psa_cipher_encrypt() and psa_cipher_decrypt() sometimes add a zero offset to
a null pointer when the cipher does not use an IV. This is undefined
behavior, although it works as naively expected on most platforms. This
can cause a crash with modern Clang+ASan (depending on compiler optimizations).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The first half of the table is not used, let's reuse index 0 for the
result instead of appending it in the end.
Signed-off-by: Janos Follath <janos.follath@arm.com>
The table size was set before the configured window size bound was
applied which lead to out of bounds access when the configured window
size bound is less.
Signed-off-by: Janos Follath <janos.follath@arm.com>
The window size starts giving diminishing returns around 6 on most
platforms and highly unlikely to be more than 31 in practical use cases.
Still, compilers and static analysers might complain about this and
better to be pedantic.
Co-authored-by: Gilles Peskine <gilles.peskine@arm.com>
Signed-off-by: Janos Follath <janos.follath@arm.com>
With small exponents (for example, when doing RSA-1024 with CRT, each
prime is 512 bits and we'll use wsize = 5 which may be smaller that the
maximum - or even worse when doing public RSA operations which typically
have a 16-bit exponent so we'll use wsize = 1) the usage of W will have
pre-computed values, then empty space, then the accumulator at the very
end.
Move X next to the precomputed values to make accesses more efficient
and intuitive.
Signed-off-by: Janos Follath <janos.follath@arm.com>
Elements of W didn't all have the same owner: all were owned by this
function, except W[x_index]. It is more robust if we make a proper copy
of X.
Signed-off-by: Janos Follath <janos.follath@arm.com>
When x is the most negative value of a two's complement type,
`(unsigned_type)(-x)` has undefined behavior, whereas `-(unsigned_type)x`
has well-defined behavior and does what was intended.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix undefined behavior (typically harmless in practice) of
mbedtls_mpi_add_mpi(), mbedtls_mpi_add_abs() and mbedtls_mpi_add_int() when
both operands are 0 and the left operand is represented with 0 limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Since they're part of the public API (even if only through a few functions),
they should be documented.
I deliberately skipped documenting how to configure the size of the type.
Right now, MBEDTLS_HAVE_INT32 and MBEDTLS_HAVE_INT64 have no Doxygen
documentation, so it's ambiguous whether they're part of the public API.
Resolving this ambiguity is out of scope of my current work.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Looking for the .data file doesn't work in out-of-tree builds. Use the
.datax file instead. `make clean` removes all .datax files, so this resolves
the issue of executables not present on the current branch being left behind
after a branch change followed by a `make clean`.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The already existing "x509_csr_check()" function is extended in order
to support/test also CSR's extensions. The test is performed by
adding an extended key usage.
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
This macro is expected to be defined out of the library, and there
is no definition in the library. Thus it needs to be excluded from
typo check.
Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
Typos of PSA macro and enum names are not checked by check_names.py.
This commit extend the check list to include PSA_XXX references.
The words should be macro/enum names defined as public_macros,
internal_macros, private_macros and enums. This commit also extend
the scope of enums to include those are defined in library/*.c.
A new type of macros "private", which are defined in library/*.c was
also added.
Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
Although negative zero is officially unsupported, we've had bugs related to
it in the past. So do test functions with a negative zero input.
There will likely be cases where we don't want to accept negative zero as if
it was valid, because it's too hard to handle. We'll add exceptions on a
case by case basis.
For the functions that are currently tested by the generated tests, the new
test cases pass.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The bignum module does not officially support "negative zero" (an
mbedtls_mpi object with s=-1 and all limbs zero). However, we have a
history of bugs where a function that should produce an official
zero (with s=1), produces a negative zero in some circumstances. So it's
good to check that the bignum functions are robust when passed a negative
zero as input. And for that, we need a way to construct a negative zero
from test case arguments.
There are checks that functions don't produce negative zeros as output in
the test suite. Skip those checks if there's a negative zero input: we
don't want functions to _create_ negative zeros, but we don't mind if
they _propagate_ negative zeros.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In mbedtls_mpi_add_mpi() and mbedtls_mpi_sub_mpi(), and by extention
mbedtls_mpi_add_int() and mbedtls_mpi_sub_int(), when the resulting value
was zero, the sign bit of the result was incorrectly set to -1 when the
left-hand operand was negative. This is not a valid mbedtls_mpi
representation. Fix this: always set the sign to +1 when the result is 0.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This exposes a bug in mbedtls_mpi_add_mpi() and mbedtls_mpi_sub_mpi() which
will be fixed in a subsequent commit.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
