Maxim Integrated / Mbed 2 deprecated DeepCover Embedded Security in IoT

MAXREFDES143#: DeepCover Embedded Security in IoT Authenticated Sensing & Notification

Dependencies:   MaximInterface mbed

The MAXREFDES143# is an Internet of Things (IoT) embedded security reference design, built to protect an industrial sensing node by means of authentication and notification to a web server. The hardware includes a peripheral module representing a protected sensor node monitoring operating temperature and remaining life of a filter (simulated through ambient light sensing) and an mbed shield representing a controller node responsible for monitoring one or more sensor nodes. The design is hierarchical with each controller node communicating data from connected sensor nodes to a web server that maintains a centralized log and dispatches notifications as necessary. The mbed shield contains a Wi-Fi module, a DS2465 coprocessor with 1-Wire® master function, an LCD, LEDs, and pushbuttons. The protected sensor node contains a DS28E15 authenticator, a DS7505 temperature sensor, and a MAX44009 light sensor. The mbed shield communicates to a web server by the onboard Wi-Fi module and to the protected sensor node with I2C and 1-Wire. The MAXREFDES143# is equipped with a standard shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The simplicity of this design enables rapid integration into any star-topology IoT network requiring the heightened security with low overhead provided by the SHA-256 symmetric-key algorithm.

More information about the MAXREFDES143# is available on the Maxim Integrated website.

Diff: SensorNode.cpp

Revision:
32:0a09505a656d
Parent:
30:0784010d6975
--- a/SensorNode.cpp	Tue Apr 04 14:10:48 2017 -0500
+++ b/SensorNode.cpp	Mon Nov 06 17:34:13 2017 -0600
@@ -28,222 +28,217 @@
 * trademarks, maskwork rights, or any other form of intellectual
 * property whatsoever. Maxim Integrated Products, Inc. retains all
 * ownership rights.
-*******************************************************************************
-*/
+*******************************************************************************/
 
+#include <I2C.h>
+#include <MaximInterface/Devices/DS2465.hpp>
+#include <MaximInterface/Links/RomCommands.hpp>
+#include <MaximInterface/Platforms/mbed/Sleep.hpp>
 #include "SensorNode.hpp"
 #include "SensorData.hpp"
-#include "Masters/DS2465/DS2465.h"
-#include "RomId/RomCommands.h"
-#include "I2C.h"
 
 #ifdef TARGET_MAX32600
-#include "max32600.h"
-#include "clkman_regs.h"
-#include "tpu_regs.h"
+#include <max32600.h>
+#include <clkman_regs.h>
+#include <tpu_regs.h>
 #else
 #include <cstdlib>
 #endif
 
-using namespace OneWire;
-using namespace OneWire::RomCommands;
+using namespace MaximInterface;
 
+const ManId SensorNode::manId = {0, 0};
 bool SensorNode::rngInitialized = false;
 
-void SensorNode::initializeRng()
-{
+void SensorNode::initializeRng() {
 #ifdef TARGET_MAX32600
-  MXC_CLKMAN->clk_config |= (MXC_F_CLKMAN_CLK_CONFIG_CRYPTO_ENABLE | MXC_F_CLKMAN_CLK_CONFIG_CRYPTO_RESET_N); // Enable crypto oscillator
-  while ((MXC_CLKMAN->intfl & MXC_F_CLKMAN_INTFL_CRYPTO_STABLE) != MXC_F_CLKMAN_INTFL_CRYPTO_STABLE) ; // Wait for crypto oscillator stability
-  MXC_CLKMAN->clk_ctrl |= MXC_F_CLKMAN_CLK_CTRL_CRYPTO_GATE_N; // Disable crypto clock gating
-  MXC_CLKMAN->crypt_clk_ctrl_2_prng = MXC_CLKMAN->clk_ctrl_10_prng = 1; // Set PRNG clock to crypto clock
-  MXC_CLKMAN->clk_gate_ctrl2 |=  (1 << MXC_F_CLKMAN_CLK_GATE_CTRL2_TPU_CLK_GATER_POS); // Use dynamic clock gating
+  // Enable crypto oscillator
+  MXC_CLKMAN->clk_config |= (MXC_F_CLKMAN_CLK_CONFIG_CRYPTO_ENABLE |
+                             MXC_F_CLKMAN_CLK_CONFIG_CRYPTO_RESET_N);
+  // Wait for crypto oscillator stability
+  while ((MXC_CLKMAN->intfl & MXC_F_CLKMAN_INTFL_CRYPTO_STABLE) !=
+         MXC_F_CLKMAN_INTFL_CRYPTO_STABLE);
+  // Disable crypto clock gating
+  MXC_CLKMAN->clk_ctrl |= MXC_F_CLKMAN_CLK_CTRL_CRYPTO_GATE_N;
+  // Set PRNG clock to crypto clock
+  MXC_CLKMAN->crypt_clk_ctrl_2_prng = MXC_CLKMAN->clk_ctrl_10_prng = 1;
+  // Use dynamic clock gating
+  MXC_CLKMAN->clk_gate_ctrl2 |=
+      (1 << MXC_F_CLKMAN_CLK_GATE_CTRL2_TPU_CLK_GATER_POS);
 #endif
 }
 
-SensorNode::SensorNode(mbed::I2C & i2c, uint8_t ds7505_i2c_addr, uint8_t max44009_i2c_addr, DS2465 & ds2465)
-  : m_initialLux(1), ds2465(ds2465), selector(ds2465), ds28e15(selector), ds7505(i2c, ds7505_i2c_addr), max44009(i2c, max44009_i2c_addr)
-{
-  if (!rngInitialized)
-  {
+SensorNode::SensorNode(::mbed::I2C & i2c, uint8_t ds7505_i2c_addr,
+                       uint8_t max44009_i2c_addr, DS2465 & ds2465)
+    : initialLux_(1), ds2465(ds2465),
+      ds28e15(MaximInterface::mbed::Sleep::instance(), ds2465, &skipRom),
+      ds7505(i2c, ds7505_i2c_addr), max44009(i2c, max44009_i2c_addr) {
+  if (!rngInitialized) {
     initializeRng();
     rngInitialized = true;
   }
 }
 
-bool SensorNode::initializeSensors()
-{
-  return (max44009.read_current_lux(m_initialLux) == MAX44009::Success);
+bool SensorNode::initializeSensors() {
+  return (max44009.read_current_lux(initialLux_) == MAX44009::Success);
 }
 
-bool SensorNode::setSecret()
-{
-  DS28E15_22_25::Scratchpad scratchpad;
-  DS28E15_22_25::Page pageData;
-  
+bool SensorNode::setSecret() {
   // Create constant partial secret
+  DS28E15::Scratchpad scratchpad;
   scratchpad.fill(uint8_t(defaultPaddingByte));
-  // Read page data
-  bool result = (ds2465.readMemory(DS2465::UserMemoryPage0, pageData.data(), pageData.size(), false) == OneWireMaster::Success);
   // Calculate secret
-  if (result)
-  {
-    result = (DS28E15_22_25::computeNextSecret(ds2465, pageData, authData.pageNum, scratchpad, ds28e15.romId(), ds28e15.manId()) == ISha256MacCoproc::Success);
-  }
-  return result;
+  const Sha256::SlaveSecretData data = DS28E15::createSlaveSecretData(
+      DS28E15::Page(), authData.pageNum, scratchpad, romId_, manId);
+  return !ds2465.computeSlaveSecretWithSwap(data, 0, DS2465::FullPage);
 }
 
-bool SensorNode::checkProvisioned(bool & provisioned)
-{
-  DS28E15_22_25::BlockProtection protectionStatus;
+bool SensorNode::checkProvisioned(bool & provisioned) {
+  DS28E15::BlockProtection protectionStatus;
   bool result;
-  
-  
-  result = (ds28e15.readBlockProtection(0, protectionStatus) == OneWireSlave::Success);
-  if (result)
-  {
-    if (!protectionStatus.noProtection())
-    {
-      result = (ds28e15.readSegment(authData.pageNum, authData.segmentNum, authData.segment) == OneWireSlave::Success);
+
+  result = !ds28e15.readBlockProtection(0, protectionStatus);
+  if (result) {
+    if (!protectionStatus.noProtection()) {
+      result = !ds28e15.readSegment(authData.pageNum, authData.segmentNum,
+                                    authData.segment);
       if (result)
         provisioned = true;
-    }
-    else
-    {
+    } else {
       provisioned = false;
     }
   }
   return result;
 }
 
-bool SensorNode::checkAuthentic(unsigned int userEntropy)
-{
-  DS28E15_22_25::Scratchpad challenge;
-  DS28E15_22_25::Page pageData;
-  
+bool SensorNode::checkAuthentic(unsigned int userEntropy) {
+  DS28E15::Scratchpad challenge;
+  DS28E15::Page pageData;
+
   // Read page data
-  if (ds28e15.readPage(authData.pageNum, pageData, false) != OneWireSlave::Success)
+  if (ds28e15.readPage(authData.pageNum, pageData))
     return false;
-  
+
   // Create random challenge
   // Use hardare RNG on MAX32600
-#ifdef TARGET_MAX32600 
+#ifdef TARGET_MAX32600
   MXC_TPU->prng_user_entropy = userEntropy;
 #else
   std::srand(userEntropy);
 #endif
-  for (size_t i = 0; i < challenge.size(); i++)
-  {
+  for (size_t i = 0; i < challenge.size(); i++) {
 #ifdef TARGET_MAX32600
     challenge[i] = MXC_TPU->prng_rnd_num;
 #else
-    challenge[i] = std::rand(); 
+    challenge[i] = std::rand();
 #endif
   }
 
   // Write challenge to scratchpad
-  if (ds28e15.writeScratchpad(challenge) != OneWireSlave::Success)
+  if (ds28e15.writeScratchpad(challenge))
     return false;
   // Have device compute MAC
-  DS28E15_22_25::Mac nodeMac;
-  if (ds28e15.computeReadPageMac(0, false, nodeMac) != OneWireSlave::Success)
+  Sha256::Hash nodeMac;
+  if (ds28e15.computeReadPageMac(0, false, nodeMac))
     return false;
   // Compute expected MAC
-  DS28E15_22_25::Mac controllerMac;
-  if (DS28E15_22_25::computeAuthMac(ds2465, pageData, authData.pageNum, challenge, ds28e15.romId(), ds28e15.manId(), controllerMac) != ISha256MacCoproc::Success)
+  const Sha256::AuthMacData controllerMacData = DS28E15::createAuthMacData(
+      pageData, authData.pageNum, challenge, romId_, manId);
+  Sha256::Hash controllerMac;
+  if (ds2465.computeAuthMac(controllerMacData, controllerMac))
     return false;
   // Check if authentic
   return (nodeMac == controllerMac);
 }
 
-bool SensorNode::readSensorData(SensorData & sensorData)
-{
+bool SensorNode::readSensorData(SensorData & sensorData) {
   bool result;
   int8_t temp;
-  
+
   // Read temperature sensor
   result = (ds7505.read_current_temp(temp) == DS7505::Success);
-  
-  if (result)
-  {
+
+  if (result) {
     sensorData.temp = temp;
-    
+
     // Read light sensor
     double currentLux;
     result = (max44009.read_current_lux(currentLux) == MAX44009::Success);
-    if (result)
-    {
+    if (result) {
       // Convert lux to remaining filter life
-      sensorData.filterLife = (unsigned int)((currentLux / m_initialLux) * 100);
+      sensorData.filterLife =
+          static_cast<uint8_t>((currentLux / initialLux_) * 100);
     }
   }
-  
+
   return result;
 }
 
-bool SensorNode::checkAndWriteAuthData(SensorData & sensorData)
-{
+bool SensorNode::checkAndWriteAuthData(SensorData & sensorData) {
   bool result = true;
-  
-  if (sensorData.filterLife > authData.filterLife)
-  {
-    sensorData.filterLife = authData.filterLife;
+
+  if (sensorData.filterLife > authData.filterLife()) {
+    sensorData.filterLife = authData.filterLife();
+  } else if (sensorData.filterLife < authData.filterLife()) {
+    AuthData newAuthData = authData;
+    newAuthData.filterLife() = sensorData.filterLife;
+    const Sha256::WriteMacData macData = DS28E15::createSegmentWriteMacData(
+        authData.pageNum, authData.segmentNum, newAuthData.segment,
+        authData.segment, romId_, manId);
+    Sha256::Hash mac;
+    result = !ds2465.computeWriteMac(macData, mac);
+    if (result)
+      result = !ds28e15.writeAuthSegment(authData.pageNum, authData.segmentNum,
+                                         newAuthData.segment, mac);
+    if (result)
+      authData = newAuthData;
   }
-  else if (sensorData.filterLife < authData.filterLife)
-  {
-    AuthData oldAuthData(authData);
-    authData.filterLife = sensorData.filterLife;
-    // Write new filter life to DS28E15
-    result = (ds28e15.writeAuthSegment(ds2465, authData.pageNum, authData.segmentNum, authData.segment, oldAuthData.segment, false) == OneWireSlave::Success);
-  }
-  
+
   return result;
 }
 
-SensorNode::State SensorNode::detect(unsigned int userEntropy)
-{
+SensorNode::State SensorNode::detect(unsigned int userEntropy) {
   bool provisioned;
-  
-  ds2465.OWSetSpeed(DS2465::OverdriveSpeed);
-  
-  RomId romId;
-  if (OWReadRom(ds2465, romId) != OneWireMaster::Success)
+
+  ds2465.setSpeed(DS2465::OverdriveSpeed);
+
+  if (readRom(ds2465, romId_))
     return UnableToCommunicate;
-  ds28e15.setRomId(romId);
-  
+
   if (!checkProvisioned(provisioned))
     return UnableToCommunicate;
-  
+
   if (!provisioned)
-      return NotProvisioned;
-  
+    return NotProvisioned;
+
   if (!setSecret())
     return UnableToCommunicate;
-    
+
   if (!checkAuthentic(userEntropy))
     return NotAuthentic;
-  
+
   if (!initializeSensors())
     return UnableToCommunicate;
-  
+
   return Authentic;
 }
 
-SensorNode::State SensorNode::authenticatedReadSensorData(unsigned int userEntropy, SensorData & sensorData)
-{
-  ds2465.OWSetSpeed(DS2465::OverdriveSpeed);
-  
+SensorNode::State
+SensorNode::authenticatedReadSensorData(unsigned int userEntropy,
+                                        SensorData & sensorData) {
+  ds2465.setSpeed(DS2465::OverdriveSpeed);
+
   if (!setSecret())
     return UnableToCommunicate;
-  
+
   if (!checkAuthentic(userEntropy))
     return NotAuthentic;
-  
+
   if (!readSensorData(sensorData))
     return UnableToCommunicate;
-  
+
   if (!checkAndWriteAuthData(sensorData))
     return NotAuthentic;
-  
+
   return Authentic;
 }
\ No newline at end of file