From 1498020c2c912bf3833d7e7057042c02bfda553d Mon Sep 17 00:00:00 2001
From: mscdex <mscdex@mscdex.net>
Date: Mon, 1 Jul 2013 02:57:42 -0400
Subject: [PATCH] Parser: decode encoded-words by default in parseHeader()

---
 README.md     |  2 +-
 lib/Parser.js | 35 ++++++++++++++++++++++++++++++++---
 package.json  |  1 +
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 58afddd..1321cd8 100644
--- a/README.md
+++ b/README.md
@@ -363,7 +363,7 @@ Connection Properties
 Connection Static Methods
 -------------------------
 
-* **parseHeader**(< _string_ >rawHeader) - _object_ - Parses a raw header and returns an object keyed on header fields and the values are Arrays of header field values.
+* **parseHeader**(< _string_ >rawHeader[, < _boolean_ >disableAutoDecode]) - _object_ - Parses a raw header and returns an object keyed on header fields and the values are Arrays of header field values. Set `disableAutoDecode` to true to disable automatic decoding of MIME encoded-words that may exist in header field values.
 
 
 Connection Instance Methods
diff --git a/lib/Parser.js b/lib/Parser.js
index ce0cf7d..e8ecac5 100644
--- a/lib/Parser.js
+++ b/lib/Parser.js
@@ -2,7 +2,8 @@ var EventEmitter = require('events').EventEmitter,
     ReadableStream = require('stream').Readable || require('readable-stream'),
     inherits = require('util').inherits,
     inspect = require('util').inspect,
-    utf7 = require('utf7').imap;
+    utf7 = require('utf7').imap,
+    iconv = require('iconv-lite');
 
 var CH_LF = 10,
     LITPLACEHOLDER = String.fromCharCode(0),
@@ -17,7 +18,9 @@ var CH_LF = 10,
     RE_TAGGED = /^A(\d+) (OK|NO|BAD) (?:\[([^\]]+)\] )?(.+)$/i,
     RE_CONTINUE = /^\+ (?:\[([^\]]+)\] )?(.+)$/i,
     RE_CRLF = /\r\n/g,
-    RE_HDR = /^([^:]+):[ \t]?(.+)?$/;
+    RE_HDR = /^([^:]+):[ \t]?(.+)?$/,
+    RE_ENCWORD = /=\?([^?]*?)\?([qb])\?(.*?)\?=/gi,
+    RE_QENC = /(?:=([a-fA-F0-9]{2}))|_/g;
 
 function Parser(stream, debug) {
   if (!(this instanceof Parser))
@@ -637,7 +640,28 @@ function convStr(str, literals) {
   return str;
 }
 
-function parseHeader(str) {
+function decodeWords(str) {
+  return str.replace(RE_ENCWORD,
+    function(match, charset, encoding, word) {
+      encoding = encoding.toLowerCase();
+      if (encoding === 'q') {
+        // q-encoding, similar to quoted-printable
+        return iconv.decode(new Buffer(word.replace(RE_QENC,
+          function(match2, byte) {
+            if (match2 === '_')
+              return ' ';
+            else
+              return String.fromCharCode(parseInt(byte, 16));
+          }
+        ), 'binary'), charset);
+      } else {
+        // base64
+        return iconv.decode(new Buffer(word, 'base64'), charset);
+      }
+  });
+}
+
+function parseHeader(str, noDecode) {
   var lines = str.split(RE_CRLF),
       len = lines.length,
       header = {},
@@ -647,6 +671,8 @@ function parseHeader(str) {
     if (lines[i].length === 0)
       continue;
     if (lines[i][0] === '\t' || lines[i][0] === ' ') {
+      if (!noDecode)
+        lines[i] = decodeWords(lines[i]);
       // folded header content
       // RFC2822 says to just remove the CRLF and not the whitespace following
       // it, so we follow the RFC and include the leading whitespace ...
@@ -656,6 +682,9 @@ function parseHeader(str) {
       if (m) {
         h = m[1].toLowerCase();
         if (m[2]) {
+          if (!noDecode)
+            m[2] = decodeWords(m[2]);
+
           if (header[h] === undefined)
             header[h] = [m[2]];
           else
diff --git a/package.json b/package.json
index d628a1b..9893020 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,7 @@
   "main": "./lib/Connection",
   "dependencies": {
     "utf7": "1.0.0",
+    "iconv-lite": "0.2.10",
     "readable-stream": "1.0.2"
   },
   "scripts": {