GCR is a library for displaying certificates, and crypto UI, accessing
key stores. It also provides the viewer for crypto files on the GNOME
desktop.
GCK is a library for accessing PKCS#11 modules like smart cards, in a
(G)object oriented way.
DEBUG TRACING
==============
The Gcr and Gck libraries contain statements which help debug flow
and logic. In many cases these help you track down problems.
Use the environment variable G_MESSAGES_DEBUG='all' or G_MESSAGES_DEBUG='xxx'
to display either all messages or a specific categories of debug messages. You
can separate categories in this list with spaces, commas or semicolons. Gcr
library uses category 'Gcr', while Gck library uses category 'Gck'.
Example to display all debug messages:
$ G_MESSAGES_DEBUG=all gcr-viewer /path/to/certificate.crt
(gcr-viewer:9418): Gcr-DEBUG: gcr_pkcs11_initialize_async: starting initialize of registered modules
...
Example to display debug messages for a specific category:
$ G_MESSAGES_DEBUG="Gcr" gcr-viewer /path/to/certificate.crt
(gcr-viewer:9503): Gcr-DEBUG: gcr_pkcs11_initialize_async: starting initialize of registered modules
...
For the Gck debug messages simply replace 'Gcr' with 'Gck' in the above
examples.