Algorithm - CMAC

Functions
int	wc_InitCmac (Cmac *cmac, const byte *key, word32 keySz, int type, void *unused)
	Initialize the Cmac structure with defaults. More...
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. More...
int	wc_CmacUpdate (Cmac *cmac, const byte *in, word32 inSz)
	Add Cipher-based Message Authentication Code input data. More...
int	wc_CmacFinalNoFree (Cmac *cmac, byte *out, word32 *outSz)
	Generate the final result using Cipher-based Message Authentication Code, deferring context cleanup. More...
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(). More...
int	wc_CmacFree (Cmac *cmac)
	Clean up allocations in a CMAC context. More...
int	wc_AesCmacGenerate (byte *out, word32 *outSz, const byte *in, word32 inSz, const byte *key, word32 keySz)
	Single shot function for generating a CMAC. More...
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. More...
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. More...

Detailed Description

Function Documentation

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.

Returns

0 on success

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)

Example

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

See also

wc_AesCmacVerify

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.

Returns

0 on success

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)

Example

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

See also

wc_AesCmacGenerate

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.

Returns

0 on success

Parameters

in	input data to process
inSz	size of input data

Example

ret = wc_CMAC_Grow(cmac, in, inSz)

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().

Returns

0 on success

Parameters

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

Example

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

See also

wc_InitCmac

wc_CmacFinalNoFree

wc_CmacFinalNoFree

wc_CmacFree

wc_CmacFinalNoFree()

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

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

Returns

0 on success

Parameters

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

Example

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

See also

wc_InitCmac

wc_CmacFinal

wc_CmacFinalNoFree

wc_CmacFree

wc_CmacFree()

int wc_CmacFree

(

Cmac *

cmac

)

Clean up allocations in a CMAC context.

Returns

0 on success

Parameters

cmac	pointer to the Cmac structure

Example

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

See also

wc_InitCmac

wc_CmacFinalNoFree

wc_CmacFinal

wc_CmacFree

wc_CmacUpdate()

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

Add Cipher-based Message Authentication Code input data.

Returns

0 on success

Parameters

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

Example

ret = wc_CmacUpdate(cmac, in, inSz);

See also

wc_InitCmac

wc_CmacFinal

wc_CmacFinalNoFree

wc_CmacFree

wc_InitCmac()

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

Initialize the Cmac structure with defaults.

Returns

0 on success

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

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);
}

See also

wc_InitCmac_ex

wc_CmacUpdate

wc_CmacFinal

wc_CmacFinalNoFree

wc_CmacFree

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.

Returns

0 on success

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

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);
}

See also

wc_InitCmac_ex

wc_CmacUpdate

wc_CmacFinal

wc_CmacFinalNoFree

wc_CmacFree