upstream: use KEM API for vanilla c25519 KEX

OpenBSD-Commit-ID: 38d937b85ff770886379dd66a8f32ab0c1c35c1f

12 files changed, 170 insertions, 312 deletions

diff --git a/Makefile.in b/Makefile.in
index 2b22e9f4..89f93036 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -98,8 +98,6 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
 	ssh-ed25519.o digest-openssl.o digest-libc.o hmac.o \
 	sc25519.o ge25519.o fe25519.o ed25519.o verify.o hash.o \
 	kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \
-	kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \
-	kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \
 	sntrup4591761.o kexsntrup4591761x25519.o kexkemc.o kexkems.o \
 	platform-pledge.o platform-tracing.o platform-misc.o
 
diff --git a/kex.h b/kex.h
index 258a6471..2eec2e04 100644
--- a/kex.h
+++ b/kex.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.h,v 1.99 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: kex.h,v 1.100 2019/01/21 10:24:09 djm Exp $ */
 
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
@@ -211,6 +211,11 @@ int	 kexc25519_server(struct ssh *);
 int	 kex_kem_client(struct ssh *);
 int	 kex_kem_server(struct ssh *);
 
+int	 kex_c25519_keypair(struct kex *);
+int	 kex_c25519_enc(struct kex *, const u_char *, size_t, struct sshbuf **,
+    struct sshbuf **);
+int	 kex_c25519_dec(struct kex *, const u_char *, size_t, struct sshbuf **);
+
 int	 kex_kem_sntrup4591761x25519_keypair(struct kex *);
 int	 kex_kem_sntrup4591761x25519_enc(struct kex *, const u_char *, size_t,
     struct sshbuf **, struct sshbuf **);
diff --git a/kexc25519.c b/kexc25519.c
index 3911baf1..a06c6e44 100644
--- a/kexc25519.c
+++ b/kexc25519.c
@@ -1,6 +1,6 @@
-/* $OpenBSD: kexc25519.c,v 1.13 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: kexc25519.c,v 1.14 2019/01/21 10:24:09 djm Exp $ */
 /*
- * Copyright (c) 2001, 2013 Markus Friedl.  All rights reserved.
+ * Copyright (c) 2019 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
  * Copyright (c) 2013 Aris Adamantiadis.  All rights reserved.
  *
@@ -29,20 +29,16 @@
 
 #include <sys/types.h>
 
-#include <signal.h>
+#include <stdio.h>
 #include <string.h>
+#include <signal.h>
 
-#include <openssl/bn.h>
-#include <openssl/evp.h>
-
-#include "sshbuf.h"
-#include "ssh2.h"
 #include "sshkey.h"
-#include "cipher.h"
 #include "kex.h"
-#include "log.h"
+#include "sshbuf.h"
 #include "digest.h"
 #include "ssherr.h"
+#include "ssh2.h"
 
 extern int crypto_scalarmult_curve25519(u_char a[CURVE25519_SIZE],
     const u_char b[CURVE25519_SIZE], const u_char c[CURVE25519_SIZE])
@@ -142,3 +138,109 @@ kex_c25519_hash(
 #endif
 	return 0;
 }
+
+int
+kex_c25519_keypair(struct kex *kex)
+{
+	struct sshbuf *buf = NULL;
+	u_char *cp = NULL;
+	int r;
+
+	if ((buf = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshbuf_reserve(buf, CURVE25519_SIZE, &cp)) != 0)
+		goto out;
+	kexc25519_keygen(kex->c25519_client_key, cp);
+#ifdef DEBUG_KEXECDH
+	dump_digest("client public key c25519:", cp, CURVE25519_SIZE);
+#endif
+	kex->kem_client_pub = buf;
+	buf = NULL;
+ out:
+	sshbuf_free(buf);
+	return r;
+}
+
+int
+kex_c25519_enc(struct kex *kex, const u_char *pkblob,
+   size_t pklen, struct sshbuf **server_blobp, struct sshbuf **shared_secretp)
+{
+	struct sshbuf *server_blob = NULL;
+	struct sshbuf *buf = NULL;
+	u_char *server_pub;
+	u_char server_key[CURVE25519_SIZE];
+	int r;
+
+	*server_blobp = NULL;
+	*shared_secretp = NULL;
+
+	if (pklen != CURVE25519_SIZE) {
+		r = SSH_ERR_SIGNATURE_INVALID;
+		goto out;
+	}
+#ifdef DEBUG_KEXECDH
+	dump_digest("client public key 25519:", pkblob, CURVE25519_SIZE);
+#endif
+	/* allocate space for encrypted KEM key and ECDH pub key */
+	if ((server_blob = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshbuf_reserve(server_blob, CURVE25519_SIZE, &server_pub)) != 0)
+		goto out;
+	kexc25519_keygen(server_key, server_pub);
+	/* allocate shared secret */
+	if ((buf = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = kexc25519_shared_key_ext(server_key, pkblob, buf, 0)) < 0)
+		goto out;
+#ifdef DEBUG_KEXECDH
+	dump_digest("server public key 25519:", server_pub, CURVE25519_SIZE);
+	dump_digest("encoded shared secret:", sshbuf_ptr(buf), sshbuf_len(buf));
+#endif
+	*server_blobp = server_blob;
+	*shared_secretp = buf;
+	server_blob = NULL;
+	buf = NULL;
+ out:
+	explicit_bzero(server_key, sizeof(server_key));
+	sshbuf_free(server_blob);
+	sshbuf_free(buf);
+	return r;
+}
+
+int
+kex_c25519_dec(struct kex *kex, const u_char *pkblob,
+    size_t pklen, struct sshbuf **shared_secretp)
+{
+	struct sshbuf *buf = NULL;
+	int r;
+
+	*shared_secretp = NULL;
+
+	if (pklen != CURVE25519_SIZE) {
+		r = SSH_ERR_SIGNATURE_INVALID;
+		goto out;
+	}
+#ifdef DEBUG_KEXECDH
+	dump_digest("server public key c25519:", pkblob, CURVE25519_SIZE);
+#endif
+	/* shared secret */
+	if ((buf = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = kexc25519_shared_key_ext(kex->c25519_client_key, pkblob,
+	    buf, 0)) < 0)
+		goto out;
+#ifdef DEBUG_KEXECDH
+	dump_digest("encoded shared secret:", sshbuf_ptr(buf), sshbuf_len(buf));
+#endif
+	*shared_secretp = buf;
+	buf = NULL;
+ out:
+	sshbuf_free(buf);
+	return r;
+}
diff --git a/kexc25519c.c b/kexc25519c.c
deleted file mode 100644
index cc6e54cc..00000000
--- a/kexc25519c.c
+++ /dev/null
@@ -1,145 +0,0 @@
-/* $OpenBSD: kexc25519c.c,v 1.13 2019/01/21 10:20:12 djm Exp $ */
-/*
- * Copyright (c) 2001 Markus Friedl.  All rights reserved.
- * Copyright (c) 2010 Damien Miller.  All rights reserved.
- * Copyright (c) 2013 Aris Adamantiadis.  All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "includes.h"
-
-#include <sys/types.h>
-
-#include <stdio.h>
-#include <string.h>
-#include <signal.h>
-
-#include "sshkey.h"
-#include "cipher.h"
-#include "kex.h"
-#include "log.h"
-#include "packet.h"
-#include "ssh2.h"
-#include "sshbuf.h"
-#include "digest.h"
-#include "ssherr.h"
-
-static int
-input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh);
-
-int
-kexc25519_client(struct ssh *ssh)
-{
-	struct kex *kex = ssh->kex;
-	int r;
-
-	kexc25519_keygen(kex->c25519_client_key, kex->c25519_client_pubkey);
-#ifdef DEBUG_KEXECDH
-	dump_digest("client private key:", kex->c25519_client_key,
-	    sizeof(kex->c25519_client_key));
-#endif
-	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
-	    (r = sshpkt_put_string(ssh, kex->c25519_client_pubkey,
-	    sizeof(kex->c25519_client_pubkey))) != 0 ||
-	    (r = sshpkt_send(ssh)) != 0)
-		return r;
-
-	debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
-	ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_c25519_reply);
-	return 0;
-}
-
-static int
-input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh)
-{
-	struct kex *kex = ssh->kex;
-	struct sshkey *server_host_key = NULL;
-	struct sshbuf *shared_secret = NULL;
-	u_char *server_pubkey = NULL;
-	u_char *server_host_key_blob = NULL, *signature = NULL;
-	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t slen, pklen, sbloblen, hashlen;
-	int r;
-
-	/* hostkey */
-	if ((r = sshpkt_get_string(ssh, &server_host_key_blob,
-	    &sbloblen)) != 0 ||
-	    (r = sshkey_from_blob(server_host_key_blob, sbloblen,
-	    &server_host_key)) != 0)
-		goto out;
-	if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)
-		goto out;
-
-	/* Q_S, server public key */
-	/* signed H */
-	if ((r = sshpkt_get_string(ssh, &server_pubkey, &pklen)) != 0 ||
-	    (r = sshpkt_get_string(ssh, &signature, &slen)) != 0 ||
-	    (r = sshpkt_get_end(ssh)) != 0)
-		goto out;
-	if (pklen != CURVE25519_SIZE) {
-		r = SSH_ERR_SIGNATURE_INVALID;
-		goto out;
-	}
-
-#ifdef DEBUG_KEXECDH
-	dump_digest("server public key:", server_pubkey, CURVE25519_SIZE);
-#endif
-
-	if ((shared_secret = sshbuf_new()) == NULL) {
-		r = SSH_ERR_ALLOC_FAIL;
-		goto out;
-	}
-	if ((r = kexc25519_shared_key(kex->c25519_client_key, server_pubkey,
-	    shared_secret)) != 0)
-		goto out;
-
-	/* calc and verify H */
-	hashlen = sizeof(hash);
-	if ((r = kex_c25519_hash(
-	    kex->hash_alg,
-	    kex->client_version,
-	    kex->server_version,
-	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
-	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
-	    server_host_key_blob, sbloblen,
-	    kex->c25519_client_pubkey, sizeof(kex->c25519_client_pubkey),
-	    server_pubkey, pklen,
-	    sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
-	    hash, &hashlen)) != 0)
-		goto out;
-
-	if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
-	    kex->hostkey_alg, ssh->compat)) != 0)
-		goto out;
-
-	if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
-		r = kex_send_newkeys(ssh);
-out:
-	explicit_bzero(hash, sizeof(hash));
-	explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
-	free(server_host_key_blob);
-	free(server_pubkey);
-	free(signature);
-	sshkey_free(server_host_key);
-	sshbuf_free(shared_secret);
-	return r;
-}
diff --git a/kexc25519s.c b/kexc25519s.c
deleted file mode 100644
index ace4d5c7..00000000
--- a/kexc25519s.c
+++ /dev/null
@@ -1,136 +0,0 @@
-/* $OpenBSD: kexc25519s.c,v 1.16 2019/01/21 10:20:12 djm Exp $ */
-/*
- * Copyright (c) 2001 Markus Friedl.  All rights reserved.
- * Copyright (c) 2010 Damien Miller.  All rights reserved.
- * Copyright (c) 2013 Aris Adamantiadis.  All rights reserved.
- *
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "includes.h"
-
-#include <sys/types.h>
-#include <stdio.h>
-#include <string.h>
-#include <signal.h>
-
-#include "sshkey.h"
-#include "cipher.h"
-#include "digest.h"
-#include "kex.h"
-#include "log.h"
-#include "packet.h"
-#include "ssh2.h"
-#include "sshbuf.h"
-#include "ssherr.h"
-
-static int input_kex_c25519_init(int, u_int32_t, struct ssh *);
-
-int
-kexc25519_server(struct ssh *ssh)
-{
-	debug("expecting SSH2_MSG_KEX_ECDH_INIT");
-	ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_INIT, &input_kex_c25519_init);
-	return 0;
-}
-
-static int
-input_kex_c25519_init(int type, u_int32_t seq, struct ssh *ssh)
-{
-	struct kex *kex = ssh->kex;
-	struct sshkey *server_host_private, *server_host_public;
-	struct sshbuf *shared_secret = NULL;
-	u_char *server_host_key_blob = NULL, *signature = NULL;
-	u_char server_key[CURVE25519_SIZE];
-	u_char *client_pubkey = NULL;
-	u_char server_pubkey[CURVE25519_SIZE];
-	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t slen, pklen, sbloblen, hashlen;
-	int r;
-
-	/* generate private key */
-	kexc25519_keygen(server_key, server_pubkey);
-#ifdef DEBUG_KEXECDH
-	dump_digest("server private key:", server_key, sizeof(server_key));
-#endif
-	if ((r = kex_load_hostkey(ssh, &server_host_private,
-	    &server_host_public)) != 0)
-		goto out;
-	if ((r = sshpkt_get_string(ssh, &client_pubkey, &pklen)) != 0 ||
-	    (r = sshpkt_get_end(ssh)) != 0)
-		goto out;
-	if (pklen != CURVE25519_SIZE) {
-		r = SSH_ERR_SIGNATURE_INVALID;
-		goto out;
-	}
-#ifdef DEBUG_KEXECDH
-	dump_digest("client public key:", client_pubkey, CURVE25519_SIZE);
-#endif
-
-	if ((shared_secret = sshbuf_new()) == NULL) {
-		r = SSH_ERR_ALLOC_FAIL;
-		goto out;
-	}
-	if ((r = kexc25519_shared_key(server_key, client_pubkey,
-	    shared_secret)) < 0)
-		goto out;
-
-	/* calc H */
-	if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
-	    &sbloblen)) != 0)
-		goto out;
-	hashlen = sizeof(hash);
-	if ((r = kex_c25519_hash(
-	    kex->hash_alg,
-	    kex->client_version,
-	    kex->server_version,
-	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
-	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
-	    server_host_key_blob, sbloblen,
-	    client_pubkey, pklen,
-	    server_pubkey, sizeof(server_pubkey),
-	    sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
-	    hash, &hashlen)) != 0)
-		goto out;
-
-	/* sign H */
-	if ((r = kex->sign(ssh, server_host_private, server_host_public,
-	    &signature, &slen, hash, hashlen, kex->hostkey_alg)) < 0)
-		goto out;
-
-	/* send server hostkey, ECDH pubkey 'Q_S' and signed H */
-	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_REPLY)) != 0 ||
-	    (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 ||
-	    (r = sshpkt_put_string(ssh, server_pubkey, sizeof(server_pubkey))) != 0 ||
-	    (r = sshpkt_put_string(ssh, signature, slen)) != 0 ||
-	    (r = sshpkt_send(ssh)) != 0)
-		goto out;
-
-	if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
-		r = kex_send_newkeys(ssh);
-out:
-	explicit_bzero(hash, sizeof(hash));
-	explicit_bzero(server_key, sizeof(server_key));
-	free(server_host_key_blob);
-	free(signature);
-	free(client_pubkey);
-	sshbuf_free(shared_secret);
-	return r;
-}
diff --git a/kexkemc.c b/kexkemc.c
index 47f15c30..13f36a11 100644
--- a/kexkemc.c
+++ b/kexkemc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexkemc.c,v 1.1 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: kexkemc.c,v 1.2 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright (c) 2019 Markus Friedl.  All rights reserved.
  *
@@ -47,7 +47,18 @@ kex_kem_client(struct ssh *ssh)
 	struct kex *kex = ssh->kex;
 	int r;
 
-	if ((r = kex_kem_sntrup4591761x25519_keypair(kex)) != 0)
+	switch (kex->kex_type) {
+	case KEX_C25519_SHA256:
+		r = kex_c25519_keypair(kex);
+		break;
+	case KEX_KEM_SNTRUP4591761X25519_SHA512:
+		r = kex_kem_sntrup4591761x25519_keypair(kex);
+		break;
+	default:
+		r = SSH_ERR_INVALID_ARGUMENT;
+		break;
+	}
+	if (r != 0)
 		return r;
 	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
 	    (r = sshpkt_put_stringb(ssh, kex->kem_client_pub)) != 0 ||
@@ -87,8 +98,19 @@ input_kex_kem_reply(int type, u_int32_t seq, struct ssh *ssh)
 		goto out;
 
 	/* compute shared secret */
-	if ((r = kex_kem_sntrup4591761x25519_dec(kex, server_pubkey, pklen,
-	    &shared_secret)) != 0)
+	switch (kex->kex_type) {
+	case KEX_C25519_SHA256:
+		r = kex_c25519_dec(kex, server_pubkey, pklen, &shared_secret);
+		break;
+	case KEX_KEM_SNTRUP4591761X25519_SHA512:
+		r = kex_kem_sntrup4591761x25519_dec(kex, server_pubkey, pklen,
+		    &shared_secret);
+		break;
+	default:
+		r = SSH_ERR_INVALID_ARGUMENT;
+		break;
+	}
+	if (r !=0 )
 		goto out;
 
 	/* calc and verify H */
diff --git a/kexkems.c b/kexkems.c
index 43cf8201..89237902 100644
--- a/kexkems.c
+++ b/kexkems.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexkems.c,v 1.1 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: kexkems.c,v 1.2 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright (c) 2019 Markus Friedl.  All rights reserved.
  *
@@ -68,8 +68,20 @@ input_kex_kem_init(int type, u_int32_t seq, struct ssh *ssh)
 		goto out;
 
 	/* compute shared secret */
-	if ((r = kex_kem_sntrup4591761x25519_enc(kex, client_pubkey, pklen,
-	    &server_pubkey, &shared_secret)) != 0)
+	switch (kex->kex_type) {
+	case KEX_C25519_SHA256:
+		r = kex_c25519_enc(kex, client_pubkey, pklen, &server_pubkey,
+		    &shared_secret);
+		break;
+	case KEX_KEM_SNTRUP4591761X25519_SHA512:
+		r = kex_kem_sntrup4591761x25519_enc(kex, client_pubkey, pklen,
+		    &server_pubkey, &shared_secret);
+		break;
+	default:
+		r = SSH_ERR_INVALID_ARGUMENT;
+		break;
+	}
+	if (r !=0 )
 		goto out;
 
 	/* calc H */
diff --git a/monitor.c b/monitor.c
index b10fdebf..9f86d5b7 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.193 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.194 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1688,7 +1688,7 @@ monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
 		kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
 # endif
 #endif /* WITH_OPENSSL */
-		kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+		kex->kex[KEX_C25519_SHA256] = kex_kem_server;
 		kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_server;
 		kex->load_host_public_key=&get_hostkey_public_by_type;
 		kex->load_host_private_key=&get_hostkey_private_by_type;
diff --git a/ssh-keyscan.c b/ssh-keyscan.c
index 83a76870..9eebc144 100644
--- a/ssh-keyscan.c
+++ b/ssh-keyscan.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keyscan.c,v 1.121 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: ssh-keyscan.c,v 1.122 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
  *
@@ -271,7 +271,7 @@ keygrab_ssh2(con *c)
 	c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 # endif
 #endif
-	c->c_ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
+	c->c_ssh->kex->kex[KEX_C25519_SHA256] = kex_kem_client;
 	c->c_ssh->kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_client;
 	ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
 	/*
diff --git a/ssh_api.c b/ssh_api.c
index 73981aa3..fe9fbf5a 100644
--- a/ssh_api.c
+++ b/ssh_api.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh_api.c,v 1.11 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: ssh_api.c,v 1.12 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright (c) 2012 Markus Friedl.  All rights reserved.
  *
@@ -110,7 +110,7 @@ ssh_init(struct ssh **sshp, int is_server, struct kex_params *kex_params)
 		ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
 # endif
 #endif /* WITH_OPENSSL */
-		ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+		ssh->kex->kex[KEX_C25519_SHA256] = kex_kem_server;
 		ssh->kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_server;
 		ssh->kex->load_host_public_key=&_ssh_host_public_key;
 		ssh->kex->load_host_private_key=&_ssh_host_private_key;
@@ -128,7 +128,7 @@ ssh_init(struct ssh **sshp, int is_server, struct kex_params *kex_params)
 		ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 # endif
 #endif /* WITH_OPENSSL */
-		ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
+		ssh->kex->kex[KEX_C25519_SHA256] = kex_kem_client;
 		ssh->kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_client;
 		ssh->kex->verify_host_key =&_ssh_verify_host_key;
 	}
diff --git a/sshconnect2.c b/sshconnect2.c
index 05657fd7..be19722b 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.297 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.298 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Damien Miller.  All rights reserved.
@@ -212,7 +212,7 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port)
 	ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 # endif
 #endif
-	ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
+	ssh->kex->kex[KEX_C25519_SHA256] = kex_kem_client;
 	ssh->kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_client;
 	ssh->kex->verify_host_key=&verify_host_key_callback;
 
diff --git a/sshd.c b/sshd.c
index 330b8052..665b22b1 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.528 2019/01/21 10:20:12 djm Exp $ */
+/* $OpenBSD: sshd.c,v 1.529 2019/01/21 10:24:09 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2218,7 +2218,7 @@ do_ssh2_kex(struct ssh *ssh)
 	kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
 # endif
 #endif
-	kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+	kex->kex[KEX_C25519_SHA256] = kex_kem_server;
 	kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_kem_server;
 	kex->load_host_public_key=&get_hostkey_public_by_type;
 	kex->load_host_private_key=&get_hostkey_private_by_type;