Cannot decrypt file encrypted with enQsig

[Felix E. Klee]

On Sun, Jul 29, 2018 at 11:37 PM, Dirk Gottschalk via Gnupg-users
<gnupg-users at gnupg.org> wrote:
>> My encryption key is the sub key 04FDF78D1679DD94. The private key is
>> on a smart card. […]
>
> Does this key work as expected in other programs, MUAs for example?

I use it daily for encryption/decryption of documents, though only with
GnuPG.

> I didn't test it mysqlf, but exporting a only a sub key should be no
> problem.

*But how?*

Your suggestion doesn’t seem to work:

    >gpg --export 04FDF78D1679DD94 | gpg --keyid-format long
    gpg: WARNING: no command supplied.  Trying to guess what you mean ..
    .
    pub   rsa4096/BEF6EFD38FE8DCA0 2016-12-17 [SC] [expires: 2018-12-17]
          5EF8B6017F668171259945D6BEF6EFD38FE8DCA0
    uid                           Felix E. Klee <felix.klee at inka.de>
    sub   rsa4096/04FDF78D1679DD94 2016-12-17 [E] [expires: 2018-12-17]

> Could you provide an example file with this error, in best case
> generated from the Sender?

I can ask him of course. First I would like to see, though, if GnuPG can
tell us what’s the problem.

> Have you tried to inspect the packets in the file with
> "--list-packets"?

Here you go (again my encryption key is `04FDF78D1679DD94`):

    >gpg --list-packets encrypted.asc
    # off=0 ctb=c1 tag=1 hlen=3 plen=524 new-ctb
    :pubkey enc packet: version 3, algo 1, keyid BEF6EFD38FE8DCA0
            data: [4096 bits]
    # off=527 ctb=c1 tag=1 hlen=3 plen=524 new-ctb
    :pubkey enc packet: version 3, algo 1, keyid 04FDF78D1679DD94
            data: [4095 bits]
    # off=1054 ctb=c1 tag=1 hlen=3 plen=524 new-ctb
    :pubkey enc packet: version 3, algo 1, keyid 92663E7CA68E4EC6
            data: [4096 bits]
    # off=1581 ctb=c1 tag=1 hlen=3 plen=524 new-ctb
    :pubkey enc packet: version 3, algo 1, keyid 9D8C454A43A6D2DE
            data: [4094 bits]
    gpg: encrypted with RSA key, ID 9D8C454A43A6D2DE
    gpg: encrypted with RSA key, ID 92663E7CA68E4EC6
    gpg: encrypted with 4096-bit RSA key, ID 04FDF78D1679DD94, created 2
    016-12-17
          "Felix E. Klee <felix.klee at inka.de>"
    gpg: public key decryption failed: Missing item in object
    gpg: encrypted with 4096-bit RSA key, ID BEF6EFD38FE8DCA0, created 2
    016-12-17
          "Felix E. Klee <felix.klee at inka.de>"
    gpg: public key decryption failed: Invalid ID
    gpg: decryption failed: No secret key
    # off=2108 ctb=d2 tag=18 hlen=3 plen=1718 new-ctb
    :encrypted data packet:
            length: 1718
            mdc_method: 2

I wonder what “Missing item in object” means.