release/src/router/dnscrypt/src/libnacl/randombytes/devurandom.c

   1 #include <sys/types.h>
   2 #include <sys/stat.h>
   3 #include <fcntl.h>
   4 #include <unistd.h>
   5 #ifdef _WIN32
   6 # include <windows.h>
   7 #endif
   8
   9 /* it's really stupid that there isn't a syscall for this */
  10 /* -> Y U NO USE OPENBSD? */
  11
  12 static int fd = -1;
  13
  14 void randombytes(unsigned char *x,unsigned long long xlen)
  15 {
  16   int i;
  17
  18   if (fd == -1) {
  19     for (;;) {
  20       fd = open("/dev/urandom",O_RDONLY);
  21       if (fd != -1) break;
  22 #ifdef _WIN32
  23       Sleep(1000);
  24 #else
  25       sleep(1);
  26 #endif
  27     }
  28   }
  29
  30   while (xlen > 0) {
  31     if (xlen < 1048576) i = xlen; else i = 1048576;
  32
  33     i = read(fd,x,i);
  34     if (i < 1) {
  35 #ifdef _WIN32
  36       Sleep(1000);
  37 #else
  38       sleep(1);
  39 #endif
  40       continue;
  41     }
  42
  43     x += i;
  44     xlen -= i;
  45   }
  46 }