Regarding sd_ecb_blocks_encrypt API

[ravikiranbamidi]

In the following API, is it safe to use same buffer pointer for input and output (i.e.,  p_cleartext and  p_ciphertext respectively)?

/**@brief AES ECB block. Used to provide multiple blocks in a single call
          to @ref sd_ecb_blocks_encrypt.*/
typedef struct
{
  soc_ecb_key_t const *       p_key;           /**< Pointer to the Encryption key. */
  soc_ecb_cleartext_t const * p_cleartext;     /**< Pointer to the Cleartext data. */
  soc_ecb_ciphertext_t *      p_ciphertext;    /**< Pointer to the Ciphertext data. */
} nrf_ecb_hal_data_block_t;


/**@brief Encrypts multiple data blocks provided as an array of data block structures.
 *
 * @details: Performs 128-bit AES encryption on multiple data blocks
 *
 * @note:
 *    - The application may set the SEVONPEND bit in the SCR to 1 to make the SoftDevice sleep while
 *      the ECB is running. The SEVONPEND bit should only be cleared (set to 0) from application
 *      main or low interrupt level.
 *
 * @param[in]     block_count     Count of blocks in the p_data_blocks array.
 * @param[in,out] p_data_blocks   Pointer to the first entry in a contiguous array of
 *                                @ref nrf_ecb_hal_data_block_t structures.
 *
 * @retval ::NRF_SUCCESS
 */
SVCALL(SD_ECB_BLOCKS_ENCRYPT, uint32_t, sd_ecb_blocks_encrypt(uint8_t block_count, nrf_ecb_hal_data_block_t * p_data_blocks));

[Susheel Nuguru]

Hi Ravi,

Yes, a temp buffer is used to manage the conversion before the actual ciphertext is put into the block. So it should be safe to use the same pointers for p_cleartext and  p_ciphertext 

[ravikiranbamidi]

Thank you Susheel

[Susheel Nuguru]

You're welcome Ravi. Good luck with your project.