core: unify randomization

Non-security randomizations are changed to use boost::random,
with a global random number generator.

refs #1369

Change-Id: I5000fd02f170fa47058af790e2bea767f9c65650
diff --git a/daemon/fw/forwarder.cpp b/daemon/fw/forwarder.cpp
index 4d0deeb..45728ea 100644
--- a/daemon/fw/forwarder.cpp
+++ b/daemon/fw/forwarder.cpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,12 +21,13 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #include "forwarder.hpp"
-#include <ndn-cxx/util/random.hpp>
 #include "core/logger.hpp"
+#include "core/random.hpp"
 #include "available-strategies.hpp"
+#include <boost/random/uniform_int_distribution.hpp>
 
 namespace nfd {
 
@@ -169,7 +171,8 @@
 
   if (wantNewNonce) {
     interest = make_shared<Interest>(*interest);
-    interest->setNonce(ndn::random::generateWord32());
+    static boost::random::uniform_int_distribution<uint32_t> dist;
+    interest->setNonce(dist(getGlobalRng()));
   }
 
   // insert OutRecord
diff --git a/daemon/fw/ncc-strategy.cpp b/daemon/fw/ncc-strategy.cpp
index 6e7a32c..3b17ab1 100644
--- a/daemon/fw/ncc-strategy.cpp
+++ b/daemon/fw/ncc-strategy.cpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,9 +21,11 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #include "ncc-strategy.hpp"
+#include "core/random.hpp"
+#include <boost/random/uniform_int_distribution.hpp>
 
 namespace nfd {
 namespace fw {
@@ -140,8 +143,9 @@
   }
 
   if (isForwarded) {
-    static unsigned short seed[3];
-    time::nanoseconds deferNext = time::nanoseconds(nrand48(seed) % pitEntryInfo->maxInterval.count());
+    boost::random::uniform_int_distribution<time::nanoseconds::rep> dist(
+      0, pitEntryInfo->maxInterval.count() - 1);
+    time::nanoseconds deferNext = time::nanoseconds(dist(getGlobalRng()));
     pitEntryInfo->propagateTimer = scheduler::schedule(deferNext,
     bind(&NccStrategy::doPropagate, this,
          weak_ptr<pit::Entry>(pitEntry), weak_ptr<fib::Entry>(fibEntry)));
diff --git a/daemon/table/cs.cpp b/daemon/table/cs.cpp
index ad666d5..f1bbb0f 100644
--- a/daemon/table/cs.cpp
+++ b/daemon/table/cs.cpp
@@ -27,11 +27,15 @@
 
 #include "cs.hpp"
 #include "core/logger.hpp"
+#include "core/random.hpp"
 #include <ndn-cxx/util/crypto.hpp>
-#include "ndn-cxx/security/signature-sha256-with-rsa.hpp"
+#include <ndn-cxx/security/signature-sha256-with-rsa.hpp>
+#include <boost/random/bernoulli_distribution.hpp>
 
-#define SKIPLIST_MAX_LAYERS 32
-#define SKIPLIST_PROBABILITY 25         // 25% (p = 1/4)
+/// max skip list layers
+static const size_t SKIPLIST_MAX_LAYERS = 32;
+/// probability for an entry in layer N to appear also in layer N+1
+static const double SKIPLIST_PROBABILITY = 0.25;
 
 NFD_LOG_INIT("ContentStore");
 
@@ -265,17 +269,15 @@
 size_t
 Cs::pickRandomLayer() const
 {
-  int layer = -1;
-  int randomValue;
-
-  do
-    {
-      layer++;
-      randomValue = rand() % 100 + 1;
+  static boost::random::bernoulli_distribution<> dist(SKIPLIST_PROBABILITY);
+  // TODO rewrite using geometry_distribution
+  size_t layer;
+  for (layer = 0; layer < SKIPLIST_MAX_LAYERS; ++layer) {
+    if (!dist(getGlobalRng())) {
+      break;
     }
-  while ((randomValue < SKIPLIST_PROBABILITY) && (layer < SKIPLIST_MAX_LAYERS));
-
-  return static_cast<size_t>(layer);
+  }
+  return layer;
 }
 
 bool