From: Matt Caswell <matt@openssl.org>
Date: Thu, 27 Jul 2023 13:27:17 +0000 (+0100)
Subject: Still advance handshake even on an empty write
X-Git-Tag: openssl-3.2.0-alpha1~331
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33f6ad1724b2f32a370d01b61ef12120a75d8049;p=thirdparty%2Fopenssl.git

Still advance handshake even on an empty write

A call to SSL_write() with a zero length buffer should still advance the
handshake. Applications (including s_client) may rely on this.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21578)
---

diff --git a/ssl/quic/quic_impl.c b/ssl/quic/quic_impl.c
index 848b1b4f523..f6bd738793f 100644
--- a/ssl/quic/quic_impl.c
+++ b/ssl/quic/quic_impl.c
@@ -2076,9 +2076,6 @@ int ossl_quic_write(SSL *s, const void *buf, size_t len, size_t *written)
 
     *written = 0;
 
-    if (len == 0)
-        return 1;
-
     if (!expect_quic_with_stream_lock(s, /*remote_init=*/0, &ctx))
         return 0;
 
@@ -2104,6 +2101,11 @@ int ossl_quic_write(SSL *s, const void *buf, size_t len, size_t *written)
         goto out;
     }
 
+    if (len == 0) {
+        ret = 1;
+        goto out;
+    }
+
     if (xso_blocking_mode(ctx.xso))
         ret = quic_write_blocking(&ctx, buf, len, written);
     else if (partial_write)