Non-SSL version of the library report an error if the caller requests an SSL…

Non-SSL version of the library report an error if the caller requests an SSL connection. Possible soluiton for Issue #251

src/MQTTAsync.c

@@ -2318,6 +2318,12 @@ int MQTTAsync_connect(MQTTAsync handle, const MQTTAsync_connectOptions* options)
 			m->c->sslopts->enabledCipherSuites = MQTTStrdup(options->ssl->enabledCipherSuites);
 		m->c->sslopts->enableServerCertAuth = options->ssl->enableServerCertAuth;
 	}
+#else
+	if (options->struct_version != 0 && options->ssl)
+	{
+		rc = MQTTASYNC_SSL_NOT_SUPPORTED;
+		goto exit;
+	}
 #endif
 
 	m->c->username = options->username;

src/MQTTAsync.h

@@ -161,6 +161,10 @@
  * Return code: no more messages can be buffered
  */
 #define MQTTASYNC_MAX_BUFFERED_MESSAGES -12
+/**
+ * Return code: Attempting SSL connection using non-SSL version of library
+ */
+#define MQTTASYNC_SSL_NOT_SUPPORTED -13
 
 /**
  * Default MQTT version to connect with.  Use 3.1.1 then fall back to 3.1

src/MQTTClient.c

@@ -61,6 +61,8 @@
 
 #if defined(OPENSSL)
 #include <openssl/ssl.h>
+#else
+#define URI_SSL "ssl://"
 #endif
 
 #define URI_TCP "tcp://"
@@ -323,13 +325,16 @@ int MQTTClient_create(MQTTClient* handle, const char* serverURI, const char* cli
 	memset(m, '\0', sizeof(MQTTClients));
 	if (strncmp(URI_TCP, serverURI, strlen(URI_TCP)) == 0)
 		serverURI += strlen(URI_TCP);
-#if defined(OPENSSL)
 	else if (strncmp(URI_SSL, serverURI, strlen(URI_SSL)) == 0)
 	{
+#if defined(OPENSSL)
 		serverURI += strlen(URI_SSL);
 		m->ssl = 1;
-	}
+#else
+        rc = MQTTCLIENT_SSL_NOT_SUPPORTED;
+        goto exit;
 #endif
+	}
 	m->serverURI = MQTTStrdup(serverURI);
 	ListAppend(handles, m, sizeof(MQTTClients));
 

src/MQTTClient.h

@@ -166,6 +166,10 @@
  * Return code: A QoS value that falls outside of the acceptable range (0,1,2)
  */
 #define MQTTCLIENT_BAD_QOS -9
+/**
+ * Return code: Attempting SSL connection using non-SSL version of library
+ */
+#define MQTTCLIENT_SSL_NOT_SUPPORTED -10
 
 /**
  * Default MQTT version to connect with.  Use 3.1.1 then fall back to 3.1