Maxim Integrated / Mbed OS MAXREFDES155#

DeepCover Embedded Security in IoT: Public-key Secured Data Paths

Dependencies:   MaximInterface

The MAXREFDES155# is an internet-of-things (IoT) embedded-security reference design, built to authenticate and control a sensing node using elliptic-curve-based public-key cryptography with control and notification from a web server.

The hardware includes an ARM® mbed™ shield and attached sensor endpoint. The shield contains a DS2476 DeepCover® ECDSA/SHA-2 coprocessor, Wifi communication, LCD push-button controls, and status LEDs. The sensor endpoint is attached to the shield using a 300mm cable and contains a DS28C36 DeepCover ECDSA/SHA-2 authenticator, IR-thermal sensor, and aiming laser for the IR sensor. The MAXREFDES155# is equipped with a standard Arduino® form-factor shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The combination of these two devices represent an IoT device. Communication to the web server is accomplished with the shield Wifi circuitry. Communication from the shield to the attached sensor module is accomplished over I2C . The sensor module represents an IoT endpoint that generates small data with a requirement for message authenticity/integrity and secure on/off operational control.

The design is hierarchical with each mbed platform and shield communicating data from the sensor node to a web server that maintains a centralized log and dispatches notifications as necessary. The simplicity of this design enables rapid integration into any star-topology IoT network to provide security with the low overhead and cost provided by the ECDSA-P256 asymmetric-key and SHA-256 symmetric-key algorithms.

More information about the MAXREFDES155# is available on the Maxim Integrated website.

SensorNode.cpp@0:33d4e66780c0, 2017-02-24 (annotated)

Committer:
IanBenzMaxim
Date:
Fri Feb 24 11:23:12 2017 -0600
Revision:
0:33d4e66780c0
Child:
13:6a6225690c2e
Initial commit.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 0:33d4e66780c0 1 /*******************************************************************************
IanBenzMaxim 0:33d4e66780c0 2 * Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
IanBenzMaxim 0:33d4e66780c0 3 *
IanBenzMaxim 0:33d4e66780c0 4 * Permission is hereby granted, free of charge, to any person obtaining a
IanBenzMaxim 0:33d4e66780c0 5 * copy of this software and associated documentation files (the "Software"),
IanBenzMaxim 0:33d4e66780c0 6 * to deal in the Software without restriction, including without limitation
IanBenzMaxim 0:33d4e66780c0 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
IanBenzMaxim 0:33d4e66780c0 8 * and/or sell copies of the Software, and to permit persons to whom the
IanBenzMaxim 0:33d4e66780c0 9 * Software is furnished to do so, subject to the following conditions:
IanBenzMaxim 0:33d4e66780c0 10 *
IanBenzMaxim 0:33d4e66780c0 11 * The above copyright notice and this permission notice shall be included
IanBenzMaxim 0:33d4e66780c0 12 * in all copies or substantial portions of the Software.
IanBenzMaxim 0:33d4e66780c0 13 *
IanBenzMaxim 0:33d4e66780c0 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
IanBenzMaxim 0:33d4e66780c0 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
IanBenzMaxim 0:33d4e66780c0 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IanBenzMaxim 0:33d4e66780c0 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
IanBenzMaxim 0:33d4e66780c0 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
IanBenzMaxim 0:33d4e66780c0 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
IanBenzMaxim 0:33d4e66780c0 20 * OTHER DEALINGS IN THE SOFTWARE.
IanBenzMaxim 0:33d4e66780c0 21 *
IanBenzMaxim 0:33d4e66780c0 22 * Except as contained in this notice, the name of Maxim Integrated
IanBenzMaxim 0:33d4e66780c0 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
IanBenzMaxim 0:33d4e66780c0 24 * Products, Inc. Branding Policy.
IanBenzMaxim 0:33d4e66780c0 25 *
IanBenzMaxim 0:33d4e66780c0 26 * The mere transfer of this software does not imply any licenses
IanBenzMaxim 0:33d4e66780c0 27 * of trade secrets, proprietary technology, copyrights, patents,
IanBenzMaxim 0:33d4e66780c0 28 * trademarks, maskwork rights, or any other form of intellectual
IanBenzMaxim 0:33d4e66780c0 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
IanBenzMaxim 0:33d4e66780c0 30 * ownership rights.
IanBenzMaxim 0:33d4e66780c0 31 *******************************************************************************/
IanBenzMaxim 0:33d4e66780c0 32
IanBenzMaxim 0:33d4e66780c0 33 #include <string>
IanBenzMaxim 0:33d4e66780c0 34 #include <I2C.h>
IanBenzMaxim 0:33d4e66780c0 35 #include "RomId.h"
IanBenzMaxim 0:33d4e66780c0 36 #include "HexConversions.hpp"
IanBenzMaxim 0:33d4e66780c0 37 #include "DS2476.hpp"
IanBenzMaxim 0:33d4e66780c0 38 #include "Factory.hpp"
IanBenzMaxim 0:33d4e66780c0 39 #include "SensorNode.hpp"
IanBenzMaxim 0:33d4e66780c0 40
IanBenzMaxim 0:33d4e66780c0 41 // I2C address of the MLX90614.
IanBenzMaxim 0:33d4e66780c0 42 static const uint8_t mlx90614Addr = 0xB4;
IanBenzMaxim 0:33d4e66780c0 43
IanBenzMaxim 0:33d4e66780c0 44 /// DS2476 derives the slave secret for a certain DS28C36 from the master secret.
IanBenzMaxim 0:33d4e66780c0 45 /// @param ds2476 DS2476 that will compute slave secret.
IanBenzMaxim 0:33d4e66780c0 46 /// @param ds28c36 DS28C36 containing the slave secret of interest.
IanBenzMaxim 0:33d4e66780c0 47 /// @param[out] message Contains the HMAC input used when computing the slave secret. Output to
IanBenzMaxim 0:33d4e66780c0 48 /// prevent redundant page reads.
IanBenzMaxim 0:33d4e66780c0 49 /// @param print Optional callback for displaying informational messages to the user.
IanBenzMaxim 0:33d4e66780c0 50 /// @returns True if the operation was successful.
IanBenzMaxim 0:33d4e66780c0 51 static bool setSlaveSecret(DS2476 & ds2476, DS28C36 & ds28c36, DS2476::Buffer & message,
IanBenzMaxim 0:33d4e66780c0 52 const SensorNode::PrintHandler & print = SensorNode::PrintHandler())
IanBenzMaxim 0:33d4e66780c0 53 {
IanBenzMaxim 0:33d4e66780c0 54 if (print)
IanBenzMaxim 0:33d4e66780c0 55 {
IanBenzMaxim 0:33d4e66780c0 56 print("Computing slave secret");
IanBenzMaxim 0:33d4e66780c0 57 print("Reading DS28C36 ROM Options page for ROM ID and MAN ID");
IanBenzMaxim 0:33d4e66780c0 58 }
IanBenzMaxim 0:33d4e66780c0 59 DS28C36::Page page;
IanBenzMaxim 0:33d4e66780c0 60 DS28C36::CmdResult result = ds28c36.readMemory(DS28C36::RomOptions, page);
IanBenzMaxim 0:33d4e66780c0 61 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 62 return false;
IanBenzMaxim 0:33d4e66780c0 63 message.clear();
IanBenzMaxim 0:33d4e66780c0 64 message.reserve(75);
IanBenzMaxim 0:33d4e66780c0 65 message.assign(page.begin() + 24, page.end());
IanBenzMaxim 0:33d4e66780c0 66 OneWire::array<uint8_t, 2> manId = { page[22], page[23] };
IanBenzMaxim 0:33d4e66780c0 67 if (print)
IanBenzMaxim 0:33d4e66780c0 68 {
IanBenzMaxim 0:33d4e66780c0 69 print("Reading User Data 0 page");
IanBenzMaxim 0:33d4e66780c0 70 }
IanBenzMaxim 0:33d4e66780c0 71 result = ds28c36.readMemory(DS28C36::UserData0, page);
IanBenzMaxim 0:33d4e66780c0 72 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 73 return false;
IanBenzMaxim 0:33d4e66780c0 74 message.insert(message.end(), page.begin(), page.end());
IanBenzMaxim 0:33d4e66780c0 75 message.insert(message.end(), 32, 0x00);
IanBenzMaxim 0:33d4e66780c0 76 message.insert(message.end(), DS28C36::UserData0);
IanBenzMaxim 0:33d4e66780c0 77 message.insert(message.end(), manId.begin(), manId.end());
IanBenzMaxim 0:33d4e66780c0 78 if (print)
IanBenzMaxim 0:33d4e66780c0 79 {
IanBenzMaxim 0:33d4e66780c0 80 print(("Creating HMAC message (ROM ID | Binding Data (Page Data) | Partial Secret (Buffer) | Page # | MAN ID): " +
IanBenzMaxim 0:33d4e66780c0 81 byteArrayToHexString(&message[0], message.size())).c_str());
IanBenzMaxim 0:33d4e66780c0 82 print("Writing HMAC message to DS2476 buffer");
IanBenzMaxim 0:33d4e66780c0 83 }
IanBenzMaxim 0:33d4e66780c0 84 result = ds2476.writeBuffer(message);
IanBenzMaxim 0:33d4e66780c0 85 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 86 return false;
IanBenzMaxim 0:33d4e66780c0 87 if (print)
IanBenzMaxim 0:33d4e66780c0 88 {
IanBenzMaxim 0:33d4e66780c0 89 print("DS2476 computes slave secret from master secret (Secret A) and message in buffer");
IanBenzMaxim 0:33d4e66780c0 90 }
IanBenzMaxim 0:33d4e66780c0 91 result = ds2476.computeSha2UniqueSecret(DS2476::SecretNumA);
IanBenzMaxim 0:33d4e66780c0 92 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 93 return false;
IanBenzMaxim 0:33d4e66780c0 94 return true;
IanBenzMaxim 0:33d4e66780c0 95 }
IanBenzMaxim 0:33d4e66780c0 96
IanBenzMaxim 0:33d4e66780c0 97 SensorNode::SensorNode(mbed::I2C & i2c, DS2476 & ds2476) : i2c(i2c), ds28c36(i2c), ds2476(ds2476) { }
IanBenzMaxim 0:33d4e66780c0 98
IanBenzMaxim 0:33d4e66780c0 99 bool SensorNode::detect()
IanBenzMaxim 0:33d4e66780c0 100 {
IanBenzMaxim 0:33d4e66780c0 101 // Read ROM ID
IanBenzMaxim 0:33d4e66780c0 102 OneWire::RomId romId;
IanBenzMaxim 0:33d4e66780c0 103 return (DS28C36::readRomId(ds28c36, romId) == DS28C36::Success) && romId.valid();
IanBenzMaxim 0:33d4e66780c0 104 }
IanBenzMaxim 0:33d4e66780c0 105
IanBenzMaxim 0:33d4e66780c0 106 bool SensorNode::readTemp(TempStyle style, double & temp)
IanBenzMaxim 0:33d4e66780c0 107 {
IanBenzMaxim 0:33d4e66780c0 108 uint8_t data[2];
IanBenzMaxim 0:33d4e66780c0 109 switch (style)
IanBenzMaxim 0:33d4e66780c0 110 {
IanBenzMaxim 0:33d4e66780c0 111 case ObjectTemp:
IanBenzMaxim 0:33d4e66780c0 112 default:
IanBenzMaxim 0:33d4e66780c0 113 data[0] = 0x07;
IanBenzMaxim 0:33d4e66780c0 114 break;
IanBenzMaxim 0:33d4e66780c0 115
IanBenzMaxim 0:33d4e66780c0 116 case AmbientTemp:
IanBenzMaxim 0:33d4e66780c0 117 data[0] = 0x06;
IanBenzMaxim 0:33d4e66780c0 118 break;
IanBenzMaxim 0:33d4e66780c0 119 }
IanBenzMaxim 0:33d4e66780c0 120 int result = i2c.write(mlx90614Addr, reinterpret_cast<const char *>(data), 1, true);
IanBenzMaxim 0:33d4e66780c0 121 if (result != 0)
IanBenzMaxim 0:33d4e66780c0 122 {
IanBenzMaxim 0:33d4e66780c0 123 i2c.stop();
IanBenzMaxim 0:33d4e66780c0 124 return false;
IanBenzMaxim 0:33d4e66780c0 125 }
IanBenzMaxim 0:33d4e66780c0 126 result = i2c.read(mlx90614Addr, reinterpret_cast<char *>(data), 2, false);
IanBenzMaxim 0:33d4e66780c0 127 if (result != 0)
IanBenzMaxim 0:33d4e66780c0 128 {
IanBenzMaxim 0:33d4e66780c0 129 i2c.stop();
IanBenzMaxim 0:33d4e66780c0 130 return false;
IanBenzMaxim 0:33d4e66780c0 131 }
IanBenzMaxim 0:33d4e66780c0 132 temp = ((static_cast<uint_fast16_t>(data[1]) << 8) | data[0]) * 0.02 - 273.15;
IanBenzMaxim 0:33d4e66780c0 133 return true;
IanBenzMaxim 0:33d4e66780c0 134 }
IanBenzMaxim 0:33d4e66780c0 135
IanBenzMaxim 0:33d4e66780c0 136 bool SensorNode::getProvisioned(bool & provisioned)
IanBenzMaxim 0:33d4e66780c0 137 {
IanBenzMaxim 0:33d4e66780c0 138 return checkAuthenticatorProvisioned(ds28c36, provisioned);
IanBenzMaxim 0:33d4e66780c0 139 }
IanBenzMaxim 0:33d4e66780c0 140
IanBenzMaxim 0:33d4e66780c0 141 bool SensorNode::provision()
IanBenzMaxim 0:33d4e66780c0 142 {
IanBenzMaxim 0:33d4e66780c0 143 return provisionAuthenticator(ds28c36);
IanBenzMaxim 0:33d4e66780c0 144 }
IanBenzMaxim 0:33d4e66780c0 145
IanBenzMaxim 0:33d4e66780c0 146 bool SensorNode::authenticate()
IanBenzMaxim 0:33d4e66780c0 147 {
IanBenzMaxim 0:33d4e66780c0 148 // Compute slave secret on coprocessor.
IanBenzMaxim 0:33d4e66780c0 149 DS2476::Buffer message;
IanBenzMaxim 0:33d4e66780c0 150 if (!setSlaveSecret(ds2476, ds28c36, message))
IanBenzMaxim 0:33d4e66780c0 151 return false;
IanBenzMaxim 0:33d4e66780c0 152
IanBenzMaxim 0:33d4e66780c0 153 // Compute HMAC on coprocessor.
IanBenzMaxim 0:33d4e66780c0 154 // ROM ID, Page 0, and MAN ID are already in message.
IanBenzMaxim 0:33d4e66780c0 155 DS2476::Buffer challenge;
IanBenzMaxim 0:33d4e66780c0 156 DS2476::CmdResult result = ds2476.readRng(32, challenge);
IanBenzMaxim 0:33d4e66780c0 157 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 158 return false;
IanBenzMaxim 0:33d4e66780c0 159 std::copy(challenge.begin(), challenge.end(), message.begin() + 40);
IanBenzMaxim 0:33d4e66780c0 160 result = ds2476.writeBuffer(message);
IanBenzMaxim 0:33d4e66780c0 161 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 162 return false;
IanBenzMaxim 0:33d4e66780c0 163 DS2476::HMAC computedHmac;
IanBenzMaxim 0:33d4e66780c0 164 result = ds2476.computeSha2Hmac(computedHmac);
IanBenzMaxim 0:33d4e66780c0 165 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 166 return false;
IanBenzMaxim 0:33d4e66780c0 167
IanBenzMaxim 0:33d4e66780c0 168 // Compute HMAC on device.
IanBenzMaxim 0:33d4e66780c0 169 result = ds28c36.writeBuffer(challenge);
IanBenzMaxim 0:33d4e66780c0 170 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 171 return false;
IanBenzMaxim 0:33d4e66780c0 172 DS28C36::HMAC deviceHmac;
IanBenzMaxim 0:33d4e66780c0 173 result = ds28c36.computeAndReadHmacPageAuthentication(DS28C36::UserData0, DS28C36::SecretNumA, deviceHmac);
IanBenzMaxim 0:33d4e66780c0 174 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 175 return false;
IanBenzMaxim 0:33d4e66780c0 176
IanBenzMaxim 0:33d4e66780c0 177 return computedHmac == deviceHmac;
IanBenzMaxim 0:33d4e66780c0 178 }
IanBenzMaxim 0:33d4e66780c0 179
IanBenzMaxim 0:33d4e66780c0 180 bool SensorNode::setLaserEnabled(bool enabled, const PrintHandler & print)
IanBenzMaxim 0:33d4e66780c0 181 {
IanBenzMaxim 0:33d4e66780c0 182 if (print)
IanBenzMaxim 0:33d4e66780c0 183 {
IanBenzMaxim 0:33d4e66780c0 184 print((std::string(enabled ? "Enabling" : "Disabling") + " laser").c_str());
IanBenzMaxim 0:33d4e66780c0 185 }
IanBenzMaxim 0:33d4e66780c0 186
IanBenzMaxim 0:33d4e66780c0 187 // Compute slave secret on coprocessor.
IanBenzMaxim 0:33d4e66780c0 188 DS2476::Buffer message;
IanBenzMaxim 0:33d4e66780c0 189 if (!setSlaveSecret(ds2476, ds28c36, message, print))
IanBenzMaxim 0:33d4e66780c0 190 return false;
IanBenzMaxim 0:33d4e66780c0 191
IanBenzMaxim 0:33d4e66780c0 192 // Compute write HMAC.
IanBenzMaxim 0:33d4e66780c0 193 // ROM ID and MAN ID are already in message.
IanBenzMaxim 0:33d4e66780c0 194 if (print)
IanBenzMaxim 0:33d4e66780c0 195 {
IanBenzMaxim 0:33d4e66780c0 196 print("Reading GPIO Control page");
IanBenzMaxim 0:33d4e66780c0 197 print((std::string("Modify copy of GPIO Control page to set GPIO B state to ") +
IanBenzMaxim 0:33d4e66780c0 198 (enabled ? "conducting" : "high-impedance")).c_str());
IanBenzMaxim 0:33d4e66780c0 199 }
IanBenzMaxim 0:33d4e66780c0 200 DS28C36::Page page;
IanBenzMaxim 0:33d4e66780c0 201 DS28C36::CmdResult result = ds28c36.readMemory(DS28C36::GpioControl, page);
IanBenzMaxim 0:33d4e66780c0 202 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 203 return false;
IanBenzMaxim 0:33d4e66780c0 204 std::copy(page.begin(), page.end(), message.begin() + 8);
IanBenzMaxim 0:33d4e66780c0 205 page[1] = (enabled ? 0xAA : 0x55);
IanBenzMaxim 0:33d4e66780c0 206 std::copy(page.begin(), page.end(), message.begin() + 40);
IanBenzMaxim 0:33d4e66780c0 207 message[72] = DS28C36::GpioControl;
IanBenzMaxim 0:33d4e66780c0 208 if (print)
IanBenzMaxim 0:33d4e66780c0 209 {
IanBenzMaxim 0:33d4e66780c0 210 print(("Creating HMAC message (ROM ID | Old Page Data | New Page Data | Page # | MAN ID): " +
IanBenzMaxim 0:33d4e66780c0 211 byteArrayToHexString(&message[0], message.size())).c_str());
IanBenzMaxim 0:33d4e66780c0 212 print("Writing HMAC message to DS2476 buffer");
IanBenzMaxim 0:33d4e66780c0 213 }
IanBenzMaxim 0:33d4e66780c0 214 result = ds2476.writeBuffer(message);
IanBenzMaxim 0:33d4e66780c0 215 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 216 return false;
IanBenzMaxim 0:33d4e66780c0 217 DS2476::HMAC hmac;
IanBenzMaxim 0:33d4e66780c0 218 result = ds2476.computeSha2Hmac(hmac);
IanBenzMaxim 0:33d4e66780c0 219 if (result != DS2476::Success)
IanBenzMaxim 0:33d4e66780c0 220 return false;
IanBenzMaxim 0:33d4e66780c0 221
IanBenzMaxim 0:33d4e66780c0 222 if (print)
IanBenzMaxim 0:33d4e66780c0 223 {
IanBenzMaxim 0:33d4e66780c0 224 print(("DS2476 computes write authentication HMAC from slave secret (Secret S) and message in buffer: " +
IanBenzMaxim 0:33d4e66780c0 225 byteArrayToHexString(hmac.data(), hmac.size())).c_str());
IanBenzMaxim 0:33d4e66780c0 226 print("Write authentication HMAC is written to DS28C36 buffer");
IanBenzMaxim 0:33d4e66780c0 227 print("DS28C36 computes an HMAC to compare to the write authentication HMAC after receiving Page # and New Page Data");
IanBenzMaxim 0:33d4e66780c0 228 }
IanBenzMaxim 0:33d4e66780c0 229
IanBenzMaxim 0:33d4e66780c0 230 // Write page data.
IanBenzMaxim 0:33d4e66780c0 231 result = ds28c36.writeBuffer(DS28C36::Buffer(hmac.begin(), hmac.end()));
IanBenzMaxim 0:33d4e66780c0 232 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 233 return false;
IanBenzMaxim 0:33d4e66780c0 234 result = ds28c36.authenticatedSha2WriteMemory(DS28C36::GpioControl, DS28C36::SecretNumA, page);
IanBenzMaxim 0:33d4e66780c0 235 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 236 return false;
IanBenzMaxim 0:33d4e66780c0 237 if (print)
IanBenzMaxim 0:33d4e66780c0 238 {
IanBenzMaxim 0:33d4e66780c0 239 print("DS28C36 updates page data which changes GPIO B state");
IanBenzMaxim 0:33d4e66780c0 240 print((std::string("Laser is now ") + (enabled ? "enabled" : "disabled")).c_str());
IanBenzMaxim 0:33d4e66780c0 241 }
IanBenzMaxim 0:33d4e66780c0 242 return true;
IanBenzMaxim 0:33d4e66780c0 243 }
IanBenzMaxim 0:33d4e66780c0 244
IanBenzMaxim 0:33d4e66780c0 245 bool SensorNode::getLaserEnabled(bool & enabled)
IanBenzMaxim 0:33d4e66780c0 246 {
IanBenzMaxim 0:33d4e66780c0 247 DS28C36::Page page;
IanBenzMaxim 0:33d4e66780c0 248 DS28C36::CmdResult result = ds28c36.readMemory(DS28C36::GpioControl, page);
IanBenzMaxim 0:33d4e66780c0 249 if (result != DS28C36::Success)
IanBenzMaxim 0:33d4e66780c0 250 return false;
IanBenzMaxim 0:33d4e66780c0 251 enabled = (page[1] == 0xAA);
IanBenzMaxim 0:33d4e66780c0 252 return true;
IanBenzMaxim 0:33d4e66780c0 253 }