tls13: add handshake key schedule
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index 602d06d..536d976 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -533,11 +533,29 @@
int mbedtls_ssl_tls1_3_key_schedule_stage_early( mbedtls_ssl_context *ssl );
/**
+ * \brief Transition into handshake stage of TLS 1.3 key schedule.
+ *
+ * The TLS 1.3 key schedule can be viewed as a simple state machine
+ * with states Initial -> Early -> Handshake -> Application, and
+ * this function represents the Early -> Handshake transition.
+ *
+ * In the handshake stage, mbedtls_ssl_tls1_3_generate_handshake_keys()
+ * can be used to derive the handshake traffic keys.
+ *
+ * \param ssl The SSL context to operate on. This must be in key schedule
+ * stage \c Early.
+ *
+ * \returns \c 0 on success.
+ * \returns A negative error code on failure.
+ */
+int mbedtls_ssl_tls1_3_key_schedule_stage_handshake( mbedtls_ssl_context *ssl );
+
+/**
* \brief Compute TLS 1.3 handshake traffic keys.
*
* \param ssl The SSL context to operate on. This must be in
* key schedule stage \c Handshake, see
- * mbedtls_ssl_tls13_key_schedule_stage_handshake().
+ * mbedtls_ssl_tls1_3_key_schedule_stage_handshake().
* \param traffic_keys The address at which to store the handshake traffic key
* keys. This must be writable but may be uninitialized.
*