Correct return values for tls_construct_stoc_next_proto_neg

Return EXT_RETURN_NOT_SENT in the event that we don't send the extension,
rather than EXT_RETURN_SENT. This actually makes no difference at all to
the current control flow since this return value is ignored in this case
anyway. But lets make it correct anyway.

Follow on from CVE-2024-5535

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24716)

diff --git a/ssl/statem/extensions_srvr.c b/ssl/statem/extensions_srvr.c
index 699cc202c344eff12fcad1141e18d40de07cc802..38d34f3c17bb8513b1d19963956d1cafbc2e081a 100644 (file)
--- a/ssl/statem/extensions_srvr.c
+++ b/ssl/statem/extensions_srvr.c
@@ -1519,9 +1519,10 @@ EXT_RETURN tls_construct_stoc_next_proto_neg(SSL_CONNECTION *s, WPACKET *pkt,
             return EXT_RETURN_FAIL;
         }
         s->s3.npn_seen = 1;
+        return EXT_RETURN_SENT;
     }
 
-    return EXT_RETURN_SENT;
+    return EXT_RETURN_NOT_SENT;
 }
 #endif