text: /***************************************************************************//**
   * @file em_aes.h
   * @brief Advanced encryption standard (AES) accelerator peripheral API.
   * @version 5.0.0
   *******************************************************************************
   * @section License
   * <b>Copyright 2016 Silicon Laboratories, Inc. http://www.silabs.com</b>
   *******************************************************************************
   *
   * Permission is granted to anyone to use this software for any purpose,
   * including commercial applications, and to alter it and redistribute it
   * freely, subject to the following restrictions:
   *
   * 1. The origin of this software must not be misrepresented; you must not
   *    claim that you wrote the original software.
   * 2. Altered source versions must be plainly marked as such, and must not be
   *    misrepresented as being the original software.
   * 3. This notice may not be removed or altered from any source distribution.
   *
   * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
   * obligation to support this Software. Silicon Labs is providing the
   * Software "AS IS", with no express or implied warranties of any kind,
   * including, but not limited to, any implied warranties of merchantability
   * or fitness for any particular purpose or warranties against infringement
   * of any proprietary rights of a third party.
   *
   * Silicon Labs will not be liable for any consequential, incidental, or
   * special damages, or any other relief, or for any claim by any third party,
   * arising from your use of this Software.
   *
   ******************************************************************************/
  
  #ifndef EM_AES_H
  #define EM_AES_H
  
  #include "em_device.h"
  #if defined(AES_COUNT) && (AES_COUNT > 0)
  
  #include <stdbool.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /***************************************************************************//**
   * @addtogroup emlib
   * @{
   ******************************************************************************/
  
  /***************************************************************************//**
   * @addtogroup AES
   * @brief Advanced Encryption Standard Accelerator (AES) Peripheral API.
   *
   * @details
   *   The AES peripheral supports AES block cipher encryption and decryption with
   *   128 bit and 256 bit keys. The following block cipher modes are supported:
   *   @li CBC - Cipher Block Chaining mode
   *   @li CFB - Cipher Feedback mode
   *   @li CTR - Counter mode
   *   @li ECB - Electronic Code Book mode
   *   @li OFB - Output Feedback mode
   *
   *   The following input/output notations should be noted:
   *
   *   @li Input/output data (plaintext, ciphertext, key etc) are treated as
   *     byte arrays, starting with most significant byte. Ie, 32 bytes of
   *     plaintext (B0...B31) is located in memory in the same order, with B0 at
   *     the lower address and B31 at the higher address.
   *
   *   @li Byte arrays must always be a multiple of AES block size, ie a multiple
   *     of 16. Padding, if required, is done at the end of the byte array.
   *
   *   @li Byte arrays should be word (32 bit) aligned for performance
   *     considerations, since the array is accessed with 32 bit access type.
   *     The Cortex-M supports unaligned accesses, but with a performance penalty.
   *
   *   @li It is possible to specify the same output buffer as input buffer
   *     as long as they point to the same address. In that case the provided input
   *     buffer is replaced with the encrypted/decrypted output. Notice that the
   *     buffers must be exactly overlapping. If partly overlapping, the
   *     behaviour is undefined.
   *
   *   It is up to the user to use a cipher mode according to its requirements
   *   in order to not break security. Please refer to specific cipher mode
   *   theory for details.
   *
   *   References:
   *   @li Wikipedia - Cipher modes, http://en.wikipedia.org/wiki/Cipher_modes
   *
   *   @li Recommendation for Block Cipher Modes of Operation,
   *      NIST Special Publication 800-38A, 2001 Edition,
   *      http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
   *
   *  E.g. the following example shows how to perform an AES-128 CBC encryption:
   *
   *  Enable clocks:
   *  @include em_aes_clock_enable.c
   *
   *  Execute AES-128 CBC encryption:
   *  @include em_aes_basic_usage.c
   *
   * @{
   ******************************************************************************/
  
  /*******************************************************************************
   ******************************   TYPEDEFS   ***********************************
   ******************************************************************************/
  
  /**
   * @brief
   *   AES counter modification function pointer.
   * @details
   *   Parameters:
   *   @li ctr - Ptr to byte array (16 bytes) holding counter to be modified.
   */
  typedef void (*AES_CtrFuncPtr_TypeDef)(uint8_t *ctr);
  
  /*******************************************************************************
   *****************************   PROTOTYPES   **********************************
   ******************************************************************************/
  
  void AES_CBC128(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv,
                  bool encrypt);
  
  #if defined( AES_CTRL_AES256 )
  void AES_CBC256(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv,
                  bool encrypt);
  #endif
  
  void AES_CFB128(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv,
                  bool encrypt);
  
  #if defined( AES_CTRL_AES256 )
  void AES_CFB256(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv,
                  bool encrypt);
  #endif
  
  void AES_CTR128(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  uint8_t *ctr,
                  AES_CtrFuncPtr_TypeDef ctrFunc);
  
  #if defined( AES_CTRL_AES256 )
  void AES_CTR256(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  uint8_t *ctr,
                  AES_CtrFuncPtr_TypeDef ctrFunc);
  #endif
  
  void AES_CTRUpdate32Bit(uint8_t *ctr);
  
  void AES_DecryptKey128(uint8_t *out, const uint8_t *in);
  
  #if defined( AES_CTRL_AES256 )
  void AES_DecryptKey256(uint8_t *out, const uint8_t *in);
  #endif
  
  void AES_ECB128(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  bool encrypt);
  
  #if defined( AES_CTRL_AES256 )
  void AES_ECB256(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  bool encrypt);
  #endif
  
  /***************************************************************************//**
   * @brief
   *   Clear one or more pending AES interrupts.
   *
   * @param[in] flags
   *   Pending AES interrupt source to clear. Use a bitwise logic OR combination of
   *   valid interrupt flags for the AES module (AES_IF_nnn).
   ******************************************************************************/
  __STATIC_INLINE void AES_IntClear(uint32_t flags)
  {
    AES->IFC = flags;
  }
  
  
  /***************************************************************************//**
   * @brief
   *   Disable one or more AES interrupts.
   *
   * @param[in] flags
   *   AES interrupt sources to disable. Use a bitwise logic OR combination of
   *   valid interrupt flags for the AES module (AES_IF_nnn).
   ******************************************************************************/
  __STATIC_INLINE void AES_IntDisable(uint32_t flags)
  {
    AES->IEN &= ~(flags);
  }
  
  
  /***************************************************************************//**
   * @brief
   *   Enable one or more AES interrupts.
   *
   * @note
   *   Depending on the use, a pending interrupt may already be set prior to
   *   enabling the interrupt. Consider using AES_IntClear() prior to enabling
   *   if such a pending interrupt should be ignored.
   *
   * @param[in] flags
   *   AES interrupt sources to enable. Use a bitwise logic OR combination of
   *   valid interrupt flags for the AES module (AES_IF_nnn).
   ******************************************************************************/
  __STATIC_INLINE void AES_IntEnable(uint32_t flags)
  {
    AES->IEN |= flags;
  }
  
  
  /***************************************************************************//**
   * @brief
   *   Get pending AES interrupt flags.
   *
   * @note
   *   The event bits are not cleared by the use of this function.
   *
   * @return
   *   AES interrupt sources pending. A bitwise logic OR combination of valid
   *   interrupt flags for the AES module (AES_IF_nnn).
   ******************************************************************************/
  __STATIC_INLINE uint32_t AES_IntGet(void)
  {
    return AES->IF;
  }
  
  
  /***************************************************************************//**
   * @brief
   *   Get enabled and pending AES interrupt flags.
   *   Useful for handling more interrupt sources in the same interrupt handler.
   *
   * @note
   *   Interrupt flags are not cleared by the use of this function.
   *
   * @return
   *   Pending and enabled AES interrupt sources
   *   The return value is the bitwise AND of
   *   - the enabled interrupt sources in AES_IEN and
   *   - the pending interrupt flags AES_IF
   ******************************************************************************/
  __STATIC_INLINE uint32_t AES_IntGetEnabled(void)
  {
    uint32_t ien;
  
    ien = AES->IEN;
    return AES->IF & ien;
  }
  
  
  /***************************************************************************//**
   * @brief
   *   Set one or more pending AES interrupts from SW.
   *
   * @param[in] flags
   *   AES interrupt sources to set to pending. Use a bitwise logic OR combination
   *   of valid interrupt flags for the AES module (AES_IF_nnn).
   ******************************************************************************/
  __STATIC_INLINE void AES_IntSet(uint32_t flags)
  {
    AES->IFS = flags;
  }
  
  
  void AES_OFB128(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv);
  
  #if defined( AES_CTRL_AES256 )
  void AES_OFB256(uint8_t *out,
                  const uint8_t *in,
                  unsigned int len,
                  const uint8_t *key,
                  const uint8_t *iv);
  #endif
  
  
  /** @} (end addtogroup AES) */
  /** @} (end addtogroup emlib) */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* defined(AES_COUNT) && (AES_COUNT > 0) */
  #endif /* EM_AES_H */
  
  
  