PSA_KEY_LIFETIME_FROM_PERSISTENCE_AND_LOCATION shifts the location
value (location << 8). This can go outside the range of a 32-bit int
if the location value is above 2^23 as is the case here. Asan
rightfully complained about it. Make the value unsigned to avoid the
integer overflow.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Test keys with various persistence levels, enumerated from the
metadata tests.
For read-only keys, do not attempt to create or destroy the key
through the API, only to read a key that has been injected into
storage directly through filesystem access.
Do not test keys with a non-default location, since they require a
driver and we do not yet have a dependency mechanism to require the
presence of a driver for a specific location value.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The persistence level PSA_KEY_PERSISTENCE_READ_ONLY can now only be used
as intended, for keys that cannot be modified through normal use of the API.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Attempting to create a key with an invalid location or with read-only
persistence must be rejected.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_psa_get_stats() was written back before lifetimes were
structured as persistence and location. Fix its classification of
volatile external keys and internal keys with a non-default
persistence.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The loop exits early iff there is a nonzero limb, so i==0 means that
all limbs are 0, whether the number of limbs is 0 or not.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix a bug introduced in "Fix multiplication producing a negative zero" that
caused the sign to be forced to +1 when A > 0, B < 0 and B's low-order limb
is 0.
Add a non-regression test. More generally, systematically test combinations
of leading zeros, trailing zeros and signs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
No need to bypass the API to fill limbs. It's a better test to just
set the top bit that we want to have set, and it's one less bypass of
the API.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_mpi_read_binary{,_le} (in https://github.com/ARMmbed/mbedtls/pull/4276)
and mbedtls_mpi_read_string (in https://github.com/ARMmbed/mbedtls/pull/4644)
changed their behavior on an empty input from constructing an MPI object with
one limb to not allocating a limb. In principle, this change should be
transparent to applications, however it caused a bug in the library and it does
affect the value when writing back out, so list the change in the changelog.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In mbedtls_mpi_read_string, if the string is empty, return an empty bignum
rather than a bignum with one limb with the value 0.
Both representations are correct, so this is not, in principle, a
user-visible change. The change does leak however through
mbedtls_mpi_write_string in base 16 (but not in other bases), as it writes a
bignum with 0 limbs as "" but a bignum with the value 0 and at least one
limb as "00".
This change makes it possible to construct an empty bignum through
mbedtls_mpi_read_string, which is especially useful to construct test
cases (a common use of mbedtls_mpi_read_string, as most formats use in
production encode numbers in binary, to be read with mbedtls_mpi_read_binary
or mbedtls_mpi_read_binary_le).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix mbedtls_mpi_mul_mpi() when one of the operands is zero and the
other is negative. The sign of the result must be 1, since some
library functions do not treat {-1, 0, NULL} or {-1, n, {0}} as
representing the value 0.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Shifting TA and TB before the loop is not necessary. If A != 0, it will be
done at the start of the loop iteration. If A == 0, then lz==0 and G is
correctly set to B after 0 loop iterations.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In Mbed TLS 2.26.0, the bug was hard to trigger, since all methods for
parsing a bignum (mbedtls_mpi_read_xxx functions) constructed an mbedtls_mpi
object with at least one limb.
In the development branch, after the commit
"New internal function mbedtls_mpi_resize_clear", this bug could be
triggered by a TLS server, by passing invalid custom Diffie-Hellman
parameters with G=0 transmitted as a 0-length byte string.
Since the behavior change in mbedtls_mpi_read_binary and
mbedtls_mpi_read_binary_le (constructing 0 limbs instead of 1 when passed
empty input) turned out to have consequences despite being in principle an
internal detail, mention it in the changelog.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Fix a null pointer dereference in mbedtls_mpi_exp_mod(X, A, N, E, _RR) when
A is the value 0 represented with 0 limbs.
Make the code a little more robust against similar bugs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
