wireguard: add dos mitigation support

[vpp.git] / src / plugins / wireguard / wireguard_cookie.c

diff --git a/src/plugins/wireguard/wireguard_cookie.c b/src/plugins/wireguard/wireguard_cookie.c
index c4279b7..595b877 100644 (file)
--- a/src/plugins/wireguard/wireguard_cookie.c
+++ b/src/plugins/wireguard/wireguard_cookie.c
@@ -20,6 +20,7 @@
 #include <vlib/vlib.h>
 
 #include <wireguard/wireguard_cookie.h>
+#include <wireguard/wireguard_chachapoly.h>
 #include <wireguard/wireguard.h>
 
 static void cookie_precompute_key (uint8_t *,
@@ -57,6 +58,51 @@ cookie_checker_update (cookie_checker_t * cc, uint8_t key[COOKIE_INPUT_SIZE])
     }
 }
 
+void
+cookie_checker_create_payload (vlib_main_t *vm, cookie_checker_t *cc,
+                              message_macs_t *cm,
+                              uint8_t nonce[COOKIE_NONCE_SIZE],
+                              uint8_t ecookie[COOKIE_ENCRYPTED_SIZE],
+                              ip46_address_t *ip, u16 udp_port)
+{
+  uint8_t cookie[COOKIE_COOKIE_SIZE];
+
+  cookie_checker_make_cookie (vm, cc, cookie, ip, udp_port);
+  RAND_bytes (nonce, COOKIE_NONCE_SIZE);
+
+  wg_xchacha20poly1305_encrypt (vm, cookie, COOKIE_COOKIE_SIZE, ecookie,
+                               cm->mac1, COOKIE_MAC_SIZE, nonce,
+                               cc->cc_cookie_key);
+
+  wg_secure_zero_memory (cookie, sizeof (cookie));
+}
+
+bool
+cookie_maker_consume_payload (vlib_main_t *vm, cookie_maker_t *cp,
+                             uint8_t nonce[COOKIE_NONCE_SIZE],
+                             uint8_t ecookie[COOKIE_ENCRYPTED_SIZE])
+{
+  uint8_t cookie[COOKIE_COOKIE_SIZE];
+
+  if (cp->cp_mac1_valid == 0)
+    {
+      return false;
+    }
+
+  if (!wg_xchacha20poly1305_decrypt (vm, ecookie, COOKIE_ENCRYPTED_SIZE,
+                                    cookie, cp->cp_mac1_last, COOKIE_MAC_SIZE,
+                                    nonce, cp->cp_cookie_key))
+    {
+      return false;
+    }
+
+  clib_memcpy (cp->cp_cookie, cookie, COOKIE_COOKIE_SIZE);
+  cp->cp_birthdate = vlib_time_now (vm);
+  cp->cp_mac1_valid = 0;
+
+  return true;
+}
+
 void
 cookie_maker_mac (cookie_maker_t * cp, message_macs_t * cm, void *buf,
                  size_t len)