Don't attempt a QUIC connection without specifying ALPN

ALPN is required for a successful QUIC connection, so do not allow the
-quic option for s_client without -alpn

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20580)

diff --git a/apps/s_client.c b/apps/s_client.c
index f0ea14a284833f029f8571c547d4ce49568aeb05..2301c70449d75791df98dc9dde08e1f061486a1a 100644 (file)
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -2166,6 +2166,10 @@ int s_client_main(int argc, char **argv)
         BIO_printf(bio_err, "%s: QUIC does not support the -tfo option\n", prog);
         goto end;
     }
+    if (isquic && alpn_in == NULL) {
+        BIO_printf(bio_err, "%s: QUIC requires ALPN to be specified (e.g. \"h3\" for HTTP/3) via the -alpn option\n", prog);
+        goto end;
+    }
 #endif
 
     if (tfo)