The AWS Encryption SDK for C is a client-side encryption library designed to make it easy for everyone to encrypt and decrypt data using industry standards and best practices. It uses a data format compatible with the AWS Encryption SDKs in other languages. For more information on the AWS Encryption SDKs in all languages, see the Developer Guide.
Also, see the API documentation for the AWS Encryption SDK for C.
The only direct dependencies of this code are OpenSSL 1.0.2 or higher or 1.1.0 or higher and aws-c-common v0.3.0 or higher. You will also need a C compiler and CMake 3.9 or higher.
To integrate with KMS the AWS Encryption SDK for C also requires the AWS SDK for C++, a C++ compiler, and libcurl.
For best results when doing a build with KMS integration, do not install aws-c-common directly. Build and install the AWS SDK for C++, which will build and install aws-c-common for you. If you install aws-c-common before building the AWS SDK for C++, this will fool the AWS SDK for C++ install logic, and you will be forced to install several other dependencies manually. The minimum supported version of the AWS SDK for C++ is 1.7.36.
You need to compile both the AWS Encryption SDK for C and its dependencies as either all
shared or all static libraries. We will use all shared library builds in our examples by
using the cmake argument -DBUILD_SHARED_LIBS=ON. You can change them to static library
builds by just changing ON to OFF.
Once you have built each dependency, install it so it can be picked up by the next build.
For best results, create an EC2 instance with an instance profile that at a minimum has KMS permissions for Encrypt, Decrypt, and GenerateDataKey for at least one KMS CMK in your account. You will not need any other AWS permissions to use the AWS Encryption SDK for C.
We will demonstrate some simple build recipes for Linux, Mac, and Windows operating systems.
The Linux and Mac recipes install everything in the standard directories in /usr/local. The Windows recipe installs everything in an install directory placed at the directory you are in when you start the build process. To change the installation directory, if desired, see the Tips and Tricks section at the end of this README.
You can do (Option 1) a C and C++ build, which will include integration with KMS, or you can do (Option 2) a C only build, which will not include integration with KMS. In places where the recipes diverge, these will be labeled as (Option 1) and (Option 2). Follow one of the two options, but not both, depending on which installation you want to do.
This recipe should work with a brand new Amazon Linux instance. Start in the directory where you want to do your build.
Run the following:
sudo yum update
sudo yum install -y openssl-devel git gcc-c++ libcurl-devel
The yum repo has an old version of CMake, so download CMake 3.9 or later from their website and make sure cmake is in your path.
Both aws-sdk-cpp and aws-c-common are required, but the installation of aws-sdk-cpp will install aws-c-common for you.
Do a KMS-only build of the AWS SDK for C++. If you want to use the AWS SDK for C++ for
other AWS services, you can omit the -DBUILD_ONLY="kms" argument, but the build will take much longer.
git clone https://github.com/aws/aws-sdk-cpp.git
mkdir build-aws-sdk-cpp && cd build-aws-sdk-cpp
cmake -DBUILD_SHARED_LIBS=ON -DBUILD_ONLY="kms" -DENABLE_UNITY_BUILD=ON ../aws-sdk-cpp
make && sudo make install ; cd ..
Now skip to the "Amazon Linux: Build and install the AWS Encryption SDK for C" section below.
Run the following:
sudo yum update
sudo yum install -y openssl-devel git gcc
The yum repo has an old version of CMake, so download CMake 3.9 or later from their website and make sure cmake is in your path.
Now build and install aws-c-common:
git clone https://github.com/awslabs/aws-c-common.git
mkdir build-aws-c-common && cd build-aws-c-common
cmake -DBUILD_SHARED_LIBS=ON ../aws-c-common
make && sudo make install ; cd ..
git clone https://github.com/aws/aws-encryption-sdk-c.git
mkdir build-aws-encryption-sdk-c && cd build-aws-encryption-sdk-c
cmake -DBUILD_SHARED_LIBS=ON ../aws-encryption-sdk-c
make && sudo make install ; cd ..
You have successfully built and installed the AWS Encryption SDK for C.
These instructions have been tested on brand new Ubuntu EC2 instances. You should also be able to build on Ubuntu operating systems that are not in EC2, but you will need to manually configure AWS credentials if you are using KMS. Start in the directory where you want to do your build.
sudo apt-get update
sudo apt-get install -y libssl-dev cmake g++ libcurl4-openssl-dev zlib1g-dev
Both aws-sdk-cpp and aws-c-common are required, but the installation of aws-sdk-cpp will install aws-c-common for you.
Do a KMS-only build of the AWS SDK for C++. If you want to use the AWS SDK for C++ for
other AWS services, you can omit the -DBUILD_ONLY="kms" argument, but the build will take much longer.
git clone https://github.com/aws/aws-sdk-cpp.git
mkdir build-aws-sdk-cpp && cd build-aws-sdk-cpp
cmake -DBUILD_SHARED_LIBS=ON -DBUILD_ONLY="kms" -DENABLE_UNITY_BUILD=ON ../aws-sdk-cpp
make && sudo make install ; cd ..
Now skip to the "Ubuntu: Build and install the AWS Encryption SDK for C" section below.
sudo apt-get update
sudo apt-get install -y libssl-dev cmake gcc
Now build and install aws-c-common:
git clone https://github.com/awslabs/aws-c-common.git
mkdir build-aws-c-common && cd build-aws-c-common
cmake -DBUILD_SHARED_LIBS=ON ../aws-c-common
make && sudo make install ; cd ..
git clone https://github.com/aws/aws-encryption-sdk-c.git
mkdir build-aws-encryption-sdk-c && cd build-aws-encryption-sdk-c
cmake -DBUILD_SHARED_LIBS=ON ../aws-encryption-sdk-c
make && sudo make install ; cd ..
You have successfully built and installed the AWS Encryption SDK for C.
We recommend setting up Homebrew to install some build tools. Once it is set up, run the following:
brew install [email protected] cmake
(Note: Installing the AWS SDK for C++ through Homebrew does a full build, which takes much longer than the KMS-only build. For these reasons, we recommend doing a source build of the AWS SDK for C++ yourself, as we will demonstrate below.)
Start in the directory where you want to do your build.
Both aws-sdk-cpp and aws-c-common are required, but the installation of aws-sdk-cpp will install aws-c-common for you.
Do a KMS-only build of the AWS SDK for C++. If you want to use the AWS SDK for C++ for
other AWS services, you can omit the -DBUILD_ONLY="kms" argument, but the build will take much longer.
git clone https://github.com/aws/aws-sdk-cpp.git
mkdir build-aws-sdk-cpp && cd build-aws-sdk-cpp
cmake -DBUILD_SHARED_LIBS=ON -DBUILD_ONLY="kms" -DENABLE_UNITY_BUILD=ON ../aws-sdk-cpp
make && sudo make install ; cd ..
Now skip to the "Mac: Build and install the AWS Encryption SDK for C" section below.
Build and install aws-c-common:
git clone https://github.com/awslabs/aws-c-common.git
mkdir build-aws-c-common && cd build-aws-c-common
cmake -DBUILD_SHARED_LIBS=ON ../aws-c-common
make && sudo make install ; cd ..
Brew installed OpenSSL 1.1 to a place that is not picked up by default so we will set the directory manually in our build.
git clone https://github.com/aws/aws-encryption-sdk-c.git
mkdir build-aws-encryption-sdk-c && cd build-aws-encryption-sdk-c
cmake -DBUILD_SHARED_LIBS=ON -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl\@1.1 ../aws-encryption-sdk-c
make && sudo make install ; cd ..
You have successfully built and installed the AWS Encryption SDK for C.
Start by installing Visual Studio version 15 or later with the Windows Universal C Runtime and Git for Windows.
Use the x64 Native Tools Command Prompt for all commands listed here. Run the following commands in the directory where you want to do the build and installation.
mkdir install && mkdir build && cd build
git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg && .\bootstrap-vcpkg.bat
.\vcpkg install curl:x64-windows openssl:x64-windows && cd ..
Both aws-sdk-cpp and aws-c-common are required, but the installation of aws-sdk-cpp will install aws-c-common for you.
Do a KMS-only build of the AWS SDK for C++. If you want to use the AWS SDK for C++ for
other AWS services, you can omit the -DBUILD_ONLY="kms" argument, but the build will take much longer.
git clone https://github.com/aws/aws-sdk-cpp.git
mkdir build-aws-sdk-cpp && cd build-aws-sdk-cpp
cmake -DCMAKE_INSTALL_PREFIX=%cd%\..\..\install -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DENABLE_UNITY_BUILD=ON -DBUILD_ONLY=kms -DCMAKE_TOOLCHAIN_FILE=%cd%\..\vcpkg\scripts\buildsystems\vcpkg.cmake -G Ninja ..\aws-sdk-cpp
cmake --build . && cmake --build . --target install && cd ..
Now continue to "Windows: Build and install the AWS Encryption SDK for C" below.
Build and install aws-c-common:
git clone https://github.com/awslabs/aws-c-common.git
mkdir build-aws-c-common && cd build-aws-c-common
cmake -DCMAKE_INSTALL_PREFIX=%cd%\..\..\install -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DCMAKE_TOOLCHAIN_FILE=%cd%\..\vcpkg\scripts\buildsystems\vcpkg.cmake -G Ninja ..\aws-c-common
cmake --build . && cmake --build . --target install && cd ..
git clone https://github.com/aws/aws-encryption-sdk-c.git
mkdir build-aws-encryption-sdk-c && cd build-aws-encryption-sdk-c
cmake -DCMAKE_INSTALL_PREFIX=%cd%\..\..\install -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DCMAKE_TOOLCHAIN_FILE=%cd%\..\vcpkg\scripts\buildsystems\vcpkg.cmake -G Ninja ..\aws-encryption-sdk-c
cmake --build . && cmake --build . --target install && cd ..
You have successfully built and installed the AWS Encryption SDK for C.
Once you have installed the AWS Encryption SDK for C, you are ready to start writing your own programs with it.
When doing a C compilation (not using the KMS keyring) be sure to include the flags
-lcrypto -laws-encryption-sdk -laws-c-common.
When doing a C++ compilation (using the KMS keyring) be sure to include the flags
-std=c++11 -lcrypto -laws-encryption-sdk -laws-encryption-sdk-cpp -laws-c-common -laws-cpp-sdk-kms -laws-cpp-sdk-core.
In the examples directory of this repo are several self-standing C and C++ files. On a successful build, these files will already be compiled in the examples subdirectory of the build directory. Additionally, if you want a quick test that you have built and installed the AWS Encryption SDK successfully, you can copy any of the example files out of that directory and build them yourself.
Here are sample command lines using gcc/g++ to build a couple of the example files, assuming that the libraries and headers have been installed where your system knows how to find them.
g++ -o string string.cpp -std=c++11 -lcrypto -laws-encryption-sdk -laws-encryption-sdk-cpp -laws-c-common -laws-cpp-sdk-kms -laws-cpp-sdk-core
gcc -o raw_aes_keyring raw_aes_keyring.c -lcrypto -laws-encryption-sdk -laws-c-common
Note that the C++ files using the KMS keyring will require you to make sure that AWS credentials are set up on your machine to run properly.
When building aws-sdk-cpp, you can save time by only building the subcomponents needed
by the AWS Encryption SDK for C with -DBUILD_ONLY="kms"
The -DENABLE_UNITY_BUILD=ON option will further speed up the aws-sdk-cpp build.
To enable debug symbols, set -DCMAKE_BUILD_TYPE=Debug at initial cmake time,
or use ccmake . to update the configuration after the fact.
If desired, you can set the installations to happen in an arbitrary
directory with -DCMAKE_INSTALL_PREFIX=[path to install to] as an argument to cmake.
If you set CMAKE_INSTALL_PREFIX for the dependencies, when building the AWS
Encryption SDK for C you must either (1) set CMAKE_INSTALL_PREFIX to the same path,
which will cause it to pick up the dependencies and install to the same directory
or (2) set CMAKE_PREFIX_PATH to include the same path, which will cause it to pick
up the dependencies but NOT install to the same directory.
You can also use -DOPENSSL_ROOT_DIR=[path to where openssl was installed] to make
the build use a particular installation of OpenSSL.
By default the cmake for this project detects whether you have aws-sdk-cpp-core
and aws-sdk-cpp-kms installed in a place it can find, and only if so will it build
the C++ components, (enabling use of the KMS keyring.) You can override the detection
logic by setting -DBUILD_AWS_ENC_SDK_CPP=OFF to never build the C++ components or
by setting -DBUILD_AWS_ENC_SDK_CPP=ON to require building the C++ components (and
fail if the C++ dependencies are not found.)
This library is licensed under the Apache 2.0 License.