Functions NASDec_TS24301Msg_PDU and NASDec_TS24301Msg_PDU support security protected messages as described in TS 24.301. This section provides some important details about this support.
First, TS 24.301 specifies multiple security algorithms that can be used for security protection. This API supports two of them: the null algorithm and the AES-based algorithms. The algorithms based on SNOW3G and ZUC are not currently supported.
Finally, by design, you may provide your own implementation of the security functions exported by the asn1rt3gpp library. This would be useful in any of the following situations:
You want to use a different implementation of the AES algorithms than we have provided.
You want to implement the algorithms we have not implemented (SNOW3G, ZUC).
If you choose to provide your own implementation, the functions to implement (declared and documented in rt3gppNasSec.h) are:
rtx3gppAssignAlgorithmKeys
rtx3gppCipher
rtx3gppComputeMAC