support for Content-Type: application/pkcs7-mime

[josch]

Hi,

I received an email with these headers:

Content-Type: application/pkcs7-mime; smime-type=enveloped-data; name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"
Content-Transfer-Encoding: base64
X-Mailer: Microsoft Outlook 16.0

The body of the mail is a big base64 encoded blob. When encoding that blob I get:

This is a multipart message in MIME format.

------=_NextPart_000_034D_01D660D6.B4137450
Content-Type: text/plain;
	charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

[message text]

------=_NextPart_000_034D_01D660D6.B4137450
Content-Type: application/pkcs7-signature;
	name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
	filename="smime.p7s"

[base64 encoded signature]
------=_NextPart_000_034D_01D660D6.B4137450--

The main problem is, that currently, when this email is in my search results, I get:

ERROR:ui:Traceback (most recent call last):
  File "/home/josch/git/alot/alot/ui.py", line 723, in apply_command
    cmd.apply(self)
  File "/home/josch/git/alot/alot/commands/globals.py", line 125, in apply
    ui.buffer_open(buffers.SearchBuffer(ui, self.query,
  File "/home/josch/git/alot/alot/ui.py", line 417, in buffer_open
    self.buffer_focus(buf)
  File "/home/josch/git/alot/alot/ui.py", line 477, in buffer_focus
    self.update()
  File "/home/josch/git/alot/alot/ui.py", line 668, in update
    self.mainloop.draw_screen()
  File "/usr/lib/python3/dist-packages/urwid/main_loop.py", line 586, in draw_screen
    canvas = self._topmost_widget.render(self.screen_size, focus=True)
  File "/usr/lib/python3/dist-packages/urwid/widget.py", line 144, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python3/dist-packages/urwid/decoration.py", line 226, in render
    canv = self._original_widget.render(size, focus=focus)
  File "/usr/lib/python3/dist-packages/urwid/widget.py", line 144, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python3/dist-packages/urwid/container.py", line 1085, in render
    body = self.body.render((maxcol, maxrow-ftrim-htrim),
  File "/home/josch/git/alot/alot/buffers/buffer.py", line 19, in render
    return self.body.render(size, focus)
  File "/usr/lib/python3/dist-packages/urwid/widget.py", line 144, in cached_render
    canv = fn(self, size, focus=focus)
  File "/usr/lib/python3/dist-packages/urwid/listbox.py", line 470, in render
    middle, top, bottom = self.calculate_visible(
  File "/usr/lib/python3/dist-packages/urwid/listbox.py", line 353, in calculate_visible
    self._set_focus_complete( (maxcol, maxrow), focus )
  File "/usr/lib/python3/dist-packages/urwid/listbox.py", line 717, in _set_focus_complete
    return self._set_focus_first_selectable(
  File "/usr/lib/python3/dist-packages/urwid/listbox.py", line 687, in _set_focus_first_selectable
    middle, top, bottom = self.calculate_visible(
  File "/usr/lib/python3/dist-packages/urwid/listbox.py", line 356, in calculate_visible
    focus_widget, focus_pos = self._body.get_focus()
  File "/home/josch/git/alot/alot/walker.py", line 39, in get_focus
    return self._get_at_pos(self.focus)
  File "/home/josch/git/alot/alot/walker.py", line 72, in _get_at_pos
    widget = self._get_next_item()
  File "/home/josch/git/alot/alot/walker.py", line 85, in _get_next_item
    next_widget = self.containerclass(next_obj, **self.kwargs)
  File "/home/josch/git/alot/alot/widgets/search.py", line 26, in __init__
    self.rebuild()
  File "/home/josch/git/alot/alot/widgets/search.py", line 60, in rebuild
    width, part = build_text_part(partname, self.thread,
  File "/home/josch/git/alot/alot/widgets/search.py", line 145, in build_text_part
    content = prepare_string(name, thread, maxw)
  File "/home/josch/git/alot/alot/widgets/search.py", line 213, in prepare_string
    s = content(thread)
  File "/home/josch/git/alot/alot/widgets/search.py", line 188, in prepare_content_string
    lastcontent = ' '.join(m.get_body_text() for m in msgs)
  File "/home/josch/git/alot/alot/widgets/search.py", line 188, in <genexpr>
    lastcontent = ' '.join(m.get_body_text() for m in msgs)
  File "/home/josch/git/alot/alot/db/message.py", line 287, in get_body_text
    return extract_body_part(self.get_mime_part())
  File "/home/josch/git/alot/alot/db/utils.py", line 499, in extract_body_part
    **{'field_key': 'view'} if body_part.get_content_type() == 'text/plain'
AttributeError: 'str' object has no attribute 'get_content_type'

And the thread will not show up at all. This is not nice.

So in this feature request, I do not want to ask for support for smime signed emails, but just for the ability to:

• have these emails show up in the search results
• be able to read the body part

Thanks!

cheers, josch