Diff: WebServerInterface.cpp

Revision:

1:e1c7c1c636af

Child:

3:ac723be395d9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebServerInterface.cpp	Thu Apr 14 19:48:01 2016 +0000
@@ -0,0 +1,331 @@
+/*******************************************************************************
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************
+*/
+
+#include <vector>
+
+#include "WebServerInterface.hpp"
+#include "ESP8266.hpp"
+#include "OneWire_Masters/ISha256MacCoprocessor.hpp"
+#include "common.hpp"
+#include "mbed.h"
+
+const char WebServerInterface::wifiSsid[] = "WifiSsid";
+const char WebServerInterface::wifiPassword[] = "WifiPassword";
+const char WebServerInterface::serverAddress[] = "website.com";
+const char WebServerInterface::serverPostPath[] = "/post.php";
+const char WebServerInterface::serverChallengePath[] = "/challenge.php";
+
+// HTTP formatting constants
+static const char keyValSeparator = '=';
+static const char fieldSeparator = '&';
+static const std::string newline = "\r\n";
+static const char sessionIdKey[] = "SessionId";
+
+// Authentication MAC constants
+static const std::size_t challengeLen = 32;
+static const std::uint8_t defaultPaddingByte = 0x00;
+
+/// Select the Transport Secret for the web server in the Controller.
+/// @returns True on success.
+static bool setHttpPostSecret(ISha256MacCoprocessor & MacCoproc)
+{
+  ISha256MacCoprocessor::DevicePage fillData;
+  std::memset(fillData, defaultPaddingByte, fillData.length);
+  return (MacCoproc.computeSlaveSecret(fillData, fillData, reinterpret_cast<ISha256MacCoprocessor::SlaveSecretData &>(fillData)) == ISha256MacCoprocessor::Success);
+}
+
+WebServerInterface::WebServerInterface(ESP8266 & esp8266, mbed::Serial * pc)
+  : esp8266(esp8266), pc(pc)
+{
+  
+}
+
+bool WebServerInterface::initialize()
+{
+  esp8266.setPowered(true);
+  esp8266.reset();
+  bool result = (esp8266.performSelfTest() == ESP8266::AT_OK);
+  if (!result)
+  {
+    return false;
+  }
+  result = (esp8266.setCurrentWifiMode(ESP8266::softAP_station_mode) == ESP8266::AT_OK);
+  if (!result)
+  {
+    return false;
+  }
+  result = (esp8266.setMaxRFTXPower(10) == ESP8266::AT_OK);
+  if (!result)
+  {
+    return false;
+  }
+  result = (esp8266.joinCurrentAccessPoint(wifiSsid, wifiPassword) == ESP8266::AT_OK);
+  if (!result)
+  {
+    return false;
+  }
+  return true;
+}
+
+/// Format an HTTP GET request as a string for transmission.
+/// @param host Web server address.
+/// @param path Web server location to retrieve.
+/// @param sessionId Session ID used to identify this controller.
+/// @returns GET request string.
+static std::string formatHttpGet(const std::string & host, const std::string & path, const std::string & sessionId)
+{
+  std::ostringstream httpGetStream;
+  httpGetStream << "GET " << path;
+  if (sessionId.length() > 0)
+    httpGetStream << '?' << sessionIdKey << keyValSeparator << sessionId;
+  httpGetStream << " HTTP/1.1" << newline;
+  httpGetStream << "Host: " << host << newline;
+  httpGetStream << newline;
+  return httpGetStream.str();
+}
+
+/// Computes a MAC using the Transport Secret to sign HTTP POST requests.
+/// @param macCoproc Coprocessor such as the DS2465 used to calculate the authentication MAC.
+/// @param input Message array used for MAC calculation.
+/// @param ilen Length of array input.
+/// @param output Calculated MAC output.
+static void calculateHttpPostMac(const ISha256MacCoprocessor & macCoproc, const std::uint8_t * input, std::size_t ilen, ISha256MacCoprocessor::Mac & output)
+{
+  ISha256MacCoprocessor::DeviceScratchpad block;
+  std::size_t index = 0;
+  ISha256MacCoprocessor::AuthMacData padding;
+  std::memset(padding, defaultPaddingByte, padding.length);
+  std::memset(output, defaultPaddingByte, output.length); // Set initial hash value
+  while (index < ilen)
+  {
+    if ((index + block.length) <= ilen) // Full block
+    {
+      std::memcpy(block, &input[index], block.length);
+      index += block.length;
+    }
+    else // Partial block with padding
+    {
+      std::memcpy(block, &input[index], ilen - index);
+      std::memset(&block[ilen - index], defaultPaddingByte, block.length - (ilen - index));
+      index = ilen;
+    }
+    // Write data to coprocessor and hash block
+    macCoproc.computeAuthMac(output, block, padding, output);
+  }
+}
+
+/// Format an HTTP POST request as a string for transmission.
+/// @param host Web server address.
+/// @param path Web server location to receive POST.
+/// @param sessionId Session ID used to identify this Controller.
+/// @param macCoproc Coprocessor such as the DS2465 used to calculate the authentication MAC.
+/// @param event Event message type.
+/// @param initialPostBody Message body as determined by the event message type.
+/// @param challenge Challenge previously received from web server for use in authentication MAC.
+/// @returns POST request string.
+static std::string formatHttpPost(const std::string & host, const std::string & path, const std::string & sessionId,
+                                  const ISha256MacCoprocessor & macCoproc, PostEvent event, const std::string & initialPostBody,
+                                  const std::uint8_t (&challenge)[challengeLen])
+{
+  const std::size_t headerReserve = 115, bodyReserve = 200;
+  
+  std::string httpPost;
+  httpPost.reserve(initialPostBody.length() + headerReserve + bodyReserve);
+  
+  // Add session ID to post body
+  if (sessionId.length() > 0)
+  {
+    httpPost += sessionIdKey;
+    httpPost += keyValSeparator;
+    httpPost += sessionId;
+  }
+  
+  // Add event to post body
+  std::string eventString;
+  switch (event)
+  {
+  case SensorDataEvent:
+    eventString = "SensorData";
+    break;
+    
+  case InvalidSensorEvent:
+    eventString = "InvalidSensor";
+    break;
+  }
+  if (eventString.length() > 0)
+  {
+    if (httpPost.length() > 0)
+      httpPost += fieldSeparator;
+    httpPost += "Event";
+    httpPost += keyValSeparator;
+    httpPost += eventString;
+  }
+  
+  // Add initial post body
+  if (initialPostBody.length() > 0)
+  {
+    if (httpPost.length() > 0)
+      httpPost += fieldSeparator;
+    httpPost += initialPostBody;
+  }
+  
+  // Combine initial post body with initial secret and hash
+  std::vector<std::uint8_t> hashInput;
+  hashInput.reserve(challengeLen + httpPost.length());
+  hashInput.insert(hashInput.end(), challenge, challenge + challengeLen);
+  hashInput.insert(hashInput.end(), httpPost.begin(), httpPost.end());
+  ISha256MacCoprocessor::Mac mac;
+  calculateHttpPostMac(macCoproc, &hashInput[0], hashInput.size(), mac);
+  
+  char contentLen[5];
+  std::snprintf(contentLen, sizeof(contentLen) / sizeof(char), "%u", (hashInput.size() - challengeLen) + (mac.length * charsPerByte) + 5 /* &MAC= */);
+  
+  // Construct full post request
+  httpPost = "";
+  httpPost += "POST ";
+  httpPost += path;
+  httpPost += " HTTP/1.1";
+  httpPost += newline;
+  httpPost += "Host: ";
+  httpPost += host;
+  httpPost += newline;
+  httpPost += "Accept: */*";
+  httpPost += newline;
+  httpPost += "Content-Length: ";
+  httpPost += contentLen;
+  httpPost += newline;
+  httpPost += "Content-Type: application/x-www-form-urlencoded";
+  httpPost += newline;
+  httpPost += newline;
+  // Add post body
+  httpPost.append(reinterpret_cast<char *>(&hashInput[challengeLen]), hashInput.size() - challengeLen);
+  // Convert hash to hex string and add to post body
+  httpPost += fieldSeparator;
+  httpPost += "MAC";
+  httpPost += keyValSeparator;
+  byteArrayToHexString(mac, mac.length, httpPost);
+  httpPost += newline;
+  
+  return httpPost;
+}
+
+bool WebServerInterface::authPostHttpEvent(ISha256MacCoprocessor & macCoproc, PostEvent event, const std::string & postData, bool setSecret)
+{
+  const std::string challengeSearch(newline + newline);
+  bool result;
+  std::uint8_t challenge[challengeLen];
+  std::string response;
+  
+  std::memset(challenge, defaultPaddingByte, challengeLen);
+  response.reserve(300);
+  
+  if (setSecret)
+  {
+    result = setHttpPostSecret(macCoproc);
+    if (!result)
+      return result;
+  }
+  
+  // Open connection
+  esp8266.clearRecvData(); // Clear received data buffer
+  result = (esp8266.openConnection(ESP8266::TCP, serverAddress, 80) == ESP8266::AT_OK);
+  if (result)
+  {
+    // Request challenge
+    result = (esp8266.sendData(formatHttpGet(serverAddress, serverChallengePath, sessionId)) == ESP8266::AT_OK);
+    if (result)
+    {
+      // Receive server response
+      for (int i = 0; i < 10; i++)
+      {
+        while (esp8266.recvIpDataReadable())
+        {
+          char read = esp8266.getcRecvIpData();
+          if (pc != NULL)
+            pc->putc(read);
+          if (response.length() < response.capacity())
+          {
+            response += read;
+          }
+          else
+          {
+            wait_ms(ESP8266::sendDataRecoveryTimeMs); // Wait for ESP8266 specified recovery time
+            goto close_get_connection;
+          }
+        }
+        wait_ms(100);
+      }
+      // Close connection
+    close_get_connection:
+      esp8266.closeConnection();
+      
+      // Parse challenge from response
+      std::size_t challengePos = response.find(challengeSearch);
+      if ((challengePos != std::string::npos) && ((challengePos + challengeSearch.length() + (challengeLen * charsPerByte)) <= response.length()))
+      {
+        challengePos += challengeSearch.length();
+        for (std::size_t i = 0; i < challengeLen; i++)
+        {
+          std::sscanf(response.substr(challengePos + (i * charsPerByte), charsPerByte).c_str(), "%2hhx", &challenge[i]);
+        }
+      }
+      
+      // Post sensor data
+      result = (esp8266.openConnection(ESP8266::TCP, serverAddress, 80) == ESP8266::AT_OK);
+      if (result)
+      {
+        result = (esp8266.sendData(formatHttpPost(serverAddress, serverPostPath, sessionId, macCoproc, event, postData, challenge)) == ESP8266::AT_OK);
+        wait_ms(ESP8266::sendDataRecoveryTimeMs); // Wait for ESP8266 specified recovery time
+      }
+    }
+    
+    // Close connection
+    esp8266.closeConnection();
+  }
+  
+  return result;
+}
+
+std::string WebServerInterface::formatSensorDataPostBody(const SensorData & sensorData)
+{
+  // Create initial post body string from input data
+  std::ostringstream postBodyStream;
+  postBodyStream << "Temp" << keyValSeparator << static_cast<int>(sensorData.temp);
+  postBodyStream << fieldSeparator;
+  postBodyStream << "FilterLife" << keyValSeparator << static_cast<unsigned>(sensorData.filterLife);
+  postBodyStream << fieldSeparator;
+  postBodyStream << "TempAlarm" << keyValSeparator << (sensorData.tempAlarm() ? "true" : "false");
+  postBodyStream << fieldSeparator;
+  postBodyStream << "FilterLifeAlarm" << keyValSeparator << (sensorData.filterLifeAlarm() ? "true" : "false");
+  return postBodyStream.str();
+}
\ No newline at end of file