5 files changed, 69 insertions, 7 deletions

diff --git a/src/lib/libssl/tls13_handshake.c b/src/lib/libssl/tls13_handshake.c
index 310a2116b8..cca8560fc2 100644
--- a/src/lib/libssl/tls13_handshake.c
+++ b/src/lib/libssl/tls13_handshake.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: tls13_handshake.c,v 1.69 2021/07/01 17:53:39 jsing Exp $      */
+/*      $OpenBSD: tls13_handshake.c,v 1.70 2021/09/16 19:25:30 jsing Exp $      */
 /*
  * Copyright (c) 2018-2021 Theo Buehler <tb@openbsd.org>
  * Copyright (c) 2019 Joel Sing <jsing@openbsd.org>
@@ -331,6 +331,18 @@ tls13_handshake_advance_state_machine(struct tls13_ctx *ctx)
         return 1;
 }
 
+static int
+tls13_handshake_end_of_flight(struct tls13_ctx *ctx,
+    const struct tls13_handshake_action *previous)
+{
+        const struct tls13_handshake_action *current;
+
+        if ((current = tls13_handshake_active_action(ctx)) == NULL)
+                return 1;
+
+        return current->sender != previous->sender;
+}
+
 int
 tls13_handshake_msg_record(struct tls13_ctx *ctx)
 {
@@ -344,6 +356,7 @@ int
 tls13_handshake_perform(struct tls13_ctx *ctx)
 {
         const struct tls13_handshake_action *action;
+        int sending;
         int ret;
 
         if (!ctx->handshake_started) {
@@ -367,6 +380,13 @@ tls13_handshake_perform(struct tls13_ctx *ctx)
                 if ((action = tls13_handshake_active_action(ctx)) == NULL)
                         return TLS13_IO_FAILURE;
 
+                if (ctx->need_flush) {
+                        if ((ret = tls13_record_layer_flush(ctx->rl)) !=
+                            TLS13_IO_SUCCESS)
+                                return ret;
+                        ctx->need_flush = 0;
+                }
+
                 if (action->handshake_complete) {
                         ctx->handshake_completed = 1;
                         tls13_record_layer_handshake_completed(ctx->rl);
@@ -379,14 +399,16 @@ tls13_handshake_perform(struct tls13_ctx *ctx)
                         return TLS13_IO_SUCCESS;
                 }
 
+                sending = action->sender == ctx->mode;
+
                 DEBUGF("%s %s %s\n", tls13_handshake_mode_name(ctx->mode),
-                    (action->sender == ctx->mode) ? "sending" : "receiving",
+                    sending ? "sending" : "receiving",
                     tls13_handshake_message_name(action->handshake_type));
 
                 if (ctx->alert != 0)
                         return tls13_send_alert(ctx->rl, ctx->alert);
 
-                if (action->sender == ctx->mode)
+                if (sending)
                         ret = tls13_handshake_send_action(ctx, action);
                 else
                         ret = tls13_handshake_recv_action(ctx, action);
@@ -408,6 +430,10 @@ tls13_handshake_perform(struct tls13_ctx *ctx)
                 if (!tls13_handshake_advance_state_machine(ctx))
                         return TLS13_IO_FAILURE;
 
+                if (sending)
+                        ctx->need_flush = tls13_handshake_end_of_flight(ctx,
+                            action);
+
                 if (!tls13_handshake_set_legacy_state(ctx))
                         return TLS13_IO_FAILURE;
         }
diff --git a/src/lib/libssl/tls13_internal.h b/src/lib/libssl/tls13_internal.h
index cb59634edc..20cb52ebdd 100644
--- a/src/lib/libssl/tls13_internal.h
+++ b/src/lib/libssl/tls13_internal.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_internal.h,v 1.93 2021/09/14 14:35:09 tb Exp $ */
+/* $OpenBSD: tls13_internal.h,v 1.94 2021/09/16 19:25:30 jsing Exp $ */
 /*
  * Copyright (c) 2018 Bob Beck <beck@openbsd.org>
  * Copyright (c) 2018 Theo Buehler <tb@openbsd.org>
@@ -92,6 +92,7 @@ typedef void (*tls13_phh_sent_cb)(void *_cb_arg);
 typedef ssize_t (*tls13_read_cb)(void *_buf, size_t _buflen, void *_cb_arg);
 typedef ssize_t (*tls13_write_cb)(const void *_buf, size_t _buflen,
     void *_cb_arg);
+typedef ssize_t (*tls13_flush_cb)(void *_cb_arg);
 typedef void (*tls13_handshake_message_cb)(void *_cb_arg);
 typedef void (*tls13_info_cb)(void *_cb_arg, int _state, int _ret);
 typedef int (*tls13_ocsp_status_cb)(void *_cb_arg);
@@ -200,6 +201,7 @@ struct tls13_record_layer;
 struct tls13_record_layer_callbacks {
         tls13_read_cb wire_read;
         tls13_write_cb wire_write;
+        tls13_flush_cb wire_flush;
         tls13_alert_cb alert_recv;
         tls13_alert_cb alert_sent;
         tls13_phh_recv_cb phh_recv;
@@ -226,6 +228,7 @@ int tls13_record_layer_set_write_traffic_key(struct tls13_record_layer *rl,
     struct tls13_secret *write_key);
 ssize_t tls13_record_layer_send_pending(struct tls13_record_layer *rl);
 ssize_t tls13_record_layer_phh(struct tls13_record_layer *rl, CBS *cbs);
+ssize_t tls13_record_layer_flush(struct tls13_record_layer *rl);
 
 ssize_t tls13_read_handshake_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
 ssize_t tls13_write_handshake_data(struct tls13_record_layer *rl, const uint8_t *buf,
@@ -283,6 +286,7 @@ struct tls13_ctx {
         struct tls13_handshake_stage handshake_stage;
         int handshake_started;
         int handshake_completed;
+        int need_flush;
         int middlebox_compat;
         int send_dummy_ccs;
         int send_dummy_ccs_after;
@@ -328,6 +332,7 @@ int tls13_legacy_connect(SSL *ssl);
 int tls13_legacy_return_code(SSL *ssl, ssize_t ret);
 ssize_t tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg);
 ssize_t tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg);
+ssize_t tls13_legacy_wire_flush_cb(void *arg);
 int tls13_legacy_pending(const SSL *ssl);
 int tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len,
     int peek);
diff --git a/src/lib/libssl/tls13_legacy.c b/src/lib/libssl/tls13_legacy.c
index 3368600c60..f668dd4ea3 100644
--- a/src/lib/libssl/tls13_legacy.c
+++ b/src/lib/libssl/tls13_legacy.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: tls13_legacy.c,v 1.30 2021/09/14 14:31:21 tb Exp $ */
+/*      $OpenBSD: tls13_legacy.c,v 1.31 2021/09/16 19:25:30 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -96,6 +96,30 @@ tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg)
         return tls13_legacy_wire_write(ctx->ssl, buf, n);
 }
 
+static ssize_t
+tls13_legacy_wire_flush(SSL *ssl)
+{
+        if (BIO_flush(ssl->wbio) <= 0) {
+                if (BIO_should_write(ssl->wbio))
+                        return TLS13_IO_WANT_POLLOUT;
+
+                if (ERR_peek_error() == 0 && errno != 0)
+                        SYSerror(errno);
+
+                return TLS13_IO_FAILURE;
+        }
+
+        return TLS13_IO_SUCCESS;
+}
+
+ssize_t
+tls13_legacy_wire_flush_cb(void *arg)
+{
+        struct tls13_ctx *ctx = arg;
+
+        return tls13_legacy_wire_flush(ctx->ssl);
+}
+
 static void
 tls13_legacy_error(SSL *ssl)
 {
diff --git a/src/lib/libssl/tls13_lib.c b/src/lib/libssl/tls13_lib.c
index 6615efc4d2..1a9596adca 100644
--- a/src/lib/libssl/tls13_lib.c
+++ b/src/lib/libssl/tls13_lib.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: tls13_lib.c,v 1.61 2021/09/02 11:58:30 beck Exp $ */
+/*      $OpenBSD: tls13_lib.c,v 1.62 2021/09/16 19:25:30 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2019 Bob Beck <beck@openbsd.org>
@@ -374,6 +374,7 @@ tls13_phh_received_cb(void *cb_arg, CBS *cbs)
 static const struct tls13_record_layer_callbacks rl_callbacks = {
         .wire_read = tls13_legacy_wire_read_cb,
         .wire_write = tls13_legacy_wire_write_cb,
+        .wire_flush = tls13_legacy_wire_flush_cb,
         .alert_recv = tls13_alert_received_cb,
         .alert_sent = tls13_alert_sent_cb,
         .phh_recv = tls13_phh_received_cb,
diff --git a/src/lib/libssl/tls13_record_layer.c b/src/lib/libssl/tls13_record_layer.c
index 2e32cb8a37..6b9f5d1419 100644
--- a/src/lib/libssl/tls13_record_layer.c
+++ b/src/lib/libssl/tls13_record_layer.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_record_layer.c,v 1.63 2021/09/04 16:26:12 jsing Exp $ */
+/* $OpenBSD: tls13_record_layer.c,v 1.64 2021/09/16 19:25:30 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -1096,6 +1096,12 @@ tls13_record_layer_write(struct tls13_record_layer *rl, uint8_t content_type,
         return ret;
 }
 
+ssize_t
+tls13_record_layer_flush(struct tls13_record_layer *rl)
+{
+        return rl->cb.wire_flush(rl->cb_arg);
+}
+
 static const uint8_t tls13_dummy_ccs[] = { 0x01 };
 
 ssize_t