--- /dev/null
+/**
+ * \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 (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * This file is part of Mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_SHA256_H
+#define MBEDTLS_SHA256_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED -0x0037 /**< SHA-256 hardware accelerator failed */
+
+#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_ret().
+ */
+typedef struct mbedtls_sha256_context
+{
+ uint32_t total[2]; /*!< The number of Bytes processed. */
+ uint32_t state[8]; /*!< The intermediate digest state. */
+ unsigned char buffer[64]; /*!< The data block being processed. */
+ int is224; /*!< Determines which function to use:
+ 0: Use SHA-256, or 1: Use SHA-224. */
+}
+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.
+ */
+void mbedtls_sha256_init( mbedtls_sha256_context *ctx );
+
+/**
+ * \brief This function clears a SHA-256 context.
+ *
+ * \param ctx The SHA-256 context to clear.
+ */
+void mbedtls_sha256_free( mbedtls_sha256_context *ctx );
+
+/**
+ * \brief This function clones the state of a SHA-256 context.
+ *
+ * \param dst The destination context.
+ * \param src The context to clone.
+ */
+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 initialize.
+ * \param is224 Determines which function to use:
+ * 0: Use SHA-256, or 1: Use SHA-224.
+ *
+ * \return \c 0 on success.
+ */
+int mbedtls_sha256_starts_ret( 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.
+ * \param input The buffer holding the data.
+ * \param ilen The length of the input data.
+ *
+ * \return \c 0 on success.
+ */
+int mbedtls_sha256_update_ret( 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.
+ * \param output The SHA-224 or SHA-256 checksum result.
+ *
+ * \return \c 0 on success.
+ */
+int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
+ unsigned char output[32] );
+
+/**
+ * \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.
+ * \param data The buffer holding one block of data.
+ *
+ * \return \c 0 on success.
+ */
+int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
+ const unsigned char data[64] );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief This function starts a SHA-224 or SHA-256 checksum
+ * calculation.
+ *
+ *
+ * \deprecated Superseded by mbedtls_sha256_starts_ret() in 2.7.0.
+ *
+ * \param ctx The context to initialize.
+ * \param is224 Determines which function to use:
+ * 0: Use SHA-256, or 1: Use SHA-224.
+ */
+MBEDTLS_DEPRECATED void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
+ int is224 );
+
+/**
+ * \brief This function feeds an input buffer into an ongoing
+ * SHA-256 checksum calculation.
+ *
+ * \deprecated Superseded by mbedtls_sha256_update_ret() in 2.7.0.
+ *
+ * \param ctx The SHA-256 context to initialize.
+ * \param input The buffer holding the data.
+ * \param ilen The length of the input data.
+ */
+MBEDTLS_DEPRECATED void 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.
+ *
+ * \deprecated Superseded by mbedtls_sha256_finish_ret() in 2.7.0.
+ *
+ * \param ctx The SHA-256 context.
+ * \param output The SHA-224 or SHA-256 checksum result.
+ */
+MBEDTLS_DEPRECATED void mbedtls_sha256_finish( mbedtls_sha256_context *ctx,
+ unsigned char output[32] );
+
+/**
+ * \brief This function processes a single data block within
+ * the ongoing SHA-256 computation. This function is for
+ * internal use only.
+ *
+ * \deprecated Superseded by mbedtls_internal_sha256_process() in 2.7.0.
+ *
+ * \param ctx The SHA-256 context.
+ * \param data The buffer holding one block of data.
+ */
+MBEDTLS_DEPRECATED void mbedtls_sha256_process( mbedtls_sha256_context *ctx,
+ const unsigned char data[64] );
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+
+/**
+ * \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 input data.
+ * \param ilen The length of the input data.
+ * \param output The SHA-224 or SHA-256 checksum result.
+ * \param is224 Determines which function to use:
+ * 0: Use SHA-256, or 1: Use SHA-224.
+ */
+int mbedtls_sha256_ret( const unsigned char *input,
+ size_t ilen,
+ unsigned char output[32],
+ int is224 );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+
+/**
+ * \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).
+ *
+ * \deprecated Superseded by mbedtls_sha256_ret() in 2.7.0.
+ *
+ * \param input The buffer holding the data.
+ * \param ilen The length of the input data.
+ * \param output The SHA-224 or SHA-256 checksum result.
+ * \param is224 Determines which function to use:
+ * 0: Use SHA-256, or 1: Use SHA-224.
+ */
+MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
+ size_t ilen,
+ unsigned char output[32],
+ int is224 );
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
+
+/**
+ * \brief The SHA-224 and SHA-256 checkup routine.
+ *
+ * \return \c 0 on success.
+ * \return \c 1 on failure.
+ */
+int mbedtls_sha256_self_test( int verbose );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* mbedtls_sha256.h */