Move state machine knowledge out of the record layer
The record layer was making decisions that should really be left to the
state machine around unexpected handshake messages that are received after
the initial handshake (i.e. renegotiation related messages). This commit
removes that code from the record layer and updates the state machine
accordingly. This simplifies the state machine and paves the way for
handling other messages post-handshake such as the NewSessionTicket in
TLSv1.3.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)
diff --git a/ssl/statem/statem.c b/ssl/statem/statem.c
index ac78d2d..bd7d89a 100644
--- a/ssl/statem/statem.c
+++ b/ssl/statem/statem.c
@@ -105,7 +105,6 @@
*/
void ossl_statem_set_renegotiate(SSL *s)
{
- s->statem.state = MSG_FLOW_RENEGOTIATE;
s->statem.in_init = 1;
s->statem.request_state = TLS_ST_SW_HELLO_REQ;
}
@@ -190,10 +189,10 @@
/*
* The main message flow state machine. We start in the MSG_FLOW_UNINITED or
- * MSG_FLOW_RENEGOTIATE state and finish in MSG_FLOW_FINISHED. Valid states and
+ * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
* transitions are as follows:
*
- * MSG_FLOW_UNINITED MSG_FLOW_RENEGOTIATE
+ * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
* | |
* +-----------------------+
* v
@@ -253,15 +252,7 @@
#endif
/* Initialise state machine */
-
- if (st->state == MSG_FLOW_RENEGOTIATE) {
- s->renegotiate = 1;
- if (!server)
- s->ctx->stats.sess_connect_renegotiate++;
- }
-
if (st->state == MSG_FLOW_UNINITED
- || st->state == MSG_FLOW_RENEGOTIATE
|| st->state == MSG_FLOW_FINISHED) {
if (st->state == MSG_FLOW_UNINITED) {
st->hand_state = TLS_ST_BEFORE;
@@ -322,53 +313,14 @@
goto end;
}
- if (!SSL_IS_TLS13(s)) {
- if (!server || st->state != MSG_FLOW_RENEGOTIATE) {
- if (!ssl3_init_finished_mac(s)) {
- ossl_statem_set_error(s);
- goto end;
- }
+ if (SSL_IS_FIRST_HANDSHAKE(s) || s->renegotiate) {
+ if (!tls_setup_handshake(s)) {
+ ossl_statem_set_error(s);
+ goto end;
}
- if (server) {
- if (st->state != MSG_FLOW_RENEGOTIATE) {
- s->ctx->stats.sess_accept++;
- } else if (!s->s3->send_connection_binding &&
- !(s->options &
- SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
- /*
- * Server attempting to renegotiate with client that doesn't
- * support secure renegotiation.
- */
- SSLerr(SSL_F_STATE_MACHINE,
- SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
- ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
- ossl_statem_set_error(s);
- goto end;
- } else {
- /*
- * st->state == MSG_FLOW_RENEGOTIATE, we will just send a
- * HelloRequest
- */
- s->ctx->stats.sess_accept_renegotiate++;
-
- s->s3->tmp.cert_request = 0;
- }
- } else {
- s->ctx->stats.sess_connect++;
-
- /* mark client_random uninitialized */
- memset(s->s3->client_random, 0, sizeof(s->s3->client_random));
- s->hit = 0;
-
- s->s3->tmp.cert_req = 0;
-
- if (SSL_IS_DTLS(s)) {
- st->use_timer = 1;
- }
- }
-
- st->read_state_first_init = 1;
+ if (SSL_IS_FIRST_HANDSHAKE(s))
+ st->read_state_first_init = 1;
}
st->state = MSG_FLOW_WRITING;
@@ -826,7 +778,7 @@
/*
* Called by the record layer to determine whether application data is
- * allowed to be sent in the current handshake state or not.
+ * allowed to be received in the current handshake state or not.
*
* Return values are:
* 1: Yes (application data allowed)
@@ -836,7 +788,7 @@
{
OSSL_STATEM *st = &s->statem;
- if (st->state == MSG_FLOW_UNINITED || st->state == MSG_FLOW_RENEGOTIATE)
+ if (st->state == MSG_FLOW_UNINITED)
return 0;
if (!s->s3->in_read_app_data || (s->s3->total_renegotiations == 0))
