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/**
* \file sha256.h
*
* \brief This file contains SHA-224 and SHA-256 definitions and functions.
*
* The Secure Hash Algorithms 224 and 256 (SHA-224 and SHA-256) cryptographic
* hash functions are defined in <em>FIPS 180-4: Secure Hash Standard (SHS)</em>.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#ifndef MBEDTLS_SHA256_H
#define MBEDTLS_SHA256_H
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include <stddef.h>
#include <stdint.h>
/** SHA-256 input data was malformed. */
#define MBEDTLS_ERR_SHA256_BAD_INPUT_DATA -0x0074
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(MBEDTLS_SHA256_ALT)
// Regular implementation
//
/**
* \brief The SHA-256 context structure.
*
* The structure is used both for SHA-256 and for SHA-224
* checksum calculations. The choice between these two is
* made in the call to mbedtls_sha256_starts().
*/
typedef struct mbedtls_sha256_context {
unsigned char MBEDTLS_PRIVATE(buffer)[64]; /*!< The data block being processed. */
uint32_t MBEDTLS_PRIVATE(total)[2]; /*!< The number of Bytes processed. */
uint32_t MBEDTLS_PRIVATE(state)[8]; /*!< The intermediate digest state. */
#if defined(MBEDTLS_SHA224_C)
int MBEDTLS_PRIVATE(is224); /*!< Determines which function to use:
0: Use SHA-256, or 1: Use SHA-224. */
#endif
}
mbedtls_sha256_context;
#else /* MBEDTLS_SHA256_ALT */
#include "sha256_alt.h"
#endif /* MBEDTLS_SHA256_ALT */
/**
* \brief This function initializes a SHA-256 context.
*
* \param ctx The SHA-256 context to initialize. This must not be \c NULL.
*/
void mbedtls_sha256_init(mbedtls_sha256_context *ctx);
/**
* \brief This function clears a SHA-256 context.
*
* \param ctx The SHA-256 context to clear. This may be \c NULL, in which
* case this function returns immediately. If it is not \c NULL,
* it must point to an initialized SHA-256 context.
*/
void mbedtls_sha256_free(mbedtls_sha256_context *ctx);
/**
* \brief This function clones the state of a SHA-256 context.
*
* \param dst The destination context. This must be initialized.
* \param src The context to clone. This must be initialized.
*/
void mbedtls_sha256_clone(mbedtls_sha256_context *dst,
const mbedtls_sha256_context *src);
/**
* \brief This function starts a SHA-224 or SHA-256 checksum
* calculation.
*
* \param ctx The context to use. This must be initialized.
* \param is224 This determines which function to use. This must be
* either \c 0 for SHA-256, or \c 1 for SHA-224.
*
* \note is224 must be defined accordingly to the enabled
* MBEDTLS_SHA224_C/MBEDTLS_SHA256_C symbols otherwise the
* function will return #MBEDTLS_ERR_SHA512_BAD_INPUT_DATA.
*
* \return \c 0 on success.
* \return A negative error code on failure.
*/
int mbedtls_sha256_starts(mbedtls_sha256_context *ctx, int is224);
/**
* \brief This function feeds an input buffer into an ongoing
* SHA-256 checksum calculation.
*
* \param ctx The SHA-256 context. This must be initialized
* and have a hash operation started.
* \param input The buffer holding the data. This must be a readable
* buffer of length \p ilen Bytes.
* \param ilen The length of the input data in Bytes.
*
* \return \c 0 on success.
* \return A negative error code on failure.
*/
int mbedtls_sha256_update(mbedtls_sha256_context *ctx,
const unsigned char *input,
size_t ilen);
/**
* \brief This function finishes the SHA-256 operation, and writes
* the result to the output buffer.
*
* \param ctx The SHA-256 context. This must be initialized
* and have a hash operation started.
* \param output The SHA-224 or SHA-256 checksum result.
* This must be a writable buffer of length \c 32 bytes
* for SHA-256, \c 28 bytes for SHA-224.
*
* \return \c 0 on success.
* \return A negative error code on failure.
*/
int mbedtls_sha256_finish(mbedtls_sha256_context *ctx,
unsigned char *output);
/**
* \brief This function processes a single data block within
* the ongoing SHA-256 computation. This function is for
* internal use only.
*
* \param ctx The SHA-256 context. This must be initialized.
* \param data The buffer holding one block of data. This must
* be a readable buffer of length \c 64 Bytes.
*
* \return \c 0 on success.
* \return A negative error code on failure.
*/
int mbedtls_internal_sha256_process(mbedtls_sha256_context *ctx,
const unsigned char data[64]);
/**
* \brief This function calculates the SHA-224 or SHA-256
* checksum of a buffer.
*
* The function allocates the context, performs the
* calculation, and frees the context.
*
* The SHA-256 result is calculated as
* output = SHA-256(input buffer).
*
* \param input The buffer holding the data. This must be a readable
* buffer of length \p ilen Bytes.
* \param ilen The length of the input data in Bytes.
* \param output The SHA-224 or SHA-256 checksum result.
* This must be a writable buffer of length \c 32 bytes
* for SHA-256, \c 28 bytes for SHA-224.
* \param is224 Determines which function to use. This must be
* either \c 0 for SHA-256, or \c 1 for SHA-224.
*
* \return \c 0 on success.
* \return A negative error code on failure.
*/
int mbedtls_sha256(const unsigned char *input,
size_t ilen,
unsigned char *output,
int is224);
#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_SHA224_C)
/**
* \brief The SHA-224 checkup routine.
*
* \return \c 0 on success.
* \return \c 1 on failure.
*/
int mbedtls_sha224_self_test(int verbose);
#endif /* MBEDTLS_SHA224_C */
#if defined(MBEDTLS_SHA256_C)
/**
* \brief The SHA-256 checkup routine.
*
* \return \c 0 on success.
* \return \c 1 on failure.
*/
int mbedtls_sha256_self_test(int verbose);
#endif /* MBEDTLS_SHA256_C */
#endif /* MBEDTLS_SELF_TEST */
#ifdef __cplusplus
}
#endif
#endif /* mbedtls_sha256.h */