feat(tls_cxx): Publish mbedtls component

Adds examples and tests.
Also supports DTLS now.

components/mbedtls_cxx/include/mbedtls_wrap.hpp

@@ -0,0 +1,141 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+
+#include <utility>
+#include <memory>
+#include <mbedtls/timing.h>
+#include <mbedtls/ssl_cookie.h>
+#include "mbedtls/ssl.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/error.h"
+
+namespace idf::mbedtls_cxx {
+
+using const_buf = std::pair<const unsigned char *, std::size_t>;
+using buf = std::pair<unsigned char *, std::size_t>;
+
+struct TlsConfig {
+    bool is_dtls;
+    uint32_t timeout;
+    const_buf client_id;
+};
+
+/**
+ * @brief Application wrapper of (D)TLS for authentication and creating encrypted communication channels
+ */
+class Tls {
+public:
+    /**
+     * High level configs for this class are per below: (server/client, with/out verification, TLS/DTLS)
+     */
+    enum class is_server : bool {
+    };
+    enum class do_verify : bool {
+    };
+    enum class is_dtls : bool {
+    };
+
+    Tls();
+
+    virtual ~Tls();
+
+    bool init(is_server server, do_verify verify, TlsConfig *config = nullptr);
+
+    bool init_dtls_cookies();
+
+    bool set_client_id();
+
+    bool deinit();
+
+    int handshake();
+
+    int write(const unsigned char *buf, size_t len);
+
+    int read(unsigned char *buf, size_t len);
+
+    [[nodiscard]] bool set_own_cert(const_buf crt, const_buf key);
+
+    [[nodiscard]] bool set_ca_cert(const_buf crt);
+
+    bool set_hostname(const char *name);
+
+    virtual int send(const unsigned char *buf, size_t len) = 0;
+
+    virtual int recv(unsigned char *buf, size_t len) = 0;
+
+    virtual int recv_timeout(unsigned char *buf, size_t len, int timeout)
+    {
+        return recv(buf, len);
+    }
+
+    size_t get_available_bytes();
+
+protected:
+    /**
+     * mbedTLS internal structures (available after inheritance)
+     */
+    mbedtls_ssl_context ssl_{};
+    mbedtls_x509_crt public_cert_{};
+    mbedtls_pk_context pk_key_{};
+    mbedtls_x509_crt ca_cert_{};
+    mbedtls_ssl_config conf_{};
+    mbedtls_ctr_drbg_context ctr_drbg_{};
+    mbedtls_entropy_context entropy_{};
+    mbedtls_timing_delay_context timer_{};
+    mbedtls_ssl_cookie_ctx cookie_{};
+    const_buf client_id_{};
+
+    virtual void delay() {}
+
+    bool is_server_{false};
+    bool is_dtls_{false};
+
+    bool set_session();
+
+    bool get_session();
+
+    void reset_session();
+
+    bool is_session_loaded();
+
+private:
+    static void print_error(const char *function, int error_code);
+
+    static int bio_write(void *ctx, const unsigned char *buf, size_t len);
+
+    static int bio_read(void *ctx, unsigned char *buf, size_t len);
+
+    static int bio_read_tout(void *ctx, unsigned char *buf, size_t len, uint32_t timeout);
+
+    int mbedtls_pk_parse_key(mbedtls_pk_context *ctx,
+                             const unsigned char *key, size_t keylen,
+                             const unsigned char *pwd, size_t pwdlen);
+
+    struct unique_session {
+        unique_session()
+        {
+            ::mbedtls_ssl_session_init(&s);
+        }
+
+        ~unique_session()
+        {
+            ::mbedtls_ssl_session_free(&s);
+        }
+
+        mbedtls_ssl_session *ptr()
+        {
+            return &s;
+        }
+
+        mbedtls_ssl_session s;
+    };
+
+    std::unique_ptr<unique_session> session_;
+
+};
+}