In the PSA crypto library, the code for verification of ECDSA is the same for
both MBEDTLS_PSA_BUILTIN_ALG_ECDSA and
MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA. So, the guards should allow for
either one to enable the code blocks. The original implementation only had
the check for ECDSA. In order to make this work, config_psa.h was updated
to ensure when MBEDTLS_CRYPTO_CONFIG is disabled, the setting for DETERMINISTIC
is only updated if MBEDTLS_ECDSA_C is also enabled.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Mbed TLS requires users of DTLS to configure timer callbacks
needed to implement the wait-and-retransmit logic of DTLS.
Previously, the presence of these timer callbacks was checked
at every invocation of `mbedtls_ssl_fetch_input()`, so lowest
layer of the messaging stack interfacing with the underlying
transport.
This commit removes this recurring check and instead checks the
presence of timers once at the beginning of the handshake.
The main rationale for this change is that it is a step towards
separating the various layers of the messaging stack more cleanly:
datagram layer, record layer, message layer, retransmission layer.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
Migrate to new syntax where the PUBLIC attribute is explicitly defined.
Avoids issues caused sometimes where cmake does not allow the mixing of
old-style and new-style syntax
Signed-off-by: Raef Coles <raef.coles@arm.com>
Allows required targets to have prefixes added to them, so that external
projects can avoid target names clashing.
Signed-off-by: Raef Coles <raef.coles@arm.com>
The calculation of the expected key size when not using the test_size_function
was not correct. The function has now been updated to handle all cases
properly to ensure the expected key size is correct for key pairs, public
keys, and symmetric keys.
Cleaned up some comments and removed unused includes.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Previous guard was using original naming and did not
get updated to the new name. Guard is now using correct
definition of TEST_DRIVER_KEY_CONTEXT_SIZE_FUNCTION.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Removed TBD comment that is no longer relevant since
that portion of the code has been updated.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Updated get_expected_key_size in psa_crypto_driver_wrappers to properly
handle using the new size_function from PSA crypto drivers. Created
initial infrastructure to support size_function for the PSA crypto
drivers.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
The psa crypto library was generically using PSA_WANT_ALG_xxx, but
should have been using the correct MBEDTLS_PSA_BUILTIN_ALG_xxx
definition since that code is the builtin version. There were also
a couple of spots that needed to ensure the code block was enabled
for either ECDSA or DETERMINISTIC_ECDSA, not just one of them.
Fixed all the new ALG_ECDSA_DETERMINISTIC names to be
ALG_DETERMINISTIC_ECDSA instead.
Fixed test to use correct definitions.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
The CCM specification (NIST SP 800-38C) mandates that the formatting of
the additional data length l(a) changes when it is greater _or equal_ to
2^16 - 2^8 (>= 0xFF00). Since such lengths are not supported in mbed TLS,
the operation should fail in such cases.
This commit fixes an off-by-one error which allowed encryption/decryption
to be executed when l(a) was equal to 0xFF00, resulting in an
incorrect/non-standard length format being used.
Fixes#3719.
Signed-off-by: Fredrik Strupe <fredrik.strupe@silabs.com>
* Stores bits in psa_persistent_key_storage_format.
* psa_load_persistent_key_into_slot still imports plaintext keys which
ensures that the bits value gets set.
* Updates key specification to match new implementation.
* Expands persistent store and load tests with to check for bits
attribute.
* Removes bits storage from psa_se_key_data_storage_t.
Signed-off-by: Torstein Nesse <torstein.nesse@silabs.com>
* #3742 After input of a key as SECRET in the derivation, allow the
derivation result to be used as key.
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
* #3741 Allow key agreement inside derivation with a key that's allowed
for the relevant agreement.
Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
This change fixes the decrypt cipher setup function to return the
appropriate error code of PSA_ERROR_NOT_SUPPORTED instead of
PSA_ERROR_BAD_STATE for invalid locations when the setup call is made.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
This reverts commit 9c46a60e6c.
When the library is dynamically linked against Glibc (as is usually
the case with Glibc), it now requires a recent Glibc at runtime if it
was compiled with a recent Glibc. This is a loss of functionality for
no demonstrated benefit.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In psa_generate_key_internal() for ECC keys, remove the check that the
bit-size according to Mbed TLS is equal to the requested bit-size.
This check was necessary back when the PSA API encoded curves and key
sizes independently, in order to reject combinations such as SECP256R1
with a 512-bit size. Since the curve encoding changed to specifying a
curve family and a size separately, the Mbed TLS curve id (grp_id) and
the curve data (curve_info) are now determined from the size, and
checking that (curve_info->bit_size == bits) is now only a redundant
sanity check.
This check is actually buggy, because PSA Crypto and Mbed TLS don't
have exactly the same notion of key size. PSA thinks Curve25519 is
255-bit and secp224k1 is 225-bit, but Mbed TLS thinks they're 256-bit
and 224-bit respectively. Removing the check allows key generation to
work for these curves.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_ecp_curve_list() now lists Curve25519 and Curve448 under the names
"x25519" and "x448". These curves support ECDH but not ECDSA.
This was meant ever since the introduction of mbedtls_ecdsa_can_do()
in 0082f9df6f, but
2c69d10bac had removed the claim
that Montgomery curves support ECDH except through Everest.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
... as opposed to PSA_ERROR_BAD_STATE.
The spec on psa_cipher_finish() states that PSA_ERROR_INVALID_ARGUMENT
should be returned when:
"The total input size passed to this operation is not valid for this
particular algorithm. For example, the algorithm is a based on block
cipher and requires a whole number of blocks, but the total input size
is not a multiple of the block size."
Currently, there is a distinction between encryption and decryption
on whether INVALID_ARGUMENT or BAD_STATE is returned, but this is not
a part of the spec.
This fix ensures that PSA_ERROR_INVALID_ARGUMENT is returned
consistently on invalid cipher input sizes.
Signed-off-by: Fredrik Strupe <fredrik.strupe@silabs.com>
With the new feature MBEDTLS_PSA_CRYPTO_CONFIG, needed to
add support that when the feature is disabled, if there
are defines like MBEDTLS_ECDSA_C defined, then the PSA_WANT_
equivalent define is also enabled. This ensures the guards in
the library psa_crypto will work properly.
Also fixed an error return code in the driver wrapper for cipher
encrypt setup so it will properly pass unit tests.
Ensured config.py full works properly with the new
MBEDTLS_PSA_CRYPTO_CONFIG, it should not be set when the full
option is used.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Starting with commit 49e94e3, the do/while loop in
`rsa_prepare_blinding()` was changed to a `do...while(0)`, which
prevents retry from being effective and leaves dead code.
Restore the while condition to retry, and lift the calls to finish the
computation out of the while loop by by observing that they are
performed only when `mbedtls_mpi_inv_mod()` returns zero.
Signed-off-by: Peter Kolbus <peter.kolbus@garmin.com>
The version features library needed updating to support the new
MBEDTLS_PSA_CRYPTO_CONFIG definition.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
Initial changes to PSA crypto core to support configuration
of ECDSA algorithm using PSA crypto configuration mechanism.
Guards using MBEDTLS_ECDSA_C and MBEDTLS_ECDSA_DETERMINISTIC have
been changed to be based off PSA_WANT_ALG_ECDSA and
PSA_WANT_ALG_ECDSA_DETERMINISTIC. Added new tests to all.sh to
confirm new settings are working properly. Current code does not
pass the tests since built in signature verification is not in place.
Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
According to https://www.bearssl.org/ctmul.html even single-precision
multiplication is not constant-time on some older platforms.
An added benefit of the new code is that it removes the somewhat mysterious
constant 0x1ff - which was selected because at that point the maximum value of
padlen was 256. The new code is perhaps a bit more readable for that reason.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The previous code used comparison operators >= and == that are quite likely to
be compiled to branches by some compilers on some architectures (with some
optimisation levels).
For example, take the following function:
void old_update( size_t data_len, size_t *padlen )
{
*padlen *= ( data_len >= *padlen + 1 );
}
With Clang 3.8, let's compile it for the Arm v6-M architecture:
% clang --target=arm-none-eabi -march=armv6-m -Os foo.c -S -o - |
sed -n '/^old_update:$/,/\.size/p'
old_update:
.fnstart
@ BB#0:
.save {r4, lr}
push {r4, lr}
ldr r2, [r1]
adds r4, r2, #1
movs r3, #0
cmp r4, r0
bls .LBB0_2
@ BB#1:
mov r2, r3
.LBB0_2:
str r2, [r1]
pop {r4, pc}
.Lfunc_end0:
.size old_update, .Lfunc_end0-old_update
We can see an unbalanced secret-dependant branch, resulting in a total
execution time depends on the value of the secret (here padlen) in a
straightforward way.
The new version, based on bit operations, doesn't have this issue:
new_update:
.fnstart
@ BB#0:
ldr r2, [r1]
subs r0, r0, #1
subs r0, r0, r2
asrs r0, r0, #31
bics r2, r0
str r2, [r1]
bx lr
.Lfunc_end1:
.size new_update, .Lfunc_end1-new_update
(As a bonus, it's smaller and uses less stack.)
While there's no formal guarantee that the version based on bit operations in
C won't be translated using branches by the compiler, experiments tend to show
that's the case [1], and it is commonly accepted knowledge in the practical
crypto community that if we want to sick to C, bit operations are the safest
bet [2].
[1] https://github.com/mpg/ct/blob/master/results
[2] https://github.com/veorq/cryptocoding
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
