Update state of TLS 1.3 functionality in architecture document
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/docs/architecture/tls13-experimental.md b/docs/architecture/tls13-experimental.md
index bcf3e34..3db16e0 100644
--- a/docs/architecture/tls13-experimental.md
+++ b/docs/architecture/tls13-experimental.md
@@ -38,3 +38,12 @@
- The HKDF key derivation function on which the TLS 1.3 key schedule is based,
is already present as an independent module controlled by `MBEDTLS_HKDF_C`
independently of the development of the TLS 1.3 prototype.
+
+- The TLS 1.3-specific HKDF-based key derivation functions (see RFC 8446):
+ * HKDF-Expand-Label
+ * Derive-Secret
+ - Secret evolution
+ * The traffic {Key,IV} generation from secret
+ Those functions are implemented in `library/ssl_tls13_keys.c` and
+ tested in `test_suite_ssl` using test vectors from RFC 8448 and
+ https://tls13.ulfheim.net/.