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.

Bitmap.cpp@10:71359af61af8, 2017-04-10 (annotated)

Committer:
IanBenzMaxim
Date:
Mon Apr 10 11:55:33 2017 -0500
Revision:
10:71359af61af8
Parent:
0:33d4e66780c0
Child:
11:989eabe2a376
Reduced copying and dynamic allocations during rendering. Added support for partial redrawing of a scene.

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 <algorithm>
IanBenzMaxim 0:33d4e66780c0 34 #include "Bitmap.hpp"
IanBenzMaxim 0:33d4e66780c0 35
IanBenzMaxim 0:33d4e66780c0 36 static const int minWidthHeight = 1;
IanBenzMaxim 0:33d4e66780c0 37 static const int rowsPerPage = Bitmap::pixelsPerSegment;
IanBenzMaxim 0:33d4e66780c0 38
IanBenzMaxim 0:33d4e66780c0 39 template <typename T>
IanBenzMaxim 0:33d4e66780c0 40 static T divideRoundUp(const T dividend, const T divisor)
IanBenzMaxim 0:33d4e66780c0 41 {
IanBenzMaxim 0:33d4e66780c0 42 return (dividend / divisor) + (((dividend % divisor) == 0) ? 0 : 1);
IanBenzMaxim 0:33d4e66780c0 43 }
IanBenzMaxim 0:33d4e66780c0 44
IanBenzMaxim 0:33d4e66780c0 45 Bitmap::Bitmap(int width, int height, const uint8_t * data, Format format) :
IanBenzMaxim 0:33d4e66780c0 46 m_width(std::max(width, minWidthHeight)), m_height(std::max(height, minWidthHeight)),
IanBenzMaxim 0:33d4e66780c0 47 m_data(divideRoundUp(height, rowsPerPage) * width, 0x00)
IanBenzMaxim 0:33d4e66780c0 48 {
IanBenzMaxim 0:33d4e66780c0 49 load(data, format);
IanBenzMaxim 0:33d4e66780c0 50 }
IanBenzMaxim 0:33d4e66780c0 51
IanBenzMaxim 0:33d4e66780c0 52 void Bitmap::load(const uint8_t * data, Format format)
IanBenzMaxim 0:33d4e66780c0 53 {
IanBenzMaxim 0:33d4e66780c0 54 if (data != NULL)
IanBenzMaxim 0:33d4e66780c0 55 {
IanBenzMaxim 0:33d4e66780c0 56 switch (format)
IanBenzMaxim 0:33d4e66780c0 57 {
IanBenzMaxim 0:33d4e66780c0 58 case NativeFormat:
IanBenzMaxim 0:33d4e66780c0 59 std::copy(data, data + m_data.size(), m_data.begin());
IanBenzMaxim 0:33d4e66780c0 60 break;
IanBenzMaxim 0:33d4e66780c0 61
IanBenzMaxim 0:33d4e66780c0 62 case ScanLineFormat:
IanBenzMaxim 0:33d4e66780c0 63 {
IanBenzMaxim 0:33d4e66780c0 64 const int segments = divideRoundUp(width(), pixelsPerSegment);
IanBenzMaxim 0:33d4e66780c0 65 for (int row = 0; row < height(); row++)
IanBenzMaxim 0:33d4e66780c0 66 {
IanBenzMaxim 0:33d4e66780c0 67 for (int segment = 0; segment < segments; segment++)
IanBenzMaxim 0:33d4e66780c0 68 {
IanBenzMaxim 0:33d4e66780c0 69 uint8_t segmentData = data[row * segments + segment];
IanBenzMaxim 0:33d4e66780c0 70 for (int pixel = 0; pixel < pixelsPerSegment; pixel++)
IanBenzMaxim 0:33d4e66780c0 71 {
IanBenzMaxim 0:33d4e66780c0 72 setPixelEnabled(segment * pixelsPerSegment + pixel, row, (segmentData & 0x80) == 0x80);
IanBenzMaxim 0:33d4e66780c0 73 segmentData <<= 1;
IanBenzMaxim 0:33d4e66780c0 74 }
IanBenzMaxim 0:33d4e66780c0 75 }
IanBenzMaxim 0:33d4e66780c0 76 }
IanBenzMaxim 0:33d4e66780c0 77 }
IanBenzMaxim 0:33d4e66780c0 78 break;
IanBenzMaxim 0:33d4e66780c0 79 }
IanBenzMaxim 0:33d4e66780c0 80 }
IanBenzMaxim 0:33d4e66780c0 81 }
IanBenzMaxim 0:33d4e66780c0 82
IanBenzMaxim 0:33d4e66780c0 83 bool Bitmap::pixelEnabled(int x, int y) const
IanBenzMaxim 0:33d4e66780c0 84 {
IanBenzMaxim 0:33d4e66780c0 85 bool enabled;
IanBenzMaxim 0:33d4e66780c0 86 if ((x >= 0) && (x < m_width) && (y >= 0) && (y < m_height))
IanBenzMaxim 0:33d4e66780c0 87 {
IanBenzMaxim 0:33d4e66780c0 88 const int page = (m_height - y - 1) / rowsPerPage;
IanBenzMaxim 0:33d4e66780c0 89 y = rowsPerPage - (y % rowsPerPage) - 1;
IanBenzMaxim 0:33d4e66780c0 90 enabled = m_data[page * m_width + x] & (1 << y);
IanBenzMaxim 0:33d4e66780c0 91 }
IanBenzMaxim 0:33d4e66780c0 92 else
IanBenzMaxim 0:33d4e66780c0 93 {
IanBenzMaxim 0:33d4e66780c0 94 enabled = false;
IanBenzMaxim 0:33d4e66780c0 95 }
IanBenzMaxim 0:33d4e66780c0 96 return enabled;
IanBenzMaxim 0:33d4e66780c0 97 }
IanBenzMaxim 0:33d4e66780c0 98
IanBenzMaxim 0:33d4e66780c0 99 void Bitmap::setPixelEnabled(int x, int y, bool enabled)
IanBenzMaxim 0:33d4e66780c0 100 {
IanBenzMaxim 0:33d4e66780c0 101 if ((x >= 0) && (x < m_width) && (y >= 0) && (y < m_height))
IanBenzMaxim 0:33d4e66780c0 102 {
IanBenzMaxim 0:33d4e66780c0 103 const int page = (m_height - y - 1) / rowsPerPage;
IanBenzMaxim 0:33d4e66780c0 104 y = rowsPerPage - (y % rowsPerPage) - 1;
IanBenzMaxim 0:33d4e66780c0 105 if (enabled)
IanBenzMaxim 0:33d4e66780c0 106 m_data[page * m_width + x] |= (1 << y);
IanBenzMaxim 0:33d4e66780c0 107 else
IanBenzMaxim 0:33d4e66780c0 108 m_data[page * m_width + x] &= ~(1 << y);
IanBenzMaxim 0:33d4e66780c0 109 }
IanBenzMaxim 0:33d4e66780c0 110 }
IanBenzMaxim 0:33d4e66780c0 111
IanBenzMaxim 0:33d4e66780c0 112 void Bitmap::overlay(const Bitmap & src, int srcX, int srcY)
IanBenzMaxim 0:33d4e66780c0 113 {
IanBenzMaxim 0:33d4e66780c0 114 for (int x = 0; (x < src.width()) && (x + srcX < this->width()); x++)
IanBenzMaxim 0:33d4e66780c0 115 {
IanBenzMaxim 0:33d4e66780c0 116 if (x + srcX >= 0)
IanBenzMaxim 0:33d4e66780c0 117 {
IanBenzMaxim 0:33d4e66780c0 118 for (int y = 0; (y < src.height()) && (y + srcY < this->height()); y++)
IanBenzMaxim 0:33d4e66780c0 119 {
IanBenzMaxim 0:33d4e66780c0 120 if (y + srcY >= 0)
IanBenzMaxim 0:33d4e66780c0 121 {
IanBenzMaxim 0:33d4e66780c0 122 this->setPixelEnabled(x + srcX, y + srcY, src.pixelEnabled(x, y));
IanBenzMaxim 0:33d4e66780c0 123 }
IanBenzMaxim 0:33d4e66780c0 124 }
IanBenzMaxim 0:33d4e66780c0 125 }
IanBenzMaxim 0:33d4e66780c0 126 }
IanBenzMaxim 0:33d4e66780c0 127 }
IanBenzMaxim 10:71359af61af8 128
IanBenzMaxim 10:71359af61af8 129 void Bitmap::clear()
IanBenzMaxim 10:71359af61af8 130 {
IanBenzMaxim 10:71359af61af8 131 std::fill(m_data.begin(), m_data.end(), 0);
IanBenzMaxim 10:71359af61af8 132 }
IanBenzMaxim 10:71359af61af8 133
IanBenzMaxim 10:71359af61af8 134 void Bitmap::clear(int x, int y, int width, int height)
IanBenzMaxim 10:71359af61af8 135 {
IanBenzMaxim 10:71359af61af8 136 if (!((x >= 0) && (x < m_width) && (y >= 0) && (y < m_height)))
IanBenzMaxim 10:71359af61af8 137 {
IanBenzMaxim 10:71359af61af8 138 return;
IanBenzMaxim 10:71359af61af8 139 }
IanBenzMaxim 10:71359af61af8 140 if ((x + width) > m_width)
IanBenzMaxim 10:71359af61af8 141 {
IanBenzMaxim 10:71359af61af8 142 width = m_width - x;
IanBenzMaxim 10:71359af61af8 143 }
IanBenzMaxim 10:71359af61af8 144 if ((y + height) > m_height)
IanBenzMaxim 10:71359af61af8 145 {
IanBenzMaxim 10:71359af61af8 146 height = m_height - y;
IanBenzMaxim 10:71359af61af8 147 }
IanBenzMaxim 10:71359af61af8 148
IanBenzMaxim 10:71359af61af8 149 const int startX = x;
IanBenzMaxim 10:71359af61af8 150 const int startY = y;
IanBenzMaxim 10:71359af61af8 151 while (x < (startX + width))
IanBenzMaxim 10:71359af61af8 152 {
IanBenzMaxim 10:71359af61af8 153 y = startY;
IanBenzMaxim 10:71359af61af8 154 while (y < (startY + height))
IanBenzMaxim 10:71359af61af8 155 {
IanBenzMaxim 10:71359af61af8 156 if (((y % rowsPerPage) == 0) && ((y + rowsPerPage) < (startY + height)))
IanBenzMaxim 10:71359af61af8 157 {
IanBenzMaxim 10:71359af61af8 158 const int page = (m_height - y - 1) / rowsPerPage;
IanBenzMaxim 10:71359af61af8 159 m_data[page * m_width + x] = 0;
IanBenzMaxim 10:71359af61af8 160 y += rowsPerPage;
IanBenzMaxim 10:71359af61af8 161 }
IanBenzMaxim 10:71359af61af8 162 else
IanBenzMaxim 10:71359af61af8 163 {
IanBenzMaxim 10:71359af61af8 164 setPixelEnabled(x, y, false);
IanBenzMaxim 10:71359af61af8 165 y++;
IanBenzMaxim 10:71359af61af8 166 }
IanBenzMaxim 10:71359af61af8 167 }
IanBenzMaxim 10:71359af61af8 168 x++;
IanBenzMaxim 10:71359af61af8 169 }
IanBenzMaxim 10:71359af61af8 170 }