CRYPT_SHA256_DataSizeSet Function

C

int CRYPT_SHA256_DataSizeSet(
    CRYPT_SHA256_CTX* sha256, 
    unsigned int msgSize
);

Description

The PIC32MZ hardware encryption module needs to know the size of the data before it starts processing. This function sets that value.

Preconditions

None.

Parameters

Parameters	Description
sha256	Pointer to CRYPT_SHA256_CTX structure which holds the hash values.
msgSize	Size of the data (in bytes) that will be processed.

Returns

BAD_FUNC_ARG - An invalid pointer was passed to the function.
0 - An invalid pointer was not passed to the function.

Remarks

All SHA256 hashes have to start at a particular value before adding new data to it. This function sets the necessary values for the structure.

Example

CRYPT_SHA256_CTX sha256;
uint8_t buffer[1024];
uint8_t sha256sum[SHA256_DIGEST_SIZE];

CRYPT_SHA256_Initialize(&sha256);
CRYPT_SHA256DataSizeSet(&sha256, sizeof(buffer));
CRYPT_SHA256_DataAdd(&sha256, buffer, sizeof(buffer));
CRYPT_SHA256_Finalize(&sha256, sha256sum);