose html/plain part to print
$print_part = null;
if (isset($html_part) && !empty($this->opt['prefer_html'])) {
$print_part = $structure->parts[$html_part];
} elseif (isset($enriched_part)) {
$print_part = $structure->parts[$enriched_part];
} elseif (isset($markdown_part)) {
$print_part = $structure->parts[$markdown_part];
} elseif (isset($plain_part)) {
$print_part = $structure->parts[$plain_part];
}
// add the right message body
if (is_object($print_part)) {
$print_part->type = 'content';
// Allow plugins to handle also this part
$plugin = $this->app->plugins->exec_hook('message_part_structure', [
'object' => $this,
'structure' => $print_part,
'mimetype' => $print_part->mimetype,
'recursive' => true,
]);
if (!$plugin['abort']) {
$this->add_part($print_part);
}
}
// show plaintext warning
elseif (isset($html_part) && empty($this->parts)) {
$c = new rcube_message_part();
$c->type = 'content';
$c->ctype_primary = 'text';
$c->ctype_secondary = 'plain';
$c->mimetype = 'text/plain';
$c->realtype = 'text/html';
$this->add_part($c);
}
}
// this is an encrypted message -> create a plaintext body with the according message
elseif ($mimetype == 'multipart/encrypted') {
$p = new rcube_message_part();
$p->type = 'content';
$p->ctype_primary = 'text';
$p->ctype_secondary = 'plain';
$p->mimetype = 'text/plain';
$p->realtype = 'multipart/encrypted';
$p->mime_id = $structure->mime_id;
$this->add_part($p);
// add encrypted payload part as attachment
if (!empty($structure->parts)) {
for ($i = 0; $i < count($structure->parts); $i++) {
$subpart = $structure->parts[$i];
if ($subpart->mimetype == 'application/octet-stream' || !empty($subpart->filename)) {
$this->add_attachment($subpart);
}
}
}
}
// this is an S/MIME encrypted message -> create a plaintext body with the according message
elseif ($mimetype == 'application/pkcs7-mime' || $mimetype == 'application/x-pkcs7-mime') {
$p = new rcube_message_part();
$p->type = 'content';
$p->ctype_primary = 'text';
$p->ctype_secondary = 'plain';
$p->mimetype = 'text/plain';
$p->realtype = 'application/pkcs7-mime';
$p->mime_id = $structure->mime_id;
$this->add_part($p);
if (!empty($structure->filename)) {
$this->add_attachment($structure);
}
}
// message contains multiple parts
elseif (!empty($structure->parts)) {
// iterate over parts
foreach ($structure->parts as $mail_part) {
$primary_type = $mail_part->ctype_primary;
$secondary_type = $mail_part->ctype_secondary;
$part_mimetype = $mail_part->mimetype;
// multipart/alternative or message/rfc822
if ($primary_type == 'multipart' || $part_mimetype == 'message/rfc822') {
// list message/rfc822 as attachment as well
if ($part_mimetype == 'message/rfc822') {
$this->add_attachment($mail_part);
}
$this->parse_structure($mail_part, true);
}
// part text/[plain|html] or delivery status
elseif ((in_array($part_mimetype, ['text/plain', 'text/html', 'text/markdown', 'text/x-markdown']) && $mail_part->disposition != 'attachment')
|| in_array($part_mimetype, ['message/delivery-status', 'text/rfc822-headers', 'message/disposition-notification'])
) {
// Allow plugins to handle also this part
$plugin = $this->app->plugins->exec_hook('message_part_structure', [
'object' => $this,
'structure' => $mail_part,
'mimetype' => $part_mimetype,
'recursive' => true,
]);
if ($plugin['abort']) {
continue;
}
if ($part_mimetype == 'text/html' && $mail_part->size) {
$this->got_html_part = true;
}
$mail_part = $plugin['structure'];
[$primary_type, $secondary_type] = explode('/', $plugin['mimetype']);
// add text part if it matches the prefs
if (!$this->parse_alternative
|| ($secondary_type == 'html' && $this->opt['prefer_html'])
|| ($secondary_type == 'plain' && !$this->opt['prefer_html'])
) {
$mail_part->type = 'content';
$this->add_part($mail_part);
}
// list as attachment as well
if (!empty($mail_part->filename)) {
$this->add_attachment($mail_part);
}
}
// ignore "virtual" protocol parts
elseif ($primary_type == 'protocol') {
continue;
}
// part is Microsoft Outlook TNEF (winmail.dat)
// Note: It can be application/ms-tnef or application/vnd.ms-tnef
elseif ($primary_type == 'application' && str_contains($secondary_type, 'ms-tnef')
&& $this->tnef_decode
) {
$tnef_parts = (array) $this->tnef_decode($mail_part);
foreach ($tnef_parts as $tpart) {
$this->mime_parts[$tpart->mime_id] = $tpart;
if (strpos($tpart->mime_id, '.html')) {
if ($this->opt['prefer_html']) {
$tpart->type = 'content';
// Reset type on the plain text part that usually is added to winmail.dat messages
// (on the same level in the structure as the attachment itself)
$level = count(explode('.', $mail_part->mime_id));
foreach ($this->parts as $p) {
if ($p->type == 'content' && $p->mimetype == 'text/plain'
&& count(explode('.', $p->mime_id)) == $level
) {
$p->type = null;
}
}
}
$this->add_part($tpart);
} else {
$this->add_attachment($tpart);
}
}
// add winmail.dat to the list if it's content is unknown
if (empty($tnef_parts) && !empty($mail_part->filename)) {
$this->mime_parts[$mail_part->mime_id] = $mail_part;
$this->add_attachment($mail_part);
}
}
// part is a file/attachment
elseif (
preg_match('/^(inline|attach)/', $mail_part->disposition)
|| !empty($mail_part->headers['content-id'])
|| ($mail_part->filename
&& (empty($mail_part->disposition) || preg_match('/^[a-z0-9!#$&.+^_-]+$/i', $mail_part->disposition)))
) {
// skip apple resource forks
if ($message_ctype_secondary == 'appledouble' && $secondary_type == 'applefile') {
continue;
}
if (!empty($mail_part->headers['content-id'])) {
$mail_part->content_id = preg_replace(['/^</', '/>$/'], '', $mail_part->headers['content-id']);
}
if (!empty($mail_part->headers['content-location'])) {
$mail_part->content_location = '';
if (!empty($mail_part->headers['content-base'])) {
$mail_part->content_location = $mail_part->headers['content-base'];
}
$mail_part->content_location .= $mail_part->headers['content-location'];
}
// application/smil message's are known to use inline images that aren't really inline (#8870)
// TODO: This code probably does not belong here. I.e. we should not default to
// disposition=inline in rcube_imap::structure_part().
if ($primary_type === 'image'
&& !empty($structure->ctype_parameters['type'])
&& $structure->ctype_parameters['type'] === 'application/smil'
) {
$mail_part->disposition = 'attachment';
}
// part belongs to a related message
// Note: mixed is not supposed to contain inline images, but we've found such examples (#5905)
if (preg_match('/^multipart\/(related|relative|mixed)/', $mimetype)) {
$this->add_attachment($mail_part);
continue;
}
// Any non-inline attachment
if (!preg_match('/^inline/i', $mail_part->disposition) || empty($mail_part->headers['content-id'])) {
// Content-Type name regexp according to RFC4288.4.2
if (!preg_match('/^[a-z0-9!#$&.+^_-]+\/[a-z0-9!#$&.+^_-]+$/i', $part_mimetype)) {
// replace malformed content type with application/octet-stream (#1487767)
$mail_part->ctype_primary = 'application';
$mail_part->ctype_secondary = 'octet-stream';
$mail_part->mimetype = 'application/octet-stream';
}
$this->add_attachment($mail_part);
}
}
// calendar part not marked as attachment (#1490325)
elseif ($part_mimetype == 'text/calendar') {
if (!$mail_part->filename) {
$mail_part->filename = 'calendar.ics';
}
$this->add_attachment($mail_part);
}
// Last resort, non-text and non-multipart part of multipart/mixed message (#7117)
elseif ($mimetype == 'multipart/mixed'
&& $primary_type && $primary_type != 'text' && $primary_type != 'multipart'
) {
$this->add_attachment($mail_part);
}
}
// if this is a related part try to resolve references
// Note: mixed is not supposed to contain inline images, but we've found such examples (#5905)
if (preg_match('/^multipart\/(related|relative|mixed)/', $mimetype)) {
$a_replaces = [];
foreach ($this->attachments as $attachment) {
$part_url = $this->get_part_url($attachment->mime_id, $attachment->ctype_primary);
// We did not yet check if the values of these
// Content-Id/Content-Location headers are actually present in
// the corresponding HTML part body, because it's too expensive
// right now.
// Storing the replacement references just in case.
if (isset($attachment->content_id)) {
$a_replaces['cid:' . $attachment->content_id] = $part_url;
}
if (!empty($attachment->content_location)) {
$a_replaces[$attachment->content_location] = $part_url;
}
}
// add replace array to each content part
// (will be applied later when part body is available)
foreach ($this->parts as $i => $part) {
if ($part->type == 'content') {
$this->parts[$i]->replaces = $a_replaces;
}
}
}
}
// message is a single part non-text
elseif ($structure->filename || preg_match('/^application\//i', $mimetype)) {
$this->add_attachment($structure);
}
}
private function find_parent_part($child_part, $start_part)
{
$parts = $start_part->mime_parts ?? $start_part->parts;
foreach ($parts as $mime_part) {
if ($mime_part->mime_id === $child_part->mime_id) {
return $start_part;
} elseif (!empty($mime_part->parts)) {
return $this->find_parent_part($child_part, $mime_part);
}
}
}
private function find_html_parts($initial_part)
{
// Find the parent part of the initial part.
$parent_part = $this->find_parent_part($initial_part, $this);
if (empty($parent_part)) {
// Shouldn't happen, but who knows...
// TODO: handle this error more explicitly?
return [];
}
$html_parts = [];
foreach ($parent_part->parts as $child_part) {
if ($child_part->mimetype === 'text/html') {
$html_parts[] = $child_part;
}
}
return $html_parts;
}
/**
* Fill a flat array with references to all parts, indexed by part numbers
*
* @param rcube_message_part $part Message body structure
*/
private function get_mime_numbers(&$part)
{
if (strlen($part->mime_id)) {
$this->mime_parts[$part->mime_id] = &$part;
}
for ($i = 0; $i < count($part->parts); $i++) {
$this->get_mime_numbers($part->parts[$i]);
}
}
/**
* Add a part to the list of attachments (with context check)
*
* @param rcube_message_part $part Message part
*/
private function add_attachment($part)
{
if ($this->check_context($part)) {
// It may happen that we add the same part to the array many times
// use part ID index to prevent from duplicates
$this->attachments[$part->mime_id] = $part;
}
}
/**
* Add a part to object parts array(s) (with context check)
*
* @param rcube_message_part $part Message part
*/
private function add_part($part)
{
if ($this->check_context($part)) {
$this->parts[] = $part;
}
}
/**
* Check if specified part belongs to the current context
*
* @param rcube_message_part $part Message part
*
* @return bool True if the part belongs to the current context, False otherwise
*/
private function check_context($part)
{
return $this->context === null || str_starts_with($part->mime_id, $this->context . '.');
}
/**
* Decode a Microsoft Outlook TNEF part (winmail.dat)
*
* @param rcube_message_part $part Message part to decode
*
* @return rcube_message_part[] List of message parts extracted from TNEF
*/
public function tnef_decode(&$part)
{
// @TODO: attachment may be huge, handle body via file
$body = $this->get_part_body($part->mime_id);
$tnef = new rcube_tnef_decoder();
$tnef_arr = $tnef->decompress($body, true);
$parts = [];
unset($body);
// HTML body
if (!empty($tnef_arr['message'])) {
$tpart = new rcube_message_part();
$tpart->encoding = 'stream';
$tpart->ctype_primary = 'text';
$tpart->ctype_secondary = 'html';
$tpart->mimetype = 'text/html';
$tpart->mime_id = 'winmail.' . $part->mime_id . '.html';
$tpart->size = strlen($tnef_arr['message']);
$tpart->body = $tnef_arr['message'];
$tpart->charset = RCUBE_CHARSET;
$parts[] = $tpart;
}
// Attachments
foreach ($tnef_arr['attachments'] as $pid => $winatt) {
$tpart = new rcube_message_part();
$tpart->filename = $this->fix_attachment_name(trim($winatt['name']), $part);
$tpart->encoding = 'stream';
$tpart->ctype_primary = trim(strtolower($winatt['type']));
$tpart->ctype_secondary = trim(strtolower($winatt['subtype']));
$tpart->mimetype = $tpart->ctype_primary . '/' . $tpart->ctype_secondary;
$tpart->mime_id = 'winmail.' . $part->mime_id . '.' . $pid;
$tpart->size = $winatt['size'] ?? 0;
$tpart->body = $winatt['stream'];
if (!empty($winatt['content-id'])) {
$tpart->content_id = $winatt['content-id'];
}
$parts[] = $tpart;
unset($tnef_arr[$pid]);
}
return $parts;
}
/**
* Parse message body for UUencoded attachments bodies
*
* @param rcube_message_part $part Message part to decode
*
* @return rcube_message_part[] List of message parts extracted from the file
*/
public function uu_decode(&$part)
{
// @TODO: messages may be huge, handle body via file
$part->body = $this->get_part_body($part->mime_id);
$parts = [];
$pid = 0;
// FIXME: line length is max.65?
$uu_regexp_begin = '/begin [0-7]{3,4} ([^\r\n]+)\r?\n/s';
$uu_regexp_end = '/`\r?\nend((\r?\n)|($))/s';
while (preg_match($uu_regexp_begin, $part->body, $matches, \PREG_OFFSET_CAPTURE)) {
$startpos = $matches[0][1];
if (!preg_match($uu_regexp_end, $part->body, $m, \PREG_OFFSET_CAPTURE, $startpos)) {
break;
}
$endpos = $m[0][1];
$begin_len = strlen($matches[0][0]);
$end_len = strlen($m[0][0]);
// extract attachment body
$filebody = substr($part->body, $startpos + $begin_len, $endpos - $startpos - $begin_len - 1);
$filebody = str_replace("\r\n", "\n", $filebody);
// remove attachment body from the message body
$part->body = substr_replace($part->body, '', $startpos, $endpos + $end_len - $startpos);
// mark body as modified so it will not be cached by rcube_imap_cache
$part->body_modified = true;
// add attachments to the structure
$uupart = new rcube_message_part();
$uupart->filename = trim($matches[1][0]);
$uupart->encoding = 'stream';
$uupart->body = convert_uudecode($filebody);
$uupart->size = strlen($uupart->body);
$uupart->mime_id = 'uu.' . $part->mime_id . '.' . $pid;
$ctype = rcube_mime::file_content_type($uupart->body, $uupart->filename, 'application/octet-stream', true);
$uupart->mimetype = $ctype;
[$uupart->ctype_primary, $uupart->ctype_secondary] = explode('/', $ctype);
$parts[] = $uupart;
$pid++;
}
return $parts;
}
/**
* Fix attachment name encoding if needed and possible
*
* @param string $name Attachment name
* @param rcube_message_part $part Message part
*
* @return string Fixed attachment name
*/
protected function fix_attachment_name($name, $part)
{
if ($name == rcube_charset::clean($name)) {
return $name;
}
$charsets = [];
// find charset from part or its parent(s)
if ($part->charset) {
$charsets[] = $part->charset;
} else {
// check first part (common case)
$n = strpos($part->mime_id, '.') ? preg_replace('/\.[0-9]+$/', '', $part->mime_id) . '.1' : 1;
$_part = $this->mime_parts[$n] ?? null;
if ($_part && $_part->charset) {
$charsets[] = $_part->charset;
}
// check parents' charset
$items = explode('.', $part->mime_id);
for ($i = count($items) - 1; $i > 0; $i--) {
array_pop($items);
$parent = $this->mime_parts[implode('.', $items)] ?? null;
if ($parent && $parent->charset) {
$charsets[] = $parent->charset;
}
}
}
if ($this->headers->charset) {
$charsets[] = $this->headers->charset;
}
if ($charset = rcube_charset::check($name, $charsets)) {
$name = rcube_charset::convert($name, $charset);
$part->charset = $charset;
}
return $name;
}
/**
* Deprecated methods (to be removed)
*/
public static function unfold_flowed($text)
{
return rcube_mime::unfold_flowed($text);
}
public static function format_flowed($text, $length = 72)
{
return rcube_mime::format_flowed($text, $length);
}
}