From 400db91166f7bf594f5c62a99d507528727153d6 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Wed, 3 Oct 2018 15:04:24 +0100
Subject: [PATCH] Handle UTF-8 validation in packet__read_string.

---
 lib/packet_datatypes.c   |  6 ++++++
 src/handle_connect.c     | 19 +------------------
 src/handle_publish.c     |  5 -----
 src/handle_subscribe.c   |  7 -------
 src/handle_unsubscribe.c |  7 -------
 5 files changed, 7 insertions(+), 37 deletions(-)

diff --git a/lib/packet_datatypes.c b/lib/packet_datatypes.c
index 3065f124..9e31974f 100644
--- a/lib/packet_datatypes.c
+++ b/lib/packet_datatypes.c
@@ -108,6 +108,12 @@ int packet__read_string(struct mosquitto__packet *packet, char **str, int *lengt
 		return MOSQ_ERR_NOMEM;
 	}
 
+	if(mosquitto_validate_utf8(*str, slen)){
+		mosquitto__free(*str);
+		*str = NULL;
+		return MOSQ_ERR_MALFORMED_UTF8;
+	}
+
 	*length = slen;
 	return MOSQ_ERR_SUCCESS;
 }
diff --git a/src/handle_connect.c b/src/handle_connect.c
index 2384baab..e2780daf 100644
--- a/src/handle_connect.c
+++ b/src/handle_connect.c
@@ -292,11 +292,6 @@ int handle__connect(struct mosquitto_db *db, struct mosquitto *context)
 		}
 	}
 
-	if(mosquitto_validate_utf8(client_id, slen) != MOSQ_ERR_SUCCESS){
-		rc = 1;
-		goto handle_connect_error;
-	}
-
 	if(will){
 		will_struct = mosquitto__calloc(1, sizeof(struct mosquitto_message));
 		if(!will_struct){
@@ -311,14 +306,6 @@ int handle__connect(struct mosquitto_db *db, struct mosquitto *context)
 			rc = 1;
 			goto handle_connect_error;
 		}
-		if(mosquitto_validate_utf8(will_topic, slen)){
-			log__printf(NULL, MOSQ_LOG_INFO,
-					"Malformed UTF-8 in will topic string from %s, disconnecting.",
-					client_id);
-
-			rc = 1;
-			goto handle_connect_error;
-		}
 
 		if(context->listener->mount_point){
 			slen = strlen(context->listener->mount_point) + strlen(will_topic) + 1;
@@ -368,12 +355,8 @@ int handle__connect(struct mosquitto_db *db, struct mosquitto *context)
 	if(username_flag){
 		rc = packet__read_string(&context->in_packet, &username, &slen);
 		if(rc == MOSQ_ERR_SUCCESS){
-			if(mosquitto_validate_utf8(username, slen) != MOSQ_ERR_SUCCESS){
-				rc = MOSQ_ERR_PROTOCOL;
-				goto handle_connect_error;
-			}
-
 			if(password_flag){
+				/* FIXME - MQTT 5 this is binary data */
 				rc = packet__read_string(&context->in_packet, &password, &slen);
 				if(rc == MOSQ_ERR_NOMEM){
 					rc = MOSQ_ERR_NOMEM;
diff --git a/src/handle_publish.c b/src/handle_publish.c
index a6a10d4f..e9aa7016 100644
--- a/src/handle_publish.c
+++ b/src/handle_publish.c
@@ -70,11 +70,6 @@ int handle__publish(struct mosquitto_db *db, struct mosquitto *context)
 		return 1;
 	}
 
-	if(mosquitto_validate_utf8(topic, slen) != MOSQ_ERR_SUCCESS){
-		mosquitto__free(topic);
-		return 1;
-	}
-
 #ifdef WITH_BRIDGE
 	if(context->bridge && context->bridge->topics && context->bridge->topic_remapping){
 		for(i=0; i<context->bridge->topic_count; i++){
diff --git a/src/handle_subscribe.c b/src/handle_subscribe.c
index 6f3286e1..e2f49e37 100644
--- a/src/handle_subscribe.c
+++ b/src/handle_subscribe.c
@@ -73,13 +73,6 @@ int handle__subscribe(struct mosquitto_db *db, struct mosquitto *context)
 				mosquitto__free(payload);
 				return 1;
 			}
-			if(mosquitto_validate_utf8(sub, slen)){
-				log__printf(NULL, MOSQ_LOG_INFO,
-						"Malformed UTF-8 in subscription string from %s, disconnecting.",
-						context->id);
-				mosquitto__free(sub);
-				return 1;
-			}
 
 			if(packet__read_byte(&context->in_packet, &qos)){
 				mosquitto__free(sub);
diff --git a/src/handle_unsubscribe.c b/src/handle_unsubscribe.c
index 4a5bf680..3bb8bd4a 100644
--- a/src/handle_unsubscribe.c
+++ b/src/handle_unsubscribe.c
@@ -74,13 +74,6 @@ int handle__unsubscribe(struct mosquitto_db *db, struct mosquitto *context)
 				mosquitto__free(sub);
 				return 1;
 			}
-			if(mosquitto_validate_utf8(sub, slen)){
-				log__printf(NULL, MOSQ_LOG_INFO,
-						"Malformed UTF-8 in unsubscription string from %s, disconnecting.",
-						context->id);
-				mosquitto__free(sub);
-				return 1;
-			}
 
 			log__printf(NULL, MOSQ_LOG_DEBUG, "\t%s", sub);
 			sub__remove(db, context, sub, db->subs);