Add client side support for parsing Hello Retry Request
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2341)
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index e5c60ae..5860a23 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -60,6 +60,7 @@
#include <openssl/bn.h>
#include <openssl/engine.h>
+static MSG_PROCESS_RETURN tls_process_hello_retry_request(SSL *s, PACKET *pkt);
static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt);
static ossl_inline int cert_req_allowed(SSL *s);
@@ -137,6 +138,17 @@
default:
break;
+ case TLS_ST_CW_CLNT_HELLO:
+ /*
+ * This must a ClientHello following a HelloRetryRequest, so the only
+ * thing we can get now is a ServerHello.
+ */
+ if (mt == SSL3_MT_SERVER_HELLO) {
+ st->hand_state = TLS_ST_CR_SRVR_HELLO;
+ return 1;
+ }
+ break;
+
case TLS_ST_CR_SRVR_HELLO:
if (mt == SSL3_MT_ENCRYPTED_EXTENSIONS) {
st->hand_state = TLS_ST_CR_ENCRYPTED_EXTENSIONS;
@@ -210,8 +222,8 @@
int ske_expected;
/*
- * Note that after a ClientHello we don't know what version we are going
- * to negotiate yet, so we don't take this branch until later
+ * Note that after writing the first ClientHello we don't know what version
+ * we are going to negotiate yet, so we don't take this branch until later.
*/
if (SSL_IS_TLS13(s)) {
if (!ossl_statem_client13_read_transition(s, mt))
@@ -234,6 +246,11 @@
st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
return 1;
}
+ } else {
+ if (mt == SSL3_MT_HELLO_RETRY_REQUEST) {
+ st->hand_state = TLS_ST_CR_HELLO_RETRY_REQUEST;
+ return 1;
+ }
}
break;
@@ -390,15 +407,23 @@
*/
/*
- * Note: There are no cases for TLS_ST_BEFORE or TLS_ST_CW_CLNT_HELLO,
- * because we haven't negotiated TLSv1.3 yet at that point. They are
- * handled by ossl_statem_client_write_transition().
+ * Note: There are no cases for TLS_ST_BEFORE because we haven't negotiated
+ * TLSv1.3 yet at that point. They are handled by
+ * ossl_statem_client_write_transition().
*/
switch (st->hand_state) {
default:
/* Shouldn't happen */
return WRITE_TRAN_ERROR;
+ case TLS_ST_CW_CLNT_HELLO:
+ /* We only hit this in the case of HelloRetryRequest */
+ return WRITE_TRAN_FINISHED;
+
+ case TLS_ST_CR_HELLO_RETRY_REQUEST:
+ st->hand_state = TLS_ST_CW_CLNT_HELLO;
+ return WRITE_TRAN_CONTINUE;
+
case TLS_ST_CR_FINISHED:
st->hand_state = (s->s3->tmp.cert_req != 0) ? TLS_ST_CW_CERT
: TLS_ST_CW_FINISHED;
@@ -779,6 +804,9 @@
case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
return HELLO_VERIFY_REQUEST_MAX_LENGTH;
+ case TLS_ST_CR_HELLO_RETRY_REQUEST:
+ return HELLO_RETRY_REQUEST_MAX_LENGTH;
+
case TLS_ST_CR_CERT:
return s->max_cert_list;
@@ -836,6 +864,9 @@
case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
return dtls_process_hello_verify(s, pkt);
+ case TLS_ST_CR_HELLO_RETRY_REQUEST:
+ return tls_process_hello_retry_request(s, pkt);
+
case TLS_ST_CR_CERT:
return tls_process_server_certificate(s, pkt);
@@ -1432,6 +1463,52 @@
return MSG_PROCESS_ERROR;
}
+static MSG_PROCESS_RETURN tls_process_hello_retry_request(SSL *s, PACKET *pkt)
+{
+ unsigned int sversion;
+ int protverr;
+ RAW_EXTENSION *extensions = NULL;
+ int al;
+ PACKET extpkt;
+
+ if (!PACKET_get_net_2(pkt, &sversion)) {
+ al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_HELLO_RETRY_REQUEST, SSL_R_LENGTH_MISMATCH);
+ goto f_err;
+ }
+
+ s->hello_retry_request = 1;
+
+ /* This will fail if it doesn't choose TLSv1.3+ */
+ protverr = ssl_choose_client_version(s, sversion);
+ if (protverr != 0) {
+ al = SSL_AD_PROTOCOL_VERSION;
+ SSLerr(SSL_F_TLS_PROCESS_HELLO_RETRY_REQUEST, protverr);
+ goto f_err;
+ }
+
+ if (!PACKET_as_length_prefixed_2(pkt, &extpkt)) {
+ al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_HELLO_RETRY_REQUEST, SSL_R_BAD_LENGTH);
+ goto f_err;
+ }
+
+ if (!tls_collect_extensions(s, &extpkt, EXT_TLS1_3_HELLO_RETRY_REQUEST,
+ &extensions, &al)
+ || !tls_parse_all_extensions(s, EXT_TLS1_3_HELLO_RETRY_REQUEST,
+ extensions, NULL, 0, &al))
+ goto f_err;
+
+ OPENSSL_free(extensions);
+
+ return MSG_PROCESS_FINISHED_READING;
+ f_err:
+ ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ ossl_statem_set_error(s);
+ OPENSSL_free(extensions);
+ return MSG_PROCESS_ERROR;
+}
+
MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
{
int al, i, ret = MSG_PROCESS_ERROR, exp_idx;
