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.

xternal/rapidjson/internal/ieee754.h@16:a004191a79ab, 2019-10-03 (annotated)

Committer:
IanBenzMaxim
Date:
Thu Oct 03 11:40:13 2019 -0500
Revision:
16:a004191a79ab
Parent:
rapidjson/internal/ieee754.h@0:33d4e66780c0 
Updated MaximInterface to version 2.0. Updated mbed-os to version 5.5.7. Cleaned up code styling.

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_IEEE754_
IanBenzMaxim 0:33d4e66780c0 16 #define RAPIDJSON_IEEE754_
IanBenzMaxim 0:33d4e66780c0 17
IanBenzMaxim 0:33d4e66780c0 18 #include "../rapidjson.h"
IanBenzMaxim 0:33d4e66780c0 19
IanBenzMaxim 0:33d4e66780c0 20 RAPIDJSON_NAMESPACE_BEGIN
IanBenzMaxim 0:33d4e66780c0 21 namespace internal {
IanBenzMaxim 0:33d4e66780c0 22
IanBenzMaxim 0:33d4e66780c0 23 class Double {
IanBenzMaxim 0:33d4e66780c0 24 public:
IanBenzMaxim 0:33d4e66780c0 25 Double() {}
IanBenzMaxim 0:33d4e66780c0 26 Double(double d) : d_(d) {}
IanBenzMaxim 0:33d4e66780c0 27 Double(uint64_t u) : u_(u) {}
IanBenzMaxim 0:33d4e66780c0 28
IanBenzMaxim 0:33d4e66780c0 29 double Value() const { return d_; }
IanBenzMaxim 0:33d4e66780c0 30 uint64_t Uint64Value() const { return u_; }
IanBenzMaxim 0:33d4e66780c0 31
IanBenzMaxim 0:33d4e66780c0 32 double NextPositiveDouble() const {
IanBenzMaxim 0:33d4e66780c0 33 RAPIDJSON_ASSERT(!Sign());
IanBenzMaxim 0:33d4e66780c0 34 return Double(u_ + 1).Value();
IanBenzMaxim 0:33d4e66780c0 35 }
IanBenzMaxim 0:33d4e66780c0 36
IanBenzMaxim 0:33d4e66780c0 37 bool Sign() const { return (u_ & kSignMask) != 0; }
IanBenzMaxim 0:33d4e66780c0 38 uint64_t Significand() const { return u_ & kSignificandMask; }
IanBenzMaxim 0:33d4e66780c0 39 int Exponent() const { return static_cast<int>(((u_ & kExponentMask) >> kSignificandSize) - kExponentBias); }
IanBenzMaxim 0:33d4e66780c0 40
IanBenzMaxim 0:33d4e66780c0 41 bool IsNan() const { return (u_ & kExponentMask) == kExponentMask && Significand() != 0; }
IanBenzMaxim 0:33d4e66780c0 42 bool IsInf() const { return (u_ & kExponentMask) == kExponentMask && Significand() == 0; }
IanBenzMaxim 0:33d4e66780c0 43 bool IsNanOrInf() const { return (u_ & kExponentMask) == kExponentMask; }
IanBenzMaxim 0:33d4e66780c0 44 bool IsNormal() const { return (u_ & kExponentMask) != 0 || Significand() == 0; }
IanBenzMaxim 0:33d4e66780c0 45 bool IsZero() const { return (u_ & (kExponentMask | kSignificandMask)) == 0; }
IanBenzMaxim 0:33d4e66780c0 46
IanBenzMaxim 0:33d4e66780c0 47 uint64_t IntegerSignificand() const { return IsNormal() ? Significand() | kHiddenBit : Significand(); }
IanBenzMaxim 0:33d4e66780c0 48 int IntegerExponent() const { return (IsNormal() ? Exponent() : kDenormalExponent) - kSignificandSize; }
IanBenzMaxim 0:33d4e66780c0 49 uint64_t ToBias() const { return (u_ & kSignMask) ? ~u_ + 1 : u_ | kSignMask; }
IanBenzMaxim 0:33d4e66780c0 50
IanBenzMaxim 0:33d4e66780c0 51 static unsigned EffectiveSignificandSize(int order) {
IanBenzMaxim 0:33d4e66780c0 52 if (order >= -1021)
IanBenzMaxim 0:33d4e66780c0 53 return 53;
IanBenzMaxim 0:33d4e66780c0 54 else if (order <= -1074)
IanBenzMaxim 0:33d4e66780c0 55 return 0;
IanBenzMaxim 0:33d4e66780c0 56 else
IanBenzMaxim 0:33d4e66780c0 57 return static_cast<unsigned>(order) + 1074;
IanBenzMaxim 0:33d4e66780c0 58 }
IanBenzMaxim 0:33d4e66780c0 59
IanBenzMaxim 0:33d4e66780c0 60 private:
IanBenzMaxim 0:33d4e66780c0 61 static const int kSignificandSize = 52;
IanBenzMaxim 0:33d4e66780c0 62 static const int kExponentBias = 0x3FF;
IanBenzMaxim 0:33d4e66780c0 63 static const int kDenormalExponent = 1 - kExponentBias;
IanBenzMaxim 0:33d4e66780c0 64 static const uint64_t kSignMask = RAPIDJSON_UINT64_C2(0x80000000, 0x00000000);
IanBenzMaxim 0:33d4e66780c0 65 static const uint64_t kExponentMask = RAPIDJSON_UINT64_C2(0x7FF00000, 0x00000000);
IanBenzMaxim 0:33d4e66780c0 66 static const uint64_t kSignificandMask = RAPIDJSON_UINT64_C2(0x000FFFFF, 0xFFFFFFFF);
IanBenzMaxim 0:33d4e66780c0 67 static const uint64_t kHiddenBit = RAPIDJSON_UINT64_C2(0x00100000, 0x00000000);
IanBenzMaxim 0:33d4e66780c0 68
IanBenzMaxim 0:33d4e66780c0 69 union {
IanBenzMaxim 0:33d4e66780c0 70 double d_;
IanBenzMaxim 0:33d4e66780c0 71 uint64_t u_;
IanBenzMaxim 0:33d4e66780c0 72 };
IanBenzMaxim 0:33d4e66780c0 73 };
IanBenzMaxim 0:33d4e66780c0 74
IanBenzMaxim 0:33d4e66780c0 75 } // namespace internal
IanBenzMaxim 0:33d4e66780c0 76 RAPIDJSON_NAMESPACE_END
IanBenzMaxim 0:33d4e66780c0 77
IanBenzMaxim 0:33d4e66780c0 78 #endif // RAPIDJSON_IEEE754_