libc++: add NaCl and PNaCl support for std::random_device
Summary:
The NaCl sandbox doesn't allow opening files under /dev, but it offers an API which provides the same capabilities. This is the same random device emulation that nacl_io performs for POSIX support, but nacl_io is an optional library so libc++ can't assume that device emulation will be performed. Note that NaCl only supports /dev/urandom, not /dev/random.
This patch also cleans up some of the preprocessor #endif, and fixes the test for Win32 (it accepts any token, and would therefore never throw regardless of the token provided).
Test Plan: ninja check-libcxx
Reviewers: dschuff, mclow.lists, danalbert
Subscribers: jfb, cfe-commits
Differential Revision: http://reviews.llvm.org/D6442
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@223068 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/random.cpp b/src/random.cpp
index 86017ef..15ed65b 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -11,23 +11,27 @@
// Must be defined before including stdlib.h to enable rand_s().
#define _CRT_RAND_S
#include <stdio.h>
-#endif
+#endif // defined(_WIN32)
#include "random"
#include "system_error"
-#ifdef __sun__
+#if defined(__sun__)
#define rename solaris_headers_are_broken
-#endif
+#endif // defined(__sun__)
#if !defined(_WIN32)
#include <fcntl.h>
#include <unistd.h>
-#endif // defined(_WIN32)
+#endif // !defined(_WIN32)
#include <errno.h>
+#if defined(_LIBCPP_USING_NACL_RANDOM)
+#include <nacl/nacl_random.h>
+#endif // defined(_LIBCPP_USING_NACL_RANDOM)
_LIBCPP_BEGIN_NAMESPACE_STD
#if defined(_WIN32)
+
random_device::random_device(const string&)
{
}
@@ -45,7 +49,39 @@
__throw_system_error(err, "random_device rand_s failed.");
return r;
}
-#else
+
+#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);
+ char* p = reinterpret_cast<char*>(&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;
+}
+
+#else // !defined(_WIN32) && !defined(_LIBCPP_USING_NACL_RANDOM)
+
random_device::random_device(const string& __token)
: __f_(open(__token.c_str(), O_RDONLY))
{
@@ -80,7 +116,8 @@
}
return r;
}
-#endif // defined(_WIN32)
+
+#endif // defined(_WIN32) || defined(_LIBCPP_USING_NACL_RANDOM)
double
random_device::entropy() const _NOEXCEPT
