The signature must have exactly the same length as the key, it can't
be longer. Fix#258
If the signature doesn't have the correct size, that's an invalid
signature, not a problem with an output buffer size. Fix the error code.
Add test cases.
In psa_asymmetric_sign, immediately reject an empty signature buffer.
This can never be right.
Add test cases (one RSA and one ECDSA).
Change the SE HAL mock tests not to use an empty signature buffer.
Zero-length keys are rejected at creation time, so we don't need any
special handling internally.
When exporting a key, we do need to take care of the case where the
output buffer is empty, but this is easy: an empty output buffer is
never valid.
Add tests for derivation.
Test both 7 bits and 9 bits, in case the implementation truncated the
bit size down and 7 was rejected as 0 rather than because it isn't a
multiple of 8.
There is no corresponding test for import because import determines
the key size from the key data, which is always a whole number of bytes.
Keys of size 0 generally don't make sense: a key is supposed to be
secret. There is one edge case which is "raw data" keys, which are
useful to store non-key objects in the same storage location as keys.
However those are also problematic because they involve a zero-length
buffer. Manipulating zero-length buffers in C requires special cases
with functions like malloc() and memcpy(). Additionally, 0 as a key
size already has a meaning "unspecified", which does not always
overlap seamlessly with the meaning "0".
Therefore, forbid keys of size 0. No implementation may accept them.
Clarify how key creation functions use attributes. Explain the meaning
of attribute values, espcially what 0 means in each field where it has
a special meaning. Explain what an algorithm usage policy can be (an
algorithm, a wildcard with ANY_HASH, or 0).
The new macro ASSERT_ALLOC_WEAK does not fail the test case if the
memory allocation fails. This is useful for tests that allocate a
large amount of memory, but that aren't useful on platforms where
allocating such a large amount is not possible.
Ideally this macro should mark the test as skipped. We don't yet have
a facility for that but we're working on it. Once we have a skip
functionality, this macro should be changed to use it.
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`.
