This CL adds pinentry support to ask for security key PIN.
Security key PINs may be required (by the manufacturer, or configured by
the user) to perform FIDO2 assertions.
PIN entry is done by calling pinentry command (or overridden by
LUCI_AUTH_PINENTRY environment variable), which we'll ask users to
install during onboarding.
Bug: 448235795
Change-Id: Ie87389330668dc5eaf8214699defec094757ca9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/7004844
Reviewed-by: Jiewei Qian <qjw@chromium.org>
Commit-Queue: Jiewei Qian <qjw@chromium.org>
Reviewed-by: Chenlin Fan <fancl@chromium.org>
