text: #include "string.h"
  #include "stdlib.h"
  #include "mbedtls/entropy.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
  
  