Attachments Lose Extension After Decryption

Gpg4win help-en
1

Background Info:
We have several users that have been using Symantec Encryption Desktop to exchange PGP encrypted emails with external business contacts. We would like to migrate these users from Symantec to Gpg4win. However, they will still need to decrypt and access emails that were exchanged using Symantec. My initial testing has been positive. I’m able to install Gpg4win, import the user’s keyring from Symantec, successfully exchange new emails with the GpgOL Plugin, and decrypt old emails that were encrypted with Symantec.

The problem I’m running into is with attachments on old emails encrypted with Symantec. The attachment can’t be opened within Outlook (not a big problem) and instead has to be decrypted and saved with Kleopatra first. However, this is leaving the file without an extension, meaning the user has to either add the extension or choose which program to use to open the file, if they can remember what file type the extension was to begin with.

Attachments to emails sent using the GpgOL Plugin to another user with Gpg4win, work perfectly and can be opened directly within Outlook.

Is there any way to open attachments on emails encrypted with Symantec directly within Outlook using Gpg4win/GpgOL? If not, is there a way to retain the file extension after decryption?

2

Hi Blake,

please see the third section for a description of the potential security problem:
https://wiki.gnupg.org/PgpPartitioned
(The problem here is that if the encrypted part is not signed, attacker may - under some circumstances for old encryption methods, add additional contents.)

Kleopatra should show the embedded file name (if there is one), however users must be instructed and trained to really check the name to avoid an additional attack surface.

If this happens occasionally, it probably is bearable.
And if you need some mails often: What do you think about considering to decrypting those once, and reencrypting it with OpenPGP/MIME?

Let me know if this good enough for your use case.
(Scripting could be considered, if you have a lot and the emails are accessible by other email clients, e.g. via IMAP.)

Best Regards,
Bernhard