OpenSSL-CMake

CMake script supplying OpenSSL libraries conveniently, encapsulating the OpenSSL build system on various platforms.

Features

• Allows usage of system OpenSSL
• Allows trivial and complex building of OpenSSL
• Allows cross compilation, especially for Android
• Defaults to prebuilt binaries

System OpenSSL

To use the system OpenSSL, simply set SYSTEM_OPENSSL=ON.

Prebuilt OpenSSL

Default behaviour is the download of a prebuilt binary. This is only intended as a convenience for debugging purposes and NOT for production use. Available prebuilt binaries can be viewed here.

Build OpenSSL

In order to build OpenSSL, set BUILD_OPENSSL=ON along with the version name, for example OPENSSL_BUILD_VERSION=3.1.5. View available versions here.

General Cross Compile

Cross compilation is enabled using CROSS=ON and the target is specified using CROSS_TARGET=mingw along with the optional CROSS_PREFIX=mingw32-.

Android Cross Compile

Android requires a special CROSS_ANDROID=ON. Using OpenSSL-CMake from Gradle's native build does not require additional settings. Otherwise, it is required to set the general NDK variables ANDROID_NDK_ROOT, ANDROID_EABI, ANDROID_ARCH, ANDROID_API, ANDROID_MACHINE.
Cross compile was tested with NDK r18b, r19c and r20.

Usage

1. Add OpenSSL-CMake as a submodule to your Git project using git submodule add <URL> external/openssl-cmake
2. Initialize the submodule using git submodule update --init
3. In your CMakeLists.txt include the directory using add_subdirectory(external/openssl-cmake)
4. Link against ssl and crypto targets, which will also include the headers

Licensing

These scripts, unless otherwise stated, are subject to the MIT license.