tree 9357b578aa06c33f131f19fa18b5a8a1470ea71e
parent 8c07beeb84dbf739a9430e365fe2389586a4c7c1
author Hanno Becker <hanno.becker@arm.com> 1558540235 +0100
committer Hanno Becker <hanno.becker@arm.com> 1559574470 +0100

Allow passing NULL pointers to mbedtls_ssl_get_peer_cid()

This commit modifies mbedtls_ssl_get_peer_cid() to also allow passing
NULL pointers in the arguments for the peer's CID value and length, in
case this information is needed.

For example, some users might only be interested in whether the use of
the CID was negotiated, in which case both CID value and length pointers
can be set to NULL. Other users might only be interested in confirming
that the use of CID was negotiated and the peer chose the empty CID,
in which case the CID value pointer only would be set to NULL.
It doesn't make sense to pass a NULL pointer for the CID length but a
non-NULL pointer for the CID value, as the caller has no way of telling
the length of the returned CID - and this case is therefore forbidden.