Document how mbedtls_asn1_store_named_data allocates val.p in the new
or modified entry.
Change the behavior to be more regular, always setting the new length
to val_len. This does not affect the previous documented behavior
since this aspect was not documented. This does not affect current
usage in Mbed TLS's X.509 module where calls with the same OID always
use the same size for the associated value.
Use the test-many-sizes framework for string writes as
well (previously, it was only used for booleans and integers). This
way, more edge cases are tested with less test code.
This commit removes buffer overwrite checks. Instead of these checks,
run the test suite under a memory sanitizer (which we do in our CI).
Omit negative integers and MPIs that would result in values that look
like negative INTEGERs, since the library doesn't respect the
specifications there, but fixing it has a serious risk of breaking
interoperability when ASN.1 is used in X.509 and other
cryptography-related applications.
Add self-contained ASN.1 parsing tests, so that ASN.1 parsing is not
solely tested through X.509 and TLS.
The tests cover every function and almost complete line coverage in
asn1parse.c.
A few test cases containing negative and edge case INTEGER values are
deliberately deactivated because the historical library behavior is at
odds with official specifications, but changing the behavior might
break interoperability.
Other than that, these tests revealed a couple of minor bugs which
will be fixed in subsequent commits.
Document preconditions on parameters, values changed through pointers,
and error codes.
This commit leaves some issues regarding integers (especially negative
integers) open, because we don't have a policy decision on how to
handle them yet.
At the end of `psa_hmac_setup_internal()`, the ipad is cleared.
However, the size that was given to clear was `key_len` which is larger
than the size of `ipad`.
Add infrastructure to run unit tests and collect the return values for
every PSA API function that returns psa_status_t.
./tests/scripts/psa_collect_statuses.py >statuses.txt
* crypto/development: (77 commits)
all.sh: disable MEMORY_BUFFER_ALLOC in cmake asan build
Unify gcc and clang cmake flags to test with UBsan
Add an input check in psa_its_set
Remove storage errors from psa_generate_random
Update getting_started.md
Update based on Jaeden's comments.
Update getting_started.md
Fix return code warnings
Update getting_started.md
Fix warnings
Add PSA_ERROR_STORAGE_FAILURE to psa_cipher_generate_iv
Remove errorneous insert
Add STORAGE_FAILURE everywhere + add missing codes
Add storage failure to psa_mac_verify_finish
Add storage failure to psa_mac_sign_finish
Add PSA_ERROR_STORAGE_FAILURE to psa_aead_*_setup functions
Added PSA_ERROR_BAD_STATE to functions with operations
Added extra bad state case to psa_hash_setup
Add missing return codes to psa_generate_key
Add PSA_ERROR_BUFFER_TOO_SMALL to psa_mac_compute
...
Previously, not all flags were supported by the gcc version that was used
(pre-4.9). Now, since the minimum version gcc version tested is 5.4,
the flags can be unified.
We were still reusing the internal HMAC-DRBG of the deterministic ECDSA
for blinding. This meant that with cryptographically low likelyhood the
result was not the same signature as the one the deterministic ECDSA
algorithm has to produce (however it is still a valid ECDSA signature).
To correct this we seed a second HMAC-DRBG with the same seed to restore
correct behavior. We also apply a label to avoid reusing the bits of the
ephemeral key for a different purpose and reduce the chance that they
leak.
This workaround can't be implemented in the restartable case without
penalising the case where external RNG is available or completely
defeating the purpose of the restartable feature, therefore in this case
the small chance of incorrect behavior remains.
Alternative implementations are often hardware accelerators and might
not need an RNG for blinding. But if they do, then we make them misuse
the RNG in the deterministic case.
There are several way around this:
- Exposing a lower level function for replacement. This would be the
optimal solution, but litters the API and is not backward compatible.
- Introducing a new compile time option for replacing the deterministic
function. This would mostly cover the same code as
MBEDTLS_ECDSA_DETERMINISTIC and would be yet another compile time flag.
- Reusing the existing MBEDTLS_ECDSA_DETERMINISTIC macro. This changes
the algorithm used by the PK layer from deterministic to randomised if
the alternative implementation is present.
This commit implements the third option. This is a temporary solution
and should be fixed at the next device driver API change.
The current interface does not allow passing an RNG, which is needed for
blinding. Using the scheme's internal HMAC-DRBG results the same
blinding values for the same key and message, diminishing the
effectiveness of the countermeasure. A new function
`mbedtls_ecdsa_det_ext` is available to address this problem.
