Data Fields
psa_cipher_chacha20_ctx_t Struct Reference

This struct is used to handle the discontinuity between the PSA API and the CRYS ChaCha20 API. More...

Detailed Description

This struct is used to handle the discontinuity between the PSA API and the CRYS ChaCha20 API.

The PSA API psa_cipher_update() function allows any size of input array, but the CRYS implementation only works on multiples of 64B. So we store any remainders from the input in the buffer, and if any more data is input, we join them with the buffer values. The psa_cipher_finish() function will then xcrypt the remaining buffer values. The buffer is also used in the setup of the operation. The psa_cipher_~_setup() functions only provide the key for the operation, but the CRYS ChaCha20 implementation also needs the counter and nonce provided by psa_cipher_set_iv(). So we store the key in the buffer until it is needed in the CRYS ChaCha20 setup.

Definition at line 39 of file psa_periph_chacha20_ctx.h.

#include <psa_periph_chacha20_ctx.h>

Data Fields

uint8_t buffer [CRYS_CHACHA_BLOCK_SIZE_IN_BYTES]
 Block buffer.
 
uint8_t buffer_length
 Current length of the data in buffer.
 
union {
   CRYS_CHACHA_EncryptMode_t   mode
 Mode of the operation.
 
   CRYS_CHACHAUserContext_t   post_setup
 Context of the CRYS ChaCha20 operation.
 
} ctx
 Context Setup values.
 
The documentation for this struct was generated from the following file: