wrap lines of base64 in chunks

Author: andris9

lib/libbase64.js

@@ -43,7 +43,19 @@ function wrap(str, lineLength) {
         return str;
     }
 
-    return str.replace(new RegExp('.{' + lineLength + '}', 'g'), '$&\r\n').trim();
+    let result = [];
+    let pos = 0;
+    let chunkLength = lineLength * 1024;
+    while (pos < str.length) {
+        let wrappedLines = str
+            .substr(pos, chunkLength)
+            .replace(new RegExp('.{' + lineLength + '}', 'g'), '$&\r\n')
+            .trim();
+        result.push(wrappedLines);
+        pos += chunkLength;
+    }
+
+    return result.join('\r\n').trim();
 }
 
 /**