Transparent encrypt and decrypt token file with gpg2 in Emacs.

Transparent encrypt and decrypt token file with gpg2 in Emacs.

[Hongyi Zhao]

On Ubuntu 20.04, I store the API token in a file with an extension
name gpg. Then I load this file in init-file.

But when I always notice that when the content of the token file is
read by Emacs, the following error will be triggered:

In the *Error* buffer:

Error while decrypting with "/usr/bin/gpg2":

gpg: no valid OpenPGP data found.
gpg: decrypt_message failed: Unknown system error

In the *Message* buffer:

Loading /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...
Decrypting /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...done
epa-file-insert-file-contents: Opening input file: Can't decrypt, No
data (no armored data); No data (expected a packet but did not find
one); Exit
Mark set [4 times]

Any hints for solving this problem?

Regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China

Re: Transparent encrypt and decrypt token file with gpg2 in Emacs.

[Jean Louis]

* Hongyi Zhao <hongyi.zhao@gmail.com> [2021-06-09 18:28]:
> Loading /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...
> Decrypting /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...done
> epa-file-insert-file-contents: Opening input file: Can't decrypt, No
> data (no armored data); No data (expected a packet but did not find
> one); Exit
> Mark set [4 times]

Send the file for review.

If it is encrypted, there should be nothing much to worry... ^‿^
-- 
Jean

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Re: Transparent encrypt and decrypt token file with gpg2 in Emacs.

[Hongyi Zhao]

On Thu, Jun 10, 2021 at 12:06 AM Jean Louis <bugs@gnu.support> wrote:
>
> * Hongyi Zhao <hongyi.zhao@gmail.com> [2021-06-09 18:28]:
> > Loading /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...
> > Decrypting /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...done
> > epa-file-insert-file-contents: Opening input file: Can't decrypt, No
> > data (no armored data); No data (expected a packet but did not find
> > one); Exit
> > Mark set [4 times]
>
> Send the file for review.
>
> If it is encrypted, there should be nothing much to worry... ^‿^

If I first store the plain/unencrypted token info into a file, say,
named as auth.el, and then encrypt it outside of Emacs with gpg(2) as
below, the problem will disappear:

$ gpg2 -o auth.el.gpg -e -r hongyi.zhao@gmail.com auth.el
# Then remove the plain version of the token info.
$ rm auth.el

But I still can't figure out how to let Emacs do the above job for me
automatically when the token file is read by Emacs in an unencrypted
format for the first time.

Regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China

Re: Transparent encrypt and decrypt token file with gpg2 in Emacs.

[Hongyi Zhao]

On Thu, Jun 10, 2021 at 10:19 AM Hongyi Zhao <hongyi.zhao@gmail.com> wrote:
>
> On Thu, Jun 10, 2021 at 12:06 AM Jean Louis <bugs@gnu.support> wrote:
> >
> > * Hongyi Zhao <hongyi.zhao@gmail.com> [2021-06-09 18:28]:
> > > Loading /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...
> > > Decrypting /home/werner/DvdMgr/screen2latex.el.git/auth.el.gpg...done
> > > epa-file-insert-file-contents: Opening input file: Can't decrypt, No
> > > data (no armored data); No data (expected a packet but did not find
> > > one); Exit
> > > Mark set [4 times]
> >
> > Send the file for review.
> >
> > If it is encrypted, there should be nothing much to worry... ^‿^
>
> If I first store the plain/unencrypted token info into a file, say,
> named as auth.el, and then encrypt it outside of Emacs with gpg(2) as
> below, the problem will disappear:
>
> $ gpg2 -o auth.el.gpg -e -r hongyi.zhao@gmail.com auth.el
> # Then remove the plain version of the token info.
> $ rm auth.el
>
> But I still can't figure out how to let Emacs do the above job for me
> automatically when the token file is read by Emacs in an unencrypted
> format for the first time.

I figured out the Emacs way of this job based on the wonderful Emacs
manual as described at
<https://www.gnu.org/software/emacs/manual/html_node/epa/Encrypting_002fdecrypting-gpg-files.html>:

<quote>
3.6 Encrypting/decrypting gpg files

By default, every file whose name ends with .gpg will be treated as
encrypted. That is, when you open such a file, the decrypted text is
inserted in the buffer rather than encrypted one. Similarly, when you
save the buffer to a foo.gpg file, encrypted data is written.

The file name pattern for encrypted files can be controlled by
epa-file-name-regexp.
</quote>

Once again, the RTFM philosophy shows its power and enduring value.

Regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China