Clarify that the 'sig_algs' set through this function are only enforced
during the key exchange and that 'mbedtls_ssl_conf_cert_profile()' should
instead be used to enforce the same algorithms when verifying certificates.
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
We want to reject small order points for two reasons:
- Those give rise to side channels attacks where the underlying field
arithmetic is not constant time (which our bignum isn't so far),
see the "May the Fourth" paper mentioned in ecp.
- Those force the shared secret to be all-bytes zero, which is bad for
protocols that might require contributory behaviour.
Honest peers will never send low-order points anyway.
While at it, test that we are clipping the input to 255 bits (ie, that
we are unsetting bit 256) as required by the RFC.
Again, honest peers will never send strings with bit 256 set. But the
RFC says to accept such strings anyway, so that's what we do.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
When parsing the basicConstraints extension, reject junk after the SEQUENCE
inside the extension (which is probably benign), and reject a SEQUENCE that
extends beyond the extension (could be very dangerous).
Add a non-regression test where a certificate that is technically malformed,
but accepted as a leaf certificate by OpenSSL and other X.509
implementations, to be accepted as a CA certificate by Mbed TLS.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The exact value doesn't matter anyway, but since we mention it, it might
as well be correct.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Reject malformed TLS 1.3 serialized sessions instead of accepting
unterminated strings or extra trailing data, and reject serialized SSL
contexts whose DTLS Connection ID length exceeds the maximum supported
size instead of overflowing the internal buffer.
Backport of #10715 (development). The dedicated CID-length test from
#10715 relies on test helpers that do not exist on 3.6 (notably
mbedtls_test_ssl_dtls_join_endpoints and mbedtls_test_ssl_perform_connection)
and is therefore omitted from this backport; the production fix and the
TLS 1.3 session-load tests are backported unchanged.
Signed-off-by: Nadav0077 <18245584+Nadav0077@users.noreply.github.com>
Those no longer allocate, so they can no longer return that error. This
was missed in the commit that removed heap allocations.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Add comments explaining why 3 passes are enough (except for 224 where 1 is enough).
For p256 and p384, this is a bit different
from some other functions as the carry is signed here.
Rm FIPS reference from the documentation, it's about the implementation.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
