43 lines · cpp
1//===-- Windows implementation of getentropy ------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/unistd/getentropy.h"10#include "hdr/errno_macros.h"11#include "src/__support/common.h"12#include "src/__support/libc_errno.h"13 14#define WIN32_LEAN_AND_MEAN15#include <Windows.h>16#include <bcrypt.h>17#include <ntstatus.h>18#pragma comment(lib, "bcrypt.lib")19 20namespace LIBC_NAMESPACE_DECL {21 22LLVM_LIBC_FUNCTION(int, getentropy, (void *buffer, size_t length)) {23 __try {24 // check the length limit25 if (length > 256)26 __leave;27 28 NTSTATUS result = ::BCryptGenRandom(nullptr, static_cast<PUCHAR>(buffer),29 static_cast<ULONG>(length),30 BCRYPT_USE_SYSTEM_PREFERRED_RNG);31 32 if (result == STATUS_SUCCESS)33 return 0;34 35 } __except (EXCEPTION_EXECUTE_HANDLER) {36 // no need to handle exceptions specially37 }38 39 libc_errno = EIO;40 return -1;41}42} // namespace LIBC_NAMESPACE_DECL43