Function srtp_unprotect

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

@brief srtp_unprotect() is the Secure RTP receiver-side packet processing function.

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.

@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).
• [other] if there has been an error in the cryptographic mechanisms.