WiFiClientSecure: use context (#7680)

* move WiFiClientSecure to WiFiClientSecureCtx and add WiFiClientSecure wrapper to handle the context
* explicitely disable context copy constructor (similar to operator=)
* move (static) probeMaxFragmentLength back from ctx to WiFiClientSecure
* route sslclient::status() to context's ::status()

libraries/ESP8266WiFi/src/BearSSLHelpers.h

@@ -134,7 +134,7 @@ class X509List {
 class WiFiClientSecure;
 
 class Session {
-  friend class WiFiClientSecure;
+  friend class WiFiClientSecureCtx;
 
   public:
     Session() { memset(&_session, 0, sizeof(_session)); }

libraries/ESP8266WiFi/src/WiFiClient.h

@@ -52,7 +52,7 @@ public:
   WiFiClient(const WiFiClient&);
   WiFiClient& operator=(const WiFiClient&);
 
-  uint8_t status();
+  virtual uint8_t status();
   virtual int connect(IPAddress ip, uint16_t port) override;
   virtual int connect(const char *host, uint16_t port) override;
   virtual int connect(const String& host, uint16_t port);

libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp

@@ -67,7 +67,7 @@ extern "C" {
 
 namespace BearSSL {
 
-void WiFiClientSecure::_clear() {
+void WiFiClientSecureCtx::_clear() {
   // TLS handshake may take more than the 5 second default timeout
   _timeout = 15000;
 
@@ -91,7 +91,7 @@ void WiFiClientSecure::_clear() {
   _cipher_cnt = 0;
 }
 
-void WiFiClientSecure::_clearAuthenticationSettings() {
+void WiFiClientSecureCtx::_clearAuthenticationSettings() {
   _use_insecure = false;
   _use_fingerprint = false;
   _use_self_signed = false;
@@ -100,7 +100,7 @@ void WiFiClientSecure::_clearAuthenticationSettings() {
 }
 
 
-WiFiClientSecure::WiFiClientSecure() : WiFiClient() {
+WiFiClientSecureCtx::WiFiClientSecureCtx() : WiFiClient() {
   _clear();
   _clearAuthenticationSettings();
   _certStore = nullptr; // Don't want to remove cert store on a clear, should be long lived
@@ -108,12 +108,7 @@ WiFiClientSecure::WiFiClientSecure() : WiFiClient() {
   stack_thunk_add_ref();
 }
 
-WiFiClientSecure::WiFiClientSecure(const WiFiClientSecure &rhs) : WiFiClient(rhs) {
+WiFiClientSecureCtx::~WiFiClientSecureCtx() {
-  *this = rhs;
-  stack_thunk_add_ref();
-}
-
-WiFiClientSecure::~WiFiClientSecure() {
   if (_client) {
     _client->unref();
     _client = nullptr;
@@ -123,7 +118,7 @@ WiFiClientSecure::~WiFiClientSecure() {
   stack_thunk_del_ref();
 }
 
-WiFiClientSecure::WiFiClientSecure(ClientContext* client,
+WiFiClientSecureCtx::WiFiClientSecureCtx(ClientContext* client,
                                      const X509List *chain, const PrivateKey *sk,
                                      int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta) {
   _clear();
@@ -140,7 +135,7 @@ WiFiClientSecure::WiFiClientSecure(ClientContext* client,
   }
 }
 
-WiFiClientSecure::WiFiClientSecure(ClientContext *client,
+WiFiClientSecureCtx::WiFiClientSecureCtx(ClientContext *client,
                                      const X509List *chain,
                                      unsigned cert_issuer_key_type, const PrivateKey *sk,
                                      int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta) {
@@ -158,12 +153,12 @@ WiFiClientSecure::WiFiClientSecure(ClientContext *client,
   }
 }
 
-void WiFiClientSecure::setClientRSACert(const X509List *chain, const PrivateKey *sk) {
+void WiFiClientSecureCtx::setClientRSACert(const X509List *chain, const PrivateKey *sk) {
   _chain = chain;
   _sk = sk;
 }
 
-void WiFiClientSecure::setClientECCert(const X509List *chain,
+void WiFiClientSecureCtx::setClientECCert(const X509List *chain,
                                         const PrivateKey *sk, unsigned allowed_usages, unsigned cert_issuer_key_type) {
   _chain = chain;
   _sk = sk;
@@ -171,7 +166,7 @@ void WiFiClientSecure::setClientECCert(const X509List *chain,
   _cert_issuer_key_type = cert_issuer_key_type;
 }
 
-void WiFiClientSecure::setBufferSizes(int recv, int xmit) {
+void WiFiClientSecureCtx::setBufferSizes(int recv, int xmit) {
   // Following constants taken from bearssl/src/ssl/ssl_engine.c (not exported unfortunately)
   const int MAX_OUT_OVERHEAD = 85;
   const int MAX_IN_OVERHEAD = 325;
@@ -187,7 +182,7 @@ void WiFiClientSecure::setBufferSizes(int recv, int xmit) {
   _iobuf_out_size = xmit;
 }
 
-bool WiFiClientSecure::stop(unsigned int maxWaitMs) {
+bool WiFiClientSecureCtx::stop(unsigned int maxWaitMs) {
   bool ret = WiFiClient::stop(maxWaitMs); // calls our virtual flush()
   // Only if we've already connected, store session params and clear the connection options
   if (_handshake_done) {
@@ -199,19 +194,19 @@ bool WiFiClientSecure::stop(unsigned int maxWaitMs) {
   return ret;
 }
 
-bool WiFiClientSecure::flush(unsigned int maxWaitMs) {
+bool WiFiClientSecureCtx::flush(unsigned int maxWaitMs) {
   (void) _run_until(BR_SSL_SENDAPP);
   return WiFiClient::flush(maxWaitMs);
 }
 
-int WiFiClientSecure::connect(IPAddress ip, uint16_t port) {
+int WiFiClientSecureCtx::connect(IPAddress ip, uint16_t port) {
   if (!WiFiClient::connect(ip, port)) {
     return 0;
   }
   return _connectSSL(nullptr);
 }
 
-int WiFiClientSecure::connect(const char* name, uint16_t port) {
+int WiFiClientSecureCtx::connect(const char* name, uint16_t port) {
   IPAddress remote_addr;
   if (!WiFi.hostByName(name, remote_addr)) {
     DEBUG_BSSL("connect: Name lookup failure\n");
@@ -224,11 +219,11 @@ int WiFiClientSecure::connect(const char* name, uint16_t port) {
   return _connectSSL(name);
 }
 
-int WiFiClientSecure::connect(const String& host, uint16_t port) {
+int WiFiClientSecureCtx::connect(const String& host, uint16_t port) {
   return connect(host.c_str(), port);
 }
 
-void WiFiClientSecure::_freeSSL() {
+void WiFiClientSecureCtx::_freeSSL() {
   // These are smart pointers and will free if refcnt==0
   _sc = nullptr;
   _sc_svr = nullptr;
@@ -245,18 +240,18 @@ void WiFiClientSecure::_freeSSL() {
   _timeout = 15000;
 }
 
-bool WiFiClientSecure::_clientConnected() {
+bool WiFiClientSecureCtx::_clientConnected() {
   return (_client && _client->state() == ESTABLISHED);
 }
 
-uint8_t WiFiClientSecure::connected() {
+uint8_t WiFiClientSecureCtx::connected() {
   if (available() || (_clientConnected() && _handshake_done && (br_ssl_engine_current_state(_eng) != BR_SSL_CLOSED))) {
     return true;
   }
   return false;
 }
 
-size_t WiFiClientSecure::_write(const uint8_t *buf, size_t size, bool pmem) {
+size_t WiFiClientSecureCtx::_write(const uint8_t *buf, size_t size, bool pmem) {
   size_t sent_bytes = 0;
 
   if (!connected() || !size || !_handshake_done) {
@@ -297,16 +292,16 @@ size_t WiFiClientSecure::_write(const uint8_t *buf, size_t size, bool pmem) {
   return sent_bytes;
 }
 
-size_t WiFiClientSecure::write(const uint8_t *buf, size_t size) {
+size_t WiFiClientSecureCtx::write(const uint8_t *buf, size_t size) {
   return _write(buf, size, false);
 }
 
-size_t WiFiClientSecure::write_P(PGM_P buf, size_t size) {
+size_t WiFiClientSecureCtx::write_P(PGM_P buf, size_t size) {
   return _write((const uint8_t *)buf, size, true);
 }
 
 // We have to manually read and send individual chunks.
-size_t WiFiClientSecure::write(Stream& stream) {
+size_t WiFiClientSecureCtx::write(Stream& stream) {
   size_t totalSent = 0;
   size_t countRead;
   size_t countSent;
@@ -329,7 +324,7 @@ size_t WiFiClientSecure::write(Stream& stream) {
   return totalSent;
 }
 
-int WiFiClientSecure::read(uint8_t *buf, size_t size) {
+int WiFiClientSecureCtx::read(uint8_t *buf, size_t size) {
   if (!ctx_present() || !_handshake_done) {
     return -1;
   }
@@ -361,7 +356,7 @@ int WiFiClientSecure::read(uint8_t *buf, size_t size) {
   return 0; // If we're connected, no error but no read.
 }
 
-int WiFiClientSecure::read() {
+int WiFiClientSecureCtx::read() {
   uint8_t c;
   if (1 == read(&c, 1)) {
     return c;
@@ -370,7 +365,7 @@ int WiFiClientSecure::read() {
   return -1;
 }
 
-int WiFiClientSecure::available() {
+int WiFiClientSecureCtx::available() {
   if (_recvapp_buf) {
     return _recvapp_len;  // Anything from last call?
   }
@@ -391,7 +386,7 @@ int WiFiClientSecure::available() {
   return 0;
 }
 
-int WiFiClientSecure::peek() {
+int WiFiClientSecureCtx::peek() {
   if (!ctx_present() || !available()) {
     DEBUG_BSSL("peek: Not connected, none left available\n");
     return -1;
@@ -403,7 +398,7 @@ int WiFiClientSecure::peek() {
   return -1;
 }
 
-size_t WiFiClientSecure::peekBytes(uint8_t *buffer, size_t length) {
+size_t WiFiClientSecureCtx::peekBytes(uint8_t *buffer, size_t length) {
   size_t to_copy = 0;
   if (!ctx_present()) {
     DEBUG_BSSL("peekBytes: Not connected\n");
@@ -426,7 +421,7 @@ size_t WiFiClientSecure::peekBytes(uint8_t *buffer, size_t length) {
    combination of both (the combination matches either). When a match is
    achieved, this function returns 0. On error, it returns -1.
 */
-int WiFiClientSecure::_run_until(unsigned target, bool blocking) {
+int WiFiClientSecureCtx::_run_until(unsigned target, bool blocking) {
   if (!ctx_present()) {
     DEBUG_BSSL("_run_until: Not connected\n");
     return -1;
@@ -550,7 +545,7 @@ int WiFiClientSecure::_run_until(unsigned target, bool blocking) {
   return -1;
 }
 
-bool WiFiClientSecure::_wait_for_handshake() {
+bool WiFiClientSecureCtx::_wait_for_handshake() {
   _handshake_done = false;
   while (!_handshake_done && _clientConnected()) {
     int ret = _run_until(BR_SSL_SENDAPP);
@@ -575,7 +570,7 @@ static uint8_t htoi (unsigned char c)
 }
 
 // Set a fingerprint by parsing an ASCII string
-bool WiFiClientSecure::setFingerprint(const char *fpStr) {
+bool WiFiClientSecureCtx::setFingerprint(const char *fpStr) {
   int idx = 0;
   uint8_t c, d;
   uint8_t fp[20];
@@ -968,7 +963,7 @@ extern "C" {
 }
 
 // Set custom list of ciphers
-bool WiFiClientSecure::setCiphers(const uint16_t *cipherAry, int cipherCount) {
+bool WiFiClientSecureCtx::setCiphers(const uint16_t *cipherAry, int cipherCount) {
   _cipher_list = nullptr;
   _cipher_list = std::shared_ptr<uint16_t>(new (std::nothrow) uint16_t[cipherCount], std::default_delete<uint16_t[]>());
   if (!_cipher_list.get()) {
@@ -980,16 +975,16 @@ bool WiFiClientSecure::setCiphers(const uint16_t *cipherAry, int cipherCount) {
   return true;
 }
 
-bool WiFiClientSecure::setCiphersLessSecure() {
+bool WiFiClientSecureCtx::setCiphersLessSecure() {
   return setCiphers(faster_suites_P, sizeof(faster_suites_P)/sizeof(faster_suites_P[0]));
 }
 
-bool WiFiClientSecure::setCiphers(std::vector<uint16_t> list) {
+bool WiFiClientSecureCtx::setCiphers(const std::vector<uint16_t>& list) {
   return setCiphers(&list[0], list.size());
 }
 
 // Installs the appropriate X509 cert validation method for a client connection
-bool WiFiClientSecure::_installClientX509Validator() {
+bool WiFiClientSecureCtx::_installClientX509Validator() {
   if (_use_insecure || _use_fingerprint || _use_self_signed) {
     // Use common insecure x509 authenticator
     _x509_insecure = std::make_shared<struct br_x509_insecure_context>();
@@ -1046,7 +1041,7 @@ bool WiFiClientSecure::_installClientX509Validator() {
 
 // Called by connect() to do the actual SSL setup and handshake.
 // Returns if the SSL handshake succeeded.
-bool WiFiClientSecure::_connectSSL(const char* hostName) {
+bool WiFiClientSecureCtx::_connectSSL(const char* hostName) {
   DEBUG_BSSL("_connectSSL: start connection\n");
   _freeSSL();
   _oom_err = false;
@@ -1136,7 +1131,7 @@ bool WiFiClientSecure::_connectSSL(const char* hostName) {
 
 // Slightly different X509 setup for servers who want to validate client
 // certificates, so factor it out as it's used in RSA and EC servers.
-bool WiFiClientSecure::_installServerX509Validator(const X509List *client_CA_ta) {
+bool WiFiClientSecureCtx::_installServerX509Validator(const X509List *client_CA_ta) {
   if (client_CA_ta) {
     _ta = client_CA_ta;
     // X509 minimal validator.  Checks dates, cert chain for trusted CA, etc.
@@ -1169,7 +1164,7 @@ bool WiFiClientSecure::_installServerX509Validator(const X509List *client_CA_ta)
 
 
 // Called by WiFiServerBearSSL when an RSA cert/key is specified.
-bool WiFiClientSecure::_connectSSLServerRSA(const X509List *chain,
+bool WiFiClientSecureCtx::_connectSSLServerRSA(const X509List *chain,
     const PrivateKey *sk,
     const X509List *client_CA_ta) {
   _freeSSL();
@@ -1205,7 +1200,7 @@ bool WiFiClientSecure::_connectSSLServerRSA(const X509List *chain,
 }
 
 // Called by WiFiServerBearSSL when an elliptic curve cert/key is specified.
-bool WiFiClientSecure::_connectSSLServerEC(const X509List *chain,
+bool WiFiClientSecureCtx::_connectSSLServerEC(const X509List *chain,
     unsigned cert_issuer_key_type, const PrivateKey *sk,
     const X509List *client_CA_ta) {
 #ifndef BEARSSL_SSL_BASIC
@@ -1251,7 +1246,7 @@ bool WiFiClientSecure::_connectSSLServerEC(const X509List *chain,
 
 // Returns an error ID and possibly a string (if dest != null) of the last
 // BearSSL reported error.
-int WiFiClientSecure::getLastSSLError(char *dest, size_t len) {
+int WiFiClientSecureCtx::getLastSSLError(char *dest, size_t len) {
   int err = 0;
   const char *t = PSTR("OK");
   const char *recv_fatal = "";

libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.h

@@ -31,13 +31,13 @@
 
 namespace BearSSL {
 
-class WiFiClientSecure : public WiFiClient {
+class WiFiClientSecureCtx : public WiFiClient {
   public:
-    WiFiClientSecure();
+    WiFiClientSecureCtx();
-    WiFiClientSecure(const WiFiClientSecure &rhs);
+    WiFiClientSecureCtx(const WiFiClientSecure &rhs) = delete;
-    ~WiFiClientSecure() override;
+    ~WiFiClientSecureCtx() override;
 
-    WiFiClientSecure& operator=(const WiFiClientSecure&) = default; // The shared-ptrs handle themselves automatically
+    WiFiClientSecureCtx& operator=(const WiFiClientSecureCtx&) = delete;
 
     int connect(IPAddress ip, uint16_t port) override;
     int connect(const String& host, uint16_t port) override;
@@ -46,12 +46,6 @@ class WiFiClientSecure : public WiFiClient {
     uint8_t connected() override;
     size_t write(const uint8_t *buf, size_t size) override;
     size_t write_P(PGM_P buf, size_t size) override;
-    size_t write(const char *buf) {
-      return write((const uint8_t*)buf, strlen(buf));
-    }
-    size_t write_P(const char *buf) {
-      return write_P((PGM_P)buf, strlen_P(buf));
-    }
     size_t write(Stream& stream); // Note this is not virtual
     int read(uint8_t *buf, size_t size) override;
     int available() override;
@@ -123,14 +117,9 @@ class WiFiClientSecure : public WiFiClient {
     // Select specific ciphers (i.e. optimize for speed over security)
     // These may be in PROGMEM or RAM, either will run properly
     bool setCiphers(const uint16_t *cipherAry, int cipherCount);
-    bool setCiphers(std::vector<uint16_t> list);
+    bool setCiphers(const std::vector<uint16_t>& list);
     bool setCiphersLessSecure(); // Only use the limited set of RSA ciphers without EC
 
-    // Check for Maximum Fragment Length support for given len before connection (possibly insecure)
-    static bool probeMaxFragmentLength(IPAddress ip, uint16_t port, uint16_t len);
-    static bool probeMaxFragmentLength(const char *hostname, uint16_t port, uint16_t len);
-    static bool probeMaxFragmentLength(const String& host, uint16_t port, uint16_t len);
-
   protected:
     bool _connectSSL(const char *hostName); // Do initial SSL handshake
 
@@ -188,10 +177,10 @@ class WiFiClientSecure : public WiFiClient {
     unsigned _cert_issuer_key_type;
 
     // Methods for handling server.available() call which returns a client connection.
-    friend class WiFiServerSecure; // Server needs to access these constructors
+    friend class WiFiClientSecure; // access to private context constructors
-    WiFiClientSecure(ClientContext *client, const X509List *chain, unsigned cert_issuer_key_type,
+    WiFiClientSecureCtx(ClientContext *client, const X509List *chain, unsigned cert_issuer_key_type,
                       const PrivateKey *sk, int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta);
-    WiFiClientSecure(ClientContext* client, const X509List *chain, const PrivateKey *sk,
+    WiFiClientSecureCtx(ClientContext* client, const X509List *chain, const PrivateKey *sk,
                       int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta);
 
     // RSA keyed server
@@ -205,8 +194,113 @@ class WiFiClientSecure : public WiFiClient {
     bool _installServerX509Validator(const X509List *client_CA_ta); // Setup X509 client cert validation, if supplied
 
     uint8_t *_streamLoad(Stream& stream, size_t size);
-};
+}; // class WiFiClientSecureCtx
 
-};
+
+class WiFiClientSecure : public WiFiClient {
+
+  // WiFiClient's "ClientContext* _client" is always nullptr in this class.
+  // Instead, all virtual functions call their counterpart in "WiFiClientecureCtx* _ctx"
+  //          which also derives from WiFiClient (this parent is the one which is eventually used)
+
+  public:
+
+    WiFiClientSecure():_ctx(new WiFiClientSecureCtx()) { }
+    WiFiClientSecure(const WiFiClientSecure &rhs): WiFiClient(), _ctx(rhs._ctx) { }
+    ~WiFiClientSecure() override { _ctx = nullptr; }
+
+    WiFiClientSecure& operator=(const WiFiClientSecure&) = default; // The shared-ptrs handle themselves automatically
+
+    uint8_t status() override { return _ctx->status(); }
+    int connect(IPAddress ip, uint16_t port) override { return _ctx->connect(ip, port); }
+    int connect(const String& host, uint16_t port) override { return _ctx->connect(host, port); }
+    int connect(const char* name, uint16_t port) override { return _ctx->connect(name, port); }
+
+    uint8_t connected() override { return _ctx->connected(); }
+    size_t write(const uint8_t *buf, size_t size) override { return _ctx->write(buf, size); }
+    size_t write_P(PGM_P buf, size_t size) override { return _ctx->write_P(buf, size); }
+    size_t write(const char *buf) { return write((const uint8_t*)buf, strlen(buf)); }
+    size_t write_P(const char *buf) { return write_P((PGM_P)buf, strlen_P(buf)); }
+    size_t write(Stream& stream) /* Note this is not virtual */ { return _ctx->write(stream); }
+    int read(uint8_t *buf, size_t size) override { return _ctx->read(buf, size); }
+    int available() override { return _ctx->available(); }
+    int read() override { return _ctx->read(); }
+    int peek() override { return _ctx->peek(); }
+    size_t peekBytes(uint8_t *buffer, size_t length) override { return _ctx->peekBytes(buffer, length); }
+    bool flush(unsigned int maxWaitMs) { return _ctx->flush(maxWaitMs); }
+    bool stop(unsigned int maxWaitMs) { return _ctx->stop(maxWaitMs); }
+    void flush() override { (void)flush(0); }
+    void stop() override { (void)stop(0); }
+
+    // Allow sessions to be saved/restored automatically to a memory area
+    void setSession(Session *session) { _ctx->setSession(session); }
+
+    // Don't validate the chain, just accept whatever is given.  VERY INSECURE!
+    void setInsecure() { _ctx->setInsecure(); }
+
+    // Assume a given public key, don't validate or use cert info at all
+    void setKnownKey(const PublicKey *pk, unsigned usages = BR_KEYTYPE_KEYX | BR_KEYTYPE_SIGN) {
+      _ctx->setKnownKey(pk, usages);
+    }
+    // Only check SHA1 fingerprint of certificate
+    bool setFingerprint(const uint8_t fingerprint[20]) {
+      return _ctx->setFingerprint(fingerprint);
+    }
+    bool setFingerprint(const char *fpStr) { return _ctx->setFingerprint(fpStr); }
+    // Accept any certificate that's self-signed
+    void allowSelfSignedCerts() { _ctx->allowSelfSignedCerts(); }
+
+    // Install certificates of trusted CAs or specific site
+    void setTrustAnchors(const X509List *ta) { _ctx->setTrustAnchors(ta); }
+    // In cases when NTP is not used, app must set a time manually to check cert validity
+    void setX509Time(time_t now) { _ctx->setX509Time(now); }
+    // Install a client certificate for this connection, in case the server requires it (i.e. MQTT)
+    void setClientRSACert(const X509List *cert, const PrivateKey *sk) { _ctx->setClientRSACert(cert, sk); }
+    void setClientECCert(const X509List *cert, const PrivateKey *sk,
+                         unsigned allowed_usages, unsigned cert_issuer_key_type) {
+      _ctx->setClientECCert(cert, sk, allowed_usages, cert_issuer_key_type);
+    }
+
+    // Sets the requested buffer size for transmit and receive
+    void setBufferSizes(int recv, int xmit) { _ctx->setBufferSizes(recv, xmit); }
+
+    // Returns whether MFLN negotiation for the above buffer sizes succeeded (after connection)
+    int getMFLNStatus() { return _ctx->getMFLNStatus(); }
+
+    // Return an error code and possibly a text string in a passed-in buffer with last SSL failure
+    int getLastSSLError(char *dest = NULL, size_t len = 0) { return _ctx->getLastSSLError(dest, len); }
+
+    // Attach a preconfigured certificate store
+    void setCertStore(CertStore *certStore) { _ctx->setCertStore(certStore); }
+
+    // Select specific ciphers (i.e. optimize for speed over security)
+    // These may be in PROGMEM or RAM, either will run properly
+    bool setCiphers(const uint16_t *cipherAry, int cipherCount) { return _ctx->setCiphers(cipherAry, cipherCount); }
+    bool setCiphers(const std::vector<uint16_t> list) { return _ctx->setCiphers(list); }
+    bool setCiphersLessSecure() { return _ctx->setCiphersLessSecure(); } // Only use the limited set of RSA ciphers without EC
+
+    // Check for Maximum Fragment Length support for given len before connection (possibly insecure)
+    static bool probeMaxFragmentLength(IPAddress ip, uint16_t port, uint16_t len);
+    static bool probeMaxFragmentLength(const char *hostname, uint16_t port, uint16_t len);
+    static bool probeMaxFragmentLength(const String& host, uint16_t port, uint16_t len);
+
+  private:
+    std::shared_ptr<WiFiClientSecureCtx> _ctx;
+
+    // Methods for handling server.available() call which returns a client connection.
+    friend class WiFiServerSecure; // Server needs to access these constructors
+    WiFiClientSecure(ClientContext *client, const X509List *chain, unsigned cert_issuer_key_type,
+                      const PrivateKey *sk, int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta):
+      _ctx(new WiFiClientSecureCtx(client, chain, cert_issuer_key_type, sk, iobuf_in_size, iobuf_out_size, client_CA_ta)) {
+    }
+
+    WiFiClientSecure(ClientContext* client, const X509List *chain, const PrivateKey *sk,
+                      int iobuf_in_size, int iobuf_out_size, const X509List *client_CA_ta):
+      _ctx(new WiFiClientSecureCtx(client, chain, sk, iobuf_in_size, iobuf_out_size, client_CA_ta)) {
+    }
+
+}; // class WiFiClientSecure
+
+}; // namespace BearSSL
 
 #endif