Function srtp_unprotect_mki

pub unsafe extern "C" fn srtp_unprotect_mki(
    ctx: srtp_t,
    srtp_hdr: *mut c_void,
    len_ptr: *mut c_int,
    use_mki: c_uint,
) -> srtp_err_status_t

@brief srtp_unprotect_mki() is the Secure RTP receiver-side packet processing function that checks for MKI.

The function call srtp_unprotect(ctx, srtp_hdr, len_ptr) verifies the Secure RTP protection of the SRTP packet pointed to by srtp_hdr (which has length *len_ptr), using the SRTP context ctx. If srtp_err_status_ok is returned, then srtp_hdr points to the resulting RTP packet and *len_ptr is the number of octets in that packet; otherwise, no assumptions should be made about the value of either data elements.

The sequence numbers of the RTP packets presented to this function need not be consecutive, but they @b must be out of order by less than 2^15 = 32,768 packets.

@warning This function assumes that the SRTP packet is aligned on a 32-bit boundary.

@param ctx is the SRTP session which applies to the particular packet.

@param srtp_hdr is a pointer to the header of the SRTP packet (before the call). after the function returns, it points to the rtp packet if srtp_err_status_ok was returned; otherwise, the value of the data to which it points is undefined.

@param len_ptr is a pointer to the length in octets of the complete srtp packet (header and body) before the function call, and of the complete rtp packet after the call, if srtp_err_status_ok was returned. Otherwise, the value of the data to which it points is undefined.

@param use_mki is a boolean to tell the system if mki is being used. If set to false then will use the first set of session keys. If set to true will use the session keys identified by the mki_index

@return

• srtp_err_status_ok if the RTP packet is valid.
• srtp_err_status_auth_fail if the SRTP packet failed the message authentication check.
• srtp_err_status_replay_fail if the SRTP packet is a replay (e.g. packet has already been processed and accepted).
• srtp_err_status_bad_mki if the MKI in the packet is not a known MKI id
• [other] if there has been an error in the cryptographic mechanisms.