1 files changed, 25 insertions, 36 deletions

diff --git a/networking/tls.c b/networking/tls.c
index cacd2e9ff..5566d7911 100644
--- a/networking/tls.c
+++ b/networking/tls.c
@@ -1534,7 +1534,7 @@ static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
                 0x00,0x0a, //extension_type: "supported_groups"
                 0x00,0x06, //ext len
                 0x00,0x04, //list len
-                0x00,0x17, //curve_secp256r1
+                0x00,0x17, //curve_secp256r1 (aka P256)
                 //0x00,0x18, //curve_secp384r1
                 //0x00,0x19, //curve_secp521r1
                 0x00,0x1d, //curve_x25519 (RFC 7748)
@@ -1890,7 +1890,7 @@ static void process_server_key(tls_state_t *tls, int len)
                 tls->flags |= GOT_EC_CURVE_X25519;
                 memcpy(tls->hsd->ecc_pub_key32, keybuf, 32);
                 break;
-        case _0x03001741: //curve_secp256r1
+        case _0x03001741: //curve_secp256r1 (aka P256)
                 /* P256 point can be transmitted odd- or even-compressed
                  * (first byte is 3 or 2) or uncompressed (4).
                  */
@@ -1967,46 +1967,35 @@ static void send_client_key_exchange(tls_state_t *tls)
                 record->key[1] = len & 0xff;
                 len += 2;
                 premaster_size = RSA_PREMASTER_SIZE;
-        } else /* ECDHE */
-        if (tls->flags & GOT_EC_CURVE_X25519) {
-                /* ECDHE, curve x25519 */
-                static const uint8_t basepoint9[CURVE25519_KEYSIZE] ALIGN8 = {9};
-                uint8_t privkey[CURVE25519_KEYSIZE]; //[32]
-
-                if (!(tls->flags & GOT_EC_KEY))
-                        bb_simple_error_msg_and_die("server did not provide EC key");
-
-                /* Generate random private key, see RFC 7748 */
-                tls_get_random(privkey, sizeof(privkey));
-                privkey[0] &= 0xf8;
-                privkey[CURVE25519_KEYSIZE-1] = ((privkey[CURVE25519_KEYSIZE-1] & 0x7f) | 0x40);
-
-                /* Compute public key */
-                curve25519(record->key + 1, privkey, basepoint9);
-
-                /* Compute premaster using peer's public key */
-                dbg("computing x25519_premaster\n");
-                curve25519(premaster, privkey, tls->hsd->ecc_pub_key32);
-
-                len = CURVE25519_KEYSIZE;
-                record->key[0] = len;
-                len++;
-                premaster_size = CURVE25519_KEYSIZE;
         } else {
-                /* ECDHE, curve P256 */
+                /* ECDHE */
                 if (!(tls->flags & GOT_EC_KEY))
                         bb_simple_error_msg_and_die("server did not provide EC key");
 
-                dbg("computing P256_premaster\n");
-                curve_P256_compute_pubkey_and_premaster(
-                                record->key + 2, premaster,
-                                /*point:*/ tls->hsd->ecc_pub_key32
-                );
-                premaster_size = P256_KEYSIZE;
-                len = 1 + P256_KEYSIZE * 2;
+                if (tls->flags & GOT_EC_CURVE_X25519) {
+                        /* ECDHE, curve x25519 */
+                        dbg("computing x25519_premaster\n");
+                        curve_x25519_compute_pubkey_and_premaster(
+                                        record->key + 1, premaster,
+                                        /*point:*/ tls->hsd->ecc_pub_key32
+                        );
+                        len = CURVE25519_KEYSIZE;
+                        //record->key[0] = len;
+                        //len++;
+                        //premaster_size = CURVE25519_KEYSIZE;
+                } else {
+                        /* ECDHE, curve P256 */
+                        dbg("computing P256_premaster\n");
+                        curve_P256_compute_pubkey_and_premaster(
+                                        record->key + 2, premaster,
+                                        /*point:*/ tls->hsd->ecc_pub_key32
+                        );
+                        record->key[1] = 4; /* "uncompressed point" */
+                        len = 1 + P256_KEYSIZE * 2;
+                }
                 record->key[0] = len;
-                record->key[1] = 4;
                 len++;
+                premaster_size = P256_KEYSIZE; // = CURVE25519_KEYSIZE = 32
         }
 
         record->type = HANDSHAKE_CLIENT_KEY_EXCHANGE;