Small protocol change for more replay attack prevention.

see the changes to Prevent_Tracking.txt

1 files changed, 12 insertions, 4 deletions

diff --git a/toxcore/onion_announce.h b/toxcore/onion_announce.h
index 01cd7243..27b25bd4 100644
--- a/toxcore/onion_announce.h
+++ b/toxcore/onion_announce.h
@@ -31,15 +31,20 @@
 
 #define ONION_ANNOUNCE_SENDBACK_DATA_LENGTH (crypto_secretbox_NONCEBYTES + sizeof(uint32_t) + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES + sizeof(IP_Port) + crypto_secretbox_MACBYTES)
 
-#define ONION_ANNOUNCE_RESPONSE_MIN_SIZE (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES + ONION_PING_ID_SIZE + crypto_box_MACBYTES)
+#define ONION_ANNOUNCE_RESPONSE_MIN_SIZE (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES + 1 + ONION_PING_ID_SIZE + crypto_box_MACBYTES)
 #define ONION_ANNOUNCE_RESPONSE_MAX_SIZE (ONION_ANNOUNCE_RESPONSE_MIN_SIZE + sizeof(Node_format)*MAX_SENT_NODES)
 
 #define ONION_DATA_RESPONSE_MIN_SIZE (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_box_MACBYTES)
 
+#if ONION_PING_ID_SIZE != crypto_box_PUBLICKEYBYTES
+#error announce response packets assume that ONION_PING_ID_SIZE is equal to crypto_box_PUBLICKEYBYTES
+#endif
+
 typedef struct {
     uint8_t public_key[crypto_box_PUBLICKEYBYTES];
     IP_Port ret_ip_port;
     uint8_t ret[ONION_RETURN_3];
+    uint8_t data_public_key[crypto_box_PUBLICKEYBYTES];
     uint64_t time;
 } Onion_Announce_Entry;
 
@@ -59,6 +64,7 @@ typedef struct {
  * public_key and secret_key is the kepair which will be used to encrypt the request.
  * ping_id is the ping id that will be sent in the request.
  * client_id is the client id of the node we are searching for.
+ * data_public_key is the public key we want others to encrypt their data packets with.
  * sendback_data is the data of ONION_ANNOUNCE_SENDBACK_DATA_LENGTH length that we expect to
  * receive back in the response.
  *
@@ -66,7 +72,7 @@ typedef struct {
  * return 0 on success.
  */
 int send_announce_request(DHT *dht, Node_format *nodes, uint8_t *public_key, uint8_t *secret_key, uint8_t *ping_id,
-                          uint8_t *client_id, uint8_t *sendback_data);
+                          uint8_t *client_id, uint8_t *data_public_key, uint8_t *sendback_data);
 
 /* Create and send an onion data request packet.
  *
@@ -75,13 +81,15 @@ int send_announce_request(DHT *dht, Node_format *nodes, uint8_t *public_key, uin
  * send the packet to that person in the form of a response)
  *
  * public_key is the real public key of the node which we want to send the data of length length to.
+ * encrypt_public_key is the public key used to encrypt the data packet.
+ *
  * nonce is the nonce to encrypt this packet with
  *
  * return -1 on failure.
  * return 0 on success.
  */
-int send_data_request(DHT *dht, Node_format *nodes, uint8_t *public_key, uint8_t *nonce, uint8_t *data,
-                      uint16_t length);
+int send_data_request(DHT *dht, Node_format *nodes, uint8_t *public_key, uint8_t *encrypt_public_key, uint8_t *nonce,
+                      uint8_t *data, uint16_t length);
 
 
 Onion_Announce *new_onion_announce(DHT *dht);