We were already rejecting them at the end, due to the fact that with the
usual (x, z) formulas they lead to the result (0, 0) so when we want to
normalize at the end, trying to compute the modular inverse of z will
give an error.
If we wanted to support those points, we'd a special case in
ecp_normalize_mxz(). But it's actually permitted by all sources (RFC
7748 say we MAY reject 0 as a result) and recommended by some to reject
those points (either to ensure contributory behaviour, or to protect
against timing attack when the underlying field arithmetic is not
constant-time).
Since our field arithmetic is indeed not constant-time, let's reject
those points before they get mixed with sensitive data (in
ecp_mul_mxz()), in order to avoid exploitable leaks caused by the
special cases they would trigger. (See the "May the Fourth" paper
https://eprint.iacr.org/2017/806.pdf)
Signed-off-by: Janos Follath <janos.follath@arm.com>
A test case for which the loop would take practically forever if it was
reached. The point would be to validate that the loop is not reached.
The test case should cause the CI to time out if starting with the
current code, ecp_check_pubkey_mx() was changed to call
ecp_check_pubkey_x25519() first and run the mbedtls_mpi_size(() test
afterwards, which would make no semantic difference in terms of memory
contents when the function returns, but would open the way for a DoS.
Signed-off-by: Janos Follath <janos.follath@arm.com>
Clang was complaining and check-names.sh too
This only duplicates macros, so no impact on code size. In 3.0 we can
probably avoid the duplication by using an internal header under
library/ but this won't work for 2.16.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
We were already rejecting them at the end, due to the fact that with the
usual (x, z) formulas they lead to the result (0, 0) so when we want to
normalize at the end, trying to compute the modular inverse of z will
give an error.
If we wanted to support those points, we'd a special case in
ecp_normalize_mxz(). But it's actually permitted by all sources
(RFC 7748 say we MAY reject 0 as a result) and recommended by some to
reject those points (either to ensure contributory behaviour, or to
protect against timing attack when the underlying field arithmetic is
not constant-time).
Since our field arithmetic is indeed not constant-time, let's reject
those points before they get mixed with sensitive data (in
ecp_mul_mxz()), in order to avoid exploitable leaks caused by the
special cases they would trigger. (See the "May the Fourth" paper
https://eprint.iacr.org/2017/806.pdf)
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Backport 2.x: Fix and test the MBEDTLS_PSA_CRYPTO_SPM build
Straightforward backport from development to developement_2.x plus one trivial commit, only one approval is enough.
Modify tests to test mbedtls_psa_cipher_operation_t,
mbedtls_transparent_test_driver_cipher_operation_t and
mbedtls_opaque_test_driver_cipher_operation_t struct initialization macros.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
Fix initialization of mbedtls_psa_cipher_operation_t by not initializing the mbedtls_cipher_context_t typed field completely.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
Tests for psa_cipher_encrypt and psa_cipher_decrypt functions.
The psa_cipher_encrypt function takes no parameter for IV and always generates
it therefore there will be a randomness in the calculation and cannot be
validated by comparing the actual output with the expected output.
The function is tested by:
- doing a prtially randomized test with an encryption then a decryption
and validating the input with output of the decryption
- validating against the multipart encryption
The combination of this two methods provides enough coverage like a
known answer test.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
Various functions for PSA hash operations call abort
on failure; test that this is done. The PSA spec does not require
this behaviour, but it makes our implementation more robust in
case the user does not abort the operation as required by the
PSA spec.
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Remove late binding of iterators to enable the creation of an object
with an actual state of a variable.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
According to the PSA specification the PSA_USAGE_SIGN_HASH has the
permission to sign a message as PSA_USAGE_SIGN_MESSAGE. Similarly the
PSA_USAGE_VERIFY_HASH has the permission to verify a message as
PSA_USAGE_VERIFY_MESSAGE. These permission will also be present when
the application queries the usage flags of the key.
Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
Various functions for PSA cipher and mac operations call abort
on failure; test that this is done. The PSA spec does not require
this behaviour, but it makes our implementation more robust in
case the user does not abort the operation as required by the
PSA spec.
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
The cipher_bad_order test happened to pass, but was not testing the
failure case it intended to test.
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
This makes it easier to ensure that crypto_spe.h is included everywhere it
needs to be, and that it's included early enough to do its job (it must be
included before any mention of psa_xxx() functions with external linkage,
because it defines macros to rename these functions).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
