Microsoft Azure C Shared Utility

C, Microsoft, Azure, Native, x86, x64, package, ARM, cmake, general-purpose, library
Install-Package Microsoft.Azure.C.SharedUtility -Version 1.1.11


This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact with any additional questions or comments.

Azure C Shared Utility

azure-c-shared-utility is a C library providing common functionality for basic tasks (like string, list manipulation, IO, etc.).


azure-c-shared-utility provides 3 tlsio implementations:

  • tlsio_schannel - runs only on Windows
  • tlsio_openssl - depends on OpenSSL being installed
  • tlsio_wolfssl - depends on WolfSSL being installed

azure-c-shared-utility depends on curl for HTTPAPI for Linux.

azure-c-shared-utility uses cmake for configuring build files.


  1. Clone azure-c-shared-utility using the recursive option:
git clone --recursive
  1. Create a folder called cmake under azure-c-shared-utility

  2. Switch to the cmake folder and run

cmake ..
  1. Build
cmake --build .

Installation and Use

Optionally, you may choose to install azure-c-shared-utility on your machine:

  1. Switch to the cmake folder and run

    cmake -Duse_installed_dependencies=ON ../
    cmake --build . --target install

    or install using the follow commands for each platform:

    On Linux:

    sudo make install

    On Windows:

    msbuild /m INSTALL.vcxproj
  2. Use it in your project (if installed)

    find_package(azure_c_shared_utility REQUIRED CONFIG)
    target_link_library(yourlib aziotsharedutil)

If running tests, this requires that umock-c, azure-ctest, and azure-c-testrunnerswitcher are installed (through CMake) on your machine.

Building the tests

In order to build the tests use:

cmake .. -Drun_unittests:bool=ON

Configuration options

In order to turn on/off the tlsio implementations use the following CMAKE options:

  • -Duse_schannel:bool={ON/OFF} - turns on/off the SChannel support
  • -Duse_openssl:bool={ON/OFF} - turns on/off the OpenSSL support. If this option is use an environment variable name OpenSSLDir should be set to point to the OpenSSL folder.
  • -Duse_wolfssl:bool={ON/OFF} - turns on/off the WolfSSL support. If this option is use an environment variable name WolfSSLDir should be set to point to the WolfSSL folder.
  • -Duse_http:bool={ON/OFF} - turns on/off the HTTP API support.
  • -Duse_installed_dependencies:bool={ON/OFF} - turns on/off building azure-c-shared-utility using installed dependencies. This package may only be installed if this flag is ON.
  • -Drun_unittests:bool={ON/OFF} - enables building of unit tests. Default is OFF.

Porting to new devices

Instructions for porting the Azure IoT C SDK to new devices are located here.