In a hypothetical build with no curves, or in the future when we add a
new curve type and possibly forget updating this function with a new
block for the new type, we write to `ret` at the beginning or the
function then immediately overwrite it with MPI_CHK(check_privkey),
which static analyzers understandably find questionable.
Use `ret` here and check the key only if it was actually set.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
I went for "may be" as I was thinking just checking the tag technically
does not guarantee that what follows is correct, but I was wrong:
according to ASN.1, when there are variants, the tag does distinguish
unambiguously between variants, so we can be more positive here.
(Whether the thing inside that variant is correct is a different
question.)
As a welcome side effect, this makes the name more standard hence more
readable.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Using return here is only correct if we know that group_load() is atomic
(either succeeds, or allocates no ressources). I'm not sure it is, and
even if it were, goto exit is more obviously correct, so let's use that.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The recent changes in pkparse made it so ECDSA (deterministic or not) is
set as the secondary alg and ECDH the first one. This broke the wrapper
in pk_wrap as it was only checking the first alg when deciding whether
to use deterministic or not. The wrapper should not have unnecessary
requirements on how algs are set up, so make the check more flexible.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
One of the calling site needs to distinguish between "the format is
potentially valid but not supported" vs "other errors", and it uses
MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE for that.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
- Fix the logic around format: we were just assuming that if the format
was not compressed, it was uncompressed, but it could also have been
just invalid.
- Remove redundant length check: the fallback does its own checks.
- Remove set_algorithm() that's not needed and introduced a depencency
on ECDSA.
- Some style / naming / scope reduction.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Also new name, for consistency, and documentation.
The signature **p, *end is mostly for parsing functions that may not
consume everything, and need to update the "current" pointer to reflect
what has been consumed. This is not the case here.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
