Implement MIME decoding for XPC wrapped header

moisseev · Oct 16, 2024 · 85cfd0a · 85cfd0a
1 parent c4021ec
commit 85cfd0a
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Showing 4 changed files with 72 additions and 7 deletions.
diff --git a/experiments/scoreColumn.js b/experiments/scoreColumn.js
@@ -102,7 +102,7 @@ var scoreColumn = class extends ExtensionCommon.ExtensionAPI {
                         // eslint-disable-next-line no-useless-assignment
                         let score = null;
                         if (column === "spamness") {
-                            score = libCommon.getScoreByHdr(hdr, localStorage.header, true);
+                            score = libCommon.getScoreByHdr(hdr, localStorage.header, true, window);
                         } else {
                             const symbols = libHeader.getSymbols(hdr, localStorage.header, true, window);
                             if (!symbols) return "";
@@ -115,7 +115,7 @@ var scoreColumn = class extends ExtensionCommon.ExtensionAPI {
                         // eslint-disable-next-line no-useless-assignment
                         let score = null;
                         if (column === "spamness") {
-                            score = libCommon.getScoreByHdr(hdr, localStorage.header, true);
+                            score = libCommon.getScoreByHdr(hdr, localStorage.header, true, window);
                             if (localStorage["display-columnImageOnlyForPositive"] && score <= 0)
                                 return "";
                         } else {

diff --git a/manifest.json b/manifest.json
@@ -4,13 +4,13 @@
     "gecko": {
       "id": "rspamd-spamness@alexander.moisseev",
       "strict_min_version": "78.0",
-      "strict_max_version": "130.*"
+      "strict_max_version": "132.*"
     }
   },
   "name": "__MSG_extensionName__",
   "description": "__MSG_extensionDescription__",
   "default_locale": "en",
-  "version": "2.4.1",
+  "version": "2.5.0",
   "author": "Alexander Moisseev (moiseev@mezonplus.ru)",
   "homepage_url": "https://github.com/moisseev/rspamd-spamness",
   "icons": {

diff --git a/scripts/libCommon.js b/scripts/libCommon.js
@@ -12,6 +12,11 @@ var libCommon = {
     ]
 };
 
+libCommon.warn = function (msg) {
+    // eslint-disable-next-line no-console
+    console.warn(msg);
+};
+
 libCommon.getImageSrc = function (normalized, id) {
     // eslint-disable-next-line no-useless-assignment
     let img = null;
@@ -38,16 +43,75 @@ libCommon.getUserHeaders = function (header) {
         : chdrs.split(", ");
 };
 
+/**
+ * Decode a MIME-encoded header.
+ * Supports 'Q' (quoted-printable) and 'B' (base64) encodings with UTF-8 charset.
+ * If an unsupported charset or encoding is encountered, the original value is returned.
+ *
+ * @param {string} headerValue - The MIME-encoded header value to decode.
+ * @param {object} [window] - Global window object, used for base64 decoding in Experiments environment.
+ * @returns {string} - The decoded header value.
+ */
+libCommon.decodeMimeHeader = function (headerValue, window) {
+    function decodeQuotedPrintable(str) {
+        return str
+            .replace(/_/g, " ")
+            .replace(/[=]([0-9A-F]{2})/g, (match, hex) => String.fromCharCode(parseInt(hex, 16)));
+    }
+
+    function decodeMimeWord(mimeWord) {
+        const regex = /^=\?([^?]+)\?([^?]+)\?(.+?)\?=$/i;
+        const match = mimeWord.match(regex);
+
+        if (!match) return mimeWord;
+
+        const [, charset, encoding, encodedText] = match;
+
+        // atob is not defined in Experiments environment
+        const b64Decode = typeof atob === "undefined" ? window.atob : atob;
+
+        let decodedText = null;
+
+        switch (encoding.toUpperCase()) {
+            case "Q":
+                decodedText = decodeQuotedPrintable(encodedText);
+                break;
+            case "B":
+                decodedText = b64Decode(encodedText);
+                break;
+            default:
+                libCommon.warn("Invalid MIME encoding (RFC 2047): " + encoding);
+        }
+
+        if (!decodedText) return mimeWord;
+
+        if (charset.toUpperCase() !== "UTF-8") {
+            libCommon.warn("Unsupported charset: " + charset);
+            return decodedText;
+        }
+
+        // Convert to UTF-8 string
+        return decodeURIComponent(escape(decodedText));
+    }
+
+    return headerValue
+        // Unfolding
+        .replace(/[\r\n]+[\s]+/g, "")
+        // Find and decode encoded words, removing any spaces between them
+        .replace(/(=\?[^?]+\?[^?]+\?[^?]+\?=)(\s+)?/gi, (_, encodedWord) => decodeMimeWord(encodedWord));
+};
+
 /**
  * Get message score from the message headers object.
  * Returns NaN if a header or message score not found.
  *
  * @param {object} hdr - Message headers object.
  * @param {string} header
  * @param {boolean} [XPC] - hdr is an XPConnect wrapped object
+ * @param {object} [window] - Global window object, used for base64 decoding in Experiments environment
  * @returns {number} - Message score
  */
-libCommon.getScoreByHdr = function (hdr, header, XPC) {
+libCommon.getScoreByHdr = function (hdr, header, XPC, window) {
     const re = [
         // X-Spamd-Result: Rspamd (milter)
         /: \S+ \[([-\d.]+?) \//,
@@ -62,8 +126,9 @@ libCommon.getScoreByHdr = function (hdr, header, XPC) {
     [...userHeaders, ...libCommon.scoreHeaders].some(function (headerName) {
         const headerStr = XPC ? hdr.getStringProperty(headerName) : hdr[headerName];
         if (!headerStr) return false;
+        const decodedHeader = XPC ? libCommon.decodeMimeHeader(headerStr, window) : headerStr;
         re.some(function (regexp) {
-            const parsed = regexp.exec(headerStr);
+            const parsed = regexp.exec(decodedHeader);
             if (parsed) {
                 score = parseFloat(parsed[1]);
             }

diff --git a/scripts/libHeader.js b/scripts/libHeader.js
@@ -18,7 +18,7 @@ libHeader.getSymbols = function (headers, header, XPC, window) {
         if (!XPC) return headers[headerName] || null;
 
         const headerStr = headers.getStringProperty(headerName);
-        return headerStr ? [headerStr] : null;
+        return headerStr ? [libCommon.decodeMimeHeader(headerStr, window)] : null;
     }
 
     function getUserHeaderStr() {