From 32e308833c957dc6a867662bb118874ba72885a5 Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@google.com>
Date: Thu, 16 Apr 2020 13:50:38 -0700
Subject: [PATCH] [random] use crypto RNG in places were non-trival random is
 required (#4840)

---
 src/core/coap/coap_message.cpp   | 2 +-
 src/core/mac/mac_types.cpp       | 4 +++-
 src/core/mac/mac_types.hpp       | 4 ++++
 src/core/net/dhcp6_client.cpp    | 2 +-
 src/core/thread/mle.cpp          | 8 ++++----
 src/core/utils/slaac_address.cpp | 4 ++--
 6 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/core/coap/coap_message.cpp b/src/core/coap/coap_message.cpp
index 838a060ac..b5ea2a1bd 100644
--- a/src/core/coap/coap_message.cpp
+++ b/src/core/coap/coap_message.cpp
@@ -286,7 +286,7 @@ otError Message::SetToken(uint8_t aTokenLength)
 
     OT_ASSERT(aTokenLength <= sizeof(token));
 
-    Random::NonCrypto::FillBuffer(token, aTokenLength);
+    Random::Crypto::FillBuffer(token, aTokenLength);
 
     return SetToken(token, aTokenLength);
 }
diff --git a/src/core/mac/mac_types.cpp b/src/core/mac/mac_types.cpp
index 65703fac5..c06c9c859 100644
--- a/src/core/mac/mac_types.cpp
+++ b/src/core/mac/mac_types.cpp
@@ -54,12 +54,14 @@ PanId GenerateRandomPanId(void)
     return panId;
 }
 
+#if !OPENTHREAD_RADIO
 void ExtAddress::GenerateRandom(void)
 {
-    Random::NonCrypto::FillBuffer(m8, sizeof(ExtAddress));
+    Random::Crypto::FillBuffer(m8, sizeof(ExtAddress));
     SetGroup(false);
     SetLocal(true);
 }
+#endif
 
 bool ExtAddress::operator==(const ExtAddress &aOther) const
 {
diff --git a/src/core/mac/mac_types.hpp b/src/core/mac/mac_types.hpp
index f38828ea0..2d3e6a0a5 100644
--- a/src/core/mac/mac_types.hpp
+++ b/src/core/mac/mac_types.hpp
@@ -73,6 +73,8 @@ typedef otPanId PanId;
  */
 typedef otShortAddress ShortAddress;
 
+#if !OPENTHREAD_RADIO
+
 /**
  * This function generates a random IEEE 802.15.4 PAN ID.
  *
@@ -81,6 +83,8 @@ typedef otShortAddress ShortAddress;
  */
 PanId GenerateRandomPanId(void);
 
+#endif
+
 /**
  * This structure represents an IEEE 802.15.4 Extended Address.
  *
diff --git a/src/core/net/dhcp6_client.cpp b/src/core/net/dhcp6_client.cpp
index d4e7e8ed1..e84df5ead 100644
--- a/src/core/net/dhcp6_client.cpp
+++ b/src/core/net/dhcp6_client.cpp
@@ -202,7 +202,7 @@ bool Dhcp6Client::ProcessNextIdentityAssociation()
         }
 
         // new transaction id
-        Random::NonCrypto::FillBuffer(mTransactionId, kTransactionIdSize);
+        Random::Crypto::FillBuffer(mTransactionId, kTransactionIdSize);
 
         mIdentityAssociationCurrent = &mIdentityAssociations[i];
 
diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index f8cbd7d03..fb29fab59 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -190,8 +190,8 @@ Mle::Mle(Instance &aInstance)
 
     // mesh-local 64
     mMeshLocal64.Clear();
-    Random::NonCrypto::FillBuffer(mMeshLocal64.GetAddress().mFields.m8 + OT_IP6_PREFIX_SIZE,
-                                  OT_IP6_ADDRESS_SIZE - OT_IP6_PREFIX_SIZE);
+    Random::Crypto::FillBuffer(mMeshLocal64.GetAddress().mFields.m8 + OT_IP6_PREFIX_SIZE,
+                               OT_IP6_ADDRESS_SIZE - OT_IP6_PREFIX_SIZE);
 
     mMeshLocal64.mPrefixLength       = MeshLocalPrefix::kLength;
     mMeshLocal64.mPreferred          = true;
@@ -1555,8 +1555,8 @@ void Mle::HandleStateChanged(otChangedFlags aFlags)
         if (!Get<ThreadNetif>().IsUnicastAddress(mMeshLocal64.GetAddress()))
         {
             // Mesh Local EID was removed, choose a new one and add it back
-            Random::NonCrypto::FillBuffer(mMeshLocal64.GetAddress().mFields.m8 + OT_IP6_PREFIX_SIZE,
-                                          OT_IP6_ADDRESS_SIZE - OT_IP6_PREFIX_SIZE);
+            Random::Crypto::FillBuffer(mMeshLocal64.GetAddress().mFields.m8 + OT_IP6_PREFIX_SIZE,
+                                       OT_IP6_ADDRESS_SIZE - OT_IP6_PREFIX_SIZE);
 
             Get<ThreadNetif>().AddUnicastAddress(mMeshLocal64);
             Get<Notifier>().Signal(OT_CHANGED_THREAD_ML_ADDR);
diff --git a/src/core/utils/slaac_address.cpp b/src/core/utils/slaac_address.cpp
index b31c4dfa4..b60b00447 100644
--- a/src/core/utils/slaac_address.cpp
+++ b/src/core/utils/slaac_address.cpp
@@ -298,7 +298,7 @@ void Slaac::GenerateIid(Ip6::NetifUnicastAddress &aAddress) const
     }
 
     otLogWarnUtil("SLAAC: Failed to generate a non-reserved IID after %d attempts", dadCounter);
-    Random::NonCrypto::FillBuffer(hash, Ip6::Address::kInterfaceIdentifierSize);
+    Random::Crypto::FillBuffer(hash, Ip6::Address::kInterfaceIdentifierSize);
     aAddress.GetAddress().SetIid(&hash[0]);
 
 exit:
@@ -319,7 +319,7 @@ void Slaac::GetIidSecretKey(IidSecretKey &aKey) const
 
     if (error != OT_ERROR_NONE)
     {
-        Random::NonCrypto::FillBuffer(aKey.m8, sizeof(IidSecretKey));
+        Random::Crypto::FillBuffer(aKey.m8, sizeof(IidSecretKey));
     }
 
     Get<Settings>().SaveSlaacIidSecretKey(aKey);