From 0c189e08b5bd066146c07c918831f5004aab05f1 Mon Sep 17 00:00:00 2001
From: arvidn <arvid@cs.umu.se>
Date: Sat, 14 Jan 2017 18:13:09 -0500
Subject: [PATCH] use /dev/random as random number source on macOS

---
 include/libtorrent/Makefile.am         |  1 +
 include/libtorrent/aux_/dev_random.hpp | 80 ++++++++++++++++++++++++++
 include/libtorrent/config.hpp          |  5 ++
 src/random.cpp                         | 23 +++++---
 4 files changed, 100 insertions(+), 9 deletions(-)
 create mode 100644 include/libtorrent/aux_/dev_random.hpp

diff --git a/include/libtorrent/Makefile.am b/include/libtorrent/Makefile.am
index bed4b50ac..aad56caa4 100644
--- a/include/libtorrent/Makefile.am
+++ b/include/libtorrent/Makefile.am
@@ -163,6 +163,7 @@ nobase_include_HEADERS = \
   aux_/cpuid.hpp                    \
   aux_/disable_warnings_push.hpp    \
   aux_/disable_warnings_pop.hpp     \
+  aux_/dev_random.hpp               \
   aux_/escape_string.hpp            \
   aux_/io.hpp                       \
   aux_/max_path.hpp                 \
diff --git a/include/libtorrent/aux_/dev_random.hpp b/include/libtorrent/aux_/dev_random.hpp
new file mode 100644
index 000000000..b8ea3c9e8
--- /dev/null
+++ b/include/libtorrent/aux_/dev_random.hpp
@@ -0,0 +1,80 @@
+/*
+
+Copyright (c) 2017, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_DEV_RANDOM_HPP_INCLUDED
+#define TORRENT_DEV_RANDOM_HPP_INCLUDED
+
+#include "libtorrent/config.hpp"
+#include "libtorrent/span.hpp"
+#include <fcntl.h>
+
+namespace libtorrent { namespace aux {
+
+	struct dev_random
+	{
+		dev_random()
+			: m_fd(open("/dev/random", O_RDONLY))
+		{
+			if (m_fd < 0)
+			{
+#ifndef BOOST_NO_EXCEPTIONS
+				throw system_error(error_code(errno, system_category()));
+#else
+				std::terminate();
+#endif
+			}
+		}
+		dev_random(dev_random const&) = delete;
+		dev_random& operator=(dev_random const&) = delete;
+
+		void read(span<char> buffer)
+		{
+			std::size_t const ret = ::read(m_fd, buffer.data(), buffer.size());
+			if (ret != buffer.size())
+			{
+#ifndef BOOST_NO_EXCEPTIONS
+				throw system_error(error_code(EIO, system_category()));
+#else
+				std::terminate();
+#endif
+			}
+		}
+
+		~dev_random() { close(m_fd); }
+
+	private:
+		int m_fd;
+	};
+}}
+
+#endif
+
diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index b81c3fa3e..ecac833a3 100644
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -153,6 +153,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #endif
 #endif // __APPLE__
 
+#define TORRENT_USE_DEV_RANDOM 1
 #define TORRENT_HAVE_MMAP 1
 
 #define TORRENT_HAS_FALLOCATE 0
@@ -413,6 +414,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_USE_CRYPTOAPI_SHA_512 0
 #endif
 
+#ifndef TORRENT_USE_DEV_RANDOM
+#define TORRENT_USE_DEV_RANDOM 0
+#endif
+
 #ifndef TORRENT_HAVE_MMAP
 #define TORRENT_HAVE_MMAP 0
 #endif
diff --git a/src/random.cpp b/src/random.cpp
index 5a9d7a6be..55a4aed6d 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -46,10 +46,16 @@ extern "C" {
 #include <openssl/err.h>
 }
 
+#include <boost/asio/ssl/error.hpp>
+
 #endif
 
 #include "libtorrent/aux_/disable_warnings_pop.hpp"
 
+#if TORRENT_USE_DEV_RANDOM
+#include "libtorrent/aux_/dev_random.hpp"
+#endif
+
 namespace libtorrent
 {
 	namespace aux
@@ -78,27 +84,26 @@ namespace libtorrent
 
 			aux::crypt_gen_random(buffer);
 
+#elif TORRENT_USE_DEV_RANDOM
+			// /dev/random
+
+			static dev_random dev;
+			dev.read(buffer);
+
 #elif defined TORRENT_USE_LIBCRYPTO
 			// openssl
 
-#ifdef TORRENT_MACOS_DEPRECATED_LIBCRYPTO
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#endif
-
 			int r = RAND_bytes(reinterpret_cast<unsigned char*>(buffer.data())
 				, int(buffer.size()));
 			if (r != 1)
 			{
 #ifndef BOOST_NO_EXCEPTIONS
-				throw system_error(error_code(int(::ERR_get_error()), system_category()));
+				throw system_error(error_code(int(::ERR_get_error())
+					, boost::asio::error::get_ssl_category()));
 #else
 				std::terminate();
 #endif
 			}
-#ifdef TORRENT_MACOS_DEPRECATED_LIBCRYPTO
-#pragma clang diagnostic pop
-#endif
 #else
 			// fallback