This requires defining a maximum RSA key size, since the RSA key size
is the signature size. Enforce the maximum RSA key size when importing
or generating a key.
Macros such as PSA_HASH_SIZE whose definitions can be the same
everywhere except in implementations that support non-standard
algorithms remain in crypto.h, at least for the time being.
This header will contain macros that calculate buffer sizes, whose
semantics are standardized but whose definitions are
implementation-specific because they depend on the available algorithms
and on some permitted buffer size tolerances.
Move size macros from crypto_struct.h to crypto_sizes.h, because these
definitions need to be available both in the frontend and in the
backend, whereas structures have different contents.
Change the representation of an ECDSA signature from the ASN.1 DER
encoding used in TLS and X.509, to the concatenation of r and s
in big-endian order with a fixed size. A fixed size helps memory and
buffer management and this representation is generally easier to use
for anything that doesn't require the ASN.1 representation. This is
the same representation as PKCS#11 (Cryptoki) except that PKCS#11
allows r and s to be truncated (both to the same length), which
complicates the implementation and negates the advantage of a
fixed-size representation.
* Distinguish randomized ECDSA from deterministic ECDSA.
* Deterministic ECDSA needs to be parametrized by a hash.
* Randomized ECDSA only uses the hash for the initial hash step,
but add ECDSA(hash) algorithms anyway so that all the signature
algorithms encode the initial hashing step.
* Add brief documentation for the ECDSA signature mechanisms.
* Also define DSA signature mechanisms while I'm at it. There were
already key types for DSA.
* PSS needs to be parametrized by a hash.
* Don't use `_MGF1` in the names of macros for OAEP and PSS. No one
ever uses anything else.
* Add brief documentation for the RSA signature mechanisms.
Doxygen interprets `\param` as starting documentation for a new param, or
to extend a previously started `\param` documentation when the same
reference is used. The intention here was to reference the function
parameter, not extend the previous documentation. Use `\p` to refer to
function parameters.
It isn't used to define other macros and it doesn't seem that useful
for users. Remove it, we can reintroduce it if needed.
Define a similar function key_type_is_raw_bytes in the implementation
with a clear semantics: it's a key that's represented as a struct
raw_data.
When calling psa_generate_key, pass the size of the parameters buffer
explicitly. This makes calls more verbose but less error-prone. This
also has the benefit that in an implementation with separation, the
frontend knows how many bytes to send to the backend without needing
to know about each key type.
Switch the default config.h back to the upstream version, plus the new
feature from this branch MBEDTLS_PSA_CRYPTO_C, plus MBEDTLS_CMAC_C
because it's a features we're using to explore the API design but
that's off by default in Mbed TLS.
Having a crypto-only version saved a bit of developer time, and it's
something we want to ship, but we also need a full build with TLS to
work, and the CI scripts assume that the default build includes TLS.
As a consequence, list-macros.sh no longer needs a special case to
pass check-names.sh.
The default config.h omits non-crypto features. Remove some features
that had been accidentally left in but have dependencies that had been
removed.
Also update configs/config-psa-crypto.h to match
include/mbedtls/config.h. They were historically identical but started
diverging when the feature-psa branch was rebased on top of a more
recent upstream.
Now the code builds with the "full" config.
Instead of rolling our own list of elliptic curve identifiers, use one
from somewhere. Pick TLS because it's the right size (16 bits) and
it's as good as any.
