Index: sys/opencrypto/crypto.c
===================================================================
--- sys/opencrypto/crypto.c
+++ sys/opencrypto/crypto.c
@@ -743,6 +743,8 @@
 	return (alg_type(alg) == ALG_AEAD);
 }
 
+#define SUPPORTED_SES (CSP_F_SEPARATE_OUTPUT | CSP_F_SEPARATE_AAD | CSP_F_ESN)
+
 /* Various sanity checks on crypto session parameters. */
 static bool
 check_csp(const struct crypto_session_params *csp)
@@ -750,8 +752,7 @@
 	struct auth_hash *axf;
 
 	/* Mode-independent checks. */
-	if ((csp->csp_flags & ~(CSP_F_SEPARATE_OUTPUT | CSP_F_SEPARATE_AAD)) !=
-	    0)
+	if ((csp->csp_flags & ~(SUPPORTED_SES)) != 0)
 		return (false);
 	if (csp->csp_ivlen < 0 || csp->csp_cipher_klen < 0 ||
 	    csp->csp_auth_klen < 0 || csp->csp_auth_mlen < 0)
Index: sys/opencrypto/cryptodev.h
===================================================================
--- sys/opencrypto/cryptodev.h
+++ sys/opencrypto/cryptodev.h
@@ -377,6 +377,7 @@
 
 #define	CSP_F_SEPARATE_OUTPUT	0x0001	/* Requests can use separate output */
 #define	CSP_F_SEPARATE_AAD	0x0002	/* Requests can use separate AAD */
+#define CSP_F_ESN		0x0004  /* Requests can use seperate ESN field */ 
 
 	int		csp_ivlen;	/* IV length in bytes. */
 
@@ -485,6 +486,8 @@
 	void		*crp_aad;	/* AAD buffer. */
 	int		crp_aad_start;	/* Location of AAD. */
 	int		crp_aad_length;	/* 0 => no AAD. */
+	uint8_t		crp_esn[4];	/* high-order ESN */
+
 	int		crp_iv_start;	/* Location of IV.  IV length is from
 					 * the session.
 					 */