Allow definition of custom network interfaces (#921)

* Allow definition of custom network interfaces

* Create network client interface class

* Change to PIMPL approach

* Add example for custom network clients

Why:

- Show users how to use multiple network interfaces

This change addresses the need by:

- Adding an example PIO project to use Wi-Fi and GSM/LTE

* Add WebSockets prefix to normal and secure client

Why:

- Avoid name collision
- Fix broken reconnect change

This change addresses the need by:

- Adding WebSockets prefix to all custom clients
- Marking custom client as secure in clientDisconnect()
  - Remove broken fix for reconnecting

examples/esp32_pio/CustomNetworkClient/.clang-format

@@ -0,0 +1 @@
+BasedOnStyle: Google

examples/esp32_pio/CustomNetworkClient/.gitignore

@@ -0,0 +1,2 @@
+.pio
+.vscode

examples/esp32_pio/CustomNetworkClient/platformio.ini

@@ -0,0 +1,25 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:esp32dev]
+platform = espressif32@6.11.0
+board = esp32dev
+framework = arduino
+monitor_speed = 115200
+upload_speed = 921600
+build_flags = 
+    -DCORE_DEBUG_LEVEL=5
+    -D WEBSOCKETS_NETWORK_TYPE=10
+	-D TINY_GSM_MODEM_SIM7600
+lib_deps =
+    digitaldragon/SSLClient@^1.3.2
+    vshymanskyy/StreamDebugger@^1.0.1
+	vshymanskyy/TinyGSM@^0.12.0
+    symlink://../../..

examples/esp32_pio/CustomNetworkClient/readme.md

@@ -0,0 +1,3 @@
+This example project shows how to use a custom NetworkClient class to switch between two underlying network interfaces.
+
+In this case it shows how a board can support Wi-Fi as well as GSM/LTE connectivity. It uses a shim to switch between the two network interfaces, thereby allowing a single binary to handle both interfaces without needing to reboot. This example can be extended to cover other network interfaces that conform to the Client() class interface.

examples/esp32_pio/CustomNetworkClient/src/main.cpp

@@ -0,0 +1,126 @@
+/*
+ * main.cpp
+ *
+ *  Created on: 15.06.2024
+ *
+ */
+
+#include <Arduino.h>
+#include <WebSocketsClient.h>
+#include <WiFiMulti.h>
+
+#include "network_client_impl.h"
+
+WiFiMulti wifiMulti;
+WebSocketsClient webSocket;
+
+#define USE_SERIAL Serial
+
+void setClock() {
+  configTime(0, 0, "pool.ntp.org", "time.nist.gov");
+
+  USE_SERIAL.print(F("Waiting for NTP time sync: "));
+  time_t nowSecs = time(nullptr);
+  while (nowSecs < 8 * 3600 * 2) {
+    delay(500);
+    USE_SERIAL.print(F("."));
+    yield();
+    nowSecs = time(nullptr);
+  }
+
+  USE_SERIAL.println();
+  struct tm timeinfo;
+  gmtime_r(&nowSecs, &timeinfo);
+  USE_SERIAL.print(F("Current time: "));
+  USE_SERIAL.print(asctime(&timeinfo));
+}
+
+void hexdump(const void *mem, uint32_t len, uint8_t cols = 16) {
+  const uint8_t *src = (const uint8_t *)mem;
+  USE_SERIAL.printf("\n[HEXDUMP] Address: 0x%08X len: 0x%X (%d)",
+                    (ptrdiff_t)src, len, len);
+  for (uint32_t i = 0; i < len; i++) {
+    if (i % cols == 0) {
+      USE_SERIAL.printf("\n[0x%08X] 0x%08X: ", (ptrdiff_t)src, i);
+    }
+    USE_SERIAL.printf("%02X ", *src);
+    src++;
+  }
+  USE_SERIAL.printf("\n");
+}
+
+void webSocketEvent(WStype_t type, uint8_t *payload, size_t length) {
+  switch (type) {
+    case WStype_DISCONNECTED:
+      USE_SERIAL.printf("[WSc] Disconnected!\n");
+      break;
+    case WStype_CONNECTED:
+      USE_SERIAL.printf("[WSc] Connected to url: %s\n", payload);
+
+      // send message to server when Connected
+      webSocket.sendTXT("Connected");
+      break;
+    case WStype_TEXT:
+      USE_SERIAL.printf("[WSc] get text: %s\n", payload);
+
+      // send message to server
+      // webSocket.sendTXT("message here");
+      break;
+    case WStype_BIN:
+      USE_SERIAL.printf("[WSc] get binary length: %u\n", length);
+      hexdump(payload, length);
+
+      // send data to server
+      // webSocket.sendBIN(payload, length);
+      break;
+    case WStype_ERROR:
+    case WStype_FRAGMENT_TEXT_START:
+    case WStype_FRAGMENT_BIN_START:
+    case WStype_FRAGMENT:
+    case WStype_FRAGMENT_FIN:
+      break;
+  }
+}
+
+void setup() {
+  USE_SERIAL.begin(115200);
+
+  USE_SERIAL.setDebugOutput(true);
+
+  USE_SERIAL.println();
+  USE_SERIAL.println();
+  USE_SERIAL.println();
+
+  for (uint8_t t = 4; t > 0; t--) {
+    USE_SERIAL.printf("[SETUP] BOOT WAIT %d...\n", t);
+    USE_SERIAL.flush();
+    delay(1000);
+  }
+
+  wifiMulti.addAP("Berge", "BlauerHimmel!");
+
+  // WiFi.disconnect();
+  while (wifiMulti.run() != WL_CONNECTED) {
+    delay(100);
+  }
+
+  // Call to enable WiFi interface to be used by the webSocketClient
+  WebSocketsNetworkClient::Impl::enableWifi();
+
+  setClock();
+
+  // server address, port and URL. This server can be flakey.
+  // Expected response: Request served by 0123456789abcdef
+  webSocket.beginSSL("echo.websocket.org", 443, "/");
+
+  // event handler
+  webSocket.onEvent(webSocketEvent);
+
+  // use HTTP Basic Authorization this is optional enable if needed
+  // webSocket.setAuthorization("user", "Password");
+
+  // try ever 5000 again if connection has failed
+  webSocket.setReconnectInterval(5000);
+}
+
+void loop() { webSocket.loop(); }

examples/esp32_pio/CustomNetworkClient/src/network_client.cpp

@@ -0,0 +1,148 @@
+#include "network_client_impl.h"
+
+WebSocketsNetworkClient::WebSocketsNetworkClient()
+    : _impl(new WebSocketsNetworkClient::Impl()) {}
+WebSocketsNetworkClient::WebSocketsNetworkClient(WiFiClient wifi_client)
+    : _impl(new WebSocketsNetworkClient::Impl()) {}
+WebSocketsNetworkClient::~WebSocketsNetworkClient() {}
+
+int WebSocketsNetworkClient::connect(IPAddress ip, uint16_t port) {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->connect(ip, port);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->connect(ip, port);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClient::connect(const char *host, uint16_t port) {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->connect(host, port);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->connect(host, port);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+int WebSocketsNetworkClient::connect(const char *host, uint16_t port,
+                                     int32_t timeout_ms) {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->connect(host, port, timeout_ms);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->connect(host, port, timeout_ms);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClient::write(uint8_t data) {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->write(data);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->write(data);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClient::write(const uint8_t *buf, size_t size) {
+  Serial.printf("Send_: %zu\n", size);
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->write(buf, size);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->write(buf, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClient::write(const char *str) {
+  const int size = strlen(str);
+  Serial.printf("Send: %zu\n", size);
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->write((const uint8_t *)str, size);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->write((const uint8_t *)str, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClient::available() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->available();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->available();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClient::read() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->read();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->read();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClient::read(uint8_t *buf, size_t size) {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->read(buf, size);
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->read(buf, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClient::peek() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->peek();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->peek();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+void WebSocketsNetworkClient::flush() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->flush();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->flush();
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+void WebSocketsNetworkClient::stop() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->stop();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->stop();
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+uint8_t WebSocketsNetworkClient::connected() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->connected();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->connected();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+WebSocketsNetworkClient::operator bool() {
+  if (_impl->gsm_client_) {
+    return _impl->gsm_client_->operator bool();
+  } else if (_impl->wifi_client_) {
+    return _impl->wifi_client_->operator bool();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}

examples/esp32_pio/CustomNetworkClient/src/network_client_impl.cpp

@@ -0,0 +1,8 @@
+#include "network_client_impl.h"
+
+std::unique_ptr<WiFiClient> WebSocketsNetworkClient::Impl::wifi_client_ = nullptr;
+std::unique_ptr<WiFiClientSecure> WebSocketsNetworkClient::Impl::wifi_client_secure_ =
+    nullptr;
+std::unique_ptr<TinyGsmClient> WebSocketsNetworkClient::Impl::gsm_client_ = nullptr;
+std::unique_ptr<SSLClient> WebSocketsNetworkClient::Impl::gsm_client_secure_ = nullptr;
+const char *WebSocketsNetworkClient::Impl::no_interface_error_ = "No interface";

examples/esp32_pio/CustomNetworkClient/src/network_client_impl.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <SSLClient.h>
+#include <TinyGSM.h>
+#include <WebSocketsNetworkClientSecure.h>
+#include <WiFiClientSecure.h>
+
+struct WebSocketsNetworkClient::Impl {
+  static void enableWifi() {
+    // Do nothing if already enabled
+    if (wifi_client_ && wifi_client_secure_) {
+      return;
+    }
+    wifi_client_ = std::unique_ptr<WiFiClient>(new WiFiClient());
+    wifi_client_secure_ =
+        std::unique_ptr<WiFiClientSecure>(new WiFiClientSecure());
+  }
+  static void disableWifi() {
+    wifi_client_ = nullptr;
+    wifi_client_secure_ = nullptr;
+  }
+  static void enableGsm(TinyGsm* tiny_gsm) {
+    // Do nothing if already enabled
+    if (gsm_client_ && gsm_client_secure_) {
+      return;
+    }
+    gsm_client_ = std::unique_ptr<TinyGsmClient>(new TinyGsmClient(*tiny_gsm));
+    gsm_client_secure_ =
+        std::unique_ptr<SSLClient>(new SSLClient(gsm_client_.get()));
+  }
+  static void disableGsm() {
+    if (gsm_client_secure_) {
+      gsm_client_secure_->stop();
+    }
+    gsm_client_secure_ = nullptr;
+    gsm_client_ = nullptr;
+  }
+
+  static std::unique_ptr<WiFiClient> wifi_client_;
+  static std::unique_ptr<WiFiClientSecure> wifi_client_secure_;
+  static std::unique_ptr<TinyGsmClient> gsm_client_;
+  static std::unique_ptr<SSLClient> gsm_client_secure_;
+
+  static const char* no_interface_error_;
+};

examples/esp32_pio/CustomNetworkClient/src/network_client_secure.cpp

@@ -0,0 +1,191 @@
+#include "network_client_impl.h"
+
+WebSocketsNetworkClientSecure::WebSocketsNetworkClientSecure() {}
+WebSocketsNetworkClientSecure::WebSocketsNetworkClientSecure(
+    WiFiClient wifi_client) {}
+WebSocketsNetworkClientSecure::~WebSocketsNetworkClientSecure() {
+  if (_impl->gsm_client_secure_) {
+    _impl->gsm_client_secure_->stop();
+  }
+}
+
+int WebSocketsNetworkClientSecure::connect(IPAddress ip, uint16_t port) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->connect(ip, port);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->connect(ip, port);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClientSecure::connect(const char *host, uint16_t port) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->connect(host, port);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->connect(host, port);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+int WebSocketsNetworkClientSecure::connect(const char *host, uint16_t port,
+                                           int32_t timeout_ms) {
+  if (_impl->gsm_client_secure_) {
+    // Ignore timeout as will cause read() to block for specified time
+    return _impl->gsm_client_secure_->connect(host, port);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->connect(host, port, timeout_ms);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClientSecure::write(uint8_t data) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->write(data);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->write(data);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClientSecure::write(const uint8_t *buf, size_t size) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->write(buf, size);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->write(buf, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+size_t WebSocketsNetworkClientSecure::write(const char *str) {
+  const int size = strlen(str);
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->write((const uint8_t *)str, size);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->write((const uint8_t *)str, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClientSecure::available() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->available();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->available();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClientSecure::read() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->read();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->read();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClientSecure::read(uint8_t *buf, size_t size) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->read(buf, size);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->read(buf, size);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+int WebSocketsNetworkClientSecure::peek() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->peek();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->peek();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+void WebSocketsNetworkClientSecure::flush() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->flush();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->flush();
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+void WebSocketsNetworkClientSecure::stop() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->stop();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->stop();
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+uint8_t WebSocketsNetworkClientSecure::connected() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->connected();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->connected();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+WebSocketsNetworkClientSecure::operator bool() {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->operator bool();
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->operator bool();
+  }
+  Serial.println(_impl->no_interface_error_);
+  return 0;
+}
+
+void WebSocketsNetworkClientSecure::setCACert(const char *rootCA) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->setCertificate(rootCA);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->setCACert(rootCA);
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+void WebSocketsNetworkClientSecure::setCACertBundle(const uint8_t *bundle) {
+  if (_impl->gsm_client_secure_) {
+    return _impl->gsm_client_secure_->setCACertBundle(bundle);
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->setCACertBundle(bundle);
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+void WebSocketsNetworkClientSecure::setInsecure() {
+  if (_impl->gsm_client_secure_) {
+    _impl->gsm_client_secure_->setInsecure();
+  } else if (_impl->wifi_client_secure_) {
+    _impl->wifi_client_secure_->setInsecure();
+  }
+  Serial.println(_impl->no_interface_error_);
+}
+
+bool WebSocketsNetworkClientSecure::verify(const char *fingerprint,
+                                           const char *domain_name) {
+  if (_impl->gsm_client_secure_) {
+    // Simply calling SSLClient::verify() will break TLS handshake
+    // Can be skipped as verification is done by SSLClient itself,
+    // ArduinoWebSockets need not call it
+    return true;
+  } else if (_impl->wifi_client_secure_) {
+    return _impl->wifi_client_secure_->verify(fingerprint, domain_name);
+  }
+  Serial.println(_impl->no_interface_error_);
+  return false;
+}

src/WebSockets.h

@@ -135,6 +135,7 @@
 #define NETWORK_UNOWIFIR4 (7)
 #define NETWORK_WIFI_NINA (8)
 #define NETWORK_SAMD_SEED (9)
+#define NETWORK_CUSTOM (10)
 
 // max size of the WS Message Header
 #define WEBSOCKETS_MAX_HEADER_SIZE (14)
@@ -286,6 +287,14 @@
 #define WEBSOCKETS_NETWORK_CLASS WiFiClient
 #define WEBSOCKETS_NETWORK_SERVER_CLASS WiFiServer
 
+#elif(WEBSOCKETS_NETWORK_TYPE == NETWORK_CUSTOM)
+#include <WebSocketsNetworkClientSecure.h>
+#include <WiFiServer.h>
+
+#define SSL_AXTLS
+#define WEBSOCKETS_NETWORK_CLASS WebSocketsNetworkClient
+#define WEBSOCKETS_NETWORK_SSL_CLASS WebSocketsNetworkClientSecure
+#define WEBSOCKETS_NETWORK_SERVER_CLASS WiFiServer
 #else
 #error "no network type selected!"
 #endif
@@ -368,7 +377,7 @@ typedef struct {
 
 #if defined(HAS_SSL)
     bool isSSL = false;    ///< run in ssl mode
-    WEBSOCKETS_NETWORK_SSL_CLASS * ssl;
+    WEBSOCKETS_NETWORK_SSL_CLASS * ssl = nullptr;
 #endif
 
     String cUrl;           ///< http url

src/WebSocketsClient.cpp

@@ -525,7 +525,7 @@ void WebSocketsClient::messageReceived(WSclient_t * client, WSopcode_t opcode, u
 void WebSocketsClient::clientDisconnect(WSclient_t * client) {
     bool event = false;
 
-#if(WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266) || (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP32) || (WEBSOCKETS_NETWORK_TYPE == NETWORK_RP2040)
+#if(WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266) || (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP32) || (WEBSOCKETS_NETWORK_TYPE == NETWORK_RP2040) || (WEBSOCKETS_NETWORK_TYPE == NETWORK_CUSTOM)
     if(client->isSSL && client->ssl) {
         if(client->ssl->connected()) {
             client->ssl->flush();

src/WebSocketsNetworkClient.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <Client.h>
+#include <WiFiClient.h>
+
+class WebSocketsNetworkClient : public Client {
+  public:
+    struct Impl;
+    std::unique_ptr<Impl> _impl;
+
+    WebSocketsNetworkClient();
+    WebSocketsNetworkClient(WiFiClient wifi_client);
+    virtual ~WebSocketsNetworkClient();
+
+    virtual int connect(IPAddress ip, uint16_t port);
+    virtual int connect(const char * host, uint16_t port);
+    virtual int connect(const char * host, uint16_t port, int32_t timeout);
+    virtual size_t write(uint8_t);
+    virtual size_t write(const uint8_t * buf, size_t size);
+    virtual size_t write(const char * str);
+    virtual int available();
+    virtual int read();
+    virtual int read(uint8_t * buf, size_t size);
+    virtual int peek();
+    virtual void flush();
+    virtual void stop();
+    virtual uint8_t connected();
+    virtual operator bool();
+};

src/WebSocketsNetworkClientSecure.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <WebSocketsNetworkClient.h>
+
+class WebSocketsNetworkClientSecure : public WebSocketsNetworkClient {
+  public:
+    WebSocketsNetworkClientSecure();
+    WebSocketsNetworkClientSecure(WiFiClient wifi_client);
+    virtual ~WebSocketsNetworkClientSecure();
+
+    int connect(IPAddress ip, uint16_t port) override;
+    int connect(const char * host, uint16_t port) override;
+    int connect(const char * host, uint16_t port, int32_t timeout) override;
+    size_t write(uint8_t) override;
+    size_t write(const uint8_t * buf, size_t size) override;
+    size_t write(const char * str) override;
+    int available() override;
+    int read() override;
+    int read(uint8_t * buf, size_t size) override;
+    int peek() override;
+    void flush() override;
+    void stop() override;
+    uint8_t connected() override;
+    operator bool() override;
+
+    void setCACert(const char * rootCA);
+    void setCACertBundle(const uint8_t * bundle);
+    void setInsecure();
+    bool verify(const char * fingerprint, const char * domain_name);
+};