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.

rapidjson/filewritestream.h@0:33d4e66780c0, 2017-02-24 (annotated)

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

Who changed what in which revision?

UserRevisionLine numberNew contents of line
IanBenzMaxim 0:33d4e66780c0 1 // Tencent is pleased to support the open source community by making RapidJSON available.
IanBenzMaxim 0:33d4e66780c0 2 //
IanBenzMaxim 0:33d4e66780c0 3 // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
IanBenzMaxim 0:33d4e66780c0 4 //
IanBenzMaxim 0:33d4e66780c0 5 // Licensed under the MIT License (the "License"); you may not use this file except
IanBenzMaxim 0:33d4e66780c0 6 // in compliance with the License. You may obtain a copy of the License at
IanBenzMaxim 0:33d4e66780c0 7 //
IanBenzMaxim 0:33d4e66780c0 8 // http://opensource.org/licenses/MIT
IanBenzMaxim 0:33d4e66780c0 9 //
IanBenzMaxim 0:33d4e66780c0 10 // Unless required by applicable law or agreed to in writing, software distributed
IanBenzMaxim 0:33d4e66780c0 11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
IanBenzMaxim 0:33d4e66780c0 12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
IanBenzMaxim 0:33d4e66780c0 13 // specific language governing permissions and limitations under the License.
IanBenzMaxim 0:33d4e66780c0 14
IanBenzMaxim 0:33d4e66780c0 15 #ifndef RAPIDJSON_FILEWRITESTREAM_H_
IanBenzMaxim 0:33d4e66780c0 16 #define RAPIDJSON_FILEWRITESTREAM_H_
IanBenzMaxim 0:33d4e66780c0 17
IanBenzMaxim 0:33d4e66780c0 18 #include "stream.h"
IanBenzMaxim 0:33d4e66780c0 19 #include <cstdio>
IanBenzMaxim 0:33d4e66780c0 20
IanBenzMaxim 0:33d4e66780c0 21 #ifdef __clang__
IanBenzMaxim 0:33d4e66780c0 22 RAPIDJSON_DIAG_PUSH
IanBenzMaxim 0:33d4e66780c0 23 RAPIDJSON_DIAG_OFF(unreachable-code)
IanBenzMaxim 0:33d4e66780c0 24 #endif
IanBenzMaxim 0:33d4e66780c0 25
IanBenzMaxim 0:33d4e66780c0 26 RAPIDJSON_NAMESPACE_BEGIN
IanBenzMaxim 0:33d4e66780c0 27
IanBenzMaxim 0:33d4e66780c0 28 //! Wrapper of C file stream for input using fread().
IanBenzMaxim 0:33d4e66780c0 29 /*!
IanBenzMaxim 0:33d4e66780c0 30 \note implements Stream concept
IanBenzMaxim 0:33d4e66780c0 31 */
IanBenzMaxim 0:33d4e66780c0 32 class FileWriteStream {
IanBenzMaxim 0:33d4e66780c0 33 public:
IanBenzMaxim 0:33d4e66780c0 34 typedef char Ch; //!< Character type. Only support char.
IanBenzMaxim 0:33d4e66780c0 35
IanBenzMaxim 0:33d4e66780c0 36 FileWriteStream(std::FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferEnd_(buffer + bufferSize), current_(buffer_) {
IanBenzMaxim 0:33d4e66780c0 37 RAPIDJSON_ASSERT(fp_ != 0);
IanBenzMaxim 0:33d4e66780c0 38 }
IanBenzMaxim 0:33d4e66780c0 39
IanBenzMaxim 0:33d4e66780c0 40 void Put(char c) {
IanBenzMaxim 0:33d4e66780c0 41 if (current_ >= bufferEnd_)
IanBenzMaxim 0:33d4e66780c0 42 Flush();
IanBenzMaxim 0:33d4e66780c0 43
IanBenzMaxim 0:33d4e66780c0 44 *current_++ = c;
IanBenzMaxim 0:33d4e66780c0 45 }
IanBenzMaxim 0:33d4e66780c0 46
IanBenzMaxim 0:33d4e66780c0 47 void PutN(char c, size_t n) {
IanBenzMaxim 0:33d4e66780c0 48 size_t avail = static_cast<size_t>(bufferEnd_ - current_);
IanBenzMaxim 0:33d4e66780c0 49 while (n > avail) {
IanBenzMaxim 0:33d4e66780c0 50 std::memset(current_, c, avail);
IanBenzMaxim 0:33d4e66780c0 51 current_ += avail;
IanBenzMaxim 0:33d4e66780c0 52 Flush();
IanBenzMaxim 0:33d4e66780c0 53 n -= avail;
IanBenzMaxim 0:33d4e66780c0 54 avail = static_cast<size_t>(bufferEnd_ - current_);
IanBenzMaxim 0:33d4e66780c0 55 }
IanBenzMaxim 0:33d4e66780c0 56
IanBenzMaxim 0:33d4e66780c0 57 if (n > 0) {
IanBenzMaxim 0:33d4e66780c0 58 std::memset(current_, c, n);
IanBenzMaxim 0:33d4e66780c0 59 current_ += n;
IanBenzMaxim 0:33d4e66780c0 60 }
IanBenzMaxim 0:33d4e66780c0 61 }
IanBenzMaxim 0:33d4e66780c0 62
IanBenzMaxim 0:33d4e66780c0 63 void Flush() {
IanBenzMaxim 0:33d4e66780c0 64 if (current_ != buffer_) {
IanBenzMaxim 0:33d4e66780c0 65 size_t result = fwrite(buffer_, 1, static_cast<size_t>(current_ - buffer_), fp_);
IanBenzMaxim 0:33d4e66780c0 66 if (result < static_cast<size_t>(current_ - buffer_)) {
IanBenzMaxim 0:33d4e66780c0 67 // failure deliberately ignored at this time
IanBenzMaxim 0:33d4e66780c0 68 // added to avoid warn_unused_result build errors
IanBenzMaxim 0:33d4e66780c0 69 }
IanBenzMaxim 0:33d4e66780c0 70 current_ = buffer_;
IanBenzMaxim 0:33d4e66780c0 71 }
IanBenzMaxim 0:33d4e66780c0 72 }
IanBenzMaxim 0:33d4e66780c0 73
IanBenzMaxim 0:33d4e66780c0 74 // Not implemented
IanBenzMaxim 0:33d4e66780c0 75 char Peek() const { RAPIDJSON_ASSERT(false); return 0; }
IanBenzMaxim 0:33d4e66780c0 76 char Take() { RAPIDJSON_ASSERT(false); return 0; }
IanBenzMaxim 0:33d4e66780c0 77 size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; }
IanBenzMaxim 0:33d4e66780c0 78 char* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
IanBenzMaxim 0:33d4e66780c0 79 size_t PutEnd(char*) { RAPIDJSON_ASSERT(false); return 0; }
IanBenzMaxim 0:33d4e66780c0 80
IanBenzMaxim 0:33d4e66780c0 81 private:
IanBenzMaxim 0:33d4e66780c0 82 // Prohibit copy constructor & assignment operator.
IanBenzMaxim 0:33d4e66780c0 83 FileWriteStream(const FileWriteStream&);
IanBenzMaxim 0:33d4e66780c0 84 FileWriteStream& operator=(const FileWriteStream&);
IanBenzMaxim 0:33d4e66780c0 85
IanBenzMaxim 0:33d4e66780c0 86 std::FILE* fp_;
IanBenzMaxim 0:33d4e66780c0 87 char *buffer_;
IanBenzMaxim 0:33d4e66780c0 88 char *bufferEnd_;
IanBenzMaxim 0:33d4e66780c0 89 char *current_;
IanBenzMaxim 0:33d4e66780c0 90 };
IanBenzMaxim 0:33d4e66780c0 91
IanBenzMaxim 0:33d4e66780c0 92 //! Implement specialized version of PutN() with memset() for better performance.
IanBenzMaxim 0:33d4e66780c0 93 template<>
IanBenzMaxim 0:33d4e66780c0 94 inline void PutN(FileWriteStream& stream, char c, size_t n) {
IanBenzMaxim 0:33d4e66780c0 95 stream.PutN(c, n);
IanBenzMaxim 0:33d4e66780c0 96 }
IanBenzMaxim 0:33d4e66780c0 97
IanBenzMaxim 0:33d4e66780c0 98 RAPIDJSON_NAMESPACE_END
IanBenzMaxim 0:33d4e66780c0 99
IanBenzMaxim 0:33d4e66780c0 100 #ifdef __clang__
IanBenzMaxim 0:33d4e66780c0 101 RAPIDJSON_DIAG_POP
IanBenzMaxim 0:33d4e66780c0 102 #endif
IanBenzMaxim 0:33d4e66780c0 103
IanBenzMaxim 0:33d4e66780c0 104 #endif // RAPIDJSON_FILESTREAM_H_