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 // Copyright (c) 2008 The Chromium Authors. All rights reserved.

 // Use of this source code is governed by a BSD-style license that can be

 // found in the LICENSE file.

 #include "base/rand_util.h"

 #include <fcntl.h>

 #include <unistd.h>

 #include "base/file_util.h"

 #include "base/logging.h"

 namespace base {

 uint64_t RandUint64() {

   uint64_t number;

   int urandom_fd = open("/dev/urandom", O_RDONLY);

   CHECK(urandom_fd >= 0);

   bool success = file_util::ReadFromFD(urandom_fd,

                                        reinterpret_cast<char*>(&number),

                                        sizeof(number));

   CHECK(success);

   close(urandom_fd);

   return number;

 }

 }  // namespace base