feat(tls_cxx): Publish mbedtls component

Adds examples and tests.
Also supports DTLS now.

components/mbedtls_cxx/examples/tls_client/CMakeLists.txt

@@ -0,0 +1,11 @@
+# For more information about build system see
+# https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
+# The following five lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.16)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+if("${IDF_TARGET}" STREQUAL "linux")
+    list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/tools/mocks/freertos/")
+endif()
+project(tls_client)

components/mbedtls_cxx/examples/tls_client/README.md

@@ -0,0 +1,4 @@
+# TCP client example
+
+This is a simple example uses `mbedtls_cxx` to connect to a remote echo server.
+The example needs a connection to internet (or a network where the TLS echo-server is available), it could be run on linux target as well as on ESP32.

components/mbedtls_cxx/examples/tls_client/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "tls_client.cpp"
+                    INCLUDE_DIRS ".")

components/mbedtls_cxx/examples/tls_client/main/idf_component.yml

@@ -0,0 +1,7 @@
+dependencies:
+  idf: ">=5.0"
+  espressif/mbedtls_cxx:
+    version: "*"
+    override_path: "../../.."
+  protocol_examples_common:
+    path: ${IDF_PATH}/examples/common_components/protocol_examples_common

components/mbedtls_cxx/examples/tls_client/main/tls_client.cpp

@@ -0,0 +1,152 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <sys/socket.h>
+#include <netdb.h>
+#include <unistd.h>
+#include "esp_log.h"
+#include "mbedtls_wrap.hpp"
+
+using namespace idf::mbedtls_cxx;
+
+namespace {
+constexpr auto *TAG = "simple_tls_client";
+}
+
+class TlsSocketClient: public Tls {
+public:
+    TlsSocketClient() = default;
+    ~TlsSocketClient() override
+    {
+        if (sock >= 0) {
+            ::close(sock);
+        }
+    }
+    int send(const unsigned char *buf, size_t len) override
+    {
+        return ::send(sock, buf, len, 0);
+    }
+    int recv(unsigned char *buf, size_t len) override
+    {
+        return ::recv(sock, buf, len, 0);
+    }
+    bool connect(const char *host, int port)
+    {
+        addr_info addr(host, AF_INET, SOCK_STREAM);
+        if (!addr) {
+            ESP_LOGE(TAG, "Failed to resolve host");
+            return false;
+        }
+        sock = addr.get_sock();
+        if (sock < 0) {
+            ESP_LOGE(TAG, "Failed to create socket");
+            return false;
+        }
+
+        if (::connect(sock, addr.get_addr(port), sizeof(struct sockaddr)) < 0) {
+            ESP_LOGE(TAG, "Failed to connect %d", errno);
+            return false;
+        }
+
+        if (!init(is_server{false}, do_verify{false})) {
+            return false;
+        }
+        return handshake() == 0;
+    }
+
+private:
+    int sock{-1};
+    /**
+     * RAII wrapper of the address_info
+     */
+    struct addr_info {
+        struct addrinfo *ai {
+            nullptr
+        };
+        ~addr_info()
+        {
+            freeaddrinfo(ai);
+        }
+        explicit addr_info(const char *host, int family, int type)
+        {
+            struct addrinfo hints {};
+            hints.ai_family = family;
+            hints.ai_socktype = type;
+            if (getaddrinfo(host, nullptr, &hints, &ai) < 0) {
+                freeaddrinfo(ai);
+                ai = nullptr;
+            }
+        }
+        explicit operator bool() const
+        {
+            return ai != nullptr;
+        }
+        struct sockaddr *get_addr(uint16_t port) const {
+            auto *p = (struct sockaddr_in *)ai->ai_addr;
+            p->sin_port = htons(port);
+            return (struct sockaddr *)p;
+        }
+        int get_sock() const
+        {
+            return socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+        }
+    };
+};
+
+namespace {
+
+void tls_client()
+{
+    const unsigned char message[] = "Hello\n";
+    unsigned char reply[128];
+    TlsSocketClient client;
+    if (!client.connect("tcpbin.com", 4243)) {
+        ESP_LOGE(TAG, "Failed to connect! %d", errno);
+        return;
+    }
+    if (client.write(message, sizeof(message)) < 0) {
+        ESP_LOGE(TAG, "Failed to write!");
+        return;
+    }
+    int len = client.read(reply, sizeof(reply));
+    if (len < 0) {
+        ESP_LOGE(TAG, "Failed to read!");
+        return;
+    }
+    ESP_LOGI(TAG, "Successfully received: %.*s", len, reply);
+}
+
+} // namespace
+
+#if CONFIG_IDF_TARGET_LINUX
+/**
+ * Linux target: We're already connected, just run the client
+ */
+int main()
+{
+    tls_client();
+    return 0;
+}
+#else
+/**
+ * ESP32 chipsets:  Need to initialize system components
+ *                  and connect to network
+ */
+
+#include "nvs_flash.h"
+#include "esp_event.h"
+#include "protocol_examples_common.h"
+#include "esp_netif.h"
+
+extern "C" void app_main()
+{
+    ESP_ERROR_CHECK(nvs_flash_init());
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+    ESP_ERROR_CHECK(example_connect());
+
+    tls_client();
+}
+#endif

components/mbedtls_cxx/examples/tls_client/sdkconfig.defaults

@@ -0,0 +1 @@
+CONFIG_ESP_MAIN_TASK_STACK_SIZE=8192