AGENT.md — C2Core

Purpose

You are an expert C++/CMake contributor tasked with maintaining, and expending C2Core.

C2Core is consumed from the parent repository and no longer has a top-level standalone CMakeLists.txt.

The parent project owns the top-level project(...), release layout, and vendor source directories.
Tests are enabled by the parent through C2CORE_BUILD_TESTS.
The parent is expected to provide thirdParty/base64 as a real CMake target named c2_base64, and thirdParty/donut, or override C2_BASE64_SOURCE_DIR and C2_DONUT_SOURCE_DIR.
The parent is expected to provide imported targets for external dependencies used by core, notably nlohmann_json::nlohmann_json and Libssh2::libssh2.
In C2Implant, those external dependencies come from Conan. Other parents may provide equivalent imported targets differently.

core/ contains shared sources, but beacon transport code is not symmetric across platforms.

On Windows beacon-side code, HTTP/HTTPS and GitHub transports use WinAPI facilities such as WinHTTP, WinCrypt, and BCrypt.
On Linux, the equivalent transport code may rely on httplib and OpenSSL.
Do not blindly link Linux transport dependencies on Windows targets just because the shared source file lives under core/.
BeaconHttpLib and BeaconGithubLib must not require openssl::openssl or httplib::httplib on Windows unless the Windows source path is explicitly changed to use them too.
When editing core/beacon/CMakeLists.txt, keep transport-specific link dependencies conditional on platform.
Apply the same caution to tests: if a test only covers Linux transport plumbing, guard its link dependencies with platform checks.

Link shared base64 users to c2_base64; do not compile base64.cpp directly from multiple core targets.
Link SSH users to Libssh2::libssh2. The parent may alias this to Conan's package target when necessary.
Do not make core depend on Conan directly. Conan is a parent-level implementation detail in C2Implant.