OpenZiti C SDK

The OpenZiti C SDK allows developers to create their own custom OpenZiti network endpoint applications.

OpenZiti is a modern, programmable network overlay with associated edge components, for application-embedded, zero trust network connectivity, written by developers for developers. The SDK harnesses that power via APIs that allow developers to imagine and develop solutions beyond what OpenZiti handles by default.

This SDK does the following:

• enable network endpoint clients allow a device to dial (access) or bind (host) OpenZiti Services
• provides authentication interfaces for x509 certificates flows
• collects and submits security posture collection/submission for Posture Checks
• allows applications to bind or dial services via standard socket interfaces

Configuring Your Application to use OpenZiti C SDK

The easiest way to embed Ziti SDK in your app is to pull the project into your CMake build

FetchContent_Declare(ziti-sdk-c
        GIT_REPOSITORY https://github.com/openziti/ziti-sdk-c.git
        GIT_TAG ${LATEST_ZITI_RELEASE}
        )
FetchContent_MakeAvailable(ziti-sdk-c)

# ...
# ...

add_executable(most-secure-app-ever ${my_sources})
target_link_libraries(most-secure-app-ever PRIVATE ziti)

You will also need other libraries that OpenZiti SDK uses (they are specified in vcpkg.json):

library	usage
libuv	event loop
openssl	TLS
zlib	HTTPS compression
llhttp	HTTP parsing
libsodium	OpenZiti end-to-end encryption

There are multiple ways to get those 3rd party dependencies into your build: system level, CMake FetchContent, vcpkg, etc. We recommend using vcpkg.

If you want to contribute/build/hack this SDK in standalone mode see the BUILD.md for information on how to do it.

Using OpenZiti in Your Application

High-Level (Zitilib) API

The high-level API was developed to simplify embedding OpenZiti in an application. The main feature of this API is presenting Ziti connections as regular socket file descriptors (or handles on Windows). These sockets can be used both blocking and non-blocking modes.

SDK Initialization and Teardown

There are just three functions that cover SDK initialization and teardown.

function	purpose
Ziti_lib_init()	initializes Ziti SDK background event loop that runs all internal SDK tasks
Ziti_load_context()	loads an enrolled ziti identity from the provided file
Ziti_lib_shutdown()	gracefully shuts down all loaded identities and terminates the event loop

#include <ziti/zitilib.h>

int main(int argc, char *argv[]) {

    const char *identity_file = process_args(argc, argv);

    Ziti_lib_init();
    ziti_context ztx = Ziti_load_context(identity_file);

    ...


    Ziti_lib_shutdown();
}

Once ziti_context is loaded it can be used to dial a service or bind to a service (provided the identity has proper access to it).

Dialing a service

function	usage
Ziti_connect(sock, ztx, service, terminator)	connects given socket to the service/terminator within the context
Ziti_connect_addr(sock, hostname, port)	connects given socket to the specified intercept address

      ziti_socket_t sock = Ziti_socket(SOCK_STREAM);
      int error = Ziti_connect(sock, ztx, "my-secure-service", NULL);

      // use sock as normal socket
      do {
          write(sock, ...);
          read(sock, ...);

      } while (!done);

      close(sock);

Binding to a service

function	usage
Ziti_bind(srv, ztx, service, terminator)	binds given socket to the service/terminator within the context
Ziti_listen(sock, backlog)	sets maximum number of pending inbound connections (similar to TCP backlog)
Ziti_accept(srv, caller, caller_len)	accepts incoming connection and returns peer socket/handle

      ziti_socket_t srv = Ziti_socket(SOCK_STREAM);
      int error = Ziti_bind(srv, ztx, "my-secure-service", NULL);
      Ziti_listen(srv, 10); // sets accept backlog

      do {
          char caller[128];
          ziti_socket_t clt = Ziti_accept(srv, caller, (int)sizeof(caller));

          // use client as normal socket
          process_client(clt);

      } while (!done);

      close(srv);

Getting Help

---

Please use these community resources for getting help. We use GitHub issues for tracking bugs and feature requests and have limited bandwidth to address them.

• Read the docs
• Ask a question on Discourse

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