cmac.h

Functions

	Name
int	wc_InitCmac(Cmac * cmac, const byte * key, word32 keySz, int type, void * unused) Initialize the Cmac structure with defaults.
int	wc_InitCmac_ex(Cmac * cmac, const byte * key, word32 keySz, int type, void * unused, void * heap, int devId) Initialize the Cmac structure with defaults.
int	wc_CmacUpdate(Cmac * cmac, const byte * in, word32 inSz) Add Cipher-based Message Authentication Code input data.
int	wc_CmacFinalNoFree(Cmac * cmac, byte * out, word32 * outSz) Generate the final result using Cipher-based Message Authentication Code, deferring context cleanup.
int	wc_CmacFinal(Cmac * cmac, byte * out, word32 * outSz) Generate the final result using Cipher_based Message Authentication Code, and clean up the context with wc_CmacFree().
int	wc_CmacFree(Cmac * cmac) Clean up allocations in a CMAC context.
int	wc_AesCmacGenerate(byte * out, word32 * outSz, const byte * in, word32 inSz, const byte * key, word32 keySz) Single shot function for generating a CMAC.
int	wc_AesCmacVerify(const byte * check, word32 checkSz, const byte * in, word32 inSz, const byte * key, word32 keySz) Single shot function for validating a CMAC.
int	wc_CMAC_Grow(Cmac * cmac, const byte * in, int inSz) Only used with WOLFSSL_HASH_KEEP when hardware requires single-shot and the updates must be cached in memory.

Functions Documentation

function wc_InitCmac

int wc_InitCmac(
    Cmac * cmac,
    const byte * key,
    word32 keySz,
    int type,
    void * unused
)

Initialize the Cmac structure with defaults.

Parameters:

• cmac pointer to the Cmac structure
• key key pointer
• keySz size of the key pointer (16, 24 or 32)
• type Always WC_CMAC_AES = 1
• unused not used, exists for potential future use around compatibility

See:

• wc_InitCmac_ex
• wc_CmacUpdate
• wc_CmacFinal
• wc_CmacFinalNoFree
• wc_CmacFree

Return: 0 on success

Example

Cmac cmac[1];
ret = wc_InitCmac(cmac, key, keySz, WC_CMAC_AES, NULL);
if (ret == 0) {
    ret = wc_CmacUpdate(cmac, in, inSz);
}
if (ret == 0) {
    ret = wc_CmacFinal(cmac, out, outSz);
}

function wc_InitCmac_ex

int wc_InitCmac_ex(
    Cmac * cmac,
    const byte * key,
    word32 keySz,
    int type,
    void * unused,
    void * heap,
    int devId
)

Initialize the Cmac structure with defaults.

Parameters:

• cmac pointer to the Cmac structure
• key key pointer
• keySz size of the key pointer (16, 24 or 32)
• type Always WC_CMAC_AES = 1
• unused not used, exists for potential future use around compatibility
• heap pointer to the heap hint used for dynamic allocation. Typically used with our static memory option. Can be NULL.
• devId ID to use with crypto callbacks or async hardware. Set to INVALID_DEVID (-2) if not used

See:

• wc_InitCmac_ex
• wc_CmacUpdate
• wc_CmacFinal
• wc_CmacFinalNoFree
• wc_CmacFree

Return: 0 on success

Example

Cmac cmac[1];
ret = wc_InitCmac_ex(cmac, key, keySz, WC_CMAC_AES, NULL, NULL, INVALID_DEVID);
if (ret == 0) {
    ret = wc_CmacUpdate(cmac, in, inSz);
}
if (ret == 0) {
    ret = wc_CmacFinal(cmac, out, &outSz);
}

function wc_CmacUpdate

int wc_CmacUpdate(
    Cmac * cmac,
    const byte * in,
    word32 inSz
)

Add Cipher-based Message Authentication Code input data.

Parameters:

• cmac pointer to the Cmac structure
• in input data to process
• inSz size of input data

See:

• wc_InitCmac
• wc_CmacFinal
• wc_CmacFinalNoFree
• wc_CmacFree

Return: 0 on success

Example

ret = wc_CmacUpdate(cmac, in, inSz);

function wc_CmacFinalNoFree

int wc_CmacFinalNoFree(
    Cmac * cmac,
    byte * out,
    word32 * outSz
)

Generate the final result using Cipher-based Message Authentication Code, deferring context cleanup.

Parameters:

• cmac pointer to the Cmac structure
• out pointer to return the result
• outSz pointer size of output (in/out)

See:

• wc_InitCmac
• wc_CmacFinal
• wc_CmacFinalNoFree
• wc_CmacFree

Return: 0 on success

Example

ret = wc_CmacFinalNoFree(cmac, out, &outSz);
(void)wc_CmacFree(cmac);

function wc_CmacFinal

int wc_CmacFinal(
    Cmac * cmac,
    byte * out,
    word32 * outSz
)

Generate the final result using Cipher-based Message Authentication Code, and clean up the context with wc_CmacFree().

Parameters:

• cmac pointer to the Cmac structure
• out pointer to return the result
• outSz pointer size of output (in/out)

See:

• wc_InitCmac
• wc_CmacFinalNoFree
• wc_CmacFinalNoFree
• wc_CmacFree

Return: 0 on success

Example

ret = wc_CmacFinal(cmac, out, &outSz);

function wc_CmacFree

int wc_CmacFree(
    Cmac * cmac
)

Clean up allocations in a CMAC context.

Parameters:

• cmac pointer to the Cmac structure

See:

• wc_InitCmac
• wc_CmacFinalNoFree
• wc_CmacFinal
• wc_CmacFree

Return: 0 on success

Example

ret = wc_CmacFinalNoFree(cmac, out, &outSz);
(void)wc_CmacFree(cmac);

function wc_AesCmacGenerate

int wc_AesCmacGenerate(
    byte * out,
    word32 * outSz,
    const byte * in,
    word32 inSz,
    const byte * key,
    word32 keySz
)

Single shot function for generating a CMAC.

Parameters:

• out pointer to return the result
• outSz pointer size of output (in/out)
• in input data to process
• inSz size of input data
• key key pointer
• keySz size of the key pointer (16, 24 or 32)

See: wc_AesCmacVerify

Return: 0 on success

Example

ret = wc_AesCmacGenerate(mac, &macSz, msg, msgSz, key, keySz);

function wc_AesCmacVerify

int wc_AesCmacVerify(
    const byte * check,
    word32 checkSz,
    const byte * in,
    word32 inSz,
    const byte * key,
    word32 keySz
)

Single shot function for validating a CMAC.

Parameters:

• check pointer to return the result
• checkSz size of checkout buffer
• in input data to process
• inSz size of input data
• key key pointer
• keySz size of the key pointer (16, 24 or 32)

See: wc_AesCmacGenerate

Return: 0 on success

Example

ret = wc_AesCmacVerify(mac, macSz, msg, msgSz, key, keySz);

function wc_CMAC_Grow

int wc_CMAC_Grow(
    Cmac * cmac,
    const byte * in,
    int inSz
)

Only used with WOLFSSL_HASH_KEEP when hardware requires single-shot and the updates must be cached in memory.

Parameters:

• in input data to process
• inSz size of input data

Return: 0 on success

Example

ret = wc_CMAC_Grow(cmac, in, inSz)

Source code

int wc_InitCmac(Cmac* cmac,
                const byte* key, word32 keySz,
                int type, void* unused);

int wc_InitCmac_ex(Cmac* cmac,
                const byte* key, word32 keySz,
                int type, void* unused, void* heap, int devId);

int wc_CmacUpdate(Cmac* cmac,
                  const byte* in, word32 inSz);


int wc_CmacFinalNoFree(Cmac* cmac,
                 byte* out, word32* outSz);

int wc_CmacFinal(Cmac* cmac,
                 byte* out, word32* outSz);

int wc_CmacFree(Cmac* cmac);

int wc_AesCmacGenerate(byte* out, word32* outSz,
                       const byte* in, word32 inSz,
                       const byte* key, word32 keySz);

int wc_AesCmacVerify(const byte* check, word32 checkSz,
                     const byte* in, word32 inSz,
                     const byte* key, word32 keySz);


int wc_CMAC_Grow(Cmac* cmac, const byte* in, int inSz);

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Updated on 2024-04-26 at 01:10:30 +0000