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>
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>
Test both 0 represented with 0 limbs ("0 (null)") and 0 represented
with 1 limb ("0 (1 limb)"), because occasionally there are bugs with
0-limb bignums and occasionally there are bugs with removing leading
zero limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_mpi_exp_mod can be called in three ways regarding the speed-up
parameter _RR: null (unused), zero (will be updated), nonzero (will be
used). Systematically test all three.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Remove the RR parameter to the mbedtls_mpi_exp_mod test function.
It was never used in the test data, so there is no loss of functionality.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Test mbedtls_mpi_safe_cond_assign() and mbedtls_mpi_safe_cond_swap()
with their "unsafe" counterparts mbedtls_mpi_copy() and
mbedtls_mpi_swap(). This way we don't need to repeat the coverage of
test cases.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Similarly to "Overhaul testing of mbedtls_mpi_copy", simplify the code
to test mbedtls_mpi_swap to have just one function for distinct MPIs
and one function for swapping an MPI with itself, covering all cases
of size (0, 1, >1) and sign (>0, <0).
The test cases are exactly the same as for mbedtls_mpi_copy with the
following replacements:
* `Copy` -> `Swap`
* ` to ` -> ` with `
* `_copy` -> `_swap`
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Replace the two test functions mbedtls_mpi_copy_sint (supporting signed
inputs but always with exactly one limb) and mbedtls_mpi_copy_binary
(supporting arbitrary-sized inputs but not negative inputs) by a single
function that supports both arbitrary-sized inputs and arbitrary-signed
inputs. This will allows testing combinations like negative source and
zero-sized destination.
Also generalize mpi_copy_self to support arbitrary inputs.
Generate a new list of test cases systematically enumerating all
possibilities among various categories: zero with 0 or 1 limb, negative or
positive with 1 limb, negative or positive with >1 limb. I used the
following Perl script:
```
sub rhs { $_ = $_[0]; s/bead/beef/; s/ca5cadedb01dfaceacc01ade/face1e55ca11ab1ecab005e5/; $_ }
%v = (
"zero (null)" => "",
"zero (1 limb)" => "0",
"small positive" => "bead",
"large positive" => "ca5cadedb01dfaceacc01ade",
"small negative" => "-bead",
"large negative" => "-ca5cadedb01dfaceacc01ade",
);
foreach $s (sort keys %v) {
foreach $d (sort keys %v) {
printf "Copy %s to %s\nmbedtls_mpi_copy:\"%s\":\"%s\"\n\n",
$s, $d, $v{$s}, rhs($v{$d});
}
}
foreach $s (sort keys %v) {
printf "Copy self: %s\nmpi_copy_self:\"%s\"\n\n", $s, $v{$s};
}
```
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This is mostly to look for cases where the sign bit may have been left at 0
after zerozing memory, or a value of 0 with the sign bit set to -11. Both of
these mostly work fine, so they can go otherwise undetected by unit tests,
but they can break when certain combinations of functions are used.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Replace calls to mbedtls_mpi_read_string() with a wrapper
mbedtls_test_read_mpi() when reading test data except for the purpose
of testing mbedtls_mpi_read_string() itself. The wrapper lets the test
data control precisely how many limbs the constructed MPI has.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This test helper reads an MPI from a string and guarantees control over the
number of limbs of the MPI, allowing test cases to construct values with or
without leading zeros, including 0 with 0 limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@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>
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>
Do more iterations with small values. This makes it more likely that a
mistake on bounds will be detected.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Slightly simplify is_significantly_above_a_power_of_2() to make it
easier to understand:
* Remove the explicit negative answer for x <= 4. The only functional
difference this makes is that is_significantly_above_a_power_of_2(3)
is now true.
* Shift the most significant bit of x to position 8 rather than 15.
This makes the final comparison easier to explain.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Add unit tests for mbedtls_mpi_fill_random() and mbedtls_mpi_random()
when the resulting MPI object previously had a nonzero value. I wrote
those to catch a bug that I introduced during the development of
mbedtls_mpi_random() (but does not appear in a committed version).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_mpi_random() uses mbedtls_mpi_cmp_mpi_ct(), which requires its
two arguments to have the same storage size. This was not the case
when the upper bound passed to mbedtls_mpi_random() had leading zero
limbs.
Fix this by forcing the result MPI to the desired size. Since this is
not what mbedtls_mpi_fill_random() does, don't call it from
mbedtls_mpi_random(), but instead call a new auxiliary function.
Add tests to cover this and other conditions with varying sizes for
the two arguments.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Instead of generating blinding values and keys in a not-quite-uniform way
(https://github.com/ARMmbed/mbedtls/issues/4245) with copy-pasted code,
use mbedtls_mpi_random().
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_dhm_make_params() with x_size != size of P is not likely to be
useful, but it's supported, so test it.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Repeat a few tests that use random data. This way the code is
exercised with a few different random values.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Improve the validation of the output from mbedtls_dhm_make_params:
* Test that the output in the byte buffer matches the value in the
context structure.
* Test that the calculated values are in the desired range.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Since mbedtls_mpi_random() is not specific to ECC code, move it from
the ECP module to the bignum module.
This increases the code size in builds without short Weierstrass
curves (including builds without ECC at all) that do not optimize out
unused functions.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Rename mbedtls_ecp_gen_privkey_sw to mbedtls_mpi_random since it has
no particular connection to elliptic curves beyond the fact that its
operation is defined by the deterministic ECDSA specification. This is
a generic function that generates a random MPI between 1 inclusive and
N exclusive.
Slightly generalize the function to accept a different lower bound,
which adds a negligible amount of complexity.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Add unit tests for private key generation on short Weierstrass curves.
These tests validate that the result is within the desired range.
Additionally, they validate that after performing many iterations, the
range is covered to an acceptable extent: for tiny ranges, all values
must be reached; for larger ranges, all value bits must reach both 0
and 1.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
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>
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>
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>
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>
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>
The test "PSA generate key: RSA, 1024 bits, good, encrypt (OAEP
SHA-256)" had a dependency on MBEDTLS_GENPRIME, but this was not listed
in the dependencies. Add MBEDTLS_GENPRIME to the test's dependencies to
ensure it has what it needs to run.
Signed-off-by: Jaeden Amero <jaeden.amero@arm.com>
Fix a pointer mismatch when int32_t is not int, for example on Cortex-M where
in32_t is long int. Fix#4530
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
To avoid the MAC tests from being run when only part of the driver
wrappers (not including MAC) are being configured for test.
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
