SNIP_CLASSIC_SECOC_SECTION_7_4_1_Authentication_during_direct_transmission

7.4.1 Authentication during direct transmission For transmission of an Authentic I-PDU using bus interfaces that allow ad-hoc transmission (e.g. CanIf), the PDU Router module triggers the transmit operation of the SecOC module for an Authentic I-PDU.In this case, the SecOC module prepares the creation of aSecured I-PDUon basis of the Authentic I-PDU by allocating internal buffer capacities and by copying the Authentic I-PDU to a local buffer location. Afterwards it returns from SecOC_[If|Tp]Transmit. [SWS_SecOC_00058]⌈ The SecOC module shall allocate internal buffer capacities to store the Authentic I-PDU and the Authentication Information in a consecutive memory location. ⌋(SRS_SecOC_00006) The actual creation of the Secured I-PDU is processed during the next subsequent call of the scheduled main function. This includes calculating the Authentication Information according to SWS_SecOC_00031 and adding the Authentication Information (i.e. the Authenticator and the possibly truncated Freshness Value) consecutively to the buffer location directly behind the Authentic I-PDU. Thereafter, SecOC module triggers the transmission of the Secured I-PDU to the destination lower layer module by calling PduR_SecOCTransmit at the PduR. [SWS_SecOC_00060]⌈ For transmission of Authentic I-PDUs using bus interfaces that allow ad-hoc transmission (e.g. CanIf), the SecOC module shall calculate the Authenticator in the scheduled main function according to the overall approach specified in SWS_SecOC_00031. ⌋(SRS_SecOC_00010, SRS_SecOC_00012, SRS_SecOC_00013) [SWS_SecOC_00061]⌈ For transmission of Authentic I-PDUs using bus interfaces that allow ad-hoc communication (e.g. CanIf), the SecOC module shall create the Secured I-PDU in the scheduled main function. ⌋(SRS_SecOC_00010, SRS_SecOC_00012, SRS_SecOC_00013) [SWS_SecOC_00062]⌈ The SecOC module shall provide the complete Secured I-PDU for further transmission to the destination lower layer module by triggering PduR_SecOCTransmit. ⌋(SRS_SecOC_00010, SRS_SecOC_00012, SRS_SecOC_00013) [SWS_SecOC_00063]⌈ If the PDU Router module notifies the SecOC module that the destination lower layer module has either confirmed the transmission of the Secured I-PDU or reported an error during transmission by calling SecOC_[If|Tp]TxConfirmation, the SecOC module shall pass the received result of the respective Authentic I-PDU to the upper layer module by calling PduR_SecOC[If|Tp]TxConfirmation. ⌋(SRS_SecOC_00010, SRS_SecOC_00012, SRS_SecOC_00013) [SWS_SecOC_00064]⌈ For transmission of Authentic I-PDUs using bus interfaces that allow ad-hoc communication (e.g. CanIf), the SecOC module shall free the buffer that contains the Secured I-PDU if SecOC_TxConfirmation is called for the Secured I-PDU. ⌋(SRS_SecOC_00010, SRS_SecOC_00012, SRS_SecOC_00013)