1 files changed, 103 insertions, 0 deletions
diff --git a/src/lib/protocols/threema.c b/src/lib/protocols/threema.c
new file mode 100644
index 000000000..348b70988
--- /dev/null
+++ b/src/lib/protocols/threema.c
@@ -0,0 +1,103 @@
+/*
+ * threema.c
+ *
+ * Copyright (C) 2022 - ntop.org
+ *
+ * nDPI is free software: you can zmqtribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * nDPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include "ndpi_protocol_ids.h"
+
+#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_THREEMA
+
+#include "ndpi_api.h"
+
+
+static void ndpi_int_threema_add_connection(struct ndpi_detection_module_struct * const ndpi_struct,
+                                            struct ndpi_flow_struct * const flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found Threema\n");
+  ndpi_set_detected_protocol(ndpi_struct, flow,
+                             NDPI_PROTOCOL_UNKNOWN,
+                             NDPI_PROTOCOL_THREEMA,
+                             NDPI_CONFIDENCE_DPI);
+}
+
+static void ndpi_search_threema(struct ndpi_detection_module_struct *ndpi_struct,
+                                struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct *packet = &ndpi_struct->packet;
+
+  NDPI_LOG_DBG(ndpi_struct, "search Threema\n");
+
+  if (ntohs(packet->tcp->source) != 5222 && ntohs(packet->tcp->dest) != 5222) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  switch (flow->packet_counter)
+  {
+    case 1:
+      if (packet->payload_packet_len != 48)
+      {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+      }
+      return;
+    case 2:
+      if (packet->payload_packet_len != 80)
+      {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+      }
+      return;
+    case 3:
+      if (packet->payload_packet_len != 191)
+      {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+      }
+      return;
+    case 4:
+      return; // packet length varies
+    default:
+      break;
+  }
+
+  if (packet->payload_packet_len < 2)
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  uint16_t len = le16toh(get_u_int16_t(packet->payload, 0));
+  if (len + 2 != packet->payload_packet_len)
+  {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  ndpi_int_threema_add_connection(ndpi_struct, flow);
+}
+
+void init_threema_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+                            u_int32_t *id,
+                            NDPI_PROTOCOL_BITMASK *detection_bitmask)
+{
+  ndpi_set_bitmask_protocol_detection("Threema", ndpi_struct, detection_bitmask, *id,
+    NDPI_PROTOCOL_THREEMA,
+    ndpi_search_threema,
+    NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+    SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+    ADD_TO_DETECTION_BITMASK
+  );
+  *id += 1;
+}