/*
 * Copyright (c) CompanyNameMagicTag 2018-2020. All rights reserved.
 * Description: Cryptographic algorithm function.
 */

#ifndef MBEDTLS_AES_ALT_H
#define MBEDTLS_AES_ALT_H


/**
 * \brief The AES context-type definition.
 */
typedef struct mbedtls_aes_context {
    int nr;                     /*!< The number of rounds. */
    uint32_t *rk;               /*!< AES round keys. */
    uint32_t buf[68];           /*!< Unaligned data buffer. This buffer can
                                     hold 32 extra Bytes, which can be used for
                                     one of the following purposes:
                                     <ul><li>Alignment if VIA padlock is
                                             used.</li>
                                     <li>Simplifying key expansion in the 256-bit
                                         case by generating an extra round key.
                                         </li></ul> */
}
mbedtls_aes_context;

/**
 * \brief          This function initializes the specified AES context.
 *
 *                 It must be the first API called before using
 *                 the context.
 *
 * \param ctx      The AES context to initialize. This must not be \c NULL.
 */
void mbedtls_aes_init(mbedtls_aes_context *ctx);

/**
 * \brief          This function releases and clears the specified AES context.
 *
 * \param ctx      The AES context to clear.
 *                 If this is \c NULL, this function does nothing.
 *                 Otherwise, the context must have been at least initialized.
 */
void mbedtls_aes_free(mbedtls_aes_context *ctx);
/**
 * \brief          This function sets the encryption key.
 *
 * \param ctx      The AES context to which the key should be bound.
 *                 It must be initialized.
 * \param key      The encryption key.
 *                 This must be a readable buffer of size \p keybits bits.
 * \param keybits  The size of data passed in bits. Valid options are:
 *                 <ul><li>128 bits</li>
 *                 <li>192 bits</li>
 *                 <li>256 bits</li></ul>
 *
 * \return         \c 0 on success.
 * \return         #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
 */
int mbedtls_aes_setkey_enc(mbedtls_aes_context *ctx, const unsigned char *key,
                           unsigned int keybits);

/**
 * \brief          This function sets the decryption key.
 *
 * \param ctx      The AES context to which the key should be bound.
 *                 It must be initialized.
 * \param key      The decryption key.
 *                 This must be a readable buffer of size \p keybits bits.
 * \param keybits  The size of data passed. Valid options are:
 *                 <ul><li>128 bits</li>
 *                 <li>192 bits</li>
 *                 <li>256 bits</li></ul>
 *
 * \return         \c 0 on success.
 * \return         #MBEDTLS_ERR_AES_INVALID_KEY_LENGTH on failure.
 */
int mbedtls_aes_setkey_dec(mbedtls_aes_context *ctx, const unsigned char *key,
                           unsigned int keybits);
/**
 * \brief          This function performs an AES single-block encryption or
 *                 decryption operation.
 *
 *                 It performs the operation defined in the \p mode parameter
 *                 (encrypt or decrypt), on the input data buffer defined in
 *                 the \p input parameter.
 *
 *                 mbedtls_aes_init(), and either mbedtls_aes_setkey_enc() or
 *                 mbedtls_aes_setkey_dec() must be called before the first
 *                 call to this API with the same context.
 *
 * \param ctx      The AES context to use for encryption or decryption.
 *                 It must be initialized and bound to a key.
 * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
 *                 #MBEDTLS_AES_DECRYPT.
 * \param input    The buffer holding the input data.
 *                 It must be readable and at least \c 16 Bytes long.
 * \param output   The buffer where the output data will be written.
 *                 It must be writeable and at least \c 16 Bytes long.

 * \return         \c 0 on success.
 */
int mbedtls_aes_crypt_ecb(mbedtls_aes_context *ctx,
                          int mode,
                          const unsigned char input[16],
                          unsigned char output[16]);

#if defined(MBEDTLS_CIPHER_MODE_CBC)
/**
 * \brief  This function performs an AES-CBC encryption or decryption operation
 *         on full blocks.
 *
 *         It performs the operation defined in the \p mode
 *         parameter (encrypt/decrypt), on the input data buffer defined in
 *         the \p input parameter.
 *
 *         It can be called as many times as needed, until all the input
 *         data is processed. mbedtls_aes_init(), and either
 *         mbedtls_aes_setkey_enc() or mbedtls_aes_setkey_dec() must be called
 *         before the first call to this API with the same context.
 *
 * \note   This function operates on full blocks, that is, the input size
 *         must be a multiple of the AES block size of \c 16 Bytes.
 *
 * \note   Upon exit, the content of the IV is updated so that you can
 *         call the same function again on the next
 *         block(s) of data and get the same result as if it was
 *         encrypted in one call. This allows a "streaming" usage.
 *         If you need to retain the contents of the IV, you should
 *         either save it manually or use the cipher module instead.
 *
 *
 * \param ctx      The AES context to use for encryption or decryption.
 *                 It must be initialized and bound to a key.
 * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
 *                 #MBEDTLS_AES_DECRYPT.
 * \param length   The length of the input data in Bytes. This must be a
 *                 multiple of the block size (\c 16 Bytes).
 * \param iv       Initialization vector (updated after use).
 *                 It must be a readable and writeable buffer of \c 16 Bytes.
 * \param input    The buffer holding the input data.
 *                 It must be readable and of size \p length Bytes.
 * \param output   The buffer holding the output data.
 *                 It must be writeable and of size \p length Bytes.
 *
 * \return         \c 0 on success.
 * \return         #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
 *                 on failure.
 */
int mbedtls_aes_crypt_cbc(mbedtls_aes_context *ctx,
                          int mode,
                          size_t length,
                          unsigned char iv[16],
                          const unsigned char *input,
                          unsigned char *output);
#endif /* MBEDTLS_CIPHER_MODE_CBC */


#endif /* aes_alt.h */