stm32f2xx_cryp.c

STM32+Grlib

/**
  * @brief  Initializes the CRYP Keys according to the specified parameters in
  *         the CRYP_KeyInitStruct.
  * @param  CRYP_KeyInitStruct: pointer to a CRYP_KeyInitTypeDef structure that
  *         contains the configuration information for the CRYP Keys.
  * @retval None
  */
void CRYP_KeyInit(CRYP_KeyInitTypeDef* CRYP_KeyInitStruct)
{
  /* Key Initialisation */
  CRYP->K0LR = CRYP_KeyInitStruct->CRYP_Key0Left;
  CRYP->K0RR = CRYP_KeyInitStruct->CRYP_Key0Right;
  CRYP->K1LR = CRYP_KeyInitStruct->CRYP_Key1Left;
  CRYP->K1RR = CRYP_KeyInitStruct->CRYP_Key1Right;
  CRYP->K2LR = CRYP_KeyInitStruct->CRYP_Key2Left;
  CRYP->K2RR = CRYP_KeyInitStruct->CRYP_Key2Right;
  CRYP->K3LR = CRYP_KeyInitStruct->CRYP_Key3Left;
  CRYP->K3RR = CRYP_KeyInitStruct->CRYP_Key3Right;
}

/**
  * @brief  Fills each CRYP_KeyInitStruct member with its default value.
  * @param  CRYP_KeyInitStruct: pointer to a CRYP_KeyInitTypeDef structure 
  *         which will be initialized.
  * @retval None
  */
void CRYP_KeyStructInit(CRYP_KeyInitTypeDef* CRYP_KeyInitStruct)
{
  CRYP_KeyInitStruct->CRYP_Key0Left  = 0;
  CRYP_KeyInitStruct->CRYP_Key0Right = 0;
  CRYP_KeyInitStruct->CRYP_Key1Left  = 0;
  CRYP_KeyInitStruct->CRYP_Key1Right = 0;
  CRYP_KeyInitStruct->CRYP_Key2Left  = 0;
  CRYP_KeyInitStruct->CRYP_Key2Right = 0;
  CRYP_KeyInitStruct->CRYP_Key3Left  = 0;
  CRYP_KeyInitStruct->CRYP_Key3Right = 0;
}
/**
  * @brief  Initializes the CRYP Initialization Vectors(IV) according to the
  *         specified parameters in the CRYP_IVInitStruct.
  * @param  CRYP_IVInitStruct: pointer to a CRYP_IVInitTypeDef structure that contains
  *         the configuration information for the CRYP Initialization Vectors(IV).
  * @retval None
  */
void CRYP_IVInit(CRYP_IVInitTypeDef* CRYP_IVInitStruct)
{
  CRYP->IV0LR = CRYP_IVInitStruct->CRYP_IV0Left;
  CRYP->IV0RR = CRYP_IVInitStruct->CRYP_IV0Right;
  CRYP->IV1LR = CRYP_IVInitStruct->CRYP_IV1Left;
  CRYP->IV1RR = CRYP_IVInitStruct->CRYP_IV1Right;
}

/**
  * @brief  Fills each CRYP_IVInitStruct member with its default value.
  * @param  CRYP_IVInitStruct: pointer to a CRYP_IVInitTypeDef Initialization 
  *         Vectors(IV) structure which will be initialized.
  * @retval None
  */
void CRYP_IVStructInit(CRYP_IVInitTypeDef* CRYP_IVInitStruct)
{
  CRYP_IVInitStruct->CRYP_IV0Left  = 0;
  CRYP_IVInitStruct->CRYP_IV0Right = 0;
  CRYP_IVInitStruct->CRYP_IV1Left  = 0;
  CRYP_IVInitStruct->CRYP_IV1Right = 0;
}

/**
  * @brief  Flushes the IN and OUT FIFOs (that is read and write pointers of the 
  *         FIFOs are reset)
  * @note   The FIFOs must be flushed only when BUSY flag is reset.  
  * @param  None
  * @retval None
  */
void CRYP_FIFOFlush(void)
{
  /* Reset the read and write pointers of the FIFOs */
  CRYP->CR |= CRYP_CR_FFLUSH;
}

/**
  * @brief  Enables or disables the CRYP peripheral.
  * @param  NewState: new state of the CRYP peripheral.
  *          This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void CRYP_Cmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the Cryptographic processor */
    CRYP->CR |= CRYP_CR_CRYPEN;
  }
  else
  {
    /* Disable the Cryptographic processor */
    CRYP->CR &= ~CRYP_CR_CRYPEN;
  }
}
/**
  * @}
  */
  
/** @defgroup CRYP_Group2 CRYP Data processing functions
 *  @brief    CRYP Data processing functions
 *
@verbatim    
 ===============================================================================
                      CRYP Data processing functions
 ===============================================================================  
  This section provides functions allowing the encryption and decryption 
  operations: 
  - Enter data to be treated in the IN FIFO : using CRYP_DataIn() function.
  - Get the data result from the OUT FIFO : using CRYP_DataOut() function.

@endverbatim
  * @{
  */

/**
  * @brief  Writes data in the Data Input register (DIN).
  * @note   After the DIN register has been read once or several times, 
  *         the FIFO must be flushed (using CRYP_FIFOFlush() function).  
  * @param  Data: data to write in Data Input register
  * @retval None
  */
void CRYP_DataIn(uint32_t Data)
{
  CRYP->DR = Data;
}

/**
  * @brief  Returns the last data entered into the output FIFO.
  * @param  None
  * @retval Last data entered into the output FIFO.
  */
uint32_t CRYP_DataOut(void)
{
  return CRYP->DOUT;
}
/**
  * @}
  */
  
/** @defgroup CRYP_Group3 Context swapping functions
 *  @brief   Context swapping functions
 *
@verbatim   
 ===============================================================================
                             Context swapping functions
 ===============================================================================  

  This section provides functions allowing to save and store CRYP Context

  It is possible to interrupt an encryption/ decryption/ key generation process 
  to perform another processing with a higher priority, and to complete the 
  interrupted process later on, when the higher-priority task is complete. To do 
  so, the context of the interrupted task must be saved from the CRYP registers 
  to memory, and then be restored from memory to the CRYP registers.
   
  1. To save the current context, use CRYP_SaveContext() function
  2. To restore the saved context, use CRYP_RestoreContext() function 


@endverbatim
  * @{
  */
  
/**
  * @brief  Saves the CRYP peripheral Context. 
  * @note   This function stops DMA transfer before to save the context. After 
  *         restoring the context, you have to enable the DMA again (if the DMA
  *         was previously used).
  * @param  CRYP_ContextSave: pointer to a CRYP_Context structure that contains
  *         the repository for current context.
  * @param  CRYP_KeyInitStruct: pointer to a CRYP_KeyInitTypeDef structure that 
  *         contains the configuration information for the CRYP Keys.  
  * @retval None
  */
ErrorStatus CRYP_SaveContext(CRYP_Context* CRYP_ContextSave,
                             CRYP_KeyInitTypeDef* CRYP_KeyInitStruct)
{
  __IO uint32_t timeout = 0;
  uint32_t ckeckmask = 0, bitstatus;    
  ErrorStatus status = ERROR;

  /* Stop DMA transfers on the IN FIFO by clearing the DIEN bit in the CRYP_DMACR */
  CRYP->DMACR &= ~(uint32_t)CRYP_DMACR_DIEN;
    
  /* Wait until both the IN and OUT FIFOs are empty  
    (IFEM=1 and OFNE=0 in the CRYP_SR register) and the 
     BUSY bit is cleared. */

  if ((CRYP->CR & (uint32_t)(CRYP_CR_ALGOMODE_TDES_ECB | CRYP_CR_ALGOMODE_TDES_CBC)) != (uint32_t)0 )/* TDES */
  { 
    ckeckmask =  CRYP_SR_IFEM | CRYP_SR_BUSY ;
  }
  else /* AES or DES */
  {
    ckeckmask =  CRYP_SR_IFEM | CRYP_SR_BUSY | CRYP_SR_OFNE;
  }           
   
  do 
  {
    bitstatus = CRYP->SR & ckeckmask;
    timeout++;
  }
  while ((timeout != MAX_TIMEOUT) && (bitstatus != CRYP_SR_IFEM));
     
  if ((CRYP->SR & ckeckmask) != CRYP_SR_IFEM)
  {
    status = ERROR;
  }
  else
  {      
    /* Stop DMA transfers on the OUT FIFO by 
       - writing the DOEN bit to 0 in the CRYP_DMACR register 
       - and clear the CRYPEN bit. */

    CRYP->DMACR &= ~(uint32_t)CRYP_DMACR_DOEN;
    CRYP->CR &= ~(uint32_t)CRYP_CR_CRYPEN;

    /* Save the current configuration (bits [9:2] in the CRYP_CR register) */
    CRYP_ContextSave->CR_bits9to2  = CRYP->CR & (CRYP_CR_KEYSIZE  | 
                                                 CRYP_CR_DATATYPE | 
                                                 CRYP_CR_ALGOMODE |
                                                 CRYP_CR_ALGODIR); 

    /* and, if not in ECB mode, the initialization vectors. */
    CRYP_ContextSave->CRYP_IV0LR = CRYP->IV0LR;
    CRYP_ContextSave->CRYP_IV0RR = CRYP->IV0RR;
    CRYP_ContextSave->CRYP_IV1LR = CRYP->IV1LR;
    CRYP_ContextSave->CRYP_IV1RR = CRYP->IV1RR;

    /* save The key value */
    CRYP_ContextSave->CRYP_K0LR = CRYP_KeyInitStruct->CRYP_Key0Left; 
    CRYP_ContextSave->CRYP_K0RR = CRYP_KeyInitStruct->CRYP_Key0Right; 
    CRYP_ContextSave->CRYP_K1LR = CRYP_KeyInitStruct->CRYP_Key1Left; 
    CRYP_ContextSave->CRYP_K1RR = CRYP_KeyInitStruct->CRYP_Key1Right; 
    CRYP_ContextSave->CRYP_K2LR = CRYP_KeyInitStruct->CRYP_Key2Left; 
    CRYP_ContextSave->CRYP_K2RR = CRYP_KeyInitStruct->CRYP_Key2Right; 
    CRYP_ContextSave->CRYP_K3LR = CRYP_KeyInitStruct->CRYP_Key3Left; 
    CRYP_ContextSave->CRYP_K3RR = CRYP_KeyInitStruct->CRYP_Key3Right; 

   /* When needed, save the DMA status (pointers for IN and OUT messages, 
      number of remaining bytes, etc.) */
     
    status = SUCCESS;
  }

   return status;
}

/**
  * @brief  Restores the CRYP peripheral Context.
  * @note   Since teh DMA transfer is stopped in CRYP_SaveContext() function,
  *         after restoring the context, you have to enable the DMA again (if the
  *         DMA was previously used).  
  * @param  CRYP_ContextRestore: pointer to a CRYP_Context structure that contains
  *         the repository for saved context.
  * @note   The data that were saved during context saving must be rewrited into
  *         the IN FIFO.
  * @retval None
  */
void CRYP_RestoreContext(CRYP_Context* CRYP_ContextRestore)  
{

  /* Configure the processor with the saved configuration */
  CRYP->CR = CRYP_ContextRestore->CR_bits9to2;

  /* restore The key value */
  CRYP->K0LR = CRYP_ContextRestore->CRYP_K0LR; 
  CRYP->K0RR = CRYP_ContextRestore->CRYP_K0RR;
  CRYP->K1LR = CRYP_ContextRestore->CRYP_K1LR;
  CRYP->K1RR = CRYP_ContextRestore->CRYP_K1RR;
  CRYP->K2LR = CRYP_ContextRestore->CRYP_K2LR;
  CRYP->K2RR = CRYP_ContextRestore->CRYP_K2RR;
  CRYP->K3LR = CRYP_ContextRestore->CRYP_K3LR;
  CRYP->K3RR = CRYP_ContextRestore->CRYP_K3RR;

  /* and the initialization vectors. */
  CRYP->IV0LR = CRYP_ContextRestore->CRYP_IV0LR;