psa_key_derivation requires the caller to specify a maximum capacity.
This commit adds a special value that indicates that the maximum
capacity should be the maximum supported by the algorithm. This is
currently meant only for selection algorithms used on the shared
secret produced by a key agreement.
On key import and key generation, for RSA, reject key sizes that are
not a multiple of 8. Such keys are not well-supported in Mbed TLS and
are hardly ever used in practice.
The previous commit removed support for non-byte-aligned keys at the
PSA level. This commit actively rejects such keys and adds
corresponding tests (test keys generated with "openssl genrsa").
Remove the need for an extra function mbedtls_rsa_get_bitlen. Use
mbedtls_rsa_get_len, which is only correct for keys whose size is a
multiple of 8. Key sizes that aren't a multiple of 8 are extremely
rarely used, so in practice this is not a problematic limitation.
Skip all writing to the target buffer if its size is 0, since in this
case the pointer might be invalid and this would cause the calls to
memcpy and memset to have undefined behavior.
Change the import/export format of private elliptic curve keys from
RFC 5915 to the raw secret value. This commit updates the format
specification and the import code, but not the export code.
Wipe the whole MAC intermediate buffer, not just the requested MAC
size. With truncated MAC algorithms, the requested MAC size may be
smaller than what is written to the intermediate buffer.
There was a lot of repetition between psa_aead_encrypt and
psa_aead_decrypt. Refactor the code into a new function psa_aead_setup.
The new code should behave identically except that in some cases where
multiple error conditions apply, the code may now return a different
error code.
Internally, I rearranged some of the code:
* I removed a check that the key type was in CATEGORY_SYMMETRIC because
it's redundant with mbedtls_cipher_info_from_psa which enumerates
supported key types explicitly.
* The order of some validations is different to allow the split between
setup and data processing. The code now calls a more robust function
psa_aead_abort in case of any error after the early stage of the setup.
OFB and CFB are streaming modes. XTS is a not a cipher mode but it
doesn't use a separate padding step. This leaves only CBC as a block
cipher mode that needs a padding step.
Since CBC is the only mode that uses a separate padding step, and is
likely to remain the only mode in the future, encode the padding mode
directly in the algorithm constant, rather than building up an
algorithm value from a chaining mode and a padding mode. This greatly
simplifies the interface as well as some parts of the implementation.
Mbed TLS distinguishes "invalid padding" from "valid padding but the
rest of the signature is invalid". This has little use in practice and
PSA doesn't report this distinction. We just report "invalid
signature".
There were only 5 categories (now 4). Reduce the category mask from 7
bits to 3.
Combine unformatted, not-necessarily-uniform keys (HMAC, derivation)
with raw data.
Reintroduce a KEY_TYPE_IS_UNSTRUCTURED macro (which used to exist
under the name KEY_TYPE_IS_RAW_DATA macro) for key types that don't
have any structure, including both should-be-uniform keys (such as
block cipher and stream cipher keys) and not-necessarily-uniform
keys (such as HMAC keys and secrets for key derivation).
The last slot in the array was not freed due to an off-by-one error.
Amend the fill_slots test to serve as a non-regression test for this
issue: without this bug fix, it would cause a memory leak.
MBEDTLS_PK_WRITE_C only requires either MBEDTLS_RSA_C or MBEDTLS_ECP_C to be defined.
Added wrappers to handle the cases where only one has been defined.
Moved mbedtls_pk_init to be within the ifdefs, so it's only called if appropriate.
In psa_generator_import_key, if generating a DES or 3DES key, set the
parity bits.
Add tests for deriving a DES key. Also test deriving an AES key while
I'm at it.
In psa_generator_hkdf_read, return BAD_STATE if we're trying to
construct more output than the algorithm allows. This can't happen
through the API due to the capacity limit, but it could potentially
happen in an internal call.
Also add a test case that verifies that we can set up HKDF with its
maximum capacity and read up to the maximum capacity.
New key type PSA_KEY_TYPE_DERIVE. New usage flag PSA_KEY_USAGE_DERIVE.
New function psa_key_derivation.
No key derivation algorithm is implemented yet. The code may not
compile with -Wunused.
Write some unit test code for psa_key_derivation. Most of it cannot be
used yet due to the lack of a key derivation algorithm.
Add an API for byte generators: psa_crypto_generator_t,
PSA_CRYPTO_GENERATOR_INIT, psa_crypto_generator_init,
psa_get_generator_capacity, psa_generator_read,
psa_generator_import_key, psa_generator_abort.
This commit does not yet implement any generator algorithm, it only
provides the framework. This code may not compile with -Wunused.
In psa_mac_setup and psa_hmac_setup_internal, perform a sanity check
on the hash size and the hash block size respectively. These sanity
checks should only trigger on an incompletely or incorrectly
implemented hash function.
Remove the check on the block size in psa_hmac_finish_internal
because at this point it has already been checked and used.
In the common case (key no longer than the block size), psa_hash_setup
was being called twice in succession. With current implementations
this is just a small performance loss, but potentially with
alternative implementations this could have lead to a memory leak.
