From 272f17bfa3d8002707337d1080c2cb2326ade290 Mon Sep 17 00:00:00 2001
From: lwvmobile <lwvmobile@gmail.com>
Date: Mon, 20 Jul 2026 11:31:31 -0400
Subject: [PATCH] MBE: Add DMRA Late Entry IV and Forced AES Alg Decryption
 support  (w/ known key) for SDRTrunk .mbe files; #298

---
 src/dsd_file.c | 39 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/dsd_file.c b/src/dsd_file.c
index caff4ba..8395a3a 100644
--- a/src/dsd_file.c
+++ b/src/dsd_file.c
@@ -1038,7 +1038,7 @@ uint16_t ambe2_str_to_decode(dsd_opts * opts, dsd_state * state, char * ambe_str
     //run LFSR evaluate stored codewords for matching IV or replace if not match or not set
     if (ambe2_counter == 17)
     {
-      if (state->payload_mi != 0)
+      if (state->forced_alg_id == 0x21 && state->payload_mi != 0)
       {
         fprintf (stderr, "\n");
         LFSR(state);
@@ -1561,6 +1561,43 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
 
       }
 
+      else if ((alg_id == 0x24 || alg_id == 0x25) && state->payload_mi != 0)
+      {
+
+        uint8_t ks_bytes[375];
+        memset(ks_bytes, 0, sizeof(ks_bytes));
+
+        uint8_t aes_key[32];
+        memset(aes_key, 0, sizeof(aes_key));
+
+        uint8_t empty[32];
+        memset(empty, 0, sizeof(empty));
+
+        //Load key from A1 - A4
+        for (int i = 0; i < 8; i++)
+        {
+          aes_key[i+0]  = (state->A1[0] >> (56-(i*8))) & 0xFF;
+          aes_key[i+8]  = (state->A2[0] >> (56-(i*8))) & 0xFF;
+          aes_key[i+16] = (state->A3[0] >> (56-(i*8))) & 0xFF;
+          aes_key[i+24] = (state->A4[0] >> (56-(i*8))) & 0xFF;
+        }
+
+        //check to see if a key is actually loaded
+        if (memcmp (aes_key, empty, sizeof(aes_key)) != 0)
+        {
+
+          if (alg_id == 0x24) //128, or 256
+            aes_ofb_keystream_output(state->aes_iv, aes_key, ks_bytes, 0, 16); //16*16=256
+          else aes_ofb_keystream_output(state->aes_iv, aes_key, ks_bytes, 2, 16); //16*16=256
+
+          unpack_byte_array_into_bit_array(ks_bytes+16, ks, 256-16); //unpack starting after discards
+
+          ks_available = 1;
+
+        }
+
+      }
+
     }
     //TODO: This
     else if (state->forced_alg_id == 1) //Basic Privacy