False Start support.
(Called "cut through" for historical reasons in this patch.)
Enables SSL3+ clients to send application data immediately following the
Finished message even when negotiating full-handshakes. With this
patch, clients can negotiate SSL connections in 1-RTT even when
performing full-handshakes.
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index eec32b2..c536600 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -3308,6 +3308,48 @@
SSL_callback_ctrl(ssl, SSL_CTRL_SET_MSG_CALLBACK, (void (*)(void))cb);
}
+int SSL_cutthrough_complete(const SSL *s)
+ {
+ return (!s->server && /* cutthrough only applies to clients */
+ !s->hit && /* full-handshake */
+ s->version >= SSL3_VERSION &&
+ s->s3->in_read_app_data == 0 && /* cutthrough only applies to write() */
+ (SSL_get_mode((SSL*)s) & SSL_MODE_HANDSHAKE_CUTTHROUGH) && /* cutthrough enabled */
+ ssl3_can_cutthrough(s) && /* cutthrough allowed */
+ s->s3->previous_server_finished_len == 0 && /* not a renegotiation handshake */
+ (s->state == SSL3_ST_CR_SESSION_TICKET_A || /* ready to write app-data*/
+ s->state == SSL3_ST_CR_FINISHED_A));
+ }
+
+int ssl3_can_cutthrough(const SSL *s)
+ {
+ const SSL_CIPHER *c;
+
+ /* require a strong enough cipher */
+ if (SSL_get_cipher_bits(s, NULL) < 128)
+ return 0;
+
+ /* require ALPN or NPN extension */
+ if (!s->s3->alpn_selected
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ && !s->s3->next_proto_neg_seen
+#endif
+ )
+ {
+ return 0;
+ }
+
+ /* require a forward-secret cipher */
+ c = SSL_get_current_cipher(s);
+ if (!c || (c->algorithm_mkey != SSL_kEDH &&
+ c->algorithm_mkey != SSL_kEECDH))
+ {
+ return 0;
+ }
+
+ return 1;
+ }
+
/* Allocates new EVP_MD_CTX and sets pointer to it into given pointer
* vairable, freeing EVP_MD_CTX previously stored in that variable, if
* any. If EVP_MD pointer is passed, initializes ctx with this md
