From 6bd37821a9aae21bfdd4a3ee44fb41cef79e7d9a Mon Sep 17 00:00:00 2001
From: lwvmobile <lwvmobile@gmail.com>
Date: Sat, 8 Oct 2022 07:08:23 -0400
Subject: [PATCH] NXDN96 Scrambler Support; Force Key Priority CLI;

---
 src/dsd_main.c    | 26 ++++++++++++++++----------
 src/dsd_ncurses.c |  4 ++--
 src/nxdn_data.c   | 18 ++++++++++++++++++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/src/dsd_main.c b/src/dsd_main.c
index 3ea8ee3..59a161c 100644
--- a/src/dsd_main.c
+++ b/src/dsd_main.c
@@ -625,15 +625,15 @@ usage ()
   printf ("Display Options:\n");
   printf ("  -N            Use NCurses Terminal\n");
   printf ("                 dsd-fme -N 2> log.ans \n");
-  printf ("  -e            Show Frame Info and errorbars (default)\n");
-  printf ("  -pe           Show P25 encryption sync bits\n");
-  printf ("  -pl           Show P25 link control bits\n");
-  printf ("  -ps           Show P25 status bits and low speed data\n");
-  printf ("  -pt           Show P25 talkgroup info\n");
-  printf ("  -q            Don't show Frame Info/errorbars\n");
+  // printf ("  -e            Show Frame Info and errorbars (default)\n");
+  // printf ("  -pe           Show P25 encryption sync bits\n");
+  // printf ("  -pl           Show P25 link control bits\n");
+  // printf ("  -ps           Show P25 status bits and low speed data\n");
+  // printf ("  -pt           Show P25 talkgroup info\n");
+  // printf ("  -q            Don't show Frame Info/errorbars\n");
   printf ("  -s            Datascope (disables other display options)\n");
   printf ("  -t            Show symbol timing during sync\n");
-  printf ("  -v <num>      Frame information Verbosity\n");
+  // printf ("  -v <num>      Frame information Verbosity\n");
   printf ("  -z <num>      Frame rate for datascope\n");
   printf ("\n");
   printf ("Input/Output options:\n");
@@ -702,7 +702,7 @@ usage ()
   printf ("  -mc           Use only C4FM modulation optimizations\n");
   printf ("  -mg           Use only GFSK modulation optimizations\n");
   printf ("  -mq           Use only QPSK modulation optimizations\n");
-  printf ("  -m2           Use Phase 2 6000 sps CQPSK modulation optimizations (testing, not fully implemented) \n");
+  printf ("  -m2           Use Phase 2 6000 sps CQPSK modulation optimizations (4 Level, not 8 Level LSM) \n");
   printf ("  -F            Relax P25 Phase 2 MAC_SIGNAL CRC Checksum Pass/Fail\n");
   printf ("                 Use this feature to allow MAC_SIGNAL even if bad CRC errors.\n");
   printf ("  -F            Enable DMR BS Stereo Passive Frame Sync\n");
@@ -715,8 +715,9 @@ usage ()
   printf ("  -H <hex>      Manually Enter **tera 10 Privacy Key (40-Bit/10-Char Hex Value)\n");
   printf ("                (32/64-Char values can only be entered in the NCurses Terminal)\n");
   printf ("\n");
-  printf ("  -R <dec>      Manually Enter NXDN 4800 EHR Scrambler Key Value \n");
+  printf ("  -R <dec>      Manually Enter NXDN 4800/9600 EHR Scrambler Key Value \n");
   printf ("                 \n");
+  printf ("  -4            Force Privacy Key over FID and SVC bits \n");
   printf ("\n");
   exit (0);
 }
@@ -956,7 +957,7 @@ main (int argc, char **argv)
   exitflag = 0;
   signal (SIGINT, sigfun);
 
-  while ((c = getopt (argc, argv, "haep:P:qstv:z:i:o:d:c:g:nw:B:C:R:f:m:u:x:A:S:M:G:D:L:V:U:Y:K:H:X:NQWrlZTF")) != -1)
+  while ((c = getopt (argc, argv, "haep:P:qstv:z:i:o:d:c:g:nw:B:C:R:f:m:u:x:A:S:M:G:D:L:V:U:Y:K:H:X:NQWrlZTF4")) != -1)
     {
       opterr = 0;
       switch (c)
@@ -1069,6 +1070,11 @@ main (int argc, char **argv)
           state.K1 = state.H; //shim
           break;
 
+        case '4':
+          state.M = 1;
+          fprintf (stderr,"Force Privacy Key Priority over FID and SVC bits.\n");
+          break;
+
         //manually set Phase 2 TDMA WACN/SYSID/CC
         case 'X':
           sscanf (optarg, "%llX", &p2vars);
diff --git a/src/dsd_ncurses.c b/src/dsd_ncurses.c
index 63bf825..ece6121 100644
--- a/src/dsd_ncurses.c
+++ b/src/dsd_ncurses.c
@@ -94,8 +94,8 @@ char * SyncTypes[44] = {
   "DMR VOICE",
   "PROVOICE",
   "PROVOICE",
-  "NXDN DATA",
-  "NXDN DATA",
+  "NXDN VOICE", //DATA
+  "NXDN VOICE", //DATA
   "DSTAR HD",
   "DSTAR HD",
   "dPMR", //20
diff --git a/src/nxdn_data.c b/src/nxdn_data.c
index 87d2bf3..2706ad6 100644
--- a/src/nxdn_data.c
+++ b/src/nxdn_data.c
@@ -15,6 +15,17 @@ void processNXDNData (dsd_opts * opts, dsd_state * state)
   /* Remove compiler warning */
   //UNUSED_VARIABLE(dibit);
 
+  //if using NXDN Scrambling, run LFSRN (dummy ambe values) to continue seed
+  if (state->nxdn_cipher_type == 0x1 && state->R != 0)
+  {
+    char ambe_temp[49] = {0};
+    char ambe_d[49] = {0};
+    for (i = 0; i < 4; i++)
+    {
+      LFSRN(ambe_temp, ambe_d, state);
+    }
+  }
+
   if (opts->errorbars == 1)
   {
     fprintf(stderr, "DATA  - ");
@@ -105,5 +116,12 @@ void processNXDNData (dsd_opts * opts, dsd_state * state)
   {
     /* Reset all CRCs of the SACCH */
     for(i = 0; i < 4; i++) state->NxdnSacchRawPart[i].CrcIsGood = 0;
+
+    //reset Scrambler seed
+    if (state->nxdn_cipher_type == 0x1)
+    {
+      state->payload_miN = 0; 
+    }
+
   }
 } /* End processNXDNData() */