Index: sys/opencrypto/cryptodev.h
===================================================================
--- sys/opencrypto/cryptodev.h
+++ sys/opencrypto/cryptodev.h
@@ -206,7 +206,8 @@
 #define	CRYPTO_POLY1305		38
 #define	CRYPTO_AES_CCM_CBC_MAC	39	/* auth side */
 #define	CRYPTO_AES_CCM_16	40	/* cipher side */
-#define	CRYPTO_ALGORITHM_MAX	40	/* Keep updated - see below */
+#define	CRYPTO_ESN		41	/* Support for Extended Sequence Numbers */
+#define	CRYPTO_ALGORITHM_MAX	41	/* Keep updated - see below */
 
 #define	CRYPTO_ALGO_VALID(x)	((x) >= CRYPTO_ALGORITHM_MIN && \
 				 (x) <= CRYPTO_ALGORITHM_MAX)
@@ -393,7 +394,10 @@
 	int		cri_mlen;	/* Number of bytes we want from the
 					   entire hash. 0 means all. */
 	caddr_t		cri_key;	/* key to use */
+	union {
 		u_int8_t	cri_iv[EALG_MAX_BLOCK_LEN];	/* IV to use */
+		u_int8_t	cri_esn[4];			/* high-order ESN */
+	};
 	struct cryptoini *cri_next;
 };
 
@@ -411,6 +415,7 @@
 #define	CRD_F_DSA_SHA_NEEDED	0x08	/* Compute SHA-1 of buffer for DSA */
 #define	CRD_F_COMP		0x0f    /* Set when doing compression */
 #define	CRD_F_KEY_EXPLICIT	0x10	/* Key explicitly provided */
+#define	CRD_F_ESN		0x20	/* Set when ESN field is provided */
 
 	struct cryptoini	CRD_INI; /* Initialization/context data */
 #define	crd_esn		CRD_INI.cri_esn