GnuPG Version 2.2 - Additional Notes

The default OpenPGP configuration used by Perl-ECS is intended for use
with GnuPG (gpg) versions 1.4 and 2.0.  However, gpg version 2.2 is a
standard component of newer Linux systems such as Ubuntu 18.

For systems using gpg version 2.2, configuration adjustments are needed
in order to enable Perl-ECS to transmit the passphrase to gpg via stdin
(pinentry-mode loopback).

1. Create or edit $GNUPGHOME/gpg-agent.conf, adding the line:

 allow-loopback-pinentry

2. Execute the command:

 gpg-connect-agent /bye

3. In the ecs.cfg configuration file, revise the OPENPGP_CMD_ENCRYPT and
OPENPGP_CMD_DECRYPT settings to add the following.  (If needed, first
uncomment those settings.):

 --pinentry-mode loopback

4. If upgrading from an earlier gpg version, use ecstool --tweak to modify
all (addr_r) key IDs in the node table, because the IDs change when the
keyring is converted to gpg 2.2.
