examples/platforms/nrf52840/crypto/sha256_alt.h

/*
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 *     derived from this software without specific prior written permission.
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#ifndef MBEDTLS_SHA256_ALT_H
#define MBEDTLS_SHA256_ALT_H

#ifdef MBEDTLS_SHA256_ALT

#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief          SHA-256 context structure
 */
typedef union
{
    struct
    {
        uint32_t total[2];          /*!< number of bytes processed  */
        uint32_t state[8];          /*!< intermediate digest state  */
        unsigned char buffer[64];   /*!< data block being processed */
        int is224;                  /*!< 0 => SHA-256, else SHA-224 */
    };
    uint8_t reserved[256];
}
mbedtls_sha256_context;

/**
 * @brief Initialize SHA-256 context
 *
 * @param [in,out] ctx SHA-256 context to be initialized
 */
void mbedtls_sha256_init(mbedtls_sha256_context *ctx);

/**
 * @brief Clear SHA-256 context
 *
 * @param [in,out] ctx SHA-256 context to be cleared
 */
void mbedtls_sha256_free(mbedtls_sha256_context *ctx);

/**
 * @brief Clone (the state of) a SHA-256 context
 *
 * @param [out] dst The destination context
 * @param [in] src The context to be cloned
 */
void mbedtls_sha256_clone(mbedtls_sha256_context *dst,
                          const mbedtls_sha256_context *src);

/**
 * @brief SHA-256 context setup
 *
 * @param [in,out] ctx context to be initialized
 * @param [in] is224 0 = use SHA256, 1 = use SHA224
 */
void mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224);

/**
 * @brief SHA-256 process buffer
 *
 * @param [in,out] ctx SHA-256 context
 * @param [in] input buffer holding the  data
 * @param [in] ilen length of the input data
 */
void mbedtls_sha256_update(mbedtls_sha256_context *ctx, const unsigned char *input, size_t ilen);

/**
 * @brief SHA-256 final digest
 *
 * @param [in,out] ctx SHA-256 context
 * @param [out] output SHA-224/256 checksum result
 */
void mbedtls_sha256_finish(mbedtls_sha256_context *ctx, unsigned char output[32]);

/* Internal use */
void mbedtls_sha256_process(mbedtls_sha256_context *ctx, const unsigned char data[64]);

#ifdef __cplusplus
}
#endif

#endif /* MBEDTLS_SHA256_ALT */

/* MBEDTLS_SHA256_ALT was used to redifine context structure. Undefine it now to enable default mbedTLS implementation. */
#undef MBEDTLS_SHA256_ALT

#endif /* MBEDTLS_SHA256_ALT_H */