Diff: include/mbedtls/entropy.h

Revision:

0:cdf462088d13

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/mbedtls/entropy.h	Thu Jan 05 00:18:44 2017 +0000
@@ -0,0 +1,287 @@
+/**
+ * \file entropy.h
+ *
+ * \brief Entropy accumulator implementation
+ *
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  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_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
+{
+#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
+ *                  MBEDTSL_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 */