Confused about oauth2.plstore

[Julien Cubizolles <j.cubizolles@free.fr>]

I'm looking for some documentation/help about the oauth2.plstore file
used for authentication with the Google servers for instance (I'm
setting up https://github.com/dengste/org-caldav/). I've gathered that
some kind of public/private keys will be somehow encrypted into this
file to be decrypted when needed.

I actually have such a file on my system, even though I don't know what
for and when it was created. There is however a problem with it. When
org-caldav tries to use it, or when I run plstore-mode-toggle-display in
its buffer, I get the following error:

--8<---------------cut here---------------start------------->8---
epg-error "Decryption failed" ""
--8<---------------cut here---------------end--------------->8---

Here is what the file looks like (with personal data replaced by xs)

--8<---------------cut here---------------start------------->8---
;;; public entries -*- mode: plstore -*- 
(("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" :secret-access-token t :secret-refresh-token t))
;;; secret entries
"-----BEGIN PGP MESSAGE-----
Version: GnuPG v1.4.11 (GNU/Linux)

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxx
xxxxx
-----END PGP MESSAGE-----
"
--8<---------------cut here---------------end--------------->8---

Does it look right ? How can I further investigate this problem ? Is it
related to the GPG version : the file mentions 1.4.11 but the default is
2.1.15

Julien.