Authentication-Cipher Context Object Operations
[Object-Manipulation Operations]

Functions
void	fsl_shw_acco_init (fsl_shw_acco_t *auth_object, fsl_shw_acc_mode_t mode)
void	fsl_shw_acco_set_flags (fsl_shw_acco_t *auth_object, uint32_t flags)
void	fsl_shw_acco_clear_flags (fsl_shw_acco_t *auth_object, uint32_t flags)
void	fsl_shw_acco_set_ccm (fsl_shw_acco_t *auth_object, fsl_shw_key_alg_t algorithm, const uint8_t *ctr, uint8_t mac_length)
void	fsl_shw_ccm_nist_format_ctr_and_iv (fsl_shw_acco_t *auth_object, uint8_t t_length, uint32_t ad_length, uint8_t q_length, const uint8_t *n, uint32_t q)
void	fsl_shw_ccm_nist_update_ctr_and_iv (fsl_shw_acco_t *auth_object, const uint8_t *n, uint32_t q)

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Detailed Description

These functions operate on a fsl_shw_acco_t. Their purpose is to set flags, fields, etc., in order to control the operation of fsl_shw_gen_encrypt() and fsl_shw_auth_decrypt().

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Function Documentation

void fsl_shw_acco_clear_flags	(	fsl_shw_acco_t *	auth_object,
		uint32_t	flags
	)

Clear some flags in a Authentication-Cipher Context Object.

Turns off the flags specified in flags. Other flags are untouched.

Parameters:

	auth_object	Pointer to object to operate on.
	flags	The flags to reset (one or more from fsl_shw_auth_ctx_flags_t ORed together).

void fsl_shw_acco_init	(	fsl_shw_acco_t *	auth_object,
		fsl_shw_acc_mode_t	mode
	)

Initialize a Authentication-Cipher Context.

Parameters:

	auth_object	Pointer to object to operate on.
	mode	The mode for this object (only FSL_ACC_MODE_CCM supported).

void fsl_shw_acco_set_ccm	(	fsl_shw_acco_t *	auth_object,
		fsl_shw_key_alg_t	algorithm,
		const uint8_t *	ctr,
		uint8_t	mac_length
	)

Set up the Authentication-Cipher Object for CCM mode.

This will set the auth_object for CCM mode and save the ctr, and mac_length. This function can be called instead of fsl_shw_acco_init().

The parameter ctr is Counter Block 0, (counter value 0), which is for the MAC.

Parameters:

	auth_object	Pointer to object to operate on.
	algorithm	Cipher algorithm. Only AES is supported.
	ctr	The initial counter value.
	mac_length	The number of octets used for the MAC. Valid values are 4, 6, 8, 10, 12, 14, and 16.

void fsl_shw_acco_set_flags	(	fsl_shw_acco_t *	auth_object,
		uint32_t	flags
	)

Set the flags for a Authentication-Cipher Context.

Turns on the flags specified in flags. Other flags are untouched.

Parameters:

	auth_object	Pointer to object to operate on.
	flags	The flags to set (one or more from fsl_shw_auth_ctx_flags_t ORed together).

void fsl_shw_ccm_nist_format_ctr_and_iv	(	fsl_shw_acco_t *	auth_object,
		uint8_t	t_length,
		uint32_t	ad_length,
		uint8_t	q_length,
		const uint8_t *	n,
		uint32_t	q
	)

Format the First Block (IV) & Initial Counter Value per NIST CCM.

This function will also set the IV and CTR values per Appendix A of NIST Special Publication 800-38C (May 2004). It will also perform the fsl_shw_acco_set_ccm() operation with information derived from this set of parameters.

Note this function assumes the algorithm is AES. It initializes the auth_object by setting the mode to FSL_ACC_MODE_CCM and setting the flags to be FSL_ACCO_NIST_CCM.

Parameters:

	auth_object	Pointer to object to operate on.
	t_length	The number of octets used for the MAC. Valid values are 4, 6, 8, 10, 12, 14, and 16.
	ad_length	Number of octets of Associated Data (may be zero).
	q_length	A value for the size of the length of q field. Valid values are 1-8.
	n	The Nonce (packet number or other changing value). Must be (15 - q_length) octets long.
	q	The value of Q (size of the payload in octets).

void fsl_shw_ccm_nist_update_ctr_and_iv	(	fsl_shw_acco_t *	auth_object,
		const uint8_t *	n,
		uint32_t	q
	)

Update the First Block (IV) & Initial Counter Value per NIST CCM.

This function will set the IV and CTR values per Appendix A of NIST Special Publication 800-38C (May 2004).

Note this function assumes that fsl_shw_ccm_nist_format_ctr_and_iv() has previously been called on the auth_object.

Parameters:

	auth_object	Pointer to object to operate on.
	n	The Nonce (packet number or other changing value). Must be (15 - q_length) octets long.
	q	The value of Q (size of the payload in octets).