Added fix to harden quic detection and limit it to port 80/443 UDP

1 files changed, 100 insertions, 93 deletions

diff --git a/src/lib/protocols/quic.c b/src/lib/protocols/quic.c
index 2e1ad6628..cbc95519d 100644
--- a/src/lib/protocols/quic.c
+++ b/src/lib/protocols/quic.c
@@ -46,111 +46,118 @@
 static void ndpi_int_quic_add_connection(struct ndpi_detection_module_struct
                                          *ndpi_struct, struct ndpi_flow_struct *flow)
 {
-    ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_QUIC, NDPI_REAL_PROTOCOL);
+  ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_QUIC, NDPI_REAL_PROTOCOL);
 }
 
 int connect_id(const unsigned char pflags)
 {
-    u_int cid_len;
+  u_int cid_len;
     
-        // Check CID length.
-        switch (pflags & QUIC_CID_MASK)
-        {
-           case CID_LEN_8: cid_len = 8; break;
-           case CID_LEN_4: cid_len = 4; break;
-           case CID_LEN_1: cid_len = 1; break;
-           case CID_LEN_0: cid_len = 0; break;
-           default:
-               return -1;
-
-        }
-        // Return offset.
-        return cid_len + 1;
+  // Check CID length.
+  switch (pflags & QUIC_CID_MASK)
+    {
+    case CID_LEN_8: cid_len = 8; break;
+    case CID_LEN_4: cid_len = 4; break;
+    case CID_LEN_1: cid_len = 1; break;
+    case CID_LEN_0: cid_len = 0; break;
+    default:
+      return -1;
+
+    }
+  // Return offset.
+  return cid_len + 1;
 }
 
 int sequence(const unsigned char *payload)
 {
-    unsigned char conv[6] = {0};
-    u_int seq_value = -1;
-    u_int seq_lens;
-    u_int cid_offs;
-    int i;
-
-        // Search SEQ bytes length.
-        switch (payload[0] & QUIC_SEQ_MASK)
-        {
-           case SEQ_LEN_6: seq_lens = 6; break;
-           case SEQ_LEN_4: seq_lens = 4; break;
-           case SEQ_LEN_2: seq_lens = 2; break;
-           case SEQ_LEN_1: seq_lens = 1; break;
-           default:
-               return -1;
-        }
-        // Retrieve SEQ offset.
-        cid_offs = connect_id(payload[0]);
-
-        if (cid_offs >= 0 && seq_lens > 0)
-        {
-            for (i = 0; i < seq_lens; i++)
-                conv[i] = payload[cid_offs + i];
-
-        seq_value = SEQ_CONV(conv);
-        }
-        // Return SEQ dec value;
-        return seq_value;
+  unsigned char conv[6] = {0};
+  u_int seq_value = -1;
+  u_int seq_lens;
+  u_int cid_offs;
+  int i;
+
+  // Search SEQ bytes length.
+  switch (payload[0] & QUIC_SEQ_MASK)
+    {
+    case SEQ_LEN_6: seq_lens = 6; break;
+    case SEQ_LEN_4: seq_lens = 4; break;
+    case SEQ_LEN_2: seq_lens = 2; break;
+    case SEQ_LEN_1: seq_lens = 1; break;
+    default:
+      return -1;
+    }
+  // Retrieve SEQ offset.
+  cid_offs = connect_id(payload[0]);
+
+  if (cid_offs >= 0 && seq_lens > 0)
+    {
+      for (i = 0; i < seq_lens; i++)
+	conv[i] = payload[cid_offs + i];
+
+      seq_value = SEQ_CONV(conv);
+    }
+  // Return SEQ dec value;
+  return seq_value;
 }
 
 void ndpi_search_quic(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
 {
-    struct ndpi_packet_struct *packet = &flow->packet;
-    u_int ver_offs;
-
-    if(packet->udp != NULL) {
-        NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "calculating quic over udp.\n");
-
-        // Settings without version. First check if PUBLIC FLAGS & SEQ bytes are 0x0. SEQ must be 1 at least.
-        if ((packet->payload[0] == 0x00 && packet->payload[1] != 0x00) || ((packet->payload[0] & QUIC_NO_V_RES_RSV) == 0))
-        {
-            if (sequence(packet->payload) < 1)
-            {
-
-                NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
-                NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
-            }
-
-            NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
-            ndpi_int_quic_add_connection(ndpi_struct, flow);
-        }
-
-        // Check if version, than the CID length.
-        else if (packet->payload[0] & QUIC_VER_MASK)
-        {
-            // Skip CID length.
-            ver_offs = connect_id(packet->payload[0]);
-
-            if (ver_offs >= 0){
-                unsigned char vers[] = {packet->payload[ver_offs], packet->payload[ver_offs + 1],
-                                        packet->payload[ver_offs + 2], packet->payload[ver_offs + 3]};
-
-                // Version Match.
-                if (vers[0] == 'Q' && vers[1] == '0' &&
-                    (vers[2] == '2' && (vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
-                                        vers[3] == '1' || vers[3] == '0')) ||
-                    (vers[2] == '1' && (vers[3] == '9' || vers[3] == '8' || vers[3] == '7' || vers[3] == '6' ||
-                                        vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
-                                        vers[3] == '1' || vers[3] == '0')) ||
-                    (vers[2] == '0' && vers[3] == '9'))
-
-                {
-                    NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
-                    ndpi_int_quic_add_connection(ndpi_struct, flow);
-                }
-            }
-        } else
-        {
-            NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
-            NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
-        }
-    }
+  struct ndpi_packet_struct *packet = &flow->packet;
+  u_int ver_offs;
+
+  if(packet->udp != NULL) {
+    u_int16_t sport = ntohs(packet->udp->source), dport = ntohs(packet->udp->dest);
+
+    NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "calculating quic over udp.\n");
+    
+    if(((packet->payload[0] & 0xF0) != 0)
+       || (!(sport == 80 || dport == 80 || sport == 443 || dport == 443)))
+      goto exclude_quic;
+
+    // Settings without version. First check if PUBLIC FLAGS & SEQ bytes are 0x0. SEQ must be 1 at least.
+    if ((packet->payload[0] == 0x00 && packet->payload[1] != 0x00) || ((packet->payload[0] & QUIC_NO_V_RES_RSV) == 0))
+      {
+	if (sequence(packet->payload) < 1)
+	  {
+
+	    NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
+	    NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
+	  }
+
+	NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
+	ndpi_int_quic_add_connection(ndpi_struct, flow);
+      }
+
+    // Check if version, than the CID length.
+    else if (packet->payload[0] & QUIC_VER_MASK)
+      {
+	// Skip CID length.
+	ver_offs = connect_id(packet->payload[0]);
+
+	if (ver_offs >= 0){
+	  unsigned char vers[] = {packet->payload[ver_offs], packet->payload[ver_offs + 1],
+				  packet->payload[ver_offs + 2], packet->payload[ver_offs + 3]};
+
+	  // Version Match.
+	  if (vers[0] == 'Q' && vers[1] == '0' &&
+	      (vers[2] == '2' && (vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
+				  vers[3] == '1' || vers[3] == '0')) ||
+	      (vers[2] == '1' && (vers[3] == '9' || vers[3] == '8' || vers[3] == '7' || vers[3] == '6' ||
+				  vers[3] == '5' || vers[3] == '4' || vers[3] == '3' || vers[3] == '2' ||
+				  vers[3] == '1' || vers[3] == '0')) ||
+	      (vers[2] == '0' && vers[3] == '9'))
+
+	    {
+	      NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "found quic.\n");
+	      ndpi_int_quic_add_connection(ndpi_struct, flow);
+	    }
+	}
+      } else
+      {
+      exclude_quic:
+	NDPI_LOG(NDPI_PROTOCOL_QUIC, ndpi_struct, NDPI_LOG_DEBUG, "exclude quic.\n");
+	NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_QUIC);
+      }
+  }
 }
 #endif