diff --git a/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/CACert.ino b/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/CACert.ino
new file mode 100644
index 0000000000..25973db202
--- /dev/null
+++ b/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/CACert.ino
@@ -0,0 +1,86 @@
+
+const unsigned char caCert[] = {
+  0x30, 0x82, 0x03, 0xc5, 0x30, 0x82, 0x02, 0xad, 0xa0, 0x03, 0x02, 0x01,
+  0x02, 0x02, 0x10, 0x02, 0xac, 0x5c, 0x26, 0x6a, 0x0b, 0x40, 0x9b, 0x8f,
+  0x0b, 0x79, 0xf2, 0xae, 0x46, 0x25, 0x77, 0x30, 0x0d, 0x06, 0x09, 0x2a,
+  0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x05, 0x05, 0x00, 0x30, 0x6c,
+  0x31, 0x0b, 0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55,
+  0x53, 0x31, 0x15, 0x30, 0x13, 0x06, 0x03, 0x55, 0x04, 0x0a, 0x13, 0x0c,
+  0x44, 0x69, 0x67, 0x69, 0x43, 0x65, 0x72, 0x74, 0x20, 0x49, 0x6e, 0x63,
+  0x31, 0x19, 0x30, 0x17, 0x06, 0x03, 0x55, 0x04, 0x0b, 0x13, 0x10, 0x77,
+  0x77, 0x77, 0x2e, 0x64, 0x69, 0x67, 0x69, 0x63, 0x65, 0x72, 0x74, 0x2e,
+  0x63, 0x6f, 0x6d, 0x31, 0x2b, 0x30, 0x29, 0x06, 0x03, 0x55, 0x04, 0x03,
+  0x13, 0x22, 0x44, 0x69, 0x67, 0x69, 0x43, 0x65, 0x72, 0x74, 0x20, 0x48,
+  0x69, 0x67, 0x68, 0x20, 0x41, 0x73, 0x73, 0x75, 0x72, 0x61, 0x6e, 0x63,
+  0x65, 0x20, 0x45, 0x56, 0x20, 0x52, 0x6f, 0x6f, 0x74, 0x20, 0x43, 0x41,
+  0x30, 0x1e, 0x17, 0x0d, 0x30, 0x36, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30,
+  0x30, 0x30, 0x30, 0x30, 0x5a, 0x17, 0x0d, 0x33, 0x31, 0x31, 0x31, 0x31,
+  0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x5a, 0x30, 0x6c, 0x31, 0x0b,
+  0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55, 0x53, 0x31,
+  0x15, 0x30, 0x13, 0x06, 0x03, 0x55, 0x04, 0x0a, 0x13, 0x0c, 0x44, 0x69,
+  0x67, 0x69, 0x43, 0x65, 0x72, 0x74, 0x20, 0x49, 0x6e, 0x63, 0x31, 0x19,
+  0x30, 0x17, 0x06, 0x03, 0x55, 0x04, 0x0b, 0x13, 0x10, 0x77, 0x77, 0x77,
+  0x2e, 0x64, 0x69, 0x67, 0x69, 0x63, 0x65, 0x72, 0x74, 0x2e, 0x63, 0x6f,
+  0x6d, 0x31, 0x2b, 0x30, 0x29, 0x06, 0x03, 0x55, 0x04, 0x03, 0x13, 0x22,
+  0x44, 0x69, 0x67, 0x69, 0x43, 0x65, 0x72, 0x74, 0x20, 0x48, 0x69, 0x67,
+  0x68, 0x20, 0x41, 0x73, 0x73, 0x75, 0x72, 0x61, 0x6e, 0x63, 0x65, 0x20,
+  0x45, 0x56, 0x20, 0x52, 0x6f, 0x6f, 0x74, 0x20, 0x43, 0x41, 0x30, 0x82,
+  0x01, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
+  0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x01, 0x0f, 0x00, 0x30, 0x82,
+  0x01, 0x0a, 0x02, 0x82, 0x01, 0x01, 0x00, 0xc6, 0xcc, 0xe5, 0x73, 0xe6,
+  0xfb, 0xd4, 0xbb, 0xe5, 0x2d, 0x2d, 0x32, 0xa6, 0xdf, 0xe5, 0x81, 0x3f,
+  0xc9, 0xcd, 0x25, 0x49, 0xb6, 0x71, 0x2a, 0xc3, 0xd5, 0x94, 0x34, 0x67,
+  0xa2, 0x0a, 0x1c, 0xb0, 0x5f, 0x69, 0xa6, 0x40, 0xb1, 0xc4, 0xb7, 0xb2,
+  0x8f, 0xd0, 0x98, 0xa4, 0xa9, 0x41, 0x59, 0x3a, 0xd3, 0xdc, 0x94, 0xd6,
+  0x3c, 0xdb, 0x74, 0x38, 0xa4, 0x4a, 0xcc, 0x4d, 0x25, 0x82, 0xf7, 0x4a,
+  0xa5, 0x53, 0x12, 0x38, 0xee, 0xf3, 0x49, 0x6d, 0x71, 0x91, 0x7e, 0x63,
+  0xb6, 0xab, 0xa6, 0x5f, 0xc3, 0xa4, 0x84, 0xf8, 0x4f, 0x62, 0x51, 0xbe,
+  0xf8, 0xc5, 0xec, 0xdb, 0x38, 0x92, 0xe3, 0x06, 0xe5, 0x08, 0x91, 0x0c,
+  0xc4, 0x28, 0x41, 0x55, 0xfb, 0xcb, 0x5a, 0x89, 0x15, 0x7e, 0x71, 0xe8,
+  0x35, 0xbf, 0x4d, 0x72, 0x09, 0x3d, 0xbe, 0x3a, 0x38, 0x50, 0x5b, 0x77,
+  0x31, 0x1b, 0x8d, 0xb3, 0xc7, 0x24, 0x45, 0x9a, 0xa7, 0xac, 0x6d, 0x00,
+  0x14, 0x5a, 0x04, 0xb7, 0xba, 0x13, 0xeb, 0x51, 0x0a, 0x98, 0x41, 0x41,
+  0x22, 0x4e, 0x65, 0x61, 0x87, 0x81, 0x41, 0x50, 0xa6, 0x79, 0x5c, 0x89,
+  0xde, 0x19, 0x4a, 0x57, 0xd5, 0x2e, 0xe6, 0x5d, 0x1c, 0x53, 0x2c, 0x7e,
+  0x98, 0xcd, 0x1a, 0x06, 0x16, 0xa4, 0x68, 0x73, 0xd0, 0x34, 0x04, 0x13,
+  0x5c, 0xa1, 0x71, 0xd3, 0x5a, 0x7c, 0x55, 0xdb, 0x5e, 0x64, 0xe1, 0x37,
+  0x87, 0x30, 0x56, 0x04, 0xe5, 0x11, 0xb4, 0x29, 0x80, 0x12, 0xf1, 0x79,
+  0x39, 0x88, 0xa2, 0x02, 0x11, 0x7c, 0x27, 0x66, 0xb7, 0x88, 0xb7, 0x78,
+  0xf2, 0xca, 0x0a, 0xa8, 0x38, 0xab, 0x0a, 0x64, 0xc2, 0xbf, 0x66, 0x5d,
+  0x95, 0x84, 0xc1, 0xa1, 0x25, 0x1e, 0x87, 0x5d, 0x1a, 0x50, 0x0b, 0x20,
+  0x12, 0xcc, 0x41, 0xbb, 0x6e, 0x0b, 0x51, 0x38, 0xb8, 0x4b, 0xcb, 0x02,
+  0x03, 0x01, 0x00, 0x01, 0xa3, 0x63, 0x30, 0x61, 0x30, 0x0e, 0x06, 0x03,
+  0x55, 0x1d, 0x0f, 0x01, 0x01, 0xff, 0x04, 0x04, 0x03, 0x02, 0x01, 0x86,
+  0x30, 0x0f, 0x06, 0x03, 0x55, 0x1d, 0x13, 0x01, 0x01, 0xff, 0x04, 0x05,
+  0x30, 0x03, 0x01, 0x01, 0xff, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d, 0x0e,
+  0x04, 0x16, 0x04, 0x14, 0xb1, 0x3e, 0xc3, 0x69, 0x03, 0xf8, 0xbf, 0x47,
+  0x01, 0xd4, 0x98, 0x26, 0x1a, 0x08, 0x02, 0xef, 0x63, 0x64, 0x2b, 0xc3,
+  0x30, 0x1f, 0x06, 0x03, 0x55, 0x1d, 0x23, 0x04, 0x18, 0x30, 0x16, 0x80,
+  0x14, 0xb1, 0x3e, 0xc3, 0x69, 0x03, 0xf8, 0xbf, 0x47, 0x01, 0xd4, 0x98,
+  0x26, 0x1a, 0x08, 0x02, 0xef, 0x63, 0x64, 0x2b, 0xc3, 0x30, 0x0d, 0x06,
+  0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x05, 0x05, 0x00,
+  0x03, 0x82, 0x01, 0x01, 0x00, 0x1c, 0x1a, 0x06, 0x97, 0xdc, 0xd7, 0x9c,
+  0x9f, 0x3c, 0x88, 0x66, 0x06, 0x08, 0x57, 0x21, 0xdb, 0x21, 0x47, 0xf8,
+  0x2a, 0x67, 0xaa, 0xbf, 0x18, 0x32, 0x76, 0x40, 0x10, 0x57, 0xc1, 0x8a,
+  0xf3, 0x7a, 0xd9, 0x11, 0x65, 0x8e, 0x35, 0xfa, 0x9e, 0xfc, 0x45, 0xb5,
+  0x9e, 0xd9, 0x4c, 0x31, 0x4b, 0xb8, 0x91, 0xe8, 0x43, 0x2c, 0x8e, 0xb3,
+  0x78, 0xce, 0xdb, 0xe3, 0x53, 0x79, 0x71, 0xd6, 0xe5, 0x21, 0x94, 0x01,
+  0xda, 0x55, 0x87, 0x9a, 0x24, 0x64, 0xf6, 0x8a, 0x66, 0xcc, 0xde, 0x9c,
+  0x37, 0xcd, 0xa8, 0x34, 0xb1, 0x69, 0x9b, 0x23, 0xc8, 0x9e, 0x78, 0x22,
+  0x2b, 0x70, 0x43, 0xe3, 0x55, 0x47, 0x31, 0x61, 0x19, 0xef, 0x58, 0xc5,
+  0x85, 0x2f, 0x4e, 0x30, 0xf6, 0xa0, 0x31, 0x16, 0x23, 0xc8, 0xe7, 0xe2,
+  0x65, 0x16, 0x33, 0xcb, 0xbf, 0x1a, 0x1b, 0xa0, 0x3d, 0xf8, 0xca, 0x5e,
+  0x8b, 0x31, 0x8b, 0x60, 0x08, 0x89, 0x2d, 0x0c, 0x06, 0x5c, 0x52, 0xb7,
+  0xc4, 0xf9, 0x0a, 0x98, 0xd1, 0x15, 0x5f, 0x9f, 0x12, 0xbe, 0x7c, 0x36,
+  0x63, 0x38, 0xbd, 0x44, 0xa4, 0x7f, 0xe4, 0x26, 0x2b, 0x0a, 0xc4, 0x97,
+  0x69, 0x0d, 0xe9, 0x8c, 0xe2, 0xc0, 0x10, 0x57, 0xb8, 0xc8, 0x76, 0x12,
+  0x91, 0x55, 0xf2, 0x48, 0x69, 0xd8, 0xbc, 0x2a, 0x02, 0x5b, 0x0f, 0x44,
+  0xd4, 0x20, 0x31, 0xdb, 0xf4, 0xba, 0x70, 0x26, 0x5d, 0x90, 0x60, 0x9e,
+  0xbc, 0x4b, 0x17, 0x09, 0x2f, 0xb4, 0xcb, 0x1e, 0x43, 0x68, 0xc9, 0x07,
+  0x27, 0xc1, 0xd2, 0x5c, 0xf7, 0xea, 0x21, 0xb9, 0x68, 0x12, 0x9c, 0x3c,
+  0x9c, 0xbf, 0x9e, 0xfc, 0x80, 0x5c, 0x9b, 0x63, 0xcd, 0xec, 0x47, 0xaa,
+  0x25, 0x27, 0x67, 0xa0, 0x37, 0xf3, 0x00, 0x82, 0x7d, 0x54, 0xd7, 0xa9,
+  0xf8, 0xe9, 0x2e, 0x13, 0xa3, 0x77, 0xe8, 0x1f, 0x4a
+};
+const unsigned int caCertLen = 969;
+
diff --git a/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/HTTPSRequestCACert.ino b/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/HTTPSRequestCACert.ino
new file mode 100644
index 0000000000..977f8f5c5e
--- /dev/null
+++ b/libraries/ESP8266WiFi/examples/HTTPSRequestCACert/HTTPSRequestCACert.ino
@@ -0,0 +1,132 @@
+/*
+    HTTP over TLS (HTTPS) example sketch
+
+    This example demonstrates how to use
+    WiFiClientSecure class to connect to a TLS server.
+
+    This example verifies server certificate using the
+    root CA certificate.
+
+    We fetch and display the status of
+    esp8266/Arduino project continuous integration
+    build.
+
+    Created by Ivan Grokhotkov, 2017.
+    This example is in public domain.
+*/
+
+#include <time.h>
+#include <ESP8266WiFi.h>
+#include <WiFiClientSecure.h>
+
+const char* ssid = "........";
+const char* password = "........";
+
+const char* host = "api.github.com";
+const int httpsPort = 443;
+
+// Root certificate used by api.github.com.
+// Defined in "CACert" tab.
+extern const unsigned char caCert[];
+extern const unsigned int caCertLen;
+
+WiFiClientSecure client;
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println();
+  Serial.print("connecting to ");
+  Serial.println(ssid);
+  WiFi.begin(ssid, password);
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println("");
+  Serial.println("WiFi connected");
+  Serial.println("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  // Synchronize time useing SNTP. This is necessary to verify that
+  // the TLS certificates offered by the server are currently valid.
+  Serial.print("Setting time using SNTP");
+  configTime(8 * 3600, 0, "pool.ntp.org", "time.nist.gov");
+  time_t now = time(nullptr);
+  while (now < 1000) {
+    delay(500);
+    Serial.print(".");
+    now = time(nullptr);
+  }
+  Serial.println("");
+  struct tm timeinfo;
+  gmtime_r(&now, &timeinfo);
+  Serial.print("Current time: ");
+  Serial.print(asctime(&timeinfo));
+
+  // Load root certificate in DER format into WiFiClientSecure object
+  bool res = client.setCACert(caCert, caCertLen);
+  if (!res) {
+    Serial.println("Failed to load root CA certificate!");
+    while (true) {
+      yield();
+    }
+  }
+}
+
+void loop() {
+  // Connect to remote server
+  Serial.print("connecting to ");
+  Serial.println(host);
+  if (!client.connect(host, httpsPort)) {
+    Serial.println("connection failed");
+    return;
+  }
+
+  // Verify validity of server's certificate
+  if (client.verifyCertChain(host)) {
+    Serial.println("Server certificate verified");
+  } else {
+    Serial.println("ERROR: certificate verification failed!");
+    return;
+  }
+
+  String url = "/repos/esp8266/Arduino/commits/master/status";
+  Serial.print("requesting URL: ");
+  Serial.println(url);
+
+  client.print(String("GET ") + url + " HTTP/1.1\r\n" +
+               "Host: " + host + "\r\n" +
+               "User-Agent: BuildFailureDetectorESP8266\r\n" +
+               "Connection: close\r\n\r\n");
+
+  Serial.println("request sent");
+  while (client.connected()) {
+    String line = client.readStringUntil('\n');
+    if (line == "\r") {
+      Serial.println("headers received");
+      break;
+    }
+  }
+  String line = client.readStringUntil('\n');
+  if (line.startsWith("{\"state\":\"success\"")) {
+    Serial.println("esp8266/Arduino CI successfull!");
+  } else {
+    Serial.println("esp8266/Arduino CI has failed");
+  }
+  Serial.println("reply was:");
+  Serial.println("==========");
+  Serial.println(line);
+  Serial.println("==========");
+  Serial.println();
+
+  static int repeat = 0;
+  if (++repeat == 3) {
+    Serial.println("Done");
+    while (true) {
+      delay(1000);
+    }
+  }
+  delay(10000);
+}
+
+
diff --git a/libraries/ESP8266WiFi/src/WiFiClientSecure.cpp b/libraries/ESP8266WiFi/src/WiFiClientSecure.cpp
index 1352980016..1cef85e08e 100644
--- a/libraries/ESP8266WiFi/src/WiFiClientSecure.cpp
+++ b/libraries/ESP8266WiFi/src/WiFiClientSecure.cpp
@@ -94,6 +94,9 @@ class SSLContext
         ssl_ext_set_host_name(ext, hostName);
         ssl_ext_set_max_fragment_size(ext, 4096);
         s_io_ctx = ctx;
+        if (_ssl) {
+            ssl_free(_ssl);
+        }
         _ssl = ssl_client_new(_ssl_ctx, 0, nullptr, 0, ext);
         uint32_t t = millis();
 
@@ -239,7 +242,7 @@ class SSLContext
             }
             return 0;
         }
-        DEBUGV(":wcs ra %d", rc);
+        DEBUGV(":wcs ra %d\r\n", rc);
         _read_ptr = data;
         _available = rc;
         return _available;
@@ -311,13 +314,10 @@ int WiFiClientSecure::connect(const char* name, uint16_t port)
 
 int WiFiClientSecure::_connectSSL(const char* hostName)
 {
-    if (_ssl) {
-        _ssl->unref();
-        _ssl = nullptr;
+    if (!_ssl) {
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
-
-    _ssl = new SSLContext;
-    _ssl->ref();
     _ssl->connect(_client, hostName, 5000);
 
     auto status = ssl_handshake_status(*_ssl);
@@ -521,14 +521,18 @@ bool WiFiClientSecure::_verifyDN(const char* domain_name)
     const char* san = NULL;
     int i = 0;
     while ((san = ssl_get_cert_subject_alt_dnsname(*_ssl, i)) != NULL) {
-        if (matchName(String(san), domain_name_str)) {
+        String san_str(san);
+        san_str.toLowerCase();
+        if (matchName(san_str, domain_name_str)) {
             return true;
         }
         DEBUGV("SAN %d: '%s', no match\r\n", i, san);
         ++i;
     }
     const char* common_name = ssl_get_cert_dn(*_ssl, SSL_X509_CERT_COMMON_NAME);
-    if (common_name && matchName(String(common_name), domain_name_str)) {
+    String common_name_str(common_name);
+    common_name_str.toLowerCase();
+    if (common_name && matchName(common_name_str, domain_name_str)) {
         return true;
     }
     DEBUGV("CN: '%s', no match\r\n", (common_name)?common_name:"(null)");
@@ -553,7 +557,8 @@ bool WiFiClientSecure::verifyCertChain(const char* domain_name)
 bool WiFiClientSecure::setCACert(const uint8_t* pk, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_X509_CACERT, pk, size);
 }
@@ -561,7 +566,8 @@ bool WiFiClientSecure::setCACert(const uint8_t* pk, size_t size)
 bool WiFiClientSecure::setCertificate(const uint8_t* pk, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_X509_CERT, pk, size);
 }
@@ -569,7 +575,8 @@ bool WiFiClientSecure::setCertificate(const uint8_t* pk, size_t size)
 bool WiFiClientSecure::setPrivateKey(const uint8_t* pk, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_RSA_KEY, pk, size);
 }
@@ -577,7 +584,8 @@ bool WiFiClientSecure::setPrivateKey(const uint8_t* pk, size_t size)
 bool WiFiClientSecure::loadCACert(Stream& stream, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_X509_CACERT, stream, size);
 }
@@ -585,7 +593,8 @@ bool WiFiClientSecure::loadCACert(Stream& stream, size_t size)
 bool WiFiClientSecure::loadCertificate(Stream& stream, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_X509_CERT, stream, size);
 }
@@ -593,7 +602,8 @@ bool WiFiClientSecure::loadCertificate(Stream& stream, size_t size)
 bool WiFiClientSecure::loadPrivateKey(Stream& stream, size_t size)
 {
     if (!_ssl) {
-        return false;
+        _ssl = new SSLContext;
+        _ssl->ref();
     }
     return _ssl->loadObject(SSL_OBJ_RSA_KEY, stream, size);
 }