Add a test entry point for a handshake with a specially crafted context.
This can be used for defense in depths for scenarios that we think can't
happen, but might actually happen due to a bug, or due to a new feature that
is insufficiently tested. This can also be a proxy for testing aspects of
renegotiation or session resumption in circumstances that are hard to
arrange.
In this commit, use it to test a DTLS handshake with `ssl->badmac_seen`
:(actually `ssl->badmac_seen_or_in_hsfraglen` in the 3.6 branch) set to a
nonzero value. This can't happen, as far as I know (`badmac_seen` can only
be nonzero during renegotiation, not during a nominal handshake or in
session resumption). But it could happen, for example, if
`mbedtls_ssl_session_reset()` failed to reset `badmac_seen`, as was the case
in Mbed TLS 4.0.0 to 4.1.0.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In `ssl_client2`, the existing option `renegotiate=1` causes the client to
initiate renegotiation immediately after the initial handshake. Add a
variant `renegotiate=2` that initiates renegotiation after one data exchange.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
After a message with a bad MAC (invalid application data record), try to
renegotiate:
* Test cases where renegotiation (nominal or delayed) is rejected.
Nothing bad happens.
* A test where renegotiation is misparsed and rejected.
The subsequent parsing fails.
* A test where the renegotiation request is delayed.
This causes a heap buffer overflow in `ssl_buffer_message()`.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This can be used to simulate data messages received in the wrong epoch, or
to cause a handshake message to be buffered.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Non-regression test for a bug introduced with TLS handshake defragmentation
support in Mbed TLS 3.6.3, whereby the confusion between the `badmac_seen`
meaning and the `in_hsfraglen` meaning of `ssl->badmac_seen_or_in_hsfraglen`
causes renegotiation to be processed incorrectly after receiving a message
with a bad MAC.
The bug doesn't affect Mbed TLS 4.0.0 and above, but it's still good to have
more testing.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Let test code customize the kitchen sink function
`mbedtls_test_ssl_perform_handshake()` at a few points.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Since Mbed TLS 4.0, this is just the low-level error code. But keep the
combination for uniformity with the rest of the file, and to reduce the
differences with the 3.6 branch.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Announce the security fix together with the overflow fix, since the two bugs
are pretty much indistinguishable from a black-box perspective, despite
being due to independent problems in the code.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
