crys_hmac

This file contains all of the enums and definitions that are used for the CRYS HMAC APIs, as well as the APIs themselves. More...

Data Structures
struct	CRYS_HMACUserContext_t

Macros
#define	CRYS_HMAC_KEY_SIZE_IN_BYTES   64
#define	CRYS_HMAC_SHA2_1024BIT_KEY_SIZE_IN_BYTES   128

Typedefs
typedef struct CRYS_HMACUserContext_t	CRYS_HMACUserContext_t

Functions
CRYSError_t	CRYS_HMAC_Init (CRYS_HMACUserContext_t *ContextID_ptr, CRYS_HASH_OperationMode_t OperationMode, uint8_t *key_ptr, uint16_t keySize)
	This function initializes the HMAC machine. More...
CRYSError_t	CRYS_HMAC_Update (CRYS_HMACUserContext_t *ContextID_ptr, uint8_t *DataIn_ptr, size_t DataInSize)
	This function processes a block of data to be HASHed. More...
CRYSError_t	CRYS_HMAC_Finish (CRYS_HMACUserContext_t *ContextID_ptr, CRYS_HASH_Result_t HmacResultBuff)
	This function finalizes the HMAC processing of a data block. More...
CRYSError_t	CRYS_HMAC_Free (CRYS_HMACUserContext_t *ContextID_ptr)
	This function is a service function that frees the context if the operation has failed. More...
CRYSError_t	CRYS_HMAC (CRYS_HASH_OperationMode_t OperationMode, uint8_t *key_ptr, uint16_t keySize, uint8_t *DataIn_ptr, size_t DataSize, CRYS_HASH_Result_t HmacResultBuff)
	This function processes a single buffer of data, and returns the data buffer's message digest. More...

Detailed Description

This file contains all of the enums and definitions that are used for the CRYS HMAC APIs, as well as the APIs themselves.

HMAC is a wrapping algorithm that uses a HASH function (one of the supported HASH algorithms, as specified in the HASH chapter) and a key, to generate a unique authentication code over the input data. HMAC calculation can be performed in either of the following two modes of operation:

• Integrated operation - Processes all data in a single function call. This flow is applicable when all data is available prior to the cryptographic operation.
• Block operation - Processes a subset of the data buffers, and is called multiple times in a sequence. This flow is applicable when the next data buffer becomes available only during/after processing of the current data buffer.

The following is a typical HMAC Block operation flow:

1. CRYS_HMAC_Init: This function initializes the HMAC machine on the CRYS level by setting the context pointer that is used on the entire HMAC operation.
2. CRYS_HMAC_Update: This function runs an HMAC operation on a block of data allocated by the user. This function may be called as many times as required.
3. CRYS_HMAC_Finish: This function ends the HMAC operation. It returns the digest result and clears the context.

Function Documentation

CRYSError_t CRYS_HMAC	(	CRYS_HASH_OperationMode_t	OperationMode,
		uint8_t *	key_ptr,
		uint16_t	keySize,
		uint8_t *	DataIn_ptr,
		size_t	DataSize,
		CRYS_HASH_Result_t	HmacResultBuff
	)

This function processes a single buffer of data, and returns the data buffer's message digest.

Returns

CRYS_OK on success.

A non-zero value from crys_hmac_error.h on failure.

Parameters

[in]	OperationMode	One of the supported HASH modes, as defined in CRYS_HASH_OperationMode_t.
[in]	key_ptr	The pointer to the user's key buffer.
[in]	keySize	The key size in bytes.
[in]	DataIn_ptr	Pointer to the input data to be HASHed. The size of the scatter/gather list representing the data buffer is limited to 128 entries, and the size of each entry is limited to 64KB (fragments larger than 64KB are broken into fragments <= 64KB).
[in]	DataSize	The size of the data to be hashed (in bytes).
[out]	HmacResultBuff	Pointer to the word-aligned 64 byte buffer. The actual size of the HMAC result depends on CRYS_HASH_OperationMode_t.

CRYSError_t CRYS_HMAC_Finish	(	CRYS_HMACUserContext_t *	ContextID_ptr,
		CRYS_HASH_Result_t	HmacResultBuff
	)

This function finalizes the HMAC processing of a data block.

It receives a handle to the HMAC context that was previously initialized by CRYS_HMAC_Init, or by CRYS_HMAC_Update. It completes the HASH calculation on the ipad and text, and then executes a new HASH operation with the key XOR opad and the previous HASH operation result.

Returns

CRYS_OK on success.

A non-zero value from crys_hmac_error.h on failure.

Parameters

[in]	ContextID_ptr	Pointer to the HMAC context buffer allocated by the user, which is used for the HMAC machine operation.
[out]	HmacResultBuff	Pointer to the word-aligned 64 byte buffer. The actual size of the HASH result depends on CRYS_HASH_OperationMode_t.

CRYSError_t CRYS_HMAC_Free

(

CRYS_HMACUserContext_t *

ContextID_ptr

)

This function is a service function that frees the context if the operation has failed.

The function executes the following major steps:

1. Checks the validity of all of the inputs of the function.
2. Clears the user's context.
3. Exits the handler with the OK code.

Returns

CRYS_OK on success.

a non-zero value from crys_hmac_error.h on failure.

Parameters

[in]

ContextID_ptr

Pointer to the HMAC context buffer allocated by the user, which is used for the HMAC machine operation.

CRYSError_t CRYS_HMAC_Init	(	CRYS_HMACUserContext_t *	ContextID_ptr,
		CRYS_HASH_OperationMode_t	OperationMode,
		uint8_t *	key_ptr,
		uint16_t	keySize
	)

This function initializes the HMAC machine.

It allocates and initializes the HMAC Context. It initiates a HASH session and processes a HASH update on the Key XOR ipad, then stores it in the context

Returns

CRYS_OK on success.

A non-zero value from crys_hmac_error.h on failure.

Parameters

[in]	ContextID_ptr	Pointer to the HMAC context buffer allocated by the user, which is used for the HMAC machine operation.
[in]	OperationMode	One of the supported HASH modes, as defined in CRYS_HASH_OperationMode_t.
[in]	key_ptr	The pointer to the user's key buffer.
[in]	keySize	The key size in bytes.

CRYSError_t CRYS_HMAC_Update	(	CRYS_HMACUserContext_t *	ContextID_ptr,
		uint8_t *	DataIn_ptr,
		size_t	DataInSize
	)

This function processes a block of data to be HASHed.

It receives a handle to the HMAC Context, and updates the HASH value with the new data.

Returns

CRYS_OK on success.

A non-zero value from crys_hmac_error.h on failure.

Parameters

[in]	ContextID_ptr	Pointer to the HMAC context buffer allocated by the user that is used for the HMAC machine operation.
[in]	DataIn_ptr	Pointer to the input data to be HASHed. The size of the scatter/gather list representing the data buffer is limited to 128 entries, and the size of each entry is limited to 64KB (fragments larger than 64KB are broken into fragments <= 64KB).
[in]	DataInSize	Byte size of the input data. Must be > 0. If not a multiple of the HASH block size (64 for SHA-1 and SHA-224/256, 128 for SHA-384/512), no further calls to CRYS_HMAC_Update are allowed in this context, and only CRYS_HMAC_Finish can be called to complete the computation.