From a0c8e5b75a4c274074c918ecfed1d7fd920f4d2f Mon Sep 17 00:00:00 2001
From: Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>
Date: Wed, 2 Sep 2026 23:35:20 +0200
Subject: [PATCH] Add fptrial.sh: a labelled verification protocol

Thirteen real fprintd-verify runs produced four matches and nine misses and no
rate, because nothing recorded which finger each run used. This script runs the
protocol -- N quick taps with the enrolled finger, then N with a different one
-- tells the user which finger and which tap they are on, and records the label
and the wall-clock latency from prompt to client result per tap. The daemon's
transcript has the frames; this has the labels. A loop change is measured
against this, one variable at a time.
---
 packaging/fptrial.sh | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 packaging/fptrial.sh

diff --git a/packaging/fptrial.sh b/packaging/fptrial.sh
new file mode 100644
index 0000000..81eb405
--- /dev/null
+++ b/packaging/fptrial.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+# fptrial.sh -- a labelled verification protocol against fingerprintd.
+#
+#   fptrial.sh [correct_taps] [wrong_taps]     defaults 10 and 5
+#
+# Runs fprintd-verify once per tap and tells you which finger to use before
+# each one. The daemon's transcript records every frame; THIS records the label
+# and the wall-clock time from "press now" to the client seeing a result, which
+# is the latency a user feels. Unlabelled runs cannot be turned into a rate.
+C=${1:-10}; W=${2:-5}
+OUT=/tmp/fptrial-$(date +%Y%m%d-%H%M%S).log
+now() { date +%s%N; }
+run() {  # $1 = label
+    printf '\n>>> %s -- press and LIFT (quick tap) ... ' "$1"
+    t0=$(now)
+    res=$(timeout 20 fprintd-verify user 2>&1 | grep -E 'Verify result' | tail -1)
+    t1=$(now)
+    ms=$(( (t1 - t0) / 1000000 ))
+    verdict=$(printf '%s' "$res" | grep -oE 'verify-(match|no-match|unknown-error)' || echo timeout)
+    printf '%s  (%d ms)\n' "$verdict" "$ms"
+    printf '%s %s %d\n' "$1" "$verdict" "$ms" >> "$OUT"
+    sleep 1
+}
+echo "labelled trial -> $OUT"
+i=1; while [ $i -le $C ]; do run "CORRECT $i/$C"; i=$((i+1)); done
+echo; echo "===== now switch to a DIFFERENT finger ====="; sleep 3
+i=1; while [ $i -le $W ]; do run "WRONG $i/$W"; i=$((i+1)); done
+echo
+echo "===== summary ====="
+awk '$1=="CORRECT"{c++; if($3=="verify-match")cm++; ct+=$4}
+     $1=="WRONG"  {w++; if($3=="verify-match")wm++; wt+=$4}
+     END{printf "  correct finger: %d/%d matched  (false negatives %d)  mean %d ms\n", cm,c,c-cm,(c?ct/c:0);
+         printf "  wrong finger:   %d/%d matched  (false ACCEPTS %d)   mean %d ms\n", wm,w,wm,(w?wt/w:0)}' "$OUT"
+echo "  per-tap log: $OUT"