Previously, ecp_add_mixed(), commputing say P+Q, would allow for the
Q parameter to have an unset Z coordinate as a shortcut for Z == 1.
This was leveraged during computation and usage of the T-table
(storing low multiples of the to-be-multiplied point on the curve).
It is a potentially error-prone corner case, though, since an MPIs
with unset data pointer coordinate and limb size 0 is also a valid
representation of the number 0.
As a first step towards removing ECP points with unset Z coordinate,
the constant time T-array getter ecp_select_comb() has previously
been modified to return 'full' mbedtls_ecp_point structures,
including a 1-initialized Z-coordinate.
Similarly, this commit ...
- Modifies ecp_normalize_jac_many() to set the Z coordinates
of the points it operates on to 1 instead of freeing them.
- Frees the Z-coordinates of the T[]-array explicitly
once the computation and normalization of the T-table has finished.
As a minimal functional difference between old and new code,
the new code also frees the Z-coordinate of T[0]=P, which the
old code did not.
- Modifies ecp_add_mixed() to no longer allow unset Z coordinates.
Except for the post-precomputation storage form of the T[] array,
the code does therefore no longer use EC points with unset Z coordinate.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
psa_aead_encrypt_setup() and psa_aead_decrypt_setup() were returning
PSA_ERROR_INVALID_ARGUMENT, while the same failed checks were producing
PSA_ERROR_NOT_SUPPORTED if they happened in psa_aead_encrypt() or
psa_aead_decrypt().
The PSA Crypto API 1.1 spec will specify PSA_ERROR_INVALID_ARGUMENT
in the case that the supplied algorithm is not an AEAD one.
Also move these shared checks to a helper function, to reduce code
duplication and ensure that the functions remain in sync.
Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
ecp_select_comb() did previously not set the Z coordinate of the target point.
Instead, callers would either set it explicitly or leave it uninitialized,
relying on the (only partly upheld) convention that sometimes an uninitialized
Z value represents 1.
This commit modifies ecp_select_comb() to always set the Z coordinate to 1.
This comes at the cost of memory for a single coordinate, which seems worth
it for the increased robustness.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
This improves readibility and prepares for further changes
like the introduction of a single double-width temporary for
ECP arithmetic.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
Fix library references, tests and programs.
Testing is performed in the already present all.sh test.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
`ecp_add_mixed()` and `ecp_double_jac()` are the core subroutines
for elliptic curve arithmetic, and as such crucial for the performance
of ECP primitives like ECDHE and ECDSA.
This commit provides a very slight simplification and performance and
memory usage improvement to `ecp_add_mixed()` by removing the use of
three temporary MPIs used for coordinate calculations.
Where those variables were used, the code now writes directly to the
coordinate MPIs of the target elliptic curve point.
This is a valid change even if there is aliasing between input and
output, since at the time any of the coordinate MPIs in question is
written, the corresponding coordinates of both inputs are no longer
read.
(The analogous change in `ecp_double_jac()` can not be made since
this property does not hold for `ecp_double_jac()`.)
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
This commit removes code from the Montgomery multiplication routine
`mpi_montmul()` which seems to serve no purpose.
Details: `mpi_montmul()` uses a temporary storage `T` for intermediate
results which is assumed to be of twice the size as the inputs to be
multiplied, and which is used as follows: After the i-th (i=0,1,...)
iteration, the n-limb word starting at `T->p + i + 1` contains the
Montgomery multiplication of B with the limbs 0,..,i of A, and the
variable `d` points to `T->p + i + 1`. In particular, after `n` iterations,
`T->p + n` holds the full multiplication
(subject to conditional subtraction).
As a consequence of this way of using the temporary `T`, the contents
of `{T->p, ..., T->p + i}` are irrelevant after the i-th iteration. Nonetheless,
the code copies `A[i]` to `T->p[i]` at the end of the i-th iterations, which is
redundant and can be removed.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
* Updated the default argument to create less noise with argument
passing.
* Reworded ChangeLog to match MbedTLS documentation/ announcement
requirements
Signed-off-by: Archana <archana.madhavan@silabs.com>
Pylint errors are fixed.
The Python script is improved to take default arguments when not
passed (eg invoked from root of the tree)
check-generated-files.sh and CMakeLists.sh updated.
Signed-off-by: Archana <archana.madhavan@silabs.com>
Moved python script generate_driver_wrappers.py under scripts and
corresponding template file under script/data_files.
Signed-off-by: Archana <archana.madhavan@silabs.com>
The file psa_crypto_driver_wrappers.c is deleted to be autogenerated.
Updated psa_crypto_driver_wrappers.h, this file only contains the
prototypes for the driver wrappers, we don't expect this to be auto
generated.
Signed-off-by: Archana <archana.madhavan@silabs.com>
