Describe the approach of platform-specific code and draw a comparison
with the constant-time module.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
These cover the fact that we need to test our test framework to make
sure it really detects incorrect accesses.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
* Rename config options to have MBEDTLS_TEST_ prefix
* Clarify that these config options should not exist in mbedtls_config.h
Signed-off-by: David Horstmann <david.horstmann@arm.com>
This is already covered in the design exploration and since the other
approach was chose, we do not need to discuss it in the detailed design
section.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
New tests are needed (rather than existing ones) because the complexity
of setting up careful-access tests would make it difficult to build atop
existing tests.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
This consists in outlining the prototyping and evaluation of different
possible testing approaches.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
Add lengths to structs in the convenience functions to allocate and copy
input and output buffers. It seems better to ensure we always store a
buffer with its length.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
And clarify our potential use of it as a starting point for writing
memory poisoning tests from scratch.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
In light of choosing Valgrind/ASan over mprotect()-based poisoning,
update the detailed design of copy validation.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
Main changes:
* New tests are easier to write than first stated
* Use of existing tests is ledd beneficial
* But using existing tests is a benefit if it can be done transparently
Signed-off-by: David Horstmann <david.horstmann@arm.com>
Consider MSan, ASan and Valgrind as options for implementing memory
poisoning tests. Come to the altered conclusion that Valgrind is the
best option.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
* Remove references to the platform - this is unlikely to affect whether
copies are optimized.
* Note that the evaluation should test extreme optimisation settings.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
There are many reasons why a driver might violate the security requirements
for plaintext or ciphertext buffers, so mandate copying.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
It's a security violation, although it's not clear whether it really needs
to influence the design.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
