1 files changed, 17 insertions, 92 deletions

diff --git a/src/lib/libssl/ssl_tlsext.c b/src/lib/libssl/ssl_tlsext.c
index 5cebd1d630..46f30aa47e 100644
--- a/src/lib/libssl/ssl_tlsext.c
+++ b/src/lib/libssl/ssl_tlsext.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.c,v 1.57 2020/01/26 03:29:30 beck Exp $ */
+/* $OpenBSD: ssl_tlsext.c,v 1.58 2020/01/30 17:09:23 jsing Exp $ */
 /*
  * Copyright (c) 2016, 2017, 2019 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -16,6 +16,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+
 #include <openssl/curve25519.h>
 #include <openssl/ocsp.h>
 
@@ -1255,82 +1256,46 @@ tlsext_keyshare_client_needs(SSL *s)
 int
 tlsext_keyshare_client_build(SSL *s, CBB *cbb)
 {
-        uint8_t *public_key = NULL, *private_key = NULL;
-        CBB client_shares, key_exchange;
+        CBB client_shares;
 
-        /* Generate and provide key shares. */
         if (!CBB_add_u16_length_prefixed(cbb, &client_shares))
                 return 0;
 
-        /* XXX - other groups. */
-
-        /* Generate X25519 key pair. */
-        if ((public_key = malloc(X25519_KEY_LENGTH)) == NULL)
-                goto err;
-        if ((private_key = malloc(X25519_KEY_LENGTH)) == NULL)
-                goto err;
-        X25519_keypair(public_key, private_key);
-
-        /* Add the group and serialize the public key. */
-        if (!CBB_add_u16(&client_shares, tls1_ec_nid2curve_id(NID_X25519)))
-                goto err;
-        if (!CBB_add_u16_length_prefixed(&client_shares, &key_exchange))
-                goto err;
-        if (!CBB_add_bytes(&key_exchange, public_key, X25519_KEY_LENGTH))
-                goto err;
+        if (!tls13_key_share_public(S3I(s)->hs_tls13.key_share,
+            &client_shares))
+                return 0;
 
         if (!CBB_flush(cbb))
-                goto err;
-
-        S3I(s)->hs_tls13.x25519_public = public_key;
-        S3I(s)->hs_tls13.x25519_private = private_key;
+                return 0;
 
         return 1;
-
- err:
-        freezero(public_key, X25519_KEY_LENGTH);
-        freezero(private_key, X25519_KEY_LENGTH);
-
-        return 0;
 }
 
 int
 tlsext_keyshare_server_parse(SSL *s, CBS *cbs, int *alert)
 {
         CBS client_shares;
-        CBS key_exchange;
         uint16_t group;
-        size_t out_len;
 
         if (!CBS_get_u16_length_prefixed(cbs, &client_shares))
                 goto err;
 
-        if (CBS_len(cbs) != 0)
-                goto err;
-
         while (CBS_len(&client_shares) > 0) {
 
                 /* Unpack client share. */
                 if (!CBS_get_u16(&client_shares, &group))
                         goto err;
 
-                if (!CBS_get_u16_length_prefixed(&client_shares, &key_exchange))
-                        goto err;
-
                 /*
-                 * Skip this client share if not X25519
                  * XXX support other groups later.
                  * XXX enforce group can only appear once.
                  */
-                if (S3I(s)->hs_tls13.x25519_peer_public != NULL ||
-                    group != tls1_ec_nid2curve_id(NID_X25519))
+                if (S3I(s)->hs_tls13.key_share == NULL ||
+                    tls13_key_share_group(S3I(s)->hs_tls13.key_share) != group)
                         continue;
 
-                if (CBS_len(&key_exchange) != X25519_KEY_LENGTH)
-                        goto err;
-
-                if (!CBS_stow(&key_exchange, &S3I(s)->hs_tls13.x25519_peer_public,
-                    &out_len))
+                if (!tls13_key_share_peer_public(S3I(s)->hs_tls13.key_share,
+                    group, &client_shares))
                         goto err;
         }
 
@@ -1353,68 +1318,28 @@ tlsext_keyshare_server_needs(SSL *s)
 int
 tlsext_keyshare_server_build(SSL *s, CBB *cbb)
 {
-        uint8_t *public_key = NULL, *private_key = NULL;
-        CBB key_exchange;
-
-        /* XXX deduplicate with client code */
-
-        /* X25519 */
-        if (S3I(s)->hs_tls13.x25519_peer_public == NULL)
+        if (S3I(s)->hs_tls13.key_share == NULL)
                 return 0;
 
-        /* Generate X25519 key pair. */
-        if ((public_key = malloc(X25519_KEY_LENGTH)) == NULL)
-                goto err;
-        if ((private_key = malloc(X25519_KEY_LENGTH)) == NULL)
-                goto err;
-        X25519_keypair(public_key, private_key);
-
-        /* Add the group and serialize the public key. */
-        if (!CBB_add_u16(cbb, tls1_ec_nid2curve_id(NID_X25519)))
-                goto err;
-        if (!CBB_add_u16_length_prefixed(cbb, &key_exchange))
-                goto err;
-        if (!CBB_add_bytes(&key_exchange, public_key, X25519_KEY_LENGTH))
-                goto err;
-
-        if (!CBB_flush(cbb))
-                goto err;
-
-        S3I(s)->hs_tls13.x25519_public = public_key;
-        S3I(s)->hs_tls13.x25519_private = private_key;
+        if (!tls13_key_share_public(S3I(s)->hs_tls13.key_share, cbb))
+                return 0;
 
         return 1;
-
- err:
-        freezero(public_key, X25519_KEY_LENGTH);
-        freezero(private_key, X25519_KEY_LENGTH);
-
-        return 0;
 }
 
 int
 tlsext_keyshare_client_parse(SSL *s, CBS *cbs, int *alert)
 {
-        CBS key_exchange;
         uint16_t group;
-        size_t out_len;
 
         /* Unpack server share. */
         if (!CBS_get_u16(cbs, &group))
                 goto err;
 
-        /* Handle other groups and verify that they're valid. */
-        if (group != tls1_ec_nid2curve_id(NID_X25519))
-                goto err;
-
-        if (!CBS_get_u16_length_prefixed(cbs, &key_exchange))
-                goto err;
-
-        if (CBS_len(&key_exchange) != X25519_KEY_LENGTH)
-                goto err;
+        /* XXX - Handle other groups and verify that they're valid. */
 
-        if (!CBS_stow(&key_exchange, &S3I(s)->hs_tls13.x25519_peer_public,
-            &out_len))
+        if (!tls13_key_share_peer_public(S3I(s)->hs_tls13.key_share,
+            group, cbs))
                 goto err;
 
         return 1;