From 166cf4ed0fb0cff4629b0dfc3b733d73d2fe4b60 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=90=D0=BD=D1=82=D0=BE=D0=BD=20=D0=A2=D1=80=D0=BE=D1=88?=
 =?UTF-8?q?=D0=B8=D0=BD?= <i@atroshin.ru>
Date: Mon, 17 Aug 2026 21:40:12 +0300
Subject: [PATCH] Decode KIc/KID algorithms unconditionally; expand
 packet-length labels

---
 frontend/index.html                |  4 ++--
 simtrace2_pysniff/server/decode.py | 19 ++++++++++++++-----
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/frontend/index.html b/frontend/index.html
index d9b418a..7833d04 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -664,7 +664,7 @@ function cmdRows(cmd) {
 
         const sec = t.secured;
         if (sec && !sec.raw) {
-            rows.push(['Secured packet', 'CPL ' + sec.cpl + ' · CHL ' + sec.chl]);
+            rows.push(['Secured packet', 'Command Packet Length ' + sec.cpl + ' · Command Header Length ' + sec.chl]);
             const s = sec.spi || {};
             rows.push(['SPI', '0x' + (s.hex || '') + ' — ' + (s.counter || '') +
                 (s.ciphering ? ', ciphering' : '') + ', ' + (s.rc_cc_ds || '') + ', ' + (s.por || '')]);
@@ -679,7 +679,7 @@ function cmdRows(cmd) {
 
         const rp = t.response_packet;
         if (rp && !rp.raw) {
-            rows.push(['Response packet', 'RPL ' + rp.rpl + ' · RHL ' + rp.rhl]);
+            rows.push(['Response packet', 'Response Packet Length ' + rp.rpl + ' · Response Header Length ' + rp.rhl]);
             rows.push(['TAR', '0x' + rp.tar]);
             rows.push(['CNTR', '0x' + rp.cntr]);
             rows.push(['PCNTR', rp.pcntr]);
diff --git a/simtrace2_pysniff/server/decode.py b/simtrace2_pysniff/server/decode.py
index b86a138..c815053 100644
--- a/simtrace2_pysniff/server/decode.py
+++ b/simtrace2_pysniff/server/decode.py
@@ -1727,7 +1727,7 @@ _OTA_POR = {0: 'no PoR', 1: 'PoR required', 2: 'PoR only on error'}
 
 # TS 102 225 §5.1.2 / §5.1.3 — KIc / KID algorithms (low nibble)
 _KIC_ALGO = {0: 'implicit', 1: 'DES', 2: 'AES-CBC', 5: '3DES-CBC (2 keys)', 9: '3DES-CBC (3 keys)'}
-_KID_CC_ALGO = {0: 'implicit', 1: 'DES', 5: '3DES-CBC', 2: 'AES-CMAC'}
+_KID_CC_ALGO = {0: 'implicit', 1: 'DES', 5: '3DES-CBC (2 keys)', 9: '3DES-CBC (3 keys)', 2: 'AES-CMAC'}
 _KID_RC_ALGO = {0: 'implicit', 1: 'CRC16', 5: 'CRC32', 3: 'proprietary'}
 
 # TS 102 225 §5.2 Table 5 + TS 31.115 §7 — Response status codes
@@ -1798,12 +1798,21 @@ def _decode_secured_packet(body):
         'pcntr': pcntr,
         'data': data.hex().upper(),
     }
+    kic_algo = _KIC_ALGO.get(kic & 0x0F, 'reserved')
+    if not (spi1 & 0x08):  # SPI says no ciphering → KIc unused
+        kic_algo += ' (unused)'
+    result['kic'] = {'key': kic >> 4, 'algo': kic_algo}
     if rc_cc_ds_kind == 2:  # CC
-        result['kid'] = {'key': kid >> 4, 'algo': _KID_CC_ALGO.get(kid & 0x0F, 'reserved')}
+        kid_algo = _KID_CC_ALGO.get(kid & 0x0F, 'reserved')
     elif rc_cc_ds_kind == 1:  # RC
-        result['kid'] = {'key': kid >> 4, 'algo': _KID_RC_ALGO.get(kid & 0x0F, 'reserved')}
-    else:
-        result['kid'] = {'key': kid >> 4, 'algo': 'implicit'}
+        kid_algo = _KID_RC_ALGO.get(kid & 0x0F, 'reserved')
+    elif rc_cc_ds_kind == 3:  # DS — no simple nibble table
+        kid_algo = 'DS'
+    else:  # none — decode the nibble anyway (CC interpretation)
+        kid_algo = _KID_CC_ALGO.get(kid & 0x0F, 'reserved')
+    if rc_cc_ds_kind == 0:
+        kid_algo += ' (unused)'
+    result['kid'] = {'key': kid >> 4, 'algo': kid_algo}
     if rc_cc_ds:
         result['rc_cc_ds'] = rc_cc_ds.hex().upper()
     return result