stockholm/tv/5pkgs/simple/pinentry-urxvt/default.nix

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with import ./lib;
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{ pkgs, ... }@args:
let
# config cannot be declared in the input attribute set because that would
# cause callPackage to inject the wrong config. Instead, get it from ...
# via args.
config = args.config or {};
cfg = eval.config;
eval = lib.evalModules {
modules = lib.singleton {
_file = toString ./default.nix;
imports = lib.singleton config;
options = {
appName = lib.mkOption {
default = "pinentry-urxvt";
type = lib.types.str;
};
display = lib.mkOption {
default = null;
type = lib.types.nullOr lib.types.str;
};
xwud.className = lib.mkOption {
default = "PinentryUrxvtXwudFloat";
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type = lib.types.str;
};
};
};
};
in
# pinentry-urxvt - A mechanism for PIN entry utilizing rxvt-unicode
#
# This spawns a PIN entry terminal on top of a tinted screenshot of the
# current display's root window. The display for spawning the terminal can
# be predefined, in which case both the current and the predefined display
# will show the screenshot.
#
# The purpose of the screenshot, aside from looking nice, is to prevent entry
# of the PIN into the wrong window, e.g. by accidentally moving the cursor
# while typing. If necessary, the screenshot can be closed by sending 'q',
# 'Q', or ctrl-c while its focused.
#
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pkgs.write "pinentry-urxvt" {
"/bin/pinentry".link = pkgs.writeDash "pinentry-urxvt-wrapper" ''
set -efu
trap cleanup EXIT
cleanup() {
${pkgs.utillinux}/bin/kill -- $(${pkgs.coreutils}/bin/cat "$displayers")
rm "$displayers"
rm "$screenshot"
}
displayers=$(${pkgs.coreutils}/bin/mktemp -t pinentry-urxvt.$$.displayers.XXXXXXXX)
screenshot=$(${pkgs.coreutils}/bin/mktemp -t pinentry-urxvt.$$.screenshot.XXXXXXXX)
${pkgs.xorg.xwd}/bin/xwd -root |
${pkgs.imagemagick}/bin/convert xwd:- -fill \#424242 -colorize 80% xwd:"$screenshot"
display_screenshot() {
${pkgs.exec "pinentry-urxvt.display_screenshot" {
filename = "${pkgs.xorg.xwud}/bin/xwud";
argv = [
cfg.xwud.className
"-noclick"
];
}} < "$screenshot" &
wait_for_screenshot $! && echo $! >>"$displayers"
}
# Wait for the xwud window by trying to intercept the call to munmap().
# If it cannot be intercepted within 0.1s, assume that attaching strace
# wasn't fast enough or xwud doesn't call munmap() anymore. In either
# case fall back to search the window by class name, assuming there can
# be only one per display.
wait_for_screenshot() {
if ! \
${pkgs.coreutils}/bin/timeout 0.1 \
${pkgs.strace}/bin/strace -p "$1" -e munmap 2>&1 |
read -r _
then
until ${pkgs.xdotool}/bin/xdotool search \
--classname ${lib.shell.escape cfg.xwud.className}
do
${pkgs.coreutils}/bin/sleep 0.1
done
fi
}
display_screenshot
${lib.optionalString (cfg.display != null) /* sh */ ''
if test "$DISPLAY" != ${lib.shell.escape cfg.display}; then
export DISPLAY=${lib.shell.escape cfg.display}
display_screenshot
fi
''}
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exec 3<&0 4>&1 5>&2
${pkgs.rxvt_unicode}/bin/urxvt \
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-name ${lib.shell.escape cfg.appName} \
-e ${pkgs.writeDash "pinentry-urxvt-tty" ''
set -efu
exec 2>&5
TTY=$(${pkgs.coreutils}/bin/tty)
while read -r line <&3; do
case $line in
'OPTION ttyname='*)
echo "OPTION ttyname=$TTY"
;;
*)
echo "$line"
esac
done | ${pkgs.pinentry.tty}/bin/pinentry-tty "$@" >&4
''} \
"$@"
'';
}