| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include <__config> |
| |
| #if defined(_LIBCPP_USING_WIN32_RANDOM) |
| // Must be defined before including stdlib.h to enable rand_s(). |
| # define _CRT_RAND_S |
| #endif // defined(_LIBCPP_USING_WIN32_RANDOM) |
| |
| #include <__system_error/system_error.h> |
| #include <limits> |
| #include <random> |
| |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #if defined(_LIBCPP_USING_GETENTROPY) |
| # include <sys/random.h> |
| #elif defined(_LIBCPP_USING_DEV_RANDOM) |
| # include <fcntl.h> |
| # include <unistd.h> |
| # if __has_include(<sys/ioctl.h>) && __has_include(<linux/random.h>) |
| # include <linux/random.h> |
| # include <sys/ioctl.h> |
| # endif |
| #elif defined(_LIBCPP_USING_NACL_RANDOM) |
| # include <nacl/nacl_random.h> |
| #elif defined(_LIBCPP_USING_FUCHSIA_CPRNG) |
| # include <zircon/syscalls.h> |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if defined(_LIBCPP_USING_GETENTROPY) |
| |
| random_device::random_device(const string& __token) { |
| if (__token != "/dev/urandom") |
| __throw_system_error(ENOENT, ("random device not supported " + __token).c_str()); |
| } |
| |
| random_device::~random_device() {} |
| |
| unsigned random_device::operator()() { |
| unsigned r; |
| size_t n = sizeof(r); |
| int err = getentropy(&r, n); |
| if (err) |
| __throw_system_error(errno, "random_device getentropy failed"); |
| return r; |
| } |
| |
| #elif defined(_LIBCPP_USING_ARC4_RANDOM) |
| |
| random_device::random_device(const string&) {} |
| |
| random_device::~random_device() {} |
| |
| unsigned random_device::operator()() { return arc4random(); } |
| |
| #elif defined(_LIBCPP_USING_DEV_RANDOM) |
| |
| random_device::random_device(const string& __token) : __f_(open(__token.c_str(), O_RDONLY)) { |
| if (__f_ < 0) |
| __throw_system_error(errno, ("random_device failed to open " + __token).c_str()); |
| } |
| |
| random_device::~random_device() { close(__f_); } |
| |
| unsigned random_device::operator()() { |
| unsigned r; |
| size_t n = sizeof(r); |
| char* p = reinterpret_cast<char*>(&r); |
| while (n > 0) { |
| ssize_t s = read(__f_, p, n); |
| if (s == 0) |
| __throw_system_error(ENOMSG, "random_device got EOF"); |
| if (s == -1) { |
| if (errno != EINTR) |
| __throw_system_error(errno, "random_device got an unexpected error"); |
| continue; |
| } |
| n -= static_cast<size_t>(s); |
| p += static_cast<size_t>(s); |
| } |
| return r; |
| } |
| |
| #elif defined(_LIBCPP_USING_NACL_RANDOM) |
| |
| random_device::random_device(const string& __token) { |
| if (__token != "/dev/urandom") |
| __throw_system_error(ENOENT, ("random device not supported " + __token).c_str()); |
| int error = nacl_secure_random_init(); |
| if (error) |
| __throw_system_error(error, ("random device failed to open " + __token).c_str()); |
| } |
| |
| random_device::~random_device() {} |
| |
| unsigned random_device::operator()() { |
| unsigned r; |
| size_t n = sizeof(r); |
| size_t bytes_written; |
| int error = nacl_secure_random(&r, n, &bytes_written); |
| if (error != 0) |
| __throw_system_error(error, "random_device failed getting bytes"); |
| else if (bytes_written != n) |
| __throw_runtime_error("random_device failed to obtain enough bytes"); |
| return r; |
| } |
| |
| #elif defined(_LIBCPP_USING_WIN32_RANDOM) |
| |
| random_device::random_device(const string& __token) { |
| if (__token != "/dev/urandom") |
| __throw_system_error(ENOENT, ("random device not supported " + __token).c_str()); |
| } |
| |
| random_device::~random_device() {} |
| |
| unsigned random_device::operator()() { |
| unsigned r; |
| errno_t err = rand_s(&r); |
| if (err) |
| __throw_system_error(err, "random_device rand_s failed."); |
| return r; |
| } |
| |
| #elif defined(_LIBCPP_USING_FUCHSIA_CPRNG) |
| |
| random_device::random_device(const string& __token) { |
| if (__token != "/dev/urandom") |
| __throw_system_error(ENOENT, ("random device not supported " + __token).c_str()); |
| } |
| |
| random_device::~random_device() {} |
| |
| unsigned random_device::operator()() { |
| // Implicitly link against the vDSO system call ABI without |
| // requiring the final link to specify -lzircon explicitly when |
| // statically linking libc++. |
| # pragma comment(lib, "zircon") |
| |
| // The system call cannot fail. It returns only when the bits are ready. |
| unsigned r; |
| _zx_cprng_draw(&r, sizeof(r)); |
| return r; |
| } |
| |
| #else |
| # error "Random device not implemented for this architecture" |
| #endif |
| |
| double random_device::entropy() const noexcept { |
| #if defined(_LIBCPP_USING_DEV_RANDOM) && defined(RNDGETENTCNT) |
| int ent; |
| if (::ioctl(__f_, RNDGETENTCNT, &ent) < 0) |
| return 0; |
| |
| if (ent < 0) |
| return 0; |
| |
| if (ent > std::numeric_limits<result_type>::digits) |
| return std::numeric_limits<result_type>::digits; |
| |
| return ent; |
| #elif defined(_LIBCPP_USING_ARC4_RANDOM) || defined(_LIBCPP_USING_FUCHSIA_CPRNG) |
| return std::numeric_limits<result_type>::digits; |
| #else |
| return 0; |
| #endif |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |