PSA Crypto always passed MBEDTLS_MD_NONE to Mbed TLS, which worked well
as Mbed TLS does not use this parameter for anything beyond determining
the input lengths.
Some alternative implementations however check the consistency of the
algorithm used for pre-hash and for other uses in verification (verify
operation and mask generation) and fail if they don't match. This makes
all such verifications fail.
Furthermore, the PSA Crypto API mandates that the pre-hash and internal
uses are aligned as well.
Fixes#3990.
Signed-off-by: Janos Follath <janos.follath@arm.com>
Hashes used in RSA-PSS encoding (EMSA-PSS-ENCODE, see §9.1.1 in RFC
8017):
- H1: Hashing the message (step 2)
- H2: Hashing in the salt (step 6)
- H3: Mask generation function (step 9)
According to the standard:
- H1 and H2 MUST be done by the same hash function
- H3 is RECOMMENDED to be the same as the hash used for H1 and H2.
According to the implementation:
- H1 happens outside of the function call. It might or might not happen
and the implementation might or might not be aware of the hash used.
- H2 happens inside the function call, consistency with H1 is not
enforced and might not even be possible to detect.
- H3 is done with the same hash as H2 (with the exception of
mbedtls_rsassa_pss_verify_ext(), which takes a dedicated parameter for
the hash used in the MGF).
Issues with the documentation:
- The comments weren't always clear about the three hashes involved and
often only mentioned two of them (which two varied from function to
function).
- The documentation was giving the impression that the standard
recommends aligning H2 and H1 (which is not a recommendation but a
must).
Signed-off-by: Janos Follath <janos.follath@arm.com>
Montgomery curves are not in the expected place in the curve list.
This is a bug (https://github.com/ARMmbed/mbedtls/issues/4698), but
until this bug is fixed, document the current behavior and indicate
that it's likely to change.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
- “Fix an issue where X happens” → ”Fix X“
the extra words are just a distraction.
- “resource” → “a resource”
- “where resource is never freed” has a name: it's a resource leak
- “when running one particular test suite” → “in a test suite”
Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
Fix mbedtls_net_poll() and mbedtls_net_recv_timeout() often failing with
MBEDTLS_ERR_NET_POLL_FAILED on Windows: they were testing that the file
descriptor is in range for fd_set, but on Windows socket descriptors are not
limited to a small range. Fixes#4465.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The original formatting was in dos and the changelog
assembler would fail. The length of the description was
too long horizontally. This has been updated.
Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
in file tests/suite/test_suite_aes.function, aes_crypt_xts_size()
did not free the context upon the function exit.
The function now frees the context on exit.
Fixes#4176
Signed-off-by: JoeSubbiani <Joe.Subbiani@arm.com>
Add HKDF tests where the sequence of inputs differs from the nominal
case: missing step, duplicate step, step out of order, or invalid step.
There were already similar tests for TLS 1.2 PRF. Add one with a key
agreement which has slightly different code.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Mbed OS now provides POSIX-like time functions, although not alarm() nor
signal(). It is possible to implement MBEDTLS_TIMING_ALT on Mbed OS, so
we should not artificially prevent this in check-config. Remove the the
check that prevents implementing MBEDTLS_TIMING_ALT on Mbed OS.
Note that this limitation originally was added in the following commit,
although there isn't much context around why the restriction was
imposed: 63e7ebaaa1 ("Add material for generating yotta module"). In
2015, Mbed OS was quite a different thing: no RTOS, no threads, just an
asynchronous event loop model. I'd suppose the asynchronous event loop
model made it difficult before to implement MBEDTLS_TIMING_C on Mbed OS,
but that is no longer the case.
Fixes#4633
Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>
Rewrite mbedtls_debug_print_mpi to be simpler and smaller. Leverage
mbedtls_mpi_bitlen() instead of manually looking for the leading
zeros.
Fix#4608: the old code made an invalid memory dereference when
X->n==0 (freshly initialized bignum with the value 0).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
There was already a test case for 0 but with a non-empty representation
(X->n == 1). Add a test case with X->n == 0 (freshly initialized mpi).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
We stated that curves were listed "in order of preference", but we never
explained what the preference was, so this was not meaningful.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
MBEDTLS_ECP_WINDOW_SIZE is a compromise between memory usage (growing based
on the value) and performance (faster with larger values). There are
disminishing returns as the value grows larger. Based on Manuel's benchmarks
recorded in https://github.com/ARMmbed/mbedtls/issues/4127, 4 is a good
compromise point, with larger values bringing little advantage. So reduce
the default from 6 to 4.
Document the default value as in optimized for performance mostly, but don't
document the specific value, so we may change it later or make it
platform-dependent.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The idiom "resize an mpi to a given size" appeared 4 times. Unify it
in a single function. Guarantee that the value is set to 0, which is
required by some of the callers and not a significant expense where
not required.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Since the internal function mpi_fill_random_internal() assumes that X
has the right size, there is no need to call grow().
To further simplify the function, set the sign outside, and zero out
the non-randomized part directly.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
