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2021-04-29 14:53:40 -07:00

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C

/*
* FreeRTOS V202104.00
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/**
* @file mbedtls_freertos_port.c
* @brief Implements mbed TLS platform functions for FreeRTOS.
*/
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "FreeRTOS_Sockets.h"
/* mbed TLS includes. */
#include "mbedtls_config.h"
#include "threading_alt.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ssl.h"
/*-----------------------------------------------------------*/
/**
* @brief The number of bytes in a standard TLS record header.
*
* @note This only applies to a standard TCP+TLS connection.
* DTLS has a different length for its record headers.
*
*/
#define TLS_RECORD_HEADER_BYTE_LENGTH 5
/*-----------------------------------------------------------*/
/**
* @brief Allocates memory for an array of members.
*
* @param[in] nmemb Number of members that need to be allocated.
* @param[in] size Size of each member.
*
* @return Pointer to the beginning of newly allocated memory.
*/
void * mbedtls_platform_calloc( size_t nmemb,
size_t size )
{
size_t totalSize = nmemb * size;
void * pBuffer = NULL;
/* Check that neither nmemb nor size were 0. */
if( totalSize > 0 )
{
/* Overflow check. */
if( ( totalSize / size ) == nmemb )
{
pBuffer = pvPortMalloc( totalSize );
if( pBuffer != NULL )
{
( void ) memset( pBuffer, 0x00, totalSize );
}
}
}
return pBuffer;
}
/*-----------------------------------------------------------*/
/**
* @brief Frees the space previously allocated by calloc.
*
* @param[in] ptr Pointer to the memory to be freed.
*/
void mbedtls_platform_free( void * ptr )
{
vPortFree( ptr );
}
/*-----------------------------------------------------------*/
/**
* @brief Sends data over FreeRTOS+TCP sockets.
*
* @param[in] ctx The network context containing the socket handle.
* @param[in] buf Buffer containing the bytes to send.
* @param[in] len Number of bytes to send from the buffer.
*
* @return Number of bytes sent on success; else a negative value.
*/
int mbedtls_platform_send( void * ctx,
const unsigned char * buf,
size_t len )
{
Socket_t socket;
BaseType_t sendStatus = 0;
int returnStatus = -1;
configASSERT( ctx != NULL );
configASSERT( buf != NULL );
socket = ( Socket_t ) ctx;
sendStatus = FreeRTOS_send( socket, buf, len, 0 );
switch( sendStatus )
{
/* Socket was closed or just got closed. */
case -pdFREERTOS_ERRNO_ENOTCONN:
/* Not enough memory for the socket to create either an Rx or Tx stream. */
case -pdFREERTOS_ERRNO_ENOMEM:
/* Socket is not valid, is not a TCP socket, or is not bound. */
case -pdFREERTOS_ERRNO_EINVAL:
/* Socket received a signal, causing the read operation to be aborted. */
case -pdFREERTOS_ERRNO_EINTR:
returnStatus = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
break;
/* A timeout occurred before any data could be sent. */
case -pdFREERTOS_ERRNO_ENOSPC:
returnStatus = MBEDTLS_ERR_SSL_TIMEOUT;
break;
default:
returnStatus = ( int ) sendStatus;
break;
}
return returnStatus;
}
/*-----------------------------------------------------------*/
/**
* @brief Receives data from FreeRTOS+TCP socket.
*
* @param[in] ctx The network context containing the socket handle.
* @param[out] buf Buffer to receive bytes into.
* @param[in] len Number of bytes to receive from the network.
*
* @return Number of bytes received if successful; Negative value on error.
*/
int mbedtls_platform_recv( void * ctx,
unsigned char * buf,
size_t len )
{
Socket_t socket;
BaseType_t recvStatus = 0;
int returnStatus = -1;
configASSERT( ctx != NULL );
configASSERT( buf != NULL );
socket = ( Socket_t ) ctx;
recvStatus = FreeRTOS_recv( socket, buf, len, 0 );
switch( recvStatus )
{
/* No data could be sent because the socket was or just got closed. */
case -pdFREERTOS_ERRNO_ENOTCONN:
/* No data could be sent because there was insufficient memory. */
case -pdFREERTOS_ERRNO_ENOMEM:
/* No data could be sent because xSocket was not a valid TCP socket. */
case -pdFREERTOS_ERRNO_EINVAL:
returnStatus = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
break;
/* A timeout occurred before any data could be received. */
case 0:
returnStatus = MBEDTLS_ERR_SSL_WANT_READ;
break;
default:
returnStatus = ( int ) recvStatus;
break;
}
return returnStatus;
}
/*-----------------------------------------------------------*/
/**
* @brief Creates a mutex.
*
* @param[in, out] pMutex mbedtls mutex handle.
*/
void mbedtls_platform_mutex_init( mbedtls_threading_mutex_t * pMutex )
{
configASSERT( pMutex != NULL );
/* Create a statically-allocated FreeRTOS mutex. This should never fail as
* storage is provided. */
pMutex->mutexHandle = xSemaphoreCreateMutexStatic( &( pMutex->mutexStorage ) );
configASSERT( pMutex->mutexHandle != NULL );
}
/*-----------------------------------------------------------*/
/**
* @brief Frees a mutex.
*
* @param[in] pMutex mbedtls mutex handle.
*
* @note This function is an empty stub as nothing needs to be done to free
* a statically allocated FreeRTOS mutex.
*/
void mbedtls_platform_mutex_free( mbedtls_threading_mutex_t * pMutex )
{
/* Nothing needs to be done to free a statically-allocated FreeRTOS mutex. */
( void ) pMutex;
}
/*-----------------------------------------------------------*/
/**
* @brief Function to lock a mutex.
*
* @param[in] pMutex mbedtls mutex handle.
*
* @return 0 (success) is always returned as any other failure is asserted.
*/
int mbedtls_platform_mutex_lock( mbedtls_threading_mutex_t * pMutex )
{
BaseType_t mutexStatus = 0;
configASSERT( pMutex != NULL );
/* mutexStatus is not used if asserts are disabled. */
( void ) mutexStatus;
/* This function should never fail if the mutex is initialized. */
mutexStatus = xSemaphoreTake( pMutex->mutexHandle, portMAX_DELAY );
configASSERT( mutexStatus == pdTRUE );
return 0;
}
/*-----------------------------------------------------------*/
/**
* @brief Function to unlock a mutex.
*
* @param[in] pMutex mbedtls mutex handle.
*
* @return 0 is always returned as any other failure is asserted.
*/
int mbedtls_platform_mutex_unlock( mbedtls_threading_mutex_t * pMutex )
{
BaseType_t mutexStatus = 0;
configASSERT( pMutex != NULL );
/* mutexStatus is not used if asserts are disabled. */
( void ) mutexStatus;
/* This function should never fail if the mutex is initialized. */
mutexStatus = xSemaphoreGive( pMutex->mutexHandle );
configASSERT( mutexStatus == pdTRUE );
return 0;
}
/*-----------------------------------------------------------*/
/**
* @brief Function to generate a random number.
*
* @param[in] data Callback context.
* @param[out] output The address of the buffer that receives the random number.
* @param[in] len Maximum size of the random number to be generated.
* @param[out] olen The size, in bytes, of the #output buffer.
*
* @return 0 if no critical failures occurred,
* MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise.
*/
int mbedtls_platform_entropy_poll( void * data,
unsigned char * output,
size_t len,
size_t * olen )
{
int status = 0;
NTSTATUS rngStatus = 0;
configASSERT( output != NULL );
configASSERT( olen != NULL );
/* Context is not used by this function. */
( void ) data;
/* TLS requires a secure random number generator; use the RNG provided
* by Windows. This function MUST be re-implemented for other platforms. */
rngStatus =
BCryptGenRandom( NULL, output, len, BCRYPT_USE_SYSTEM_PREFERRED_RNG );
if( rngStatus == 0 )
{
/* All random bytes generated. */
*olen = len;
}
else
{
/* RNG failure. */
*olen = 0;
status = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
}
return status;
}
/*-----------------------------------------------------------*/
/**
* @brief Function to generate a random number based on a hardware poll.
*
* For this FreeRTOS Windows port, this function is redirected by calling
* #mbedtls_platform_entropy_poll.
*
* @param[in] data Callback context.
* @param[out] output The address of the buffer that receives the random number.
* @param[in] len Maximum size of the random number to be generated.
* @param[out] olen The size, in bytes, of the #output buffer.
*
* @return 0 if no critical failures occurred,
* MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise.
*/
int mbedtls_hardware_poll( void * data,
unsigned char * output,
size_t len,
size_t * olen )
{
return mbedtls_platform_entropy_poll( data, output, len, olen );
}
/*-----------------------------------------------------------*/