Don't calculate the bit-size of the initially generated random number.
This is not necessary to reach the desired distribution of private
keys, and creates a (tiny) side channel opportunity.
This changes the way the result is derived from the random number, but
does not affect the resulting distribution.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The library rejected an RNG input of all-bits-zero, which led to the
key 2^{254} (for Curve25519) having a 31/32 chance of being generated
compared to other keys. This had no practical impact because the
probability of non-compliance was 2^{-256}, but needlessly
complicated the code.
The exception was added in 98e28a74e3 to
avoid the case where b - 1 wraps because b is 0. Instead, change the
comparison code to avoid calculating b - 1.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Test the exact output from known RNG input. This is overly
constraining, but ensures that the code has good properties.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
If a fallback is not explicitly configured in the
mbedtls_test_rnd_buf_info structure, fail after the buffer is
exhausted.
There is no intended behavior change in this commit: all existing uses
of mbedtls_test_rnd_buffer_rand() have been updated to set
mbedtls_test_rnd_std_rand as the fallback.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
For Montgomery keys, n_bits is actually the position of the highest
bit and not the number of bits, which would be 1 more (fence vs
posts). Rename the variable accordingly to lessen the confusion.
No semantic change.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Put the Montgomery and short Weierstrass implementations of
mbedtls_ecp_gen_privkey into their own function which can be tested
independently, but will not be part of the public ABI/API.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
When mbedtls_nist_kw_wrap was called with output=NULL and out_size=0, it
performed arithmetic on the null pointer before detecting that the output
buffer is too small and returning an error code. This was unlikely to have
consequences on real-world hardware today, but it is undefined behavior and
UBSan with Clang 10 flagged it. So fix it (fix#4025).
Fix a similar-looking pattern in unwrap, though I haven't verified that it's
reachable there.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
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 call to `tests/scripts/generate_psa_tests.py` added by the commit
"generate_psa_tests.py: allow generating each file independently"
assumed that the `check` function supports multiple file names, but in
fact it does not do so. When `generate_psa_tests.py` started generating
more than one file, `check-generated-files.sh` did not detect changes to
files other than the first one listed by `generate_psa_tests.py --list`.
Fix this: change `check` to support either a single directory (with
detection of added/removed files) or a list of files (which is assumed
to be static).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
When generating expressions to construct test case data, there can be
duplicate values, for example if a value of the form C(A) is present
as such in test_suite_psa_crypto_metadata.data and also constructed by
enumerating the argument A for the constructor C. Eliminate such
duplicates in generate_expressions.
This commit removes many test cases that were exact duplicates (and
were near-duplicates differing only in whitespace before the
whitespace normalization).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Define the dependency symbols PSA_WANT_ALG_ECDSA_ANY and
PSA_WANT_ALG_RSA_PKCS1V15_SIGN_RAW as de facto synonyms of
PSA_WANT_ALG_ECDSA and PSA_WANT_ALG_RSA_PKCS1V15_SIGN respectively: if
either one is requested, the other is set.
This makes it easier to systematically determine the dependencies of
an algorithm.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In macro_collector.py, base InputsForTest on PSAMacroEnumerator rather
than PSAMacroCollector. It didn't make much sense to use
PSAMacroCollector anymore since InputsForTest didn't use anything
other than the constructor.
psa_generate_tests now generates arguments for more macros.
In particular, it now collects macro arguments from
test_suite_psa_crypto_metadata. Algorithms with parameters are now
supported.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
First build a list of all keys, then construct all the corresponding
test cases. This allows all required information to be obtained in
one go, which is a significant performance gain as the information
includes numerical values obtained by compiling a C program.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In generate_psa_tests, use InputsForTest rather than PSAMacroCollector
to gather values. This way, the enumeration of values to test includes
values used in metadata tests in addition to constructors parsed from
header files. This allows greater coverage of values built from
constructors with arguments. This doesn't make a difference yet, but
it will once algorithm constructors with arguments are supported in
generate_psa_tests.
Make the injection of numerical values optional. They are useful for
test_psa_constant_names, so keep them there. Don't use them for
not-supported tests: they might make sense, but the current code
wouldn't work since it doesn't know how to make up fake key material
or what dependencies to generate. Don't use them for storage tests:
they only make sense for supported values.
Don't inject 'PSA_SUCCESS': that's superfluous.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
On space-constrained platforms, it is a useful configuration to be able
to import/export and perform RSA key pair operations, but to exclude RSA
key generation, potentially saving flash space. It is not possible to
express this with the PSA_WANT_ configuration system at the present
time. However, in previous versions of Mbed TLS (v2.24.0 and earlier) it
was possible to configure a software PSA implementation which was
capable of making RSA signatures but not capable of generating RSA keys.
To do this, one unset MBEDTLS_GENPRIME.
Since the addition of MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR, this
expressivity was lost. Expressing that you wanted to work with RSA key
pairs forced you to include the ability to generate key pairs as well.
Change psa_crypto_rsa.c to only call mbedtls_rsa_gen_key() if
MBEDTLS_GENPRIME is also set. This restores the configuration behavior
present in Mbed TLS v2.24.0 and earlier versions.
It left as a future exercise to add the ability to PSA to be able to
express a desire for a software or accelerator configuration that
includes RSA key pair operations, like signature, but excludes key pair
generation.
Without this change, linker errors will occur when attempts to call,
which doesn't exist when MBEDTLS_GENPRIME is unset.
psa_crypto_rsa.c.obj: in function `rsa_generate_key':
psa_crypto_rsa.c:320: undefined reference to `mbedtls_rsa_gen_key'
Fixes#4512
Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>
