Commit daf534d from PR #457 breaks the build. This may reintroduce a
clang-analyse warning, but this is the wrong fix for that.
The fix removed a call to mbedtls_ecp_curve_info_from_grp_id() to find
the curve info. This fix adds that back in.
The check is already effectively performed later in the function, but
implicitly, so Clang's analysis fail to notice the functions are in
fact safe. Pulling the check up to the top helps Clang to verify the
behaviour.
Since the buffer is used in a few places, it seems Clang isn't clever
enough to realise that the first byte is never touched. So, even though
the function has a correct null check for ssl->handshake, Clang
complains. Pulling the handshake type out into its own variable is
enough for Clang's analysis to kick in though.
The function appears to be safe, since grow() is called with sensible
arguments in previous functions. Ideally Clang would be clever enough to
realise this. Even if N has size MBEDTLS_MPI_MAX_LIMBS, which will
cause the grow to fail, the affected lines in montmul won't be reached.
Having this sanity check can hardly hurt though.
Fix an issue that caused valid certificates being rejected whenever an
expired or not yet valid version of the trusted certificate was before the
valid version in the trusted certificate list.
The callback typedefs defined for mbedtls_ssl_set_bio() and
mbedtls_ssl_set_timer_cb() were not used consistently where the callbacks were
referenced in structures or in code.
- basicContraints checks are done during verification
- there is no need to set extensions that are not present to default values,
as the code using the extension will check if it was present using
ext_types. (And default values would not make sense anyway.)
- document why we made that choice
- remove the two TODOs about checking hash and CA
- remove the code that parsed certificate_type: it did nothing except store
the selected type in handshake->cert_type, but that field was never accessed
afterwards. Since handshake_params is now an internal type, we can remove that
field without breaking the ABI.
We don't implement anonymous key exchanges, and we don't intend to, so it can
never happen that an unauthenticated server requests a certificate from us.
After the record contents are decompressed, in_len is no longer
accessed directly, only in_msglen is accessed. in_len is only read by
ssl_parse_record_header() which happens before ssl_prepare_record_contents().
This is also made clear by the fact that in_len is not touched after
decrypting anyway, so if it was accessed after that it would be wrong unless
decryption is used - as this is not the case, it show in_len is not accessed.
Previously it was failing with errors about headers not found, which is
suboptimal in terms of clarity. Now give a clean error with pointer to the
documentation.
Do the checks in the .c files rather than check_config.h as it keeps them
closer to the platform-specific implementations.
