Implementation of SecRandomCopyBytes for OS X

gistfile1.m

#ifdef TARGET_OS_MAC

typedef const struct __SecRandom * SecRandomRef;

const SecRandomRef kSecRandomDefault = NULL;

int SecRandomCopyBytes( SecRandomRef rnd, size_t count, uint8_t *bytes );

int SecRandomCopyBytes( SecRandomRef rnd, size_t count, uint8_t *bytes ) {
  int fd;
  
  if( ( fd = open("/dev/urandom", O_RDONLY) ) < 0 ) {
    return -1;
  }
  
  ssize_t bytesRead;
  uint8_t *p = bytes;
  
  do {
    bytesRead = read( fd, p, count - ( p -bytes ) );
    if( bytesRead > 0 ) {
      p += bytesRead;
    }
  } while( bytesRead > 0 || ( bytesRead < 0 && errno == EINTR ) );
  
  close( fd );
  
  return bytesRead < 0 ? -1 : 0;
}

#endif