Implement RFC8773bis (draft-ietf-tls-8773bis-13)
cert_with_extern_psk for TLS 1.3, including protocol checks
and API support.
Includes unit tests for API and handshake behavior as well
as tests in the testsuite using extended examples.
Per RFC 8446 section 8, a server MUST ensure that any instance of it
would accept 0-RTT for the same 0-RTT handshake at most once. Without
this, the same ClientHello could be replayed to re-accept early data on
a subsequent connection.
After the PSK is authenticated (binder verified) in DoPreSharedKeys,
call wolfSSL_SSL_CTX_remove_session on ssl->session when the client
offered 0-RTT and the session permits it. That evicts the entry from
the internal cache (under the row's write lock) and invokes the
application's ctx->rem_sess_cb so any external cache can drop its copy
too. The session's timeout is also cleared so the live reference held
by the current handshake cannot be resumed again.
The mutation is paid only when the client actually included the
early_data extension on a 0-RTT-capable session, so normal resumptions
are unaffected and the existing remove-callback counts in
test_wolfSSL_CTX_add_session_ext_{tls13,dtls13} stay correct.
wolfSSL_SSL_CTX_remove_session was previously declared and defined only
under the OpenSSL compatibility layer. Because it is now called from
the core TLS 1.3 PSK path, the declaration in wolfssl/ssl.h and the
definition in src/ssl_sess.c are moved out of that block to match the
existing !NO_SESSION_CACHE gate under which the function is meaningful.
wolfSSL_SSL_get0_session stays in the compat block.
test_tls13_early_data_0rtt_replay verifies the behaviour. It does a
full TLS 1.3 handshake with stateful tickets (SSL_OP_NO_TICKET) and
max_early_data > 0, then tries to resume the saved session twice while
offering 0-RTT each time. A minimal single-slot external session cache
is wired up via wolfSSL_CTX_sess_set_{new,get,remove}_cb to confirm
both caches are cleared. Round 0 must resume and deliver the early
data, and rem_calls must hit 1 (the fix's single eviction). Round 1
must fall back to a full handshake (session_reused == 0), deliver no
early data, and leave rem_calls at 1.
Verified against multiple configurations (incl. --enable-all
--enable-earlydata, the no-compat -DHAVE_EXT_CACHE build, and the
os-check.yml combo). Valgrind under -g2 -O0 with OPENSSL_EXTRA +
HAVE_EXT_CACHE + HAVE_EX_DATA reports no errors and no
definitely-lost bytes.
Refs wolfSSL/wolfssl#10197
Monte Carlo testing is randomized test data.
These new tests have random keys, IVs, nonce, etc and random data to
encrypt.
100 sets of random test data are encrypted and decrypted with a check to
ensure the input to encrypt is the same as the output of decrypt.
Tags are generated and checked in the calls to encrypt and decrypt.
JacobBarthelmeh
Sean Parkinson
Ruby Martin
Reda Chouk
Tobias Frauenschläger
Brett Nicholas
Jeremiah Mackey
Daniel Pouzzner
night1rider
David Garske
Eric Blankenhorn
Mattia Moffa
Juliusz Sosinowicz