2.3.2.2 Crypto_Aead_AesCcm_Cipher

crypto_Aead_Status_E Crypto_Aead_AesCcm_Cipher(
    st_Crypto_Aead_AesCcm_ctx *ptr_aesCcmCtx_st, 
    crypto_CipherOper_E cipherOper_en, 
    uint8_t *ptr_inputData, 
    uint32_t dataLen, 
    uint8_t *ptr_outData, 
    uint8_t *ptr_nonce, 
    uint32_t nonceLen, 
    uint8_t *ptr_authTag, 
    uint32_t authTagLen, 
    uint8_t *ptr_aad, 
    uint32_t aadLen
    );

Description

This API performs AES-CCM encryption or decryption. Before using it, initialize the context by calling the Crypto_Aead_AesCcm_Init function.

Parameters


No.	Argument Type	Argument Name	Type	Description
1	st_Crypto_Aead_AesCcm_ctx*	ptr_aesCcmCtx_st	Input	AES-CCM algorithm context.
2	crypto_CipherOper_E	cipherOper_en	Input	Selection cipher operation is encryption or decryption.
3	uint8_t*	ptr_inputData	Input	Input data to encrypt or decrypt.
4	uint32_t	dataLen	Input	Length of plain data or cipher data in bytes.
5	uint8_t*	ptr_outData	Output	Pointer to store cipher text/plain text as output.
6	uint8_t*	ptr_nonce	Input	Pointer for the Nonce value.
7	uint32_t	nonceLen	Input	Length of Nonce between 7 to 13 bytes.
8	uint8_t*	ptr_authTag	Output/Input	Pointer to store authentication tag value. Provide value while decryption operation.
9	uint32_t	authTagLen	Input	Length of Authentication tag between 4 to 16 bytes.
10	uint8_t*	ptr_aad	Input	Pointer for additional authentication data. It is optional to use, so it can be NULL also.
11	uint32_t	aadLen	Input	Length of additional data in bytes, as it is optional so it can be 0 also.

Returns


Return Type	Description
crypto_Aead_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_Hash_Status_E status;
crypto_HandlerType_E handlerType_en = CRYPTO_HANDLER_SW_WOLFCRYPT;
crypto_CipherOper_E cipherOper_en = CRYPTO_CIOP_ENCRYPT;
st_Crypto_Aead_AesCcm_ctx AesCcm_ctx;
uint8_t inputData[32] = {/*data*/};
uint32_t dataLen = sizeof(inputData);
uint8_t key[32] = {/*data*/};
uint32_t keyLen = sizeof(key);
uint8_t outData[32];
uint8_t nonce[13] = {/*data*/};
uint32_t nonceLen = sizeof(nonce);
uint8_t authTag[32] = {/*data*/};
uint32_t authTagLen = 16; //tag length 4-16
uint8_t aad[32] = {/*data*/};
uint32_t aadLen = sizeof(aad);

status = Crypto_Aead_AesCcm_Init(
    &AesCcm_ctx, 
    handlerType_en, 
    key, 
    keyLen, 
    sessionID
    );

status = Crypto_Aead_AesCcm_Cipher(
    &AesCcm_ctx, 
    cipherOper_en, 
    inputData, 
    dataLen, 
    outData, 
    nonce, 
    nonceLen, 
    authTag, 
    authTagLen, 
    aad, 
    aadLen
    );