DES_Data_Encryption_Standard_api

Functions
void	DESConfigSet (uint32_t ui32Base, uint32_t ui32Config)
void	DESKeySet (uint32_t ui32Base, uint8_t *pui8Key)
bool	DESIVSet (uint32_t ui32Base, uint8_t *pui8IVdata)
void	DESDataLengthSet (uint32_t ui32Base, uint32_t ui32Length)
bool	DESDataReadNonBlocking (uint32_t ui32Base, uint8_t *pui8Dest, uint8_t ui8Length)
void	DESDataRead (uint32_t ui32Base, uint8_t *pui8Dest, uint8_t ui8Length)
bool	DESDataWriteNonBlocking (uint32_t ui32Base, uint8_t *pui8Src, uint8_t ui8Length)
void	DESDataWrite (uint32_t ui32Base, uint8_t *pui8Src, uint8_t ui8Length)
bool	DESDataProcess (uint32_t ui32Base, uint8_t *pui8Src, uint8_t *pui8Dest, uint32_t ui32Length)
uint32_t	DESIntStatus (uint32_t ui32Base, bool bMasked)
void	DESIntEnable (uint32_t ui32Base, uint32_t ui32IntFlags)
void	DESIntDisable (uint32_t ui32Base, uint32_t ui32IntFlags)
void	DESIntClear (uint32_t ui32Base, uint32_t ui32IntFlags)
void	DESIntRegister (uint32_t ui32Base, void(*pfnHandler)(void))
void	DESIntUnregister (uint32_t ui32Base)
void	DESDMAEnable (uint32_t ui32Base, uint32_t ui32Flags)
void	DESDMADisable (uint32_t ui32Base, uint32_t ui32Flags)

Detailed Description

Function Documentation

void DESConfigSet	(	uint32_t	ui32Base,
		uint32_t	ui32Config
	)

Configures the DES module for operation.

Parameters

ui32Base	is the base address of the DES module.
ui32Config	is the configuration of the DES module.

This function configures the DES module for operation.

The ui32Config parameter is a bit-wise OR of a number of configuration flags. The valid flags are grouped below based on their function.

The direction of the operation is specified with one of the following two flags. Only one is permitted.

• DES_CFG_DIR_ENCRYPT - Encryption
• DES_CFG_DIR_DECRYPT - Decryption

The operational mode of the DES engine is specified with one of the following flags. Only one is permitted.

• DES_CFG_MODE_ECB - Electronic Codebook Mode
• DES_CFG_MODE_CBC - Cipher-Block Chaining Mode
• DES_CFG_MODE_CFB - Cipher Feedback Mode

The selection of single DES or triple DES is specified with one of the following two flags. Only one is permitted.

• DES_CFG_SINGLE - Single DES
• DES_CFG_TRIPLE - Triple DES

Returns

None.

void DESDataLengthSet	(	uint32_t	ui32Base,
		uint32_t	ui32Length
	)

Sets the crytographic data length in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32Length	is the length of the data in bytes.

This function writes the cryptographic data length into the DES module. When this register is written, the engine is triggersed to start using this context.

Note

Data lengths up to (2^32 - 1) bytes are allowed.

Returns

None.

bool DESDataProcess	(	uint32_t	ui32Base,
		uint8_t *	pui8Src,
		uint8_t *	pui8Dest,
		uint32_t	ui32Length
	)

Processes blocks of data through the DES module.

Parameters

ui32Base	is the base address of the DES module.
pui8Src	is a pointer to an array of words that contains the source data for processing.
pui8Dest	is a pointer to an array of words consisting of the processed data.
ui32Length	is the length of the cryptographic data in bytes. It must be a multiple of eight.

This function takes the data contained in the pui8Src array and processes it using the DES engine. The resulting data is stored in the pui8Dest array. The function blocks until all of the data has been processed. If processing is successful, the function returns true.

Note

This functions assumes that the DES module has been configured, and initialization values and keys have been written.

Returns

true or false.

void DESDataRead	(	uint32_t	ui32Base,
		uint8_t *	pui8Dest,
		uint8_t	ui8Length
	)

Reads plaintext/ciphertext from data registers with blocking.

Parameters

ui32Base	is the base address of the DES module.
pui8Dest	is a pointer to an array of bytes.
ui8Length	the length can be from 1 to 8

This function waits until the DES module is finished and encrypted or decrypted data is ready. The output data is then stored in the pui8Dest array.

Returns

None

bool DESDataReadNonBlocking	(	uint32_t	ui32Base,
		uint8_t *	pui8Dest,
		uint8_t	ui8Length
	)

Reads plaintext/ciphertext from data registers without blocking

Parameters

ui32Base	is the base address of the DES module.
pui8Dest	is a pointer to an array of 2 words.
ui8Length	the length can be from 1 to 8

This function returns true if the data was ready when the function was called. If the data was not ready, false is returned.

Returns

True or false.

void DESDataWrite	(	uint32_t	ui32Base,
		uint8_t *	pui8Src,
		uint8_t	ui8Length
	)

Writes plaintext/ciphertext to data registers without blocking

Parameters

ui32Base	is the base address of the DES module.
pui8Src	is a pointer to an array of bytes.
ui8Length	the length can be from 1 to 8

This function waits until the DES module is ready before writing the data contained in the pui8Src array.

Returns

None.

bool DESDataWriteNonBlocking	(	uint32_t	ui32Base,
		uint8_t *	pui8Src,
		uint8_t	ui8Length
	)

Writes plaintext/ciphertext to data registers without blocking

Parameters

ui32Base	is the base address of the DES module.
pui8Src	is a pointer to an array of 2 words.
ui8Length	the length can be from 1 to 8

This function returns false if the DES module is not ready to accept data. It returns true if the data was written successfully.

Returns

true or false.

void DESDMADisable	(	uint32_t	ui32Base,
		uint32_t	ui32Flags
	)

Disables DMA request sources in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32Flags	is a bit mask of the DMA requests to be disabled.

This function disables DMA request sources in the DES module. The ui32Flags parameter should be the logical OR of any of the following:

• DES_DMA_CONTEXT_IN - Context In
• DES_DMA_DATA_OUT - Data Out
• DES_DMA_DATA_IN - Data In

Returns

None.

void DESDMAEnable	(	uint32_t	ui32Base,
		uint32_t	ui32Flags
	)

Enables DMA request sources in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32Flags	is a bit mask of the DMA requests to be enabled.

This function enables DMA request sources in the DES module. The ui32Flags parameter should be the logical OR of any of the following:

• DES_DMA_CONTEXT_IN - Context In
• DES_DMA_DATA_OUT - Data Out
• DES_DMA_DATA_IN - Data In

Returns

None.

void DESIntClear	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

Clears interrupts in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32IntFlags	is a bit mask of the interrupts to be disabled.

This function disables interrupt sources in the DES module. ui32IntFlags should be a logical OR of one or more of the following values:

• DES_INT_DMA_CONTEXT_IN - Context interrupt
• DES_INT_DMA_DATA_IN - Data input interrupt
• DES_INT_DMA_DATA_OUT - Data output interrupt

Note

The DMA done interrupts are the only interrupts that can be cleared. The remaining interrupts can be disabled instead using DESIntDisable().

Returns

None.

void DESIntDisable	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

Disables interrupts in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32IntFlags	is a bit mask of the interrupts to be disabled.

This function disables interrupt sources in the DES module. ui32IntFlags should be a logical OR of one or more of the following values:

• DES_INT_CONTEXT_IN - Context interrupt
• DES_INT_DATA_IN - Data input interrupt
• DES_INT_DATA_OUT - Data output interrupt
• DES_INT_DMA_CONTEXT_IN - Context DMA done interrupt
• DES_INT_DMA_DATA_IN - Data input DMA done interrupt
• DES_INT_DMA_DATA_OUT - Data output DMA done interrupt

Returns

None.

void DESIntEnable	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

Enables interrupts in the DES module.

Parameters

ui32Base	is the base address of the DES module.
ui32IntFlags	is a bit mask of the interrupts to be enabled.

ui32IntFlags should be a logical OR of one or more of the following values:

• DES_INT_CONTEXT_IN - Context interrupt
• DES_INT_DATA_IN - Data input interrupt
• DES_INT_DATA_OUT - Data output interrupt
• DES_INT_DMA_CONTEXT_IN - Context DMA done interrupt
• DES_INT_DMA_DATA_IN - Data input DMA done interrupt
• DES_INT_DMA_DATA_OUT - Data output DMA done interrupt

Returns

None.

void DESIntRegister	(	uint32_t	ui32Base,
		void(*)(void)	pfnHandler
	)

Registers an interrupt handler for the DES module.

Parameters

ui32Base	is the base address of the DES module.
pfnHandler	is a pointer to the function to be called when the enabled DES interrupts occur.

This function registers the interrupt handler in the interrupt vector table, and enables DES interrupts on the interrupt controller; specific DES interrupt sources must be enabled using DESIntEnable(). The interrupt handler being registered must clear the source of the interrupt using DESIntClear().

If the application is using a static interrupt vector table stored in flash, then it is not necessary to register the interrupt handler this way. Instead, IntEnable() should be used to enable DES interrupts on the interrupt controller.

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

uint32_t DESIntStatus	(	uint32_t	ui32Base,
		bool	bMasked
	)

Returns the current interrupt status of the DES module.

Parameters

ui32Base	is the base address of the DES module.
bMasked	is false if the raw interrupt status is required and true if the masked interrupt status is required.

This function gets the current interrupt status of the DES module. The value returned is a logical OR of the following values:

• DES_INT_CONTEXT_IN - Context interrupt
• DES_INT_DATA_IN - Data input interrupt
• DES_INT_DATA_OUT_INT - Data output interrupt
• DES_INT_DMA_CONTEXT_IN - Context DMA done interrupt
• DES_INT_DMA_DATA_IN - Data input DMA done interrupt
• DES_INT_DMA_DATA_OUT - Data output DMA done interrupt

Returns

A bit mask of the current interrupt status.

void DESIntUnregister

(

uint32_t

ui32Base

)

Unregisters an interrupt handler for the DES module.

Parameters

ui32Base

is the base address of the DES module.

This function unregisters the previously registered interrupt handler and disables the interrupt in the interrupt controller.

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

bool DESIVSet	(	uint32_t	ui32Base,
		uint8_t *	pui8IVdata
	)

Sets the initialization vector in the DES module.

Parameters

ui32Base	is the base address of the DES module.
pui8IVdata	is a pointer to an array of 64 bits (2 words) of data to be written into the initialization vectors registers.

This function sets the initialization vector in the DES module. It returns true if the registers were successfully written. If the context registers cannot be written at the time the function was called, then false is returned.

Returns

True or false.

void DESKeySet	(	uint32_t	ui32Base,
		uint8_t *	pui8Key
	)

Sets the key used for DES operations.

Parameters

ui32Base	is the base address of the DES module.
pui8Key	is a pointer to an array that holds the key

This function sets the key used for DES operations.

pui8Key should be 64 bits long (2 words) if single DES is being used or 192 bits (6 words) if triple DES is being used.

Returns

None.