ipsec: esp-encrypt rework

Change-Id: Ibe7f806b9d600994e83c9f1be526fdb0a1ef1833
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vnet/ipsec/esp.h b/src/vnet/ipsec/esp.h
index 8f900da..063b74b 100644
--- a/src/vnet/ipsec/esp.h
+++ b/src/vnet/ipsec/esp.h
@@ -55,7 +55,9 @@
 /* *INDENT-ON* */
 
 #define ESP_WINDOW_SIZE		(64)
-#define ESP_SEQ_MAX 		(4294967295UL)
+#define ESP_SEQ_MAX		(4294967295UL)
+#define ESP_MAX_BLOCK_SIZE	(16)
+#define ESP_MAX_ICV_SIZE	(16)
 
 u8 *format_esp_header (u8 * s, va_list * args);