Link to API documentation

The CSDK v4_beta_deprecated branch contains a beta version of the AWS IoT Embedded C SDK libraries, which has now been deprecated. No new features will be added, but this branch will continue to be maintained for critical bug fixes and security patches.

The libraries in this branch will not be released in their current form, and they have been refactored for resource constrained devices on the master branch. If you want to migrate to the use the refactored libraries, please view the ReadMe on master branch.

The AWS IoT Device SDK for C is a collection of C99 source files that allow applications to securely connect to the AWS IoT platform. It includes an MQTT 3.1.1 client, as well as libraries specific to AWS IoT, such as Thing Shadows. It is distributed in source form and may be built into firmware along with application code.

This library is a new design that inherits from both the AWS IoT Device SDK Embedded C and the libraries provided with FreeRTOS. In addition, it provides the following new features:

• Asynchronous API for both MQTT and Thing Shadow.
• Multithreaded API by default (removed the yield function).
• More efficient platform layer (especially timers).
• Complete separation of MQTT and network stack, allowing MQTT to run over any network stack.
• Configurable memory allocation (static-only or dynamic). Memory allocation functions may also be set by the user.
• Network stack based on OpenSSL when building for Linux.
• MQTT persistent session support.
• Device Defender client library for the AWS IoT Device Defender service.
• Provisioning client library for the Fleet Provisioning feature of AWS IoT Core.

Main documentation page: Building the SDK

This SDK builds with CMake, a cross-platform build tool. This repo contains a ready-to-use port for Linux.

• CMake 3.5.0 or later and a C99 compiler.
• A supported operating system. The ports provided with this repo are expected to work with all recent versions of the following operating systems, although we cannot guarantee the behavior on all systems. For reference, the version used by this repo's Travis CI builds are listed in parentheses.
  • Linux system with POSIX thread and timer APIs. (CI tests on Ubuntu 16.04).
    On Linux systems, the OpenSSL network implementation may be used instead of the default network implementation based on mbed TLS. This requires the installation of OpenSSL development libraries and header files, version 1.0.2g or later. The OpenSSL development libraries are usually called something like libssl-dev or openssl-devel when installed through a package manager.

It is required to setup an AWS account and access the AWS IoT Console for running tests and demos. Follow the links to:

• Setup an AWS account.
• Sign-in to the AWS IoT Console after setting up the AWS account.

If using the Provisioning library, a fleet provisioning template, a provisioning claim, IoT policies and IAM policies need to be setup for the AWS account. Complete the steps to setup your device and AWS IoT account outlined here.

If using the Shadow, Jobs or Defender libraries, a device needs to be registered on the AWS IoT account. Complete the following steps from the Getting Started with AWS IoT guide. The guide mentions the AWS IoT Button, but you do not need one to use this SDK. 1. Register a Device in the Registry 2. Create and Activate a Device Certificate 3. Create an AWS IoT Policy 4. Attach an AWS IoT Policy to a Device Certificate

1. Clone the source code and submodules. This SDK uses third-party libraries as submodules in the third_party directory.

   • If the source code is downloaded via git clone, nothing further needs to be done. The CMake build system can automatically clone submodules in this case.
   • For any other download, the submodules must be downloaded and placed in their respective third_party directory.
     • mbed TLS → third_party/mbedtls/mbedtls
     • tinyCBOR → third_party/tinycbor/tinycbor

2. Required ONLY for Provisioning library: (Skip if not using Provisioning library) Set the following #defines in iot_config.h. The demo requires configuration of 2 parameter name-value pairs to send to the AWS IoT Core service. Update the fleet provisioning template on the AWS IoT Console to support an extra parameter, besides the Certificate ID and Serial Number parameters (that are present in the default template created from AWS IoT Console). Refer to the Parameters section of Fleet Provisioning Template for more information.

   • Set AWS_IOT_DEMO_PROVISIONING_TEMPLATE_NAME with the name of the fleet provisioning template created in step 1. of Provisioning by claim.
   • Set AWS_IOT_DEMO_PROVISIONING_PARAMETER_NAME_SERIAL_NUMBER_VALUE with the value of the device's serial number (or an equivalent unique device identifier) that will be used to create a Thing resource by the fleet provisioning template.
   • Set AWS_IOT_DEMO_PROVISIONING_PARAMETER_2_NAME with the name of an additional parameter that the device needs to send to the fleet provisioning template. The demo requires exactly 2 different parameter name-value pairs (including serial number) to be configured.
   • Set AWS_IOT_DEMO_PROVISIONING_PARAMETER_2_VALUE with the value of the additional parameter.
   • When testing the Certificate-Signing Request (CSR) based Provisioning demo, set the AWS_IOT_DEMO_PROVISIONING_CSR_PEM macro with the Certificate-Signing Request string.

3. Optional: Set the following #define in iot_config.h. You may skip this step and instead pass these configuration settings as command line options when running the demos.

   • Set IOT_DEMO_IDENTIFIER to a MQTT client identifier that you want to use for the MQTT connection to AWS IoT Core. The corresponding command line option for this constant is -i.
   • Set IOT_DEMO_SERVER to your custom endpoint. This is found on the Settings page of the AWS IoT Console and has a format of ABCDEFG1234567.iot.us-east-2.amazonaws.com. The corresponding command line option for this constant is -h.
   • Set IOT_DEMO_ROOT_CA to the path of the root CA certificate downloaded when setting up device certificate (or Provisioning Claim for Fleet Provisioning) in AWS IoT Account Setup. The corresponding command line option for this constant is -r.
   • Set IOT_DEMO_CLIENT_CERT to the path of the client certificate downloaded when setting up device certificate (or Provisioning Claim for Fleet Provisioning) in AWS IoT Account Setup. The corresponding command line option for this constant is -c.
   • Set IOT_DEMO_PRIVATE_KEY to the path of the private downloaded when setting up device certificate (or Provisioning Claim for Fleet Provisioning) in AWS IoT Account Setup. The corresponding command line option for this constant is -k.
   • Set IOT_DEMO_USER_NAME to the username string, if any, required to authenticate to your MQTT broker. The corresponding command line option for this constant is -m.
   • Set IOT_DEMO_PASSWORD to the password string, if any, required to authenticate to your MQTT broker. The corresponding command line option for this constant is -w.

4. Make a build directory in the SDK's root directory and cd into it.

   mkdir build
   cd build

5. Run CMake from the build directory.

   cmake ..

   CMake will generate a project based on the detected operating system. On Linux, the default project is a Makefile. To build the SDK with this Makefile, run make. The resulting binaries (the demo executables) and libraries will be placed in the build/output directory.

   You may also use CMake GUI. Specify the SDK's root directory as the source directory and the build directory created in step 5 as the build directory in CMake GUI.

See the documentation page Building the SDK for a list of options that can be used to configure the build system.

Please refer to the Porting Guide for instructions on porting this SDK.

Existing ports (which may be used as examples) are present in ports. A blank template for implementing new ports is in ports/template.

This library is licensed under the MIT License.

This repository uses Mbed TLS under Apache 2.0