Add a test case for doing an ECDH calculation by calling
mbedtls_ecdh_get_params on both keys, with keys belonging to
different groups. This should fail, but currently passes.
The recently added `mbedtls_ecdh_setup()` function is not used in the
tests yet. This commit adapts the tests to the new workflow.
Having done that, the old lifecycle is not tested anymore, so we add a
new test to ensure backward compatibility.
This is mainly for the benefit of SSL modules, which only supports restart in
a limited number of cases. In the other cases (ECDHE_PSK) it would currently
return ERR_ECP_IN_PROGRESS and the user would thus call ssl_handshake() again,
but the SSL code wouldn't handle state properly and things would go wrong in
possibly unexpected ways. This is undesirable, so it should be possible for
the SSL module to choose if ECDHE should behave the old or the new way.
Not that it also brings ECDHE more in line with the other modules which
already have that choice available (by passing a NULL or valid restart
context).
Changes include:
- Integers marked with '#' in the .function files.
- Strings should have "" in .data files.
- String comparison instead of preprocessor-like replace for e.g. '=='
- Params and variables cannot have the same name in .function files
