upstream: factor out kex_load_hostkey() - this is duplicated in

both the client and server implementations for most KEX methods.

from markus@ ok djm@

OpenBSD-Commit-ID: 8232fa7c21fbfbcaf838313b0c166dc6c8762f3c

6 files changed, 33 insertions, 55 deletions

diff --git a/kex.c b/kex.c
index 0d5618ecc..a0d13a880 100644
--- a/kex.c
+++ b/kex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.144 2019/01/21 09:55:52 djm Exp $ */
+/* $OpenBSD: kex.c,v 1.145 2019/01/21 10:05:09 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -1052,6 +1052,24 @@ kex_derive_keys_bn(struct ssh *ssh, u_char *hash, u_int hashlen,
 }
 #endif
 
+int
+kex_load_hostkey(struct ssh *ssh, struct sshkey **pubp, struct sshkey **prvp)
+{
+        struct kex *kex = ssh->kex;
+
+        *pubp = NULL;
+        *prvp = NULL;
+        if (kex->load_host_public_key == NULL ||
+            kex->load_host_private_key == NULL)
+                return SSH_ERR_INVALID_ARGUMENT;
+        *pubp = kex->load_host_public_key(kex->hostkey_type,
+            kex->hostkey_nid, ssh);
+        *prvp = kex->load_host_private_key(kex->hostkey_type,
+            kex->hostkey_nid, ssh);
+        if (*pubp == NULL)
+                return SSH_ERR_NO_HOSTKEY_LOADED;
+        return 0;
+}
 
 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
 void
diff --git a/kex.h b/kex.h
index a11bd5ae6..fa65b8657 100644
--- a/kex.h
+++ b/kex.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.h,v 1.96 2019/01/21 10:03:37 djm Exp $ */
+/* $OpenBSD: kex.h,v 1.97 2019/01/21 10:05:09 djm Exp $ */
 
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
@@ -184,6 +184,7 @@ void	 kex_free(struct kex *);
 int      kex_buf2prop(struct sshbuf *, int *, char ***);
 int      kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
 void     kex_prop_free(char **);
+int      kex_load_hostkey(struct ssh *, struct sshkey **, struct sshkey **);
 
 int      kex_send_kexinit(struct ssh *);
 int      kex_input_kexinit(int, u_int32_t, struct ssh *);
diff --git a/kexc25519s.c b/kexc25519s.c
index 65df18c4b..d7cc70fee 100644
--- a/kexc25519s.c
+++ b/kexc25519s.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexc25519s.c,v 1.14 2019/01/21 09:55:52 djm Exp $ */
+/* $OpenBSD: kexc25519s.c,v 1.15 2019/01/21 10:05:09 djm Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -70,20 +70,9 @@ input_kex_c25519_init(int type, u_int32_t seq, struct ssh *ssh)
 #ifdef DEBUG_KEXECDH
         dump_digest("server private key:", server_key, sizeof(server_key));
 #endif
-        if (kex->load_host_public_key == NULL ||
-            kex->load_host_private_key == NULL) {
-                r = SSH_ERR_INVALID_ARGUMENT;
+        if ((r = kex_load_hostkey(ssh, &server_host_private,
+            &server_host_public)) != 0)
                 goto out;
-        }
-        server_host_public = kex->load_host_public_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        server_host_private = kex->load_host_private_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        if (server_host_public == NULL) {
-                r = SSH_ERR_NO_HOSTKEY_LOADED;
-                goto out;
-        }
-
         if ((r = sshpkt_get_string(ssh, &client_pubkey, &pklen)) != 0 ||
             (r = sshpkt_get_end(ssh)) != 0)
                 goto out;
diff --git a/kexdhs.c b/kexdhs.c
index 0f028aaeb..e33901bbf 100644
--- a/kexdhs.c
+++ b/kexdhs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexdhs.c,v 1.34 2019/01/21 10:03:37 djm Exp $ */
+/* $OpenBSD: kexdhs.c,v 1.35 2019/01/21 10:05:09 djm Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -81,19 +81,9 @@ input_kex_dh_init(int type, u_int32_t seq, struct ssh *ssh)
         size_t hashlen;
         int r;
 
-        if (kex->load_host_public_key == NULL ||
-            kex->load_host_private_key == NULL) {
-                r = SSH_ERR_INVALID_ARGUMENT;
+        if ((r = kex_load_hostkey(ssh, &server_host_private,
+            &server_host_public)) != 0)
                 goto out;
-        }
-        server_host_public = kex->load_host_public_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        server_host_private = kex->load_host_private_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        if (server_host_public == NULL) {
-                r = SSH_ERR_NO_HOSTKEY_LOADED;
-                goto out;
-        }
 
         /* key, cert */
         if ((r = sshpkt_get_bignum2(ssh, &dh_client_pub)) != 0 ||
diff --git a/kexecdhs.c b/kexecdhs.c
index 4ba2072df..b9254eed7 100644
--- a/kexecdhs.c
+++ b/kexecdhs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexecdhs.c,v 1.20 2019/01/21 09:55:52 djm Exp $ */
+/* $OpenBSD: kexecdhs.c,v 1.21 2019/01/21 10:05:09 djm Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -89,19 +89,9 @@ input_kex_ecdh_init(int type, u_int32_t seq, struct ssh *ssh)
         sshkey_dump_ec_key(server_key);
 #endif
 
-        if (kex->load_host_public_key == NULL ||
-            kex->load_host_private_key == NULL) {
-                r = SSH_ERR_INVALID_ARGUMENT;
+        if ((r = kex_load_hostkey(ssh, &server_host_private,
+            &server_host_public)) != 0)
                 goto out;
-        }
-        server_host_public = kex->load_host_public_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        server_host_private = kex->load_host_private_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        if (server_host_public == NULL) {
-                r = SSH_ERR_NO_HOSTKEY_LOADED;
-                goto out;
-        }
         if ((client_public = EC_POINT_new(group)) == NULL) {
                 r = SSH_ERR_ALLOC_FAIL;
                 goto out;
diff --git a/kexgexs.c b/kexgexs.c
index f8eb36545..a617d4453 100644
--- a/kexgexs.c
+++ b/kexgexs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexs.c,v 1.40 2019/01/21 10:03:37 djm Exp $ */
+/* $OpenBSD: kexgexs.c,v 1.41 2019/01/21 10:05:09 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -136,19 +136,9 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
         size_t hashlen;
         int r;
 
-        if (kex->load_host_public_key == NULL ||
-            kex->load_host_private_key == NULL) {
-                r = SSH_ERR_INVALID_ARGUMENT;
+        if ((r = kex_load_hostkey(ssh, &server_host_private,
+            &server_host_public)) != 0)
                 goto out;
-        }
-        server_host_public = kex->load_host_public_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        server_host_private = kex->load_host_private_key(kex->hostkey_type,
-            kex->hostkey_nid, ssh);
-        if (server_host_public == NULL) {
-                r = SSH_ERR_NO_HOSTKEY_LOADED;
-                goto out;
-        }
 
         /* key, cert */
         if ((r = sshpkt_get_bignum2(ssh, &dh_client_pub)) != 0 ||