The TUAK algorithm is specified in 3GPP TS 35.231, 232 and 233 and
intended as an alternative to MILENAGE. It's based around the
cryptographic function of KeccakP1600, which is part of SHA-3.
This patch adds support for TUAK to the libosmogsm authentication
core API via 'struct osmo_auth_impl'.
Unit tests covering the test cases from the 3GPP specification are added
(and are all passing).
Change-Id: Ib905b8d8bdf248e8299bf50666ee1bca8298433d
