From 908fd5314c201b2a46037a31f9ac80d3106c24cc Mon Sep 17 00:00:00 2001
From: AJ ONeal <aj@daplie.com>
Date: Thu, 19 Oct 2017 11:50:29 -0600
Subject: [PATCH] bugfix: pack multiple TXT strings correctly

---
 packer/type.txt.js | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/packer/type.txt.js b/packer/type.txt.js
index e63c36e..63e64fc 100644
--- a/packer/type.txt.js
+++ b/packer/type.txt.js
@@ -2,32 +2,44 @@
 'use strict';
 
 // Record type is just any text.
+// RFC 1035 - 3.3. Standard RRs - <character-string>
+// RFC 1035 - 3.3.14. TXT RDATA format
 
 exports.DNS_PACKER_TYPE_TXT = function (ab, dv, total, record) {
-    if (!record.data){
-        throw new Error("no data for TXT record");
+    if ('string' === typeof record.data) {
+      console.warn("[WARN] 'data' should be an array of strings, not a single string");
+      record.data = [ record.data ];
+    }
+    if (!Array.isArray(record.data) || !record.data.length){
+        throw new Error("bad data or no data for TXT record");
     }
 
     var txtLen = 0;
     var rdLenIndex = total;
-    total += 3;
+    total += 2; // saving space for rdata length
 
     // RDATA
     record.data.forEach(function(str){
 
-      str.split('').forEach(function(ch){
+      if (str.length > 255) {
+        throw new Error("bad TXT string length " + str.length + " (max 255)");
+      }
 
-      txtLen += 1;
-      // console.log(chcim);
-      dv.setUint8(total, ch.charCodeAt(0), false);
+      // size of this string
+      dv.setUint8(total, str.length, false);
       total += 1;
+      txtLen += 1;
+
+      str.split('').forEach(function(ch) {
+
+        dv.setUint8(total, ch.charCodeAt(0), false);
+        total += 1;
+        txtLen += 1;
 
       });
     });
 
-    dv.setUint16(rdLenIndex, txtLen+1, false);
-    dv.setUint8(rdLenIndex+2, txtLen, false);
-    // total +=1;
+    dv.setUint16(rdLenIndex, txtLen, false);
 
     return total;
 };