Implemented user/pass auth as per MQTT v3.1 specs

PubSubClient/PubSubClient.cpp

@@ -24,10 +24,19 @@ PubSubClient::PubSubClient(char* domain, uint16_t port, void (*callback)(char*,u
 }
 
 boolean PubSubClient::connect(char *id) {
-   return connect(id,0,0,0,0);
+   return connect(id,NULL,NULL,0,0,0,0);
 }
 
-boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage) {
+boolean PubSubClient::connect(char *id, char *user, char *pass) {
+   return connect(id,user,pass,0,0,0,0);
+}
+
+boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage)
+{
+   return connect(id,NULL,NULL,0,0,0,0);
+}
+
+boolean PubSubClient::connect(char *id, char *user, char *pass, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage) {
    if (!connected()) {
       int result = 0;
       
@@ -45,11 +54,24 @@ boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_
          for (j = 0;j<9;j++) {
             buffer[length++] = d[j];
          }
+
+         uint8_t v;
          if (willTopic) {
-            buffer[length++] = 0x06|(willQos<<3)|(willRetain<<5);
+            v = 0x06|(willQos<<3)|(willRetain<<5);
          } else {
-            buffer[length++] = 0x02;
+            v = 0x02;
          }
+
+         if(user != NULL) {
+            v = v|0x80;
+
+            if(pass != NULL) {
+               v = v|(0x80>>1);
+            }
+         }
+
+         buffer[length++] = v;
+
          buffer[length++] = ((MQTT_KEEPALIVE) >> 8);
          buffer[length++] = ((MQTT_KEEPALIVE) & 0xff);
          length = writeString(id,buffer,length);
@@ -57,6 +79,14 @@ boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_
             length = writeString(willTopic,buffer,length);
             length = writeString(willMessage,buffer,length);
          }
+
+         if(user != NULL) {
+            length = writeString(user,buffer,length);
+            if(pass != NULL) {
+               length = writeString(pass,buffer,length);
+            }
+         }
+
          write(MQTTCONNECT,buffer,length);
          lastOutActivity = millis();
          lastInActivity = millis();

PubSubClient/PubSubClient.h

@@ -58,7 +58,9 @@ public:
    PubSubClient(uint8_t *, uint16_t, void(*)(char*,uint8_t*,unsigned int));
    PubSubClient(char*, uint16_t, void(*)(char*,uint8_t*,unsigned int));
    boolean connect(char *);
-   boolean connect(char*, char*, uint8_t, uint8_t, char*);
+   boolean connect(char *, char *, char *);
+   boolean connect(char *, char *, uint8_t, uint8_t, char *);
+   boolean connect(char *, char *, char *, char *, uint8_t, uint8_t, char*);
    void disconnect();
    boolean publish(char *, char *);
    boolean publish(char *, uint8_t *, unsigned int);

PubSubClient/examples/mqtt_auth/mqtt_auth.pde

@@ -0,0 +1,37 @@
+/*
+ Basic MQTT example 
+ 
+  - connects to an MQTT server
+  - publishes "hello world" to the topic "outTopic"
+  - subscribes to the topic "inTopic"
+*/
+
+#include <SPI.h>
+#include <Ethernet.h>
+#include <PubSubClient.h>
+
+// Update these with values suitable for your network.
+byte mac[]    = {  0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
+byte server[] = { 172, 16, 0, 2 };
+byte ip[]     = { 172, 16, 0, 100 };
+
+void callback(char* topic, byte* payload, unsigned int length) {
+  // handle message arrived
+}
+
+PubSubClient client(server, 1883, callback);
+
+void setup()
+{
+  Ethernet.begin(mac, ip);
+  if (client.connect("arduinoClient", "testuser", "testpass")) {
+    client.publish("outTopic","hello world");
+    client.subscribe("inTopic");
+  }
+}
+
+void loop()
+{
+  client.loop();
+}
+