Add WiFiClient secure lib (#184)

* Provide SSL/TLS functions to ESP32 with Arduino IDE

* Generate a new random number in case of reconnection

libraries/WiFiClientSecure/src/WiFiClientSecure.cpp

@@ -0,0 +1,190 @@
+/*
+  WiFiClientSecure.cpp - Client Secure class for ESP32
+  Copyright (c) 2016 Hristo Gochkov  All right reserved.
+  Additions Copyright (C) 2017 Evandro Luis Copercini.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "WiFiClientSecure.h"
+#include <lwip/sockets.h>
+#include <lwip/netdb.h>
+#include <errno.h>
+
+#undef connect
+#undef write
+#undef read
+
+
+WiFiClientSecure::WiFiClientSecure()
+{
+    _connected = false;
+
+    sslclient = new sslclient_context;
+    ssl_init(sslclient);
+    sslclient->socket = -1;
+
+    _CA_cert = NULL;
+    _cert = NULL;
+    _private_key = NULL;
+}
+
+
+WiFiClientSecure::WiFiClientSecure(int sock)
+{
+    _connected = false;
+
+    sslclient = new sslclient_context;
+    ssl_init(sslclient);
+    sslclient->socket = sock;
+
+    if (sock >= 0) {
+        _connected = true;
+    }
+
+    _CA_cert = NULL;
+    _cert = NULL;
+    _private_key = NULL;
+}
+
+WiFiClientSecure::~WiFiClientSecure()
+{
+    stop();
+}
+
+WiFiClientSecure &WiFiClientSecure::operator=(const WiFiClientSecure &other)
+{
+    stop();
+    sslclient->socket = other.sslclient->socket;
+    _connected = other._connected;
+    return *this;
+}
+
+void WiFiClientSecure::stop()
+{
+    if (_connected && sslclient->socket >= 0) {
+        stop_ssl_socket(sslclient, _CA_cert, _cert, _private_key);
+        sslclient->socket = -1;
+        _connected = false;
+    }
+}
+
+int WiFiClientSecure::connect(IPAddress ip, uint16_t port)
+{
+    connect(ip, port, _CA_cert, _cert, _private_key);
+}
+
+int WiFiClientSecure::connect(const char *host, uint16_t port)
+{
+    connect(host, port, _CA_cert, _cert, _private_key);
+}
+
+int WiFiClientSecure::connect(IPAddress ip, uint16_t port, unsigned char *_CA_cert, unsigned char *_cert, unsigned char *_private_key)
+{
+    int ret = start_ssl_client(sslclient, ip, port, _CA_cert, _cert, _private_key);
+    if (ret < 0) {
+        log_e("lwip_connect_r: %d", errno);
+    }
+    _connected = true;
+    return 1;
+}
+
+int WiFiClientSecure::connect(const char *host, uint16_t port, unsigned char *_CA_cert, unsigned char *_cert, unsigned char *_private_key)
+{
+    struct hostent *server;
+    server = gethostbyname(host);
+    if (server == NULL) {
+        return 0;
+    }
+    IPAddress srv((const uint8_t *)(server->h_addr));
+    return connect(srv, port, _CA_cert, _cert, _private_key);
+}
+
+
+size_t WiFiClientSecure::write(uint8_t data)
+{
+    return write(&data, 1);
+}
+
+int WiFiClientSecure::read()
+{
+    uint8_t data = 0;
+    int res = read(&data, 1);
+    if (res < 0) {
+        return res;
+    }
+    return data;
+}
+
+size_t WiFiClientSecure::write(const uint8_t *buf, size_t size)
+{
+    if (!_connected) {
+        return 0;
+    }
+    int res = send_ssl_data(sslclient, buf, size);
+    if (res < 0) {
+        log_e("%d", errno);
+        stop();
+        res = 0;
+    }
+    return res;
+}
+
+int WiFiClientSecure::read(uint8_t *buf, size_t size)
+{
+    if (!available()) {
+        return -1;
+    }
+    int res = get_ssl_receive(sslclient, buf, size);
+    if (res < 0 && errno != EWOULDBLOCK) {
+        printf("%d", errno);
+        stop();
+    }
+    return res;
+}
+
+int WiFiClientSecure::available()
+{
+    if (!_connected) {
+        return 0;
+    }
+    int res = data_to_read(sslclient);
+
+    return res;
+}
+
+uint8_t WiFiClientSecure::connected()
+{
+    uint8_t dummy = 0;
+    read(&dummy, 0);
+
+    return _connected;
+}
+
+void WiFiClientSecure::setCACert(unsigned char *rootCA)
+{
+    _CA_cert = rootCA;
+}
+
+void WiFiClientSecure::setCertificate (unsigned char *client_ca)
+{
+    _cert = client_ca;
+}
+
+void WiFiClientSecure::setPrivateKey (unsigned char *private_key)
+{
+    _private_key = private_key;
+}
+