Hash-based message authentication code (HMAC) related functions

Provides functions to generate Hash-based message authentication code (HMAC). More...

Modules
	Meta backend.
	Includes all backends definitions.
	Types shared between all @ref nrf_crypto_hmac backends.
	Types shared between all Hash-based message authentication code (HMAC) related functions backends.

Typedefs
typedef nrf_crypto_backend_hmac_context_t	nrf_crypto_hmac_context_t
	Context type for HMAC. More...

Functions
ret_code_t	nrf_crypto_hmac_init (nrf_crypto_hmac_context_t *const p_context, nrf_crypto_hmac_info_t const *p_info, uint8_t const *p_key, size_t key_size)
	Initialize context object for HMAC. More...
ret_code_t	nrf_crypto_hmac_update (nrf_crypto_hmac_context_t *const p_context, uint8_t const *p_data, size_t data_size)
	Feed data to HMAC algorithm. More...
ret_code_t	nrf_crypto_hmac_finalize (nrf_crypto_hmac_context_t *const p_context, uint8_t *p_digest, size_t *const p_digest_size)
	Calculate HMAC. More...
ret_code_t	nrf_crypto_hmac_calculate (nrf_crypto_hmac_context_t *const p_context, nrf_crypto_hmac_info_t const *p_info, uint8_t *p_digest, size_t *const p_digest_size, uint8_t const *p_key, size_t key_size, uint8_t const *p_data, size_t data_size)
	Integrated HMAC wrapper function. More...

Variables
const nrf_crypto_hmac_info_t	g_nrf_crypto_hmac_sha256_info
	Information structures used to select the specific algorithm (SHA-256) More...
const nrf_crypto_hmac_info_t	g_nrf_crypto_hmac_sha512_info
	Information structures used to select the specific algorithm (SHA-512) More...

Detailed Description

Provides functions to generate Hash-based message authentication code (HMAC).

Provides functions to generate Hash-based message authentication code (HMAC) using one of the supported hash algorithms. This layer is independent of backend crypto library.

Typedef Documentation

typedef nrf_crypto_backend_hmac_context_t nrf_crypto_hmac_context_t

Context type for HMAC.

Note

The size of this type is scaled for the largest HMAC backend context that is enabled in SDK configuration header file.

Function Documentation

ret_code_t nrf_crypto_hmac_calculate	(	nrf_crypto_hmac_context_t *const	p_context,
		nrf_crypto_hmac_info_t const *	p_info,
		uint8_t *	p_digest,
		size_t *const	p_digest_size,
		uint8_t const *	p_key,
		size_t	key_size,
		uint8_t const *	p_data,
		size_t	data_size
	)

Integrated HMAC wrapper function.

Note

This is an integrated wrapper functions that can be used instead of calling other HMAC functions individually.

Parameters

[in,out]	p_context	Optional pointer to context structure. Context memory will be allocated internally if the pointer is NULL.
[in]	p_info	Pointer to static info structure. This defines the algorithm. This should be either g_nrf_crypto_hmac_sha256_info or g_nrf_crypto_hmac_sha512_info.
[out]	p_digest	Pointer to HMAC digest. Buffer must be large enough to hold the digest.
[in,out]	p_digest_size	Length of digest (result) buffer as input. Length of digest as output.
[in]	p_key	Pointer to HMAC key.
[in]	key_size	Lenth of the HMAC key in bytes.
[in]	p_data	Pointer to input data.
[in]	data_size	Length of input data.

Return values

NRF_SUCCESS	HMAC hash was successfully calculated.
NRF_ERROR_CRYPTO_INPUT_NULL	If p_key or p_data was NULL.
NRF_ERROR_CRYPTO_INPUT_LOCATION	Input data not in RAM (CC310 only).
NRF_ERROR_CRYPTO_INPUT_LENGTH	If key_size or data_size was invalid.
NRF_ERROR_CRYPTO_OUTPUT_NULL	If data_size was NULL.
NRF_ERROR_CRYPTO_OUTPUT_LENGTH	If data_size is not enough to hold the digest.
NRF_ERROR_CRYPTO_ALLOC_FAILED	Unable to allocate memory for the context.
NRF_ERROR_CRYPTO_INTERNAL	An error occurred in the crypto backend.
NRF_ERROR_CRYPTO_BUSY	The function could not be called because the nrf_crypto backend was busy. Please rerun the cryptographic routine at a later time. CC310 only.

ret_code_t nrf_crypto_hmac_finalize	(	nrf_crypto_hmac_context_t *const	p_context,
		uint8_t *	p_digest,
		size_t *const	p_digest_size
	)

Calculate HMAC.

Note

nrf_crypto_hmac_update must be called at least once before calling this.

Parameters

[in,out]	p_context	Context pointer.
[out]	p_digest	Pointer to HMAC digest (result) buffer. Must be large enough to hold the digest (32 byte for SHA-256 and 64 byte for SHA-512).
[in,out]	p_digest_size	Length of buffer as input. Length of digest as output.

Return values

NRF_SUCCESS	HMAC hash was successfully calculated.
NRF_ERROR_CRYPTO_CONTEXT_NULL	If p_context was NULL.
NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED	If p_context has not been initialized.
NRF_ERROR_CRYPTO_OUTPUT_NULL	If p_digest was NULL.
NRF_ERROR_CRYPTO_OUTPUT_LENGTH	If p_size is not enough to hold the digest.
NRF_ERROR_CRYPTO_INTERNAL	An error occurred in the crypto backend.
NRF_ERROR_CRYPTO_BUSY	The function could not be called because the nrf_crypto backend was busy. Please rerun the cryptographic routine at a later time. CC310 only.

ret_code_t nrf_crypto_hmac_init	(	nrf_crypto_hmac_context_t *const	p_context,
		nrf_crypto_hmac_info_t const *	p_info,
		uint8_t const *	p_key,
		size_t	key_size
	)

Initialize context object for HMAC.

Use to initialize a context once it has been allocated.

Note

Must be called before nrf_crypto_hmac_update. Can also be called after nrf_crypto_hmac_finalize order to start a new HMAC calculation re-using an existing context object.

Parameters

[in,out]	p_context	Pointer to context structure.
[in]	p_info	Pointer to static info structure. This defines the algorithm. This should be either g_nrf_crypto_hmac_sha256_info or g_nrf_crypto_hmac_sha512_info.
[in]	p_key	HMAC key.
[in]	key_size	Length of the HMAC key in bytes.

Return values

NRF_SUCCESS	Data successfully consumed.
NRF_ERROR_CRYPTO_CONTEXT_NULL	If p_context has not been initialized.
NRF_ERROR_CRYPTO_INPUT_NULL	If p_info or p_key was NULL.
NRF_ERROR_CRYPTO_INPUT_LENGTH	If key_size was invalid.
NRF_ERROR_CRYPTO_INPUT_LOCATION	Input data not in RAM (CC310 only).
NRF_ERROR_CRYPTO_INTERNAL	An error occurred in the crypto backend.
NRF_ERROR_CRYPTO_BUSY	The function could not be called because the nrf_crypto backend was busy. Please rerun the cryptographic routine at a later time. CC310 only.

ret_code_t nrf_crypto_hmac_update	(	nrf_crypto_hmac_context_t *const	p_context,
		uint8_t const *	p_data,
		size_t	data_size
	)

Feed data to HMAC algorithm.

Note

Must be called after nrf_crypto_hmac_init and before nrf_crypto_hmac_finalize. Can be called repeatedly to consume data as it arrives.

Parameters

[in,out]	p_context	Context pointer.
[in]	p_data	Pointer to input data buffer.
[in]	data_size	Length of input data.

Return values

NRF_SUCCESS	Data successfully consumed.
NRF_ERROR_CRYPTO_CONTEXT_NULL	If p_context has not been initialized.
NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED	If p_data was NULL.
NRF_ERROR_CRYPTO_INPUT_NULL	If p_data was NULL.
NRF_ERROR_CRYPTO_INPUT_LENGTH	If size was invalid.
NRF_ERROR_CRYPTO_INPUT_LOCATION	Input data not in RAM (CC310 only).
NRF_ERROR_CRYPTO_INTERNAL	An error occurred in the crypto backend.
NRF_ERROR_CRYPTO_BUSY	The function could not be called because the nrf_crypto backend was busy. Please rerun the cryptographic routine at a later time. CC310 only.

Variable Documentation

const nrf_crypto_hmac_info_t g_nrf_crypto_hmac_sha256_info

Information structures used to select the specific algorithm (SHA-256)

The information structure is used in a generic way but is populated by the backend, and contains backend specific data.

const nrf_crypto_hmac_info_t g_nrf_crypto_hmac_sha512_info

Information structures used to select the specific algorithm (SHA-512)

The information structure is used in a generic way but is populated by the backend, and contains backend specific data.