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>
In an X.509 certificate, a basicConstraints extension where the cA
field (BOOLEAN) is omitted but the pathLenConstraint field (INTEGER )is
present is syntactically valid, but RFC 5280 states that CAs MUST NOT emit
such a certificate.
Historically, since XySSL 0.9 in 2008, if a basicConstraints extension
started with an INTEGER field, we interpreted that field as a cA value. This
was a deliberate change:
> Fixed x509_get_ext() to accept some rare certificates (like
> www.openssl.org:443) which have an INTEGER instead of a BOOLEAN for
> Extension::BasicConstraints::cA.
However, 18 years later, this does not seem to be relevant, and the details
seem to have been lost. Furthermore, major implementations follow RFC 5280
and interpret `SEQUENCE { INTEGER n }` with cA being set to its default
value (FALSE) and pathLenConstraint set to `n`. This means that such a
certificate with n != 0 would be interpreted as a CA certificate in Mbed TLS
but as a leaf certificate elsewhere, which is dangerous.
Since CAs are not supposed to emit such certificates, stop accepting them
altogether.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In test cases for pathLenConstraint parsing in a basicConstraints extension
of an X.509 certificate, use the standard type for the leading cA field,
namely BOOLEAN. The test data was encoding that field as INTEGER, which was
accepted as a deviation from the standard since XySSL 0.9.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
It is now unreachable because:
- end_set == end_attr_data is enforced at library/x509_csr.c:236.
- end_exts == end_set is enforced at library/x509_csr.c:248.
- x509_csr_parse_extensions() only returns success if *p == end_exts, enforced
at library/x509_csr.c:188.
So after a successful x509_csr_parse_extensions() call, *p == end_exts ==
end_set == end_attr_data. The condition at line 257 cannot be true.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
