Add jwt example.

CMakeLists.txt

@@ -1,4 +1,10 @@
 cmake_minimum_required(VERSION 3.5)
+
 project(jwp-mosquitto-plugin)
 
+add_subdirectory(ext/jwt-cpp)
+
 add_library(jwp-plugin SHARED src/jwp-plugin.cpp)
+
+add_executable(jwt-example src/jwt-example.cpp)
+target_link_libraries(jwt-example PRIVATE jwt-cpp)

README.md

@@ -1 +1,7 @@
 sudo apt install mosquitto-dev g++ cmake libmosquitto-dev mosquitto-clients
+
+sudo apt install openssl libssl-dev
+
+
+openssl genpkey -algorithm Ed25519 -out priv.key
+openssl pkey -in priv.key -pubout > pub.key

src/jwt-example.cpp

@@ -0,0 +1,55 @@
+#include <jwt-cpp/jwt.h>
+#include <string>
+#include <iostream>
+
+int main(int argc, char *argv[])
+{
+    std::string pub_key = R"(-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEA+IYMWskcPLcC8IsUy6xsj3whqlzYwFWuAmVR7ue/LLw=
+-----END PUBLIC KEY-----)";
+    std::string priv_key = R"(-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEID6d/A9UnVV5xXf9RAvXSNTk/a1QNUrzfvawzEAWDh3e
+-----END PRIVATE KEY-----)";
+
+    auto token = jwt::create()
+        .set_type("JWT")
+        .set_issuer("jamesp")
+        .set_subject("jimmy")
+        .set_audience("mqtt")
+        .set_payload_claim("topics", jwt::claim(std::string{"{'/help/*', '/test/*'}"}))
+        .set_expires_at(std::chrono::system_clock::now())
+        .sign(jwt::algorithm::ed25519(pub_key, priv_key, "", ""));
+
+    std::cout << "Token: " << token << std::endl;
+
+    auto verifier = jwt::verify()
+        .allow_algorithm(jwt::algorithm::ed25519(pub_key, "", "", ""))
+        .with_issuer("jamesp");
+
+    auto decoded = jwt::decode(token);
+
+    try
+    {
+        verifier.verify(decoded);
+    }
+    catch(jwt::error::token_verification_exception& exception)
+    {
+        std::cout << exception.what() << std::endl;
+        return -1;
+    }
+
+    for(auto& e : decoded.get_header_claims())
+    {
+        std::cout << e.first << ": " << e.second.to_json() << std::endl;
+    }
+
+    std::cout << std::endl;
+
+    for(auto& e : decoded.get_payload_claims())
+    {
+        std::cout << e.first << ": " << e.second.to_json() << std::endl;
+    }
+
+    return 0;
+}
+