text: /*
   *  Platform abstraction layer
   *
   *  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)
   */
  
  #if !defined(MBEDTLS_CONFIG_FILE)
  #include "mbedtls/config.h"
  #else
  #include MBEDTLS_CONFIG_FILE
  #endif
  
  #if defined(MBEDTLS_PLATFORM_C)
  
  #include "mbedtls/platform.h"
  #include "mbedtls/platform_util.h"
  
  /* The compile time configuration of memory allocation via the macros
   * MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO takes precedence over the runtime
   * configuration via mbedtls_platform_set_calloc_free(). So, omit everything
   * related to the latter if MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO are defined. */
  #if defined(MBEDTLS_PLATFORM_MEMORY) &&                 \
      !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&        \
         defined(MBEDTLS_PLATFORM_FREE_MACRO) )
  
  #if !defined(MBEDTLS_PLATFORM_STD_CALLOC)
  static void *platform_calloc_uninit( size_t n, size_t size )
  {
      ((void) n);
      ((void) size);
      return( NULL );
  }
  
  #define MBEDTLS_PLATFORM_STD_CALLOC   platform_calloc_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */
  
  #if !defined(MBEDTLS_PLATFORM_STD_FREE)
  static void platform_free_uninit( void *ptr )
  {
      ((void) ptr);
  }
  
  #define MBEDTLS_PLATFORM_STD_FREE     platform_free_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_FREE */
  
  static void * (*mbedtls_calloc_func)( size_t, size_t ) = MBEDTLS_PLATFORM_STD_CALLOC;
  static void (*mbedtls_free_func)( void * ) = MBEDTLS_PLATFORM_STD_FREE;
  
  void * mbedtls_calloc( size_t nmemb, size_t size )
  {
      return (*mbedtls_calloc_func)( nmemb, size );
  }
  
  void mbedtls_free( void * ptr )
  {
      (*mbedtls_free_func)( ptr );
  }
  
  int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
                                void (*free_func)( void * ) )
  {
      mbedtls_calloc_func = calloc_func;
      mbedtls_free_func = free_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_MEMORY &&
            !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&
               defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */
  
  #if defined(_WIN32)
  #include <stdarg.h>
  int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... )
  {
      int ret;
      va_list argp;
  
      /* Avoid calling the invalid parameter handler by checking ourselves */
      if( s == NULL || n == 0 || fmt == NULL )
          return( -1 );
  
      va_start( argp, fmt );
  #if defined(_TRUNCATE) && !defined(__MINGW32__)
      ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp );
  #else
      ret = _vsnprintf( s, n, fmt, argp );
      if( ret < 0 || (size_t) ret == n )
      {
          s[n-1] = '\0';
          ret = -1;
      }
  #endif
      va_end( argp );
  
      return( ret );
  }
  #endif
  
  #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static int platform_snprintf_uninit( char * s, size_t n,
                                       const char * format, ... )
  {
      ((void) s);
      ((void) n);
      ((void) format);
      return( 0 );
  }
  
  #define MBEDTLS_PLATFORM_STD_SNPRINTF    platform_snprintf_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */
  
  int (*mbedtls_snprintf)( char * s, size_t n,
                            const char * format,
                            ... ) = MBEDTLS_PLATFORM_STD_SNPRINTF;
  
  int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
                                                   const char * format,
                                                   ... ) )
  {
      mbedtls_snprintf = snprintf_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
  
  #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static int platform_printf_uninit( const char *format, ... )
  {
      ((void) format);
      return( 0 );
  }
  
  #define MBEDTLS_PLATFORM_STD_PRINTF    platform_printf_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */
  
  int (*mbedtls_printf)( const char *, ... ) = MBEDTLS_PLATFORM_STD_PRINTF;
  
  int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) )
  {
      mbedtls_printf = printf_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */
  
  #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static int platform_fprintf_uninit( FILE *stream, const char *format, ... )
  {
      ((void) stream);
      ((void) format);
      return( 0 );
  }
  
  #define MBEDTLS_PLATFORM_STD_FPRINTF   platform_fprintf_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */
  
  int (*mbedtls_fprintf)( FILE *, const char *, ... ) =
                                          MBEDTLS_PLATFORM_STD_FPRINTF;
  
  int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ... ) )
  {
      mbedtls_fprintf = fprintf_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
  
  #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static void platform_exit_uninit( int status )
  {
      ((void) status);
  }
  
  #define MBEDTLS_PLATFORM_STD_EXIT   platform_exit_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_EXIT */
  
  void (*mbedtls_exit)( int status ) = MBEDTLS_PLATFORM_STD_EXIT;
  
  int mbedtls_platform_set_exit( void (*exit_func)( int status ) )
  {
      mbedtls_exit = exit_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_EXIT_ALT */
  
  #if defined(MBEDTLS_HAVE_TIME)
  
  #if defined(MBEDTLS_PLATFORM_TIME_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_TIME)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static mbedtls_time_t platform_time_uninit( mbedtls_time_t* timer )
  {
      ((void) timer);
      return( 0 );
  }
  
  #define MBEDTLS_PLATFORM_STD_TIME   platform_time_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_TIME */
  
  mbedtls_time_t (*mbedtls_time)( mbedtls_time_t* timer ) = MBEDTLS_PLATFORM_STD_TIME;
  
  int mbedtls_platform_set_time( mbedtls_time_t (*time_func)( mbedtls_time_t* timer ) )
  {
      mbedtls_time = time_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_TIME_ALT */
  
  #endif /* MBEDTLS_HAVE_TIME */
  
  #if defined(MBEDTLS_ENTROPY_NV_SEED)
  #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
  /* Default implementations for the platform independent seed functions use
   * standard libc file functions to read from and write to a pre-defined filename
   */
  int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
  {
      FILE *file;
      size_t n;
  
      if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
          return( -1 );
  
      if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
      {
          fclose( file );
          mbedtls_platform_zeroize( buf, buf_len );
          return( -1 );
      }
  
      fclose( file );
      return( (int)n );
  }
  
  int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
  {
      FILE *file;
      size_t n;
  
      if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
          return -1;
  
      if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
      {
          fclose( file );
          return -1;
      }
  
      fclose( file );
      return( (int)n );
  }
  #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
  
  #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
  #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len )
  {
      ((void) buf);
      ((void) buf_len);
      return( -1 );
  }
  
  #define MBEDTLS_PLATFORM_STD_NV_SEED_READ   platform_nv_seed_read_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
  
  #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
  /*
   * Make dummy function to prevent NULL pointer dereferences
   */
  static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len )
  {
      ((void) buf);
      ((void) buf_len);
      return( -1 );
  }
  
  #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE   platform_nv_seed_write_uninit
  #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
  
  int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
              MBEDTLS_PLATFORM_STD_NV_SEED_READ;
  int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
              MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
  
  int mbedtls_platform_set_nv_seed(
          int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
          int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) )
  {
      mbedtls_nv_seed_read = nv_seed_read_func;
      mbedtls_nv_seed_write = nv_seed_write_func;
      return( 0 );
  }
  #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
  #endif /* MBEDTLS_ENTROPY_NV_SEED */
  
  #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT)
  /*
   * Placeholder platform setup that does nothing by default
   */
  int mbedtls_platform_setup( mbedtls_platform_context *ctx )
  {
      (void)ctx;
  
      return( 0 );
  }
  
  /*
   * Placeholder platform teardown that does nothing by default
   */
  void mbedtls_platform_teardown( mbedtls_platform_context *ctx )
  {
      (void)ctx;
  }
  #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
  
  #endif /* MBEDTLS_PLATFORM_C */
  