[PATCH] RFC: hooks for clipboard manager integration

[Dov Feldstern]

# HG changeset patch
# User Dov Feldstern <dovdevel at gmail.com>
# Date 1593908715 -10800
#      Sun Jul 05 03:25:15 2020 +0300
# Node ID d4af3f470f3f04fb81bbcb079556ea56e8e43898
# Parent  dcfa9a1c9c827206f899e7ba604f42366fbd60f3
RFC: hooks for clipboard manager integration

I've been using password-store for a few months now, and am very happy with it
-- thanks to all involved!

One thing that I'm still grappling with is how to avoid having the passwords
get stored by my clipboard manager (currently copyq). I see that discussions of
this come up in the mailing list every once in a while, for various clipboard
managers; and also from the clipboard manager side, I see that many clipboard
managers discuss how to deal with the issue of passwords. But there doesn't
seem to be any standard way, which obviously makes dealing with this in a
generic way a bit difficult...

In this patch, I propose to add hooks, which can then be implemented as
appropriate for the various clipboard managers. I moved the handling for
klipper into the "default" hook, and in contrib/ I added a reference
implementation for how I'd like passwords to be handled for copyq -- so this
demonstrates that the method works for at least two password managers ;) .

I am offering this here as an RFC: is this kind of approach acceptable to the
project? If so, probably the hooking mechanism should be designed a bit more
throughly than what I've done here (I am also not very proficient in bash
programming, so there's probably a nicer way to add hooks than what I've
done...). But once such a hooking mechanism is in place, I think it offers a
more scalable solution for dealing with the variety of clipboard managers, and
will probably also find a bunch of other use cases, as well...

I'd be glad to hear any thoughts on this...

Thanks!
Dov

diff -r dcfa9a1c9c82 -r d4af3f470f3f contrib/hooks/copyq.sh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/hooks/copyq.sh	Sun Jul 05 03:25:15 2020 +0300
@@ -0,0 +1,11 @@
+hook_clip_pre_copy_pw() {
+	copyq disable
+}
+
+hook_clip_post_copy_pw() {
+	copyq enable
+}
+
+hook_clip_pre_restore() {
+	return
+}
diff -r dcfa9a1c9c82 -r d4af3f470f3f src/password-store.sh
--- a/src/password-store.sh	Thu Jun 25 23:41:11 2020 +0200
+++ b/src/password-store.sh	Sun Jul 05 03:25:15 2020 +0300
@@ -14,6 +14,7 @@
 
 PREFIX="${PASSWORD_STORE_DIR:-$HOME/.password-store}"
 EXTENSIONS="${PASSWORD_STORE_EXTENSIONS_DIR:-$PREFIX/.extensions}"
+HOOKS="${PASSWORD_STORE_HOOKS_DIR:-$PREFIX/.hooks}"
 X_SELECTION="${PASSWORD_STORE_X_SELECTION:-clipboard}"
 CLIP_TIME="${PASSWORD_STORE_CLIP_TIME:-45}"
 GENERATED_LENGTH="${PASSWORD_STORE_GENERATED_LENGTH:-25}"
@@ -152,6 +153,25 @@
 # BEGIN platform definable
 #
 
+hook_clip_pre_copy_pw() {
+	return
+}
+
+hook_clip_post_copy_pw() {
+	return
+}
+
+hook_clip_pre_restore() {
+		# It might be nice to programatically check to see if klipper exists,
+		# as well as checking for other common clipboard managers. But for now,
+		# this works fine -- if qdbus isn't there or if klipper isn't running,
+		# this essentially becomes a no-op.
+		#
+		# Clipboard managers frequently write their history out in plaintext,
+		# so we axe it here:
+		qdbus org.kde.klipper /klipper org.kde.klipper.klipper.clearClipboardHistory &>/dev/null
+}
+
 clip() {
 	if [[ -n $WAYLAND_DISPLAY ]]; then
 		local copy_cmd=( wl-copy )
@@ -175,21 +195,15 @@
 	# trailing new lines.
 	pkill -f "^$sleep_argv0" 2>/dev/null && sleep 0.5
 	local before="$("${paste_cmd[@]}" 2>/dev/null | $BASE64)"
+	hook_clip_pre_copy_pw
 	echo -n "$1" | "${copy_cmd[@]}" || die "Error: Could not copy data to the clipboard"
+	hook_clip_post_copy_pw
 	(
 		( exec -a "$sleep_argv0" bash <<<"trap 'kill %1' TERM; sleep '$CLIP_TIME' & wait" )
 		local now="$("${paste_cmd[@]}" | $BASE64)"
 		[[ $now != $(echo -n "$1" | $BASE64) ]] && before="$now"
 
-		# It might be nice to programatically check to see if klipper exists,
-		# as well as checking for other common clipboard managers. But for now,
-		# this works fine -- if qdbus isn't there or if klipper isn't running,
-		# this essentially becomes a no-op.
-		#
-		# Clipboard managers frequently write their history out in plaintext,
-		# so we axe it here:
-		qdbus org.kde.klipper /klipper org.kde.klipper.klipper.clearClipboardHistory &>/dev/null
-
+		hook_clip_pre_restore
 		echo "$before" | $BASE64 -d | "${copy_cmd[@]}"
 	) >/dev/null 2>&1 & disown
 	echo "Copied $2 to clipboard. Will clear in $CLIP_TIME seconds."
@@ -246,6 +260,10 @@
 
 source "$(dirname "$0")/platform/$(uname | cut -d _ -f 1 | tr '[:upper:]' '[:lower:]').sh" 2>/dev/null # PLATFORM_FUNCTION_FILE
 
+for hook in $HOOKS/*.sh; do
+	source $hook
+done
+
 #
 # END platform definable
 #