channel/c-write/lib/aes.h

#ifndef AES_H_
#define AES_H_

#include <stdlib.h>

#define BLOCK_LENGTH 16

typedef struct aes_padded_data_t {
    /// @brief original data, unmodified.
    uint8_t* data;
    /// @brief the last block, modified with padding added.
    uint8_t* padded_block;

    /// @brief original length.
    size_t data_length;
    /// @brief length when excluding the block to be modified.
    size_t data_length_before_pad;
    /// @brief `data_length_before_pad` + BLOCK_LENGTH
    size_t length;
} aes_padded_data_t;

aes_padded_data_t aes_create_padded_data_container();

typedef enum aes_encryption_mode_t {
    encryption,
    decryption,
} aes_encryption_mode_t;

int aes_pad_data(aes_padded_data_t* ptr, uint8_t* data, size_t length);
int aes_ecb(aes_encryption_mode_t mode, aes_padded_data_t* data, uint8_t* key);
int aes_cbc(aes_encryption_mode_t mode, aes_padded_data_t* data, uint8_t* key);

#endif // AES_H_