Seperate Session Key and Encrypted Data

[Faramir]

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El 01-10-2015 a las 7:26, Christian Loehle escribió:
> I want to use gpg to encrypt a potentially large file to some 
> (cloud-like) storage provider, the recipients are not known at the
> time of uploading. What I want to do is to send the encrypted
> session key of the file to a recipient, when I 'add' them, without
> reuploading or even touching the original file. This should be
> possible, does anyone know how to? I'm also open to other 
> suggestions

  It seems to me it would be easier to use symmetrical encryption. I
always do it using a GUI, but I found these instructions to do it. I
guess gpg will ask for the password:

gpg --symmetric filename

yields filename.gpg

gpg --symmetric -a filename

yields filename.asc


Decryption is performed using the usual "-d" switch:

    gpg -d filename

- ---

  Otherwise, you would have to encrypt the file to your own key, and
then extract the session key. I've never done that, but I found these
directions:


gpg --show-session-key [file_name]

To decrypt:

gpg --override-session-key [session key] [file_name]

- ---

  I hope it works, I wrote those directions "just in case", but never
tried them, so I may have made mistakes.

   Best Regards
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