X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2FRandom.cpp;h=8f5e3128d2036952f31ba8efcc73791a139e333b;hb=ad2f228ab1359952d37acdc4f3032e1405cca221;hp=06b3d5aea0b20a7f60e4f52d8b3b407119357957;hpb=651eb23ca2cfb7b64481f3091160cc8a1112dbc9;p=folly.git

diff --git a/folly/Random.cpp b/folly/Random.cpp
index 06b3d5ae..8f5e3128 100644
--- a/folly/Random.cpp
+++ b/folly/Random.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 Facebook, Inc.
+ * Copyright 2016 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,23 +17,51 @@
 #include <folly/Random.h>
 
 #include <atomic>
-#include <unistd.h>
-#include <sys/time.h>
+#include <mutex>
 #include <random>
 #include <array>
 
 #include <glog/logging.h>
+#include <folly/CallOnce.h>
 #include <folly/File.h>
 #include <folly/FileUtil.h>
+#include <folly/ThreadLocal.h>
+#include <folly/portability/SysTime.h>
+#include <folly/portability/Unistd.h>
+
+#ifdef _MSC_VER
+# include <wincrypt.h>
+#endif
 
 namespace folly {
 
 namespace {
 
 void readRandomDevice(void* data, size_t size) {
-  // Keep it open for the duration of the program
-  static File randomDevice("/dev/urandom");
-  PCHECK(readFull(randomDevice.fd(), data, size) == size);
+#ifdef _MSC_VER
+  static folly::once_flag flag;
+  static HCRYPTPROV cryptoProv;
+  folly::call_once(flag, [&] {
+    if (!CryptAcquireContext(&cryptoProv, nullptr, nullptr, PROV_RSA_FULL, 0)) {
+      if (GetLastError() == NTE_BAD_KEYSET) {
+        // Mostly likely cause of this is that no key container
+        // exists yet, so try to create one.
+        PCHECK(CryptAcquireContext(
+            &cryptoProv, nullptr, nullptr, PROV_RSA_FULL, CRYPT_NEWKEYSET));
+      } else {
+        LOG(FATAL) << "Failed to acquire the default crypto context.";
+      }
+    }
+  });
+  CHECK(size <= std::numeric_limits<DWORD>::max());
+  PCHECK(CryptGenRandom(cryptoProv, (DWORD)size, (BYTE*)data));
+#else
+  // Keep the random device open for the duration of the program.
+  static int randomFd = ::open("/dev/urandom", O_RDONLY);
+  PCHECK(randomFd >= 0);
+  auto bytesRead = readFull(randomFd, data, size);
+  PCHECK(bytesRead >= 0 && size_t(bytesRead) == size);
+#endif
 }
 
 class BufferedRandomDevice {
@@ -90,19 +118,14 @@ void BufferedRandomDevice::getSlow(unsigned char* data, size_t size) {
   ptr_ += size;
 }
 
-ThreadLocal<BufferedRandomDevice> bufferedRandomDevice;
 
 }  // namespace
 
 void Random::secureRandom(void* data, size_t size) {
+  static ThreadLocal<BufferedRandomDevice> bufferedRandomDevice;
   bufferedRandomDevice->get(data, size);
 }
 
-ThreadLocalPRNG::ThreadLocalPRNG() {
-  static folly::ThreadLocal<ThreadLocalPRNG::LocalInstancePRNG> localInstance;
-  local_ = localInstance.get();
-}
-
 class ThreadLocalPRNG::LocalInstancePRNG {
  public:
   LocalInstancePRNG() : rng(Random::create()) { }
@@ -110,6 +133,11 @@ class ThreadLocalPRNG::LocalInstancePRNG {
   Random::DefaultGenerator rng;
 };
 
+ThreadLocalPRNG::ThreadLocalPRNG() {
+  static folly::ThreadLocal<ThreadLocalPRNG::LocalInstancePRNG> localInstance;
+  local_ = localInstance.get();
+}
+
 uint32_t ThreadLocalPRNG::getImpl(LocalInstancePRNG* local) {
   return local->rng();
 }