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>
Larger height (e.g. H=20) trees cannot be put on the stack.
Allocate memory for them based on need using mbedtls_calloc().
Signed-off-by: Moritz Fischer <moritzf@google.com>
The loop ends when there are no more bits to process, with one twist: when
that happens, we need to clear the window one last time. Since the window
does not start empty (E_limbs==0 is not supported), the loop always starts
with a non-empty window and some bits to process. So it's correct to move
the window clearing logic to the end of the loop. This lets us exit the loop
when the end of the exponent is reached.
It would be clearer not to do the final window clearing inside the loop, so
we wouldn't need to repeat the loop termination condition (end of exponent
reached) inside the loop. However, this requires duplicating the code to
clear the window. Empirically, this causes a significant code size increase,
even if the window clearing code is placed into a function.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
We are looking at the exponent at limb granularity and therefore
exponent bits can't go below 32.
The `mpi_` prefix is also removed as it is better not to have prefix at
all than to have just a partial. (Full prefix would be overly long and
would hurt readability.)
Signed-off-by: Janos Follath <janos.follath@arm.com>
Now that we have a function that calls
mbedtls_mpi_core_ct_uint_table_lookup(), the compiler won't complain if
we make it static.
Signed-off-by: Janos Follath <janos.follath@arm.com>
On platforms with size_t different from int, mismatch between size_t and
mpi_uint can cause incorrect results or complaints from the compiler.
Signed-off-by: Janos Follath <janos.follath@arm.com>
mpi_core_exp_mod: Cast local variable explicitly
Signed-off-by: Janos Follath <janos.follath@arm.com>
In this way, in case of error, it is not possible to continue using
the same psa_pake_operation_t without reinitializing it.
This should make the PSA pake's behavior closer to what expected by
the specification
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
