/**
  ******************************************************************************
  * @file    stm32f4xx_cryp_des.c
  * @author  MCD Application Team
  * @version V1.8.1
  * @date    27-January-2022
  * @brief   This file provides high level functions to encrypt and decrypt an 
  *          input message using DES in ECB/CBC modes.
  *          It uses the stm32f4xx_cryp.c/.h drivers to access the STM32F4xx CRYP
  *          peripheral.
  *
@verbatim
  
 ===================================================================
                  ##### How to use this driver #####
 ===================================================================
 [..] 
   (#) Enable The CRYP controller clock using 
       RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_CRYP, ENABLE); function.
  
   (#) Encrypt and decrypt using DES in ECB Mode using CRYP_DES_ECB() function.
  
   (#) Encrypt and decrypt using DES in CBC Mode using CRYP_DES_CBC() function.
  
@endverbatim
  *
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_cryp.h"


/** @addtogroup STM32F4xx_StdPeriph_Driver
  * @{
  */

/** @defgroup CRYP 
  * @brief CRYP driver modules
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define DESBUSY_TIMEOUT    ((uint32_t) 0x00010000)

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/


/** @defgroup CRYP_Private_Functions
  * @{
  */ 

/** @defgroup CRYP_Group8 High Level DES functions
 *  @brief   High Level DES functions 
 *
@verbatim   
 ===============================================================================
                       ##### High Level DES functions #####
 ===============================================================================
@endverbatim
  * @{
  */

/**
  * @brief  Encrypt and decrypt using DES in ECB Mode
  * @param  Mode: encryption or decryption Mode.
  *           This parameter can be one of the following values:
  *            @arg MODE_ENCRYPT: Encryption
  *            @arg MODE_DECRYPT: Decryption
  * @param  Key: Key used for DES algorithm.
  * @param  Ilength: length of the Input buffer, must be a multiple of 8.
  * @param  Input: pointer to the Input buffer.
  * @param  Output: pointer to the returned buffer.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Operation done
  *          - ERROR: Operation failed
  */
ErrorStatus CRYP_DES_ECB(uint8_t Mode, uint8_t Key[8], uint8_t *Input, 
                         uint32_t Ilength, uint8_t *Output)
{
  CRYP_InitTypeDef DES_CRYP_InitStructure;
  CRYP_KeyInitTypeDef DES_CRYP_KeyInitStructure;
  __IO uint32_t counter = 0;
  uint32_t busystatus = 0;
  ErrorStatus status = SUCCESS;
  uint32_t keyaddr    = (uint32_t)Key;
  uint32_t inputaddr  = (uint32_t)Input;
  uint32_t outputaddr = (uint32_t)Output;
  uint32_t i = 0;

  /* Crypto structures initialisation*/
  CRYP_KeyStructInit(&DES_CRYP_KeyInitStructure);

  /* Crypto Init for Encryption process */
  if( Mode == MODE_ENCRYPT ) /* DES encryption */
  {
     DES_CRYP_InitStructure.CRYP_AlgoDir  = CRYP_AlgoDir_Encrypt;
  }
  else/* if( Mode == MODE_DECRYPT )*/ /* DES decryption */
  {      
     DES_CRYP_InitStructure.CRYP_AlgoDir  = CRYP_AlgoDir_Decrypt;
  }

  DES_CRYP_InitStructure.CRYP_AlgoMode = CRYP_AlgoMode_DES_ECB;
  DES_CRYP_InitStructure.CRYP_DataType = CRYP_DataType_8b;
  CRYP_Init(&DES_CRYP_InitStructure);

  /* Key Initialisation */
  DES_CRYP_KeyInitStructure.CRYP_Key1Left = __REV(*(uint32_t*)(keyaddr));
  keyaddr+=4;
  DES_CRYP_KeyInitStructure.CRYP_Key1Right= __REV(*(uint32_t*)(keyaddr));
  CRYP_KeyInit(& DES_CRYP_KeyInitStructure);

  /* Flush IN/OUT FIFO */
  CRYP_FIFOFlush();

  /* Enable Crypto processor */
  CRYP_Cmd(ENABLE);

  if(CRYP_GetCmdStatus() == DISABLE)
  {
    /* The CRYP peripheral clock is not enabled or the device doesn't embed 
    the CRYP peripheral (please check the device sales type. */
    status = ERROR;
  }
  else
  {
    for(i=0; ((i<Ilength) && (status != ERROR)); i+=8)
    {
      
      /* Write the Input block in the Input FIFO */
      CRYP_DataIn(*(uint32_t*)(inputaddr));
      inputaddr+=4;
      CRYP_DataIn(*(uint32_t*)(inputaddr));
      inputaddr+=4;
      
      /* Wait until the complete message has been processed */
      counter = 0;
      do
      {
        busystatus = CRYP_GetFlagStatus(CRYP_FLAG_BUSY);
        counter++;
      }while ((counter != DESBUSY_TIMEOUT) && (busystatus != RESET));
      
      if (busystatus != RESET)
      {
        status = ERROR;
      }
      else
      {
        
        /* Read the Output block from the Output FIFO */
        *(uint32_t*)(outputaddr) = CRYP_DataOut();
        outputaddr+=4;
        *(uint32_t*)(outputaddr) = CRYP_DataOut();
        outputaddr+=4;
      }
    }
    
    /* Disable Crypto */
    CRYP_Cmd(DISABLE);
  }
  return status; 
}

/**
  * @brief  Encrypt and decrypt using DES in CBC Mode
  * @param  Mode: encryption or decryption Mode.
  *          This parameter can be one of the following values:
  *            @arg MODE_ENCRYPT: Encryption
  *            @arg MODE_DECRYPT: Decryption
  * @param  Key: Key used for DES algorithm.
  * @param  InitVectors: Initialisation Vectors used for DES algorithm.
  * @param  Ilength: length of the Input buffer, must be a multiple of 8.
  * @param  Input: pointer to the Input buffer.
  * @param  Output: pointer to the returned buffer.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Operation done
  *          - ERROR: Operation failed
  */
ErrorStatus CRYP_DES_CBC(uint8_t Mode, uint8_t Key[8], uint8_t InitVectors[8],
                         uint8_t *Input, uint32_t Ilength, uint8_t *Output)
{
  CRYP_InitTypeDef DES_CRYP_InitStructure;
  CRYP_KeyInitTypeDef DES_CRYP_KeyInitStructure;
  CRYP_IVInitTypeDef DES_CRYP_IVInitStructure;
  __IO uint32_t counter = 0;
  uint32_t busystatus = 0;
  ErrorStatus status = SUCCESS;
  uint32_t keyaddr    = (uint32_t)Key;
  uint32_t inputaddr  = (uint32_t)Input;
  uint32_t outputaddr = (uint32_t)Output;
  uint32_t ivaddr     = (uint32_t)InitVectors;
  uint32_t i = 0;

  /* Crypto structures initialisation*/
  CRYP_KeyStructInit(&DES_CRYP_KeyInitStructure);

  /* Crypto Init for Encryption process */
  if(Mode == MODE_ENCRYPT) /* DES encryption */
  {
     DES_CRYP_InitStructure.CRYP_AlgoDir  = CRYP_AlgoDir_Encrypt;
  }
  else /*if(Mode == MODE_DECRYPT)*/ /* DES decryption */
  {
     DES_CRYP_InitStructure.CRYP_AlgoDir  = CRYP_AlgoDir_Decrypt;
  }

  DES_CRYP_InitStructure.CRYP_AlgoMode = CRYP_AlgoMode_DES_CBC;
  DES_CRYP_InitStructure.CRYP_DataType = CRYP_DataType_8b;
  CRYP_Init(&DES_CRYP_InitStructure);

  /* Key Initialisation */
  DES_CRYP_KeyInitStructure.CRYP_Key1Left = __REV(*(uint32_t*)(keyaddr));
  keyaddr+=4;
  DES_CRYP_KeyInitStructure.CRYP_Key1Right= __REV(*(uint32_t*)(keyaddr));
  CRYP_KeyInit(& DES_CRYP_KeyInitStructure);

  /* Initialization Vectors */
  DES_CRYP_IVInitStructure.CRYP_IV0Left = __REV(*(uint32_t*)(ivaddr));
  ivaddr+=4;
  DES_CRYP_IVInitStructure.CRYP_IV0Right= __REV(*(uint32_t*)(ivaddr));
  CRYP_IVInit(&DES_CRYP_IVInitStructure);

  /* Flush IN/OUT FIFO */
  CRYP_FIFOFlush();
  
  /* Enable Crypto processor */
  CRYP_Cmd(ENABLE);

  if(CRYP_GetCmdStatus() == DISABLE)
  {
    /* The CRYP peripheral clock is not enabled or the device doesn't embed 
    the CRYP peripheral (please check the device sales type. */
    status = ERROR;
  }
  else
  {
    for(i=0; ((i<Ilength) && (status != ERROR)); i+=8)
    {
      /* Write the Input block in the Input FIFO */
      CRYP_DataIn(*(uint32_t*)(inputaddr));
      inputaddr+=4;
      CRYP_DataIn(*(uint32_t*)(inputaddr));
      inputaddr+=4;
      
      /* Wait until the complete message has been processed */
      counter = 0;
      do
      {
        busystatus = CRYP_GetFlagStatus(CRYP_FLAG_BUSY);
        counter++;
      }while ((counter != DESBUSY_TIMEOUT) && (busystatus != RESET));
      
      if (busystatus != RESET)
      {
        status = ERROR;
      }
      else
      {
        /* Read the Output block from the Output FIFO */
        *(uint32_t*)(outputaddr) = CRYP_DataOut();
        outputaddr+=4;
        *(uint32_t*)(outputaddr) = CRYP_DataOut();
        outputaddr+=4;
      }
    }
    
    /* Disable Crypto */
    CRYP_Cmd(DISABLE);
  }
  return status; 
}

/**
  * @}
  */ 

/**
  * @}
  */ 

/**
  * @}
  */ 

/**
  * @}
  */ 

