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.

Revision:
28:e5cdaf13d299
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/esp8266-driver/ESP8266/ESP8266.cpp	Thu Jan 26 14:18:21 2017 -0600
@@ -0,0 +1,302 @@
+/* ESP8266 Example
+ * Copyright (c) 2015 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ESP8266.h"
+
+ESP8266::ESP8266(PinName tx, PinName rx, bool debug)
+    : _serial(tx, rx, 1024), _parser(_serial)
+    , _packets(0), _packets_end(&_packets)
+{
+    _serial.baud(38400);
+    _parser.debugOn(debug);
+}
+
+bool ESP8266::startup(int mode)
+{
+    //only 3 valid modes
+    if(mode < 1 || mode > 3) {
+        return false;
+    }
+
+    bool success = reset()
+        && _parser.send("AT+RFPOWER=10")
+        && _parser.recv("OK")
+        && _parser.send("AT+CWMODE_CUR=%d", mode)
+        && _parser.recv("OK")
+        && _parser.send("AT+CIPMUX=1")
+        && _parser.recv("OK");
+
+    _parser.oob("+IPD", this, &ESP8266::_packet_handler);
+
+    return success;
+}
+
+bool ESP8266::reset(void)
+{
+    return _parser.send("AT+RST")
+            && _parser.recv("ready");
+}
+
+bool ESP8266::dhcp(bool enabled, int mode)
+{
+    //only 3 valid modes
+    if(mode < 0 || mode > 2) {
+        return false;
+    }
+
+    return _parser.send("AT+CWDHCP_CUR=%d,%d", enabled?1:0, mode)
+        && _parser.recv("OK");
+}
+
+bool ESP8266::connect(const char *ap, const char *passPhrase)
+{
+    return _parser.send("AT+CWJAP_CUR=\"%s\",\"%s\"", ap, passPhrase)
+        && _parser.recv("OK");
+}
+
+bool ESP8266::disconnect(void)
+{
+    return _parser.send("AT+CWQAP") && _parser.recv("OK");
+}
+
+const char *ESP8266::getIPAddress(void)
+{
+    if (!(_parser.send("AT+CIFSR")
+        && _parser.recv("+CIFSR:STAIP,\"%15[^\"]\"", _ip_buffer)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    return _ip_buffer;
+}
+
+const char *ESP8266::getMACAddress(void)
+{
+    if (!(_parser.send("AT+CIFSR")
+        && _parser.recv("+CIFSR:STAMAC,\"%17[^\"]\"", _mac_buffer)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    return _mac_buffer;
+}
+
+const char *ESP8266::getGateway()
+{
+    if (!(_parser.send("AT+CIPSTA?")
+        && _parser.recv("+CIPSTA:gateway:\"%15[^\"]\"", _gateway_buffer)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    return _gateway_buffer;
+}
+
+const char *ESP8266::getNetmask()
+{
+    if (!(_parser.send("AT+CIPSTA?")
+        && _parser.recv("+CIPSTA:netmask:\"%15[^\"]\"", _netmask_buffer)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    return _netmask_buffer;
+}
+
+int8_t ESP8266::getRSSI()
+{
+    int8_t rssi;
+    char bssid[18];
+
+   if (!(_parser.send("AT+CWJAP?")
+        && _parser.recv("+CWJAP:\"%*[^\"]\",\"%17[^\"]\"", bssid)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    if (!(_parser.send("AT+CWLAP=\"\",\"%s\",", bssid)
+        && _parser.recv("+CWLAP:(%*d,\"%*[^\"]\",%hhd,", &rssi)
+        && _parser.recv("OK"))) {
+        return 0;
+    }
+
+    return rssi;
+}
+
+bool ESP8266::isConnected(void)
+{
+    return getIPAddress() != 0;
+}
+
+int ESP8266::scan(WiFiAccessPoint *res, unsigned limit)
+{
+    unsigned cnt = 0;
+    nsapi_wifi_ap_t ap;
+
+    if (!_parser.send("AT+CWLAP")) {
+        return NSAPI_ERROR_DEVICE_ERROR;
+    }
+
+    while (recv_ap(&ap)) {
+        if (cnt < limit) {
+            res[cnt] = WiFiAccessPoint(ap);
+        }
+
+        cnt++;
+        if (limit != 0 && cnt >= limit) {
+            break;
+        }
+    }
+
+    return cnt;
+}
+
+bool ESP8266::open(const char *type, int id, const char* addr, int port)
+{
+    //IDs only 0-4
+    if(id > 4) {
+        return false;
+    }
+
+    return _parser.send("AT+CIPSTART=%d,\"%s\",\"%s\",%d", id, type, addr, port)
+        && _parser.recv("OK");
+}
+
+bool ESP8266::send(int id, const void *data, uint32_t amount)
+{
+    //May take a second try if device is busy
+    for (unsigned i = 0; i < 2; i++) {
+        if (_parser.send("AT+CIPSEND=%d,%d", id, amount)
+            && _parser.recv(">")
+            && _parser.write((char*)data, (int)amount) >= 0) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+void ESP8266::_packet_handler()
+{
+    int id;
+    uint32_t amount;
+
+    // parse out the packet
+    if (!_parser.recv(",%d,%d:", &id, &amount)) {
+        return;
+    }
+
+    struct packet *packet = (struct packet*)malloc(
+            sizeof(struct packet) + amount);
+    if (!packet) {
+        return;
+    }
+
+    packet->id = id;
+    packet->len = amount;
+    packet->next = 0;
+
+    if (!(_parser.read((char*)(packet + 1), amount))) {
+        free(packet);
+        return;
+    }
+
+    // append to packet list
+    *_packets_end = packet;
+    _packets_end = &packet->next;
+}
+
+int32_t ESP8266::recv(int id, void *data, uint32_t amount)
+{
+    while (true) {
+        // check if any packets are ready for us
+        for (struct packet **p = &_packets; *p; p = &(*p)->next) {
+            if ((*p)->id == id) {
+                struct packet *q = *p;
+
+                if (q->len <= amount) { // Return and remove full packet
+                    memcpy(data, q+1, q->len);
+
+                    if (_packets_end == &(*p)->next) {
+                        _packets_end = p;
+                    }
+                    *p = (*p)->next;
+
+                    uint32_t len = q->len;
+                    free(q);
+                    return len;
+                } else { // return only partial packet
+                    memcpy(data, q+1, amount);
+
+                    q->len -= amount;
+                    memmove(q+1, (uint8_t*)(q+1) + amount, q->len);
+
+                    return amount;
+                }
+            }
+        }
+
+        // Wait for inbound packet
+        if (!_parser.recv("OK")) {
+            return -1;
+        }
+    }
+}
+
+bool ESP8266::close(int id)
+{
+    //May take a second try if device is busy
+    for (unsigned i = 0; i < 2; i++) {
+        if (_parser.send("AT+CIPCLOSE=%d", id)
+            && _parser.recv("OK")) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+void ESP8266::setTimeout(uint32_t timeout_ms)
+{
+    _parser.setTimeout(timeout_ms);
+}
+
+bool ESP8266::readable()
+{
+    return _serial.readable();
+}
+
+bool ESP8266::writeable()
+{
+    return _serial.writeable();
+}
+
+void ESP8266::attach(Callback<void()> func)
+{
+    _serial.attach(func);
+}
+
+bool ESP8266::recv_ap(nsapi_wifi_ap_t *ap)
+{
+    int sec;
+    bool ret = _parser.recv("+CWLAP:(%d,\"%32[^\"]\",%hhd,\"%hhx:%hhx:%hhx:%hhx:%hhx:%hhx\",%d", &sec, ap->ssid,
+                            &ap->rssi, &ap->bssid[0], &ap->bssid[1], &ap->bssid[2], &ap->bssid[3], &ap->bssid[4],
+                            &ap->bssid[5], &ap->channel);
+
+    ap->security = sec < 5 ? (nsapi_security_t)sec : NSAPI_SECURITY_UNKNOWN;
+
+    return ret;
+}