SNIP_CLASSIC_CRYIF_SECTION_7_2_1_Normal_Operation

7.2.1 Normal Operation [SWS_Csm_01039] Upstream requirements: SRS_CryptoStack_00084 ⌈To unite a single call function and the streaming approach for the crypto services, there is the mode parameter, which determines the operation mode. This service operation is a flag field, indicating the operation mode "START", "UPDATE" or "FINISH". It declares explicitly what operation shall be performed. These operation modes can be mixed, and execute multiple operations at once. The diagram in [SWS_Crypto_00018] (in [4]) shows the state machine of a job of this design.⌋ Note: The actual transaction of the states is made in the layer, which works with these states, i.e. in the Crypto Driver. [SWS_Csm_01033] ⌈The CSM crypto services shall support to process multiple operation mode inputs with a single call.⌋ [SWS_Csm_01045] ⌈If the CRYPTO_OPERATIONMODE_START and CRYPTO_OPERATIONMODE_FINISH bits are set and the CRYPTO_OPERATIONMODE_UPDATE is not set, the Csm_<Service> function shall return with E_NOT_OK.⌋ Note: The coherent single call approach could improve the performance due to less overhead. Instead of calling the explicit API multiple times, only one call is necessary. This approach is intended to be used with small data input, which demand fast processing. While operating with the streaming approach ("Start", "Update", "Finish") the dedicated Crypto Driver Object is waiting for further input ("Update") until the "Finish" state has been reached. No other job could be processed on this Crypto Driver instance meanwhile.