--- /dev/null
+/**
+ * \file entropy.h
+ *
+ * \brief Entropy accumulator implementation
+ */
+/*
+ * Copyright (C) 2006-2016, ARM Limited, 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_ENTROPY_H
+#define MBEDTLS_ENTROPY_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include <stddef.h>
+
+#if defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256)
+#include "sha512.h"
+#define MBEDTLS_ENTROPY_SHA512_ACCUMULATOR
+#else
+#if defined(MBEDTLS_SHA256_C)
+#define MBEDTLS_ENTROPY_SHA256_ACCUMULATOR
+#include "sha256.h"
+#endif
+#endif
+
+#if defined(MBEDTLS_THREADING_C)
+#include "threading.h"
+#endif
+
+#if defined(MBEDTLS_HAVEGE_C)
+#include "havege.h"
+#endif
+
+#define MBEDTLS_ERR_ENTROPY_SOURCE_FAILED -0x003C /**< Critical entropy source failure. */
+#define MBEDTLS_ERR_ENTROPY_MAX_SOURCES -0x003E /**< No more sources can be added. */
+#define MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED -0x0040 /**< No sources have been added to poll. */
+#define MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE -0x003D /**< No strong sources have been added to poll. */
+#define MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR -0x003F /**< Read/write error in file. */
+
+/**
+ * \name SECTION: Module settings
+ *
+ * The configuration options you can set for this module are in this section.
+ * Either change them in config.h or define them on the compiler command line.
+ * \{
+ */
+
+#if !defined(MBEDTLS_ENTROPY_MAX_SOURCES)
+#define MBEDTLS_ENTROPY_MAX_SOURCES 20 /**< Maximum number of sources supported */
+#endif
+
+#if !defined(MBEDTLS_ENTROPY_MAX_GATHER)
+#define MBEDTLS_ENTROPY_MAX_GATHER 128 /**< Maximum amount requested from entropy sources */
+#endif
+
+/* \} name SECTION: Module settings */
+
+#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
+#define MBEDTLS_ENTROPY_BLOCK_SIZE 64 /**< Block size of entropy accumulator (SHA-512) */
+#else
+#define MBEDTLS_ENTROPY_BLOCK_SIZE 32 /**< Block size of entropy accumulator (SHA-256) */
+#endif
+
+#define MBEDTLS_ENTROPY_MAX_SEED_SIZE 1024 /**< Maximum size of seed we read from seed file */
+#define MBEDTLS_ENTROPY_SOURCE_MANUAL MBEDTLS_ENTROPY_MAX_SOURCES
+
+#define MBEDTLS_ENTROPY_SOURCE_STRONG 1 /**< Entropy source is strong */
+#define MBEDTLS_ENTROPY_SOURCE_WEAK 0 /**< Entropy source is weak */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Entropy poll callback pointer
+ *
+ * \param data Callback-specific data pointer
+ * \param output Data to fill
+ * \param len Maximum size to provide
+ * \param olen The actual amount of bytes put into the buffer (Can be 0)
+ *
+ * \return 0 if no critical failures occurred,
+ * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise
+ */
+typedef int (*mbedtls_entropy_f_source_ptr)(void *data, unsigned char *output, size_t len,
+ size_t *olen);
+
+/**
+ * \brief Entropy source state
+ */
+typedef struct mbedtls_entropy_source_state
+{
+ mbedtls_entropy_f_source_ptr f_source; /**< The entropy source callback */
+ void * p_source; /**< The callback data pointer */
+ size_t size; /**< Amount received in bytes */
+ size_t threshold; /**< Minimum bytes required before release */
+ int strong; /**< Is the source strong? */
+}
+mbedtls_entropy_source_state;
+
+/**
+ * \brief Entropy context structure
+ */
+typedef struct mbedtls_entropy_context
+{
+ int accumulator_started;
+#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
+ mbedtls_sha512_context accumulator;
+#else
+ mbedtls_sha256_context accumulator;
+#endif
+ int source_count;
+ mbedtls_entropy_source_state source[MBEDTLS_ENTROPY_MAX_SOURCES];
+#if defined(MBEDTLS_HAVEGE_C)
+ mbedtls_havege_state havege_data;
+#endif
+#if defined(MBEDTLS_THREADING_C)
+ mbedtls_threading_mutex_t mutex; /*!< mutex */
+#endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+ int initial_entropy_run;
+#endif
+}
+mbedtls_entropy_context;
+
+/**
+ * \brief Initialize the context
+ *
+ * \param ctx Entropy context to initialize
+ */
+void mbedtls_entropy_init( mbedtls_entropy_context *ctx );
+
+/**
+ * \brief Free the data in the context
+ *
+ * \param ctx Entropy context to free
+ */
+void mbedtls_entropy_free( mbedtls_entropy_context *ctx );
+
+/**
+ * \brief Adds an entropy source to poll
+ * (Thread-safe if MBEDTLS_THREADING_C is enabled)
+ *
+ * \param ctx Entropy context
+ * \param f_source Entropy function
+ * \param p_source Function data
+ * \param threshold Minimum required from source before entropy is released
+ * ( with mbedtls_entropy_func() ) (in bytes)
+ * \param strong MBEDTLS_ENTROPY_SOURCE_STRONG or
+ * MBEDTLS_ENTROPY_SOURCE_WEAK.
+ * At least one strong source needs to be added.
+ * Weaker sources (such as the cycle counter) can be used as
+ * a complement.
+ *
+ * \return 0 if successful or MBEDTLS_ERR_ENTROPY_MAX_SOURCES
+ */
+int mbedtls_entropy_add_source( mbedtls_entropy_context *ctx,
+ mbedtls_entropy_f_source_ptr f_source, void *p_source,
+ size_t threshold, int strong );
+
+/**
+ * \brief Trigger an extra gather poll for the accumulator
+ * (Thread-safe if MBEDTLS_THREADING_C is enabled)
+ *
+ * \param ctx Entropy context
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_ENTROPY_SOURCE_FAILED
+ */
+int mbedtls_entropy_gather( mbedtls_entropy_context *ctx );
+
+/**
+ * \brief Retrieve entropy from the accumulator
+ * (Maximum length: MBEDTLS_ENTROPY_BLOCK_SIZE)
+ * (Thread-safe if MBEDTLS_THREADING_C is enabled)
+ *
+ * \param data Entropy context
+ * \param output Buffer to fill
+ * \param len Number of bytes desired, must be at most MBEDTLS_ENTROPY_BLOCK_SIZE
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_ENTROPY_SOURCE_FAILED
+ */
+int mbedtls_entropy_func( void *data, unsigned char *output, size_t len );
+
+/**
+ * \brief Add data to the accumulator manually
+ * (Thread-safe if MBEDTLS_THREADING_C is enabled)
+ *
+ * \param ctx Entropy context
+ * \param data Data to add
+ * \param len Length of data
+ *
+ * \return 0 if successful
+ */
+int mbedtls_entropy_update_manual( mbedtls_entropy_context *ctx,
+ const unsigned char *data, size_t len );
+
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/**
+ * \brief Trigger an update of the seed file in NV by using the
+ * current entropy pool.
+ *
+ * \param ctx Entropy context
+ *
+ * \return 0 if successful
+ */
+int mbedtls_entropy_update_nv_seed( mbedtls_entropy_context *ctx );
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
+#if defined(MBEDTLS_FS_IO)
+/**
+ * \brief Write a seed file
+ *
+ * \param ctx Entropy context
+ * \param path Name of the file
+ *
+ * \return 0 if successful,
+ * MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR on file error, or
+ * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED
+ */
+int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *path );
+
+/**
+ * \brief Read and update a seed file. Seed is added to this
+ * instance. No more than MBEDTLS_ENTROPY_MAX_SEED_SIZE bytes are
+ * read from the seed file. The rest is ignored.
+ *
+ * \param ctx Entropy context
+ * \param path Name of the file
+ *
+ * \return 0 if successful,
+ * MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR on file error,
+ * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED
+ */
+int mbedtls_entropy_update_seed_file( mbedtls_entropy_context *ctx, const char *path );
+#endif /* MBEDTLS_FS_IO */
+
+#if defined(MBEDTLS_SELF_TEST)
+/**
+ * \brief Checkup routine
+ *
+ * This module self-test also calls the entropy self-test,
+ * mbedtls_entropy_source_self_test();
+ *
+ * \return 0 if successful, or 1 if a test failed
+ */
+int mbedtls_entropy_self_test( int verbose );
+
+#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
+/**
+ * \brief Checkup routine
+ *
+ * Verifies the integrity of the hardware entropy source
+ * provided by the function 'mbedtls_hardware_poll()'.
+ *
+ * Note this is the only hardware entropy source that is known
+ * at link time, and other entropy sources configured
+ * dynamically at runtime by the function
+ * mbedtls_entropy_add_source() will not be tested.
+ *
+ * \return 0 if successful, or 1 if a test failed
+ */
+int mbedtls_entropy_source_self_test( int verbose );
+#endif /* MBEDTLS_ENTROPY_HARDWARE_ALT */
+#endif /* MBEDTLS_SELF_TEST */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* entropy.h */
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