commit 2b973552b981d0822f814ce3d8d83971c36834b7
parent 293bb727ed002ebc80f00f49e610417f380aee16
author: rj1 <[email protected]>
date:   Wed, 17 Aug 2022 13:08:42 -0500

added filetype detection

Diffstat:
M
upload.js
 | 
92
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------

1 file changed, 83 insertions(+), 9 deletions(-)
diff --git a/upload.js b/upload.js
@@ -2,23 +2,20 @@ browser.contextMenus.create({
   title: "Upload image [POST]",
   contexts: ["image"],
   onclick: function(info, tab) {
-    // get the image from cache:
     var download = new XMLHttpRequest();
     download.onload = function() {
-      var filename = info.srcUrl.split(/[\\/]/).pop();
+      var og_filename = info.srcUrl.split(/[\\/]/).pop(); // maybe we'll use this later
 
-      // if filename has no extension, add .png to it
-      // TODO: detect filetype and add the proper extension
-      if(filename == filename.split('.')) {
-        filename = filename + '.png';
-      }
+      formatDetect(download.response, function(extension) {
+        filename = makeid(5) + '.' + extension;
+      });
 
       var fd = new FormData();
       fd.append("files[]", download.response, filename);
       var upload = new XMLHttpRequest();
       upload.responseType = 'json';
 
-      upload.onload = function() { 
+      upload.onload = function() {
         url = upload.response.files[0].url;
         browser.tabs.create({url: url});
       }
@@ -26,11 +23,88 @@ browser.contextMenus.create({
       // upload image
       upload.open('POST', 'https://uguu.se/upload.php');
       upload.send(fd);
+
     };
-    // get uguu url
+
     download.responseType = 'blob';
     download.open('GET', info.srcUrl);
     download.send();
   }
 });
 
+function makeid(length) {
+  var result           = '';
+  var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+  var charactersLength = characters.length;
+  for (var i = 0; i < length; i++) {
+    result += characters.charAt(Math.floor(Math.random() * 
+      charactersLength));
+  }
+  return result;
+}
+
+function formatDetect(file, callback) {
+  // https://mimesniff.spec.whatwg.org/#matching-an-image-type-pattern
+  var mimes = [
+    {
+      mime: 'image/jpeg',
+      extension: 'jpg',
+      pattern: [0xFF, 0xD8, 0xFF],
+      mask: [0xFF, 0xFF, 0xFF]
+    },
+    {
+      mime: 'image/png',
+      extension: 'png',
+      pattern: [0x89, 0x50, 0x4E, 0x47],
+      mask: [0xFF, 0xFF, 0xFF, 0xFF]
+    },
+    {
+      mime: 'image/webp',
+      extension: 'webp',
+      pattern: [0x52, 0x49, 0x46, 0x46],
+      mask: [0xFF, 0xFF, 0xFF, 0xFF]
+    },
+    {
+      mime: 'image/gif',
+      extension: 'gif',
+      pattern: [0x47, 0x49, 0x46, 0x38],
+      mask: [0xFF, 0xFF, 0xFF, 0xFF]
+    },
+    {
+      mime: 'image/svg+xml',
+      extension: 'svg',
+      pattern: [0x3c, 0x3f, 0x78, 0x6d],
+      mask: [0xFF, 0xFF, 0xFF, 0xFF]
+    }
+  ];
+
+  function check(bytes, mime) {
+    for(var i = 0, l = mime.mask.length; i < l; ++i) {
+      if((bytes[i] & mime.mask[i]) - mime.pattern[i] !== 0) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  var blob = file.slice(0, 4);
+
+  var reader = new FileReader();
+  reader.onloadend = function(e) {
+    if(e.target.readyState === FileReader.DONE) {
+      var bytes = new Uint8Array(e.target.result);
+
+      for(var i=0, l = mimes.length; i<l; ++i) {
+        if(check(bytes, mimes[i])) {
+          // return the proper extension for the file
+          return callback(mimes[i].extension)
+        }
+      }
+
+      // return a default extension
+      return callback('png');
+    }
+  };
+  reader.readAsArrayBuffer(blob);
+}
+