Add the ability to send the supported_versions extension
Reviewed-by: Rich Salz <rsalz@openssl.org>
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 6598776..515b4e3 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1371,6 +1371,40 @@
return 0;
}
+
+ /* TODO(TLS1.3): Should we add this extension for versions < TLS1.3? */
+ if (!SSL_IS_DTLS(s) && s->version >= TLS1_3_VERSION) {
+ int min_version, max_version, reason, currv;
+ if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_versions)
+ || !WPACKET_start_sub_packet_u16(pkt)
+ || !WPACKET_start_sub_packet_u8(pkt)) {
+ SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
+ if (reason != 0) {
+ SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, reason);
+ return 0;
+ }
+ for (currv = max_version; currv >= min_version; currv--) {
+ /* TODO(TLS1.3): Remove this first if clause prior to release!! */
+ if (currv == TLS1_3_VERSION) {
+ if (!WPACKET_put_bytes_u16(pkt, TLS1_3_VERSION_DRAFT)) {
+ SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT,
+ ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ } else if (!WPACKET_put_bytes_u16(pkt, currv)) {
+ SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ }
+ if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
+ SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ }
+
/*
* Add padding to workaround bugs in F5 terminators. See
* https://tools.ietf.org/html/draft-agl-tls-padding-03 NB: because this
