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Modules | Data Structures | Macros | Typedefs | Functions
CryptoCell HMAC APIs

Modules

 CryptoCell Hmac definitions
 
 CryptoCell HMAC specific errors
 

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

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:

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.

Macro Definition Documentation

#define CRYS_HMAC_KEY_SIZE_IN_BYTES   64

HMAC key size after padding for MD5, SHA1, SHA256.

Definition at line 80 of file crys_hmac.h.

#define CRYS_HMAC_SHA2_1024BIT_KEY_SIZE_IN_BYTES   128

HMAC key size after padding for SHA384, SHA512

Definition at line 83 of file crys_hmac.h.

Typedef Documentation

User's context prototype - the argument type that is passed by the user to the HMAC APIs. The context saves the state of the operation and must be saved by the user till the end of the APIs flow

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 or crys_hash_error.h on failure.
Parameters
[in]OperationModeOne of the supported HASH modes, as defined in CRYS_HASH_OperationMode_t.
[in]key_ptrThe pointer to the user's key buffer.
[in]keySizeThe key size in bytes. If the key size is bigger than the HASH block, the key will be hashed. The limitations on the key size are the same as the limitations on MAX hash size.
[in]DataIn_ptrPointer 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]DataSizeThe size of the data to be hashed (in bytes).
[out]HmacResultBuffPointer 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 or crys_hash_error.h on failure.
Parameters
[in]ContextID_ptrPointer to the HMAC context buffer allocated by the user, which is used for the HMAC machine operation.
[out]HmacResultBuffPointer 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_ptrPointer 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 or crys_hash_error.h on failure.
Parameters
[in]ContextID_ptrPointer to the HMAC context buffer allocated by the user, which is used for the HMAC machine operation.
[in]OperationModeOne of the supported HASH modes, as defined in CRYS_HASH_OperationMode_t.
[in]key_ptrThe pointer to the user's key buffer.
[in]keySizeThe key size in bytes. If the key size is bigger than the HASH block, the key will be hashed. The limitations on the key size are the same as the limitations on MAX hash size.
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 or crys_hash_error.h on failure.
Parameters
[in]ContextID_ptrPointer to the HMAC context buffer allocated by the user that is used for the HMAC machine operation.
[in]DataIn_ptrPointer 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]DataInSizeByte 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.
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