--- /dev/null
+/**
+ * \file entropy_poll.h
+ *
+ * \brief Platform-specific and custom entropy polling functions
+ */
+/*
+ * 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_POLL_H
+#define MBEDTLS_ENTROPY_POLL_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Default thresholds for built-in sources, in bytes
+ */
+#define MBEDTLS_ENTROPY_MIN_PLATFORM 32 /**< Minimum for platform source */
+#define MBEDTLS_ENTROPY_MIN_HAVEGE 32 /**< Minimum for HAVEGE */
+#define MBEDTLS_ENTROPY_MIN_HARDCLOCK 4 /**< Minimum for mbedtls_timing_hardclock() */
+#if !defined(MBEDTLS_ENTROPY_MIN_HARDWARE)
+#define MBEDTLS_ENTROPY_MIN_HARDWARE 32 /**< Minimum for the hardware source */
+#endif
+
+/**
+ * \brief Entropy poll callback that provides 0 entropy.
+ */
+#if defined(MBEDTLS_TEST_NULL_ENTROPY)
+ int mbedtls_null_entropy_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
+/**
+ * \brief Platform-specific entropy poll callback
+ */
+int mbedtls_platform_entropy_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#if defined(MBEDTLS_HAVEGE_C)
+/**
+ * \brief HAVEGE based entropy poll callback
+ *
+ * Requires an HAVEGE state as its data pointer.
+ */
+int mbedtls_havege_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#if defined(MBEDTLS_TIMING_C)
+/**
+ * \brief mbedtls_timing_hardclock-based entropy poll callback
+ */
+int mbedtls_hardclock_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
+/**
+ * \brief Entropy poll callback for a hardware source
+ *
+ * \warning This is not provided by mbed TLS!
+ * See \c MBEDTLS_ENTROPY_HARDWARE_ALT in config.h.
+ *
+ * \note This must accept NULL as its first argument.
+ */
+int mbedtls_hardware_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/**
+ * \brief Entropy poll callback for a non-volatile seed file
+ *
+ * \note This must accept NULL as its first argument.
+ */
+int mbedtls_nv_seed_poll( void *data,
+ unsigned char *output, size_t len, size_t *olen );
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* entropy_poll.h */