6.4.2.2 Crypto_Mac_AesGmac_Direct

crypto_Mac_Status_E Crypto_Mac_AesGmac_Direct(
    crypto_HandlerType_E macHandlerType_en, 
    uint8_t *ptr_initVect, 
    uint32_t initVectLen, 
    uint8_t *ptr_outMac, 
    uint32_t macLen, 
    uint8_t *ptr_key, 
    uint32_t keyLen,
    uint8_t *ptr_aad,
    uint32_t aadLen,
    uint32_t sessionID
    );

Description

This API generates the MAC using AES-GMAC in a single step, without needing any prior initialization. To verify the MAC, users can compare the generated MAC with the one received from the sender along with the message.

Parameters


No.	Argument Type	Argument Name	Type	Description
1	crypto_HandlerType_E	handlerType_en	Input	Enum for crypto operation handler i.e., SW, HW
2	uint8_t*	ptr_initVect	Input	Input data to calculate the MAC
3	uint32_t	initVectLen	Input	Input length of plain data in bytes
4	uint8_t*	ptr_outMac	Output	Pointer for MAC
5	uint8_t*	macLen	Input	MAC length, min 4 bytes max 16 bytes
6	uint8_t*	ptr_key	Input	Key for the AES-GMAC cipher operation
7	uint32_t	keyLen	Input	Key length in bytes for the AES-GMAC algorithm
8	uint32_t	ptr_aad	Input	Key length in bytes for the AES-GMAC algorithm
9	uint32_t	aadLen	Input	aad length in bytes for the AES-GMAC algorithm
10	uint32_t	sessionID	Input	It defines the session ID, must be more than zero

Returns


Return Type	Description
crypto_Mac_Status_E	Function returns the status of the API.

Prerequisites

To use the HW handler, the algorithm must be enabled in Crypto v4 in MPLAB® Code Configurator.
To use the SW handler, the algorithm must be enabled in wolfCrypt, and linked to Crypto V4 in MPLAB® Code Configurator.

Example

#define sessionID 1
crypto_Mac_Status_E status;
crypto_HandlerType_E handlerType_en = CRYPTO_HANDLER_SW_WOLFCRYPT;
uint8_t inputData[32] = {/*data*/};
uint32_t dataLen = sizeof(inputData);
uint8_t key[32] = {/*data*/};
uint32_t keyLen = sizeof(key);
uint8_t mac[64];
uint32_t macLen = 16;

status = Crypto_Mac_AesGmac_Direct(
    handlerType_en, 
    inputData, 
    dataLen, 
    mac, 
    macLen, 
    key, 
    keyLen, 
    sessionID
    );