Requests the passphrase with a popup.
As from GPGME 1.15.0, the loopback pinentry is functional when exporting secret keys. It works fine when the exact passphrase is provided. If it's a wrong passphrase, GPGME does not generate an ::Error, but the app crashes with 'free(): double free detected in tcache 2'.
Hence, this patch cannot be committed to master.
Status : dangerous
Result : works and works not
Reason : a wrong passphrase means a crash
The email parameter must have a valid email address format here, else
GPGME will refuse to create the identity. This is not the case when
creating a key, where any string is accepted.
Correct format :
name <email> (comment)
Was :
name <email> comment
Though the 'comment' part was visible with the cli gpg app, it was not
shown in kleopatra and in K7.
Result : fails.
Reason : loopback passphrase provider is never called.
With default pinentry mode, the passphrase is requested normally
and the private key is exported. But this can't be done on a web server.
Enclosed in #ifdef DEVTIME.
In-place editing with a popup if user is allowed in app config file.
User must of course manage at least a private key. User identities of
target key may be selectively chosen. Optionally, certification may be
exportable and non-revocable.
