prinet-proxy: Fix memory leak

Incorrect encryption size for keepalive package. don't include
macbytes in length. Tweak length afterwards with result of
encryption function

src/main/pumpnet/prinet-proxy/keepalive.c

@@ -41,7 +41,7 @@ static void* _pumpnet_prinet_proxy_keepalive_proc(void* ctx)
                     keepalive_packet->nounce,
                     sizeof(keepalive_packet->nounce),
                     keepalive_packet->data,
-                    pumpnet_prinet_proxy_packet_get_data_len(keepalive_packet),
+                    PUMPNET_PRINET_PROXY_PACKET_KEEPALIVE_SIZE,
                     keepalive_packet->data);
 
                 keepalive_packet->length = pumpnet_prinet_proxy_packet_get_header_len() + enc_data_len;

src/main/pumpnet/prinet-proxy/packet.c

@@ -17,7 +17,7 @@ struct pumpnet_prinet_proxy_packet_data_keepalive {
 static const size_t HEADER_SIZE = sizeof(uint32_t) + sizeof(uint8_t) * SEC_PRINET_NOUNCE_LEN;
 
 static const uint32_t PACKET_KEEPALIVE_ID = 0x3000000;
-static const uint32_t PACKET_KEEPALIVE_SIZE =
+const uint32_t PUMPNET_PRINET_PROXY_PACKET_KEEPALIVE_SIZE =
         sizeof(struct pumpnet_prinet_proxy_packet_data) +
         sizeof(struct pumpnet_prinet_proxy_packet_data_keepalive);
 
@@ -61,7 +61,7 @@ struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_create_keepalive
     struct pumpnet_prinet_proxy_packet* packet;
     struct pumpnet_prinet_proxy_packet_data* data;
 
-    packet = pumpnet_prinet_proxy_packet_alloc_response(PACKET_KEEPALIVE_SIZE);
+    packet = pumpnet_prinet_proxy_packet_alloc_response(PUMPNET_PRINET_PROXY_PACKET_KEEPALIVE_SIZE);
 
     util_rand_gen_bytes(packet->nounce, SEC_PRINET_NOUNCE_LEN);
 

src/main/pumpnet/prinet-proxy/packet.h

@@ -11,6 +11,8 @@ struct pumpnet_prinet_proxy_packet {
     uint8_t data[];
 } __attribute__((__packed__));
 
+extern const uint32_t PUMPNET_PRINET_PROXY_PACKET_KEEPALIVE_SIZE;
+
 struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_alloc(size_t data_len);
 
 struct pumpnet_prinet_proxy_packet* pumpnet_prinet_proxy_packet_alloc_response(size_t data_len);