Index: head/share/man/man4/crypto.4
===================================================================
--- head/share/man/man4/crypto.4
+++ head/share/man/man4/crypto.4
@@ -60,7 +60,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 11, 2020
+.Dd October 19, 2020
 .Dt CRYPTO 4
 .Os
 .Sh NAME
@@ -108,6 +108,11 @@
 modular arithmetic (for Diffie-Hellman key exchange and other
 cryptographic protocols).
 The two modes are described separately below.
+.Sh DEPRECATION NOTICE
+The asymmetric-key operations supported by this interface will not be
+present in
+.Fx 14.0
+and later.
 .Sh THEORY OF OPERATION
 Regardless of whether symmetric-key or asymmetric-key operations are
 to be performed, use of the device requires a basic series of steps:
Index: head/sys/opencrypto/crypto.c
===================================================================
--- head/sys/opencrypto/crypto.c
+++ head/sys/opencrypto/crypto.c
@@ -1142,6 +1142,7 @@
 				, kalg
 				, flags
 			);
+		gone_in_dev(cap->cc_dev, 14, "asymmetric crypto");
 		err = 0;
 	} else
 		err = EINVAL;
Index: head/sys/opencrypto/cryptodev.c
===================================================================
--- head/sys/opencrypto/cryptodev.c
+++ head/sys/opencrypto/cryptodev.c
@@ -346,6 +346,11 @@
     &use_separate_aad, 0,
     "Use separate AAD buffer for /dev/crypto requests.");
 
+static struct timeval warninterval = { .tv_sec = 60, .tv_usec = 0 };
+SYSCTL_TIMEVAL_SEC(_kern, OID_AUTO, cryptodev_warn_interval, CTLFLAG_RW,
+    &warninterval,
+    "Delay in seconds between warnings of deprecated /dev/crypto algorithms");
+
 static	int cryptof_ioctl(struct file *, u_long, void *,
 		    struct ucred *, struct thread *);
 static	int cryptof_stat(struct file *, struct stat *,
@@ -419,6 +424,7 @@
 	struct ucred *active_cred,
 	struct thread *td)
 {
+	static struct timeval keywarn, featwarn;
 	struct crypto_session_params csp;
 	struct fcrypt *fcr = fp->f_data;
 	struct csession *cse;
@@ -818,6 +824,10 @@
 		break;
 	case CIOCKEY:
 	case CIOCKEY2:
+		if (ratecheck(&keywarn, &warninterval))
+			gone_in(14,
+			    "Asymmetric crypto operations via /dev/crypto");
+
 		if (!crypto_userasymcrypto) {
 			SDT_PROBE1(opencrypto, dev, ioctl, error, __LINE__);
 			return (EPERM);		/* XXX compat? */
@@ -833,6 +843,10 @@
 		mtx_unlock(&Giant);
 		break;
 	case CIOCASYMFEAT:
+		if (ratecheck(&featwarn, &warninterval))
+			gone_in(14,
+			    "Asymmetric crypto features via /dev/crypto");
+
 		if (!crypto_userasymcrypto) {
 			/*
 			 * NB: if user asym crypto operations are