text: /*
   *  Copyright (C) 2006-2015, 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
  
  #include <sys/types.h>
  #include <stdlib.h>
  #include <stdio.h>
  
  #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
  
  static int os_get_random(unsigned char *buf, size_t len)
  {
      int i, j;
      unsigned long tmp;
  
      for (i = 0; i < ((len + 3) & ~3) / 4; i++)
      {
          tmp = rand();
  
          for (j = 0; j < 4; j++)
          {
              if ((i * 4 + j) < len)
              {
                  buf[i * 4 + j] = (unsigned char)(tmp >> (j * 8));
              } 
              else 
              {
                  break;
              }
          }
      }
  
      return 0;
  }
  
  int mbedtls_hardware_poll( void *data, unsigned char *output, size_t len, size_t *olen )
  {
      os_get_random(output, len);
      *olen = len;
  
      return 0;
  }
  #endif
  
  