GpgOL: encrypted PGP/Inline email fails when using exchange online
Closed, ResolvedPublic

Description

Using Outlook (32 bit) as part of O365 ProPlus. Version 1708 (build 8431.2107 Click to Run), connected to Exchange Online. Windows 10 64 bit.

Kleopatra v3.0.1-gpg4win-3.0.2, GpgOL v2.0.5

S/MIME support is not enabled, Send OpenPGP mails without attachments as PGP/Inline is enabled.

I can successfully send a signed email to an external recipient.

If I try and send an encrypted email, I get a bounce back from the Exchange Server, with the following message:

'550 5.6.0 M2MCVT.StorageError.Exception: ConversionFailedException, Content conversion: Invalid S/MIME encrypted message.; storage error in content conversion.

Details

Commits
rO39f1abce9009: Change PGP/Inline behavior
Version
GpgOL v2.0.5
Lloyd created this task.Jan 2 2018, 5:31 PM
Lloyd created this object in space S1 Public.
Lloyd renamed this task from gpgol encrypted email fails when using exchange onlone to gpgol encrypted email fails when using exchange online.Jan 2 2018, 5:39 PM
fyu12136 closed this task as Resolved.Jan 3 2018, 8:49 AM
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This comment was removed by werner.
werner removed fyu12136 as the assignee of this task.Jan 3 2018, 9:27 AM
werner reopened this task as Open.
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Mak added a subscriber: Mak.Jan 6 2018, 10:52 AM
aheinecke triaged this task as High priority.Jan 8 2018, 8:56 AM
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Prio High as this makes GpgOL unusable in such a setup.

I need to test this. It's weird that just signing works as this uses the same MAPI to MIME conversion as we use with encrypted messages. Maybe we need to change the message class to something else.

My next step is to try to reproduce this in my development environment.

aheinecke lowered the priority of this task from High to Normal.Jan 8 2018, 3:25 PM

I can reproduce the issue but only for PGP/Inline, encrypted only mails. PGP/MIME works finde. This allows for an easy workaround (sending PGP MIME) so Prio down to Normal.

I have a good guess why this problem occurs as our MAPI to MIME conversion for PGP/Inline does indeed not construct an encrypted message. Sadly a fix for this is a bit involved and needs to be tested against Google Sync Accounts (for which the current code was mostly implemented).

aheinecke renamed this task from gpgol encrypted email fails when using exchange online to GpgOL: encrypted PGP/Inline email fails when using exchange online.Jan 8 2018, 3:34 PM
aheinecke added a project: gpg4win.
Lloyd added a comment.Jan 9 2018, 9:55 AM

I can confirm that PGP/MIME works ok for me.

aheinecke closed this task as Resolved.

I've changed the behavior now so that PGP/Inline also works with Exchange Online.

If you like to confirm the fix you can replace your gpgol.dll with the 2.0.6-beta9 from https://files.gpg4win.org/Beta/gpgol/

Lloyd added a comment.Jan 11 2018, 9:50 AM

I can confirm that this appears to be fixed in 2.0.6-beta9.

Thanks for the fast response.

Mak added a comment.Jan 11 2018, 2:09 PM

I can also confirm that 2.0.6-beta9 fixes my issue with this too. Also with my own exchange server!

Remote Server returned '550 5.6.0 M2MCVT.StorageError.Exception: ConversionFailedException, Content conversion: Invalid S/MIME encrypted message.; storage error in content conversion.'