Merge branch 'feature-remove-exif' of https://github.com/davejm/CyberChef into davejm-feature-remove-exif

src/core/config/Categories.js

@@ -210,6 +210,7 @@ const Categories = [
             "XPath expression",
             "CSS selector",
             "Extract EXIF",
+            "Remove EXIF",
         ]
     },
     {

src/core/config/OperationConfig.js

@@ -3388,6 +3388,19 @@ const OperationConfig = {
             }
         ]
     },
+    "Remove EXIF": {
+        description: [
+            "Removes EXIF data from a JPEG image.",
+            "<br><br>",
+            "EXIF data is metadata embedded in JPEGs.",
+            "<br><br>",
+            "EXIF data from photos usually contains information about the image file itself as well as the device used to create it.",
+        ].join("\n"),
+        run: Image.removeEXIF,
+        inputType: "byteArray",
+        outputType: "byteArray",
+        args: [],
+    },
 };
 
 export default OperationConfig;

src/core/lib/remove-exif.js

@@ -0,0 +1,153 @@
+/* piexifjs
+The MIT License (MIT)
+Copyright (c) 2014, 2015 hMatoba(https://github.com/hMatoba)
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+import Utils from "../Utils.js";
+
+// Param jpeg should be a binaryArray
+function removeEXIF(jpeg) {
+  // Convert binaryArray to char string
+  jpeg = Utils.byteArrayToChars(jpeg);
+  if (jpeg.slice(0, 2) != "\xff\xd8") {
+    throw ("Given data is not jpeg.");
+  }
+
+  var segments = splitIntoSegments(jpeg);
+  if (segments[1].slice(0, 2) == "\xff\xe1" &&
+    segments[1].slice(4, 10) == "Exif\x00\x00") {
+    segments = [segments[0]].concat(segments.slice(2));
+  } else if (segments[2].slice(0, 2) == "\xff\xe1" &&
+    segments[2].slice(4, 10) == "Exif\x00\x00") {
+    segments = segments.slice(0, 2).concat(segments.slice(3));
+  } else {
+    throw ("Exif not found.");
+  }
+
+  var new_data = segments.join("");
+
+  // Convert back to binaryArray
+  new_data = Utils.strToCharcode(new_data);
+
+  return new_data;
+};
+
+function splitIntoSegments(data) {
+  if (data.slice(0, 2) != "\xff\xd8") {
+    throw ("Given data isn't JPEG.");
+  }
+
+  var head = 2;
+  var segments = ["\xff\xd8"];
+  while (true) {
+    if (data.slice(head, head + 2) == "\xff\xda") {
+      segments.push(data.slice(head));
+      break;
+    } else {
+      var length = unpack(">H", data.slice(head + 2, head + 4))[0];
+      var endPoint = head + length + 2;
+      segments.push(data.slice(head, endPoint));
+      head = endPoint;
+    }
+
+    if (head >= data.length) {
+      throw ("Wrong JPEG data.");
+    }
+  }
+  return segments;
+}
+
+function unpack(mark, str) {
+  if (typeof(str) != "string") {
+    throw ("'unpack' error. Got invalid type argument.");
+  }
+  var l = 0;
+  for (var markPointer = 1; markPointer < mark.length; markPointer++) {
+    if (mark[markPointer].toLowerCase() == "b") {
+      l += 1;
+    } else if (mark[markPointer].toLowerCase() == "h") {
+      l += 2;
+    } else if (mark[markPointer].toLowerCase() == "l") {
+      l += 4;
+    } else {
+      throw ("'unpack' error. Got invalid mark.");
+    }
+  }
+
+  if (l != str.length) {
+    throw ("'unpack' error. Mismatch between symbol and string length. " + l + ":" + str.length);
+  }
+
+  var littleEndian;
+  if (mark[0] == "<") {
+    littleEndian = true;
+  } else if (mark[0] == ">") {
+    littleEndian = false;
+  } else {
+    throw ("'unpack' error.");
+  }
+  var unpacked = [];
+  var strPointer = 0;
+  var p = 1;
+  var val = null;
+  var c = null;
+  var length = null;
+  var sliced = "";
+
+  while (c = mark[p]) {
+    if (c.toLowerCase() == "b") {
+      length = 1;
+      sliced = str.slice(strPointer, strPointer + length);
+      val = sliced.charCodeAt(0);
+      if ((c == "b") && (val >= 0x80)) {
+        val -= 0x100;
+      }
+    } else if (c == "H") {
+      length = 2;
+      sliced = str.slice(strPointer, strPointer + length);
+      if (littleEndian) {
+        sliced = sliced.split("").reverse().join("");
+      }
+      val = sliced.charCodeAt(0) * 0x100 +
+        sliced.charCodeAt(1);
+    } else if (c.toLowerCase() == "l") {
+      length = 4;
+      sliced = str.slice(strPointer, strPointer + length);
+      if (littleEndian) {
+        sliced = sliced.split("").reverse().join("");
+      }
+      val = sliced.charCodeAt(0) * 0x1000000 +
+        sliced.charCodeAt(1) * 0x10000 +
+        sliced.charCodeAt(2) * 0x100 +
+        sliced.charCodeAt(3);
+      if ((c == "l") && (val >= 0x80000000)) {
+        val -= 0x100000000;
+      }
+    } else {
+      throw ("'unpack' error. " + c);
+    }
+
+    unpacked.push(val);
+    strPointer += length;
+    p += 1;
+  }
+
+  return unpacked;
+}
+
+export default removeEXIF;

src/core/operations/Image.js

@@ -1,4 +1,5 @@
 import * as ExifParser from "exif-parser";
+import removeEXIF from "../lib/remove-exif.js";
 import Utils from "../Utils.js";
 import FileType from "./FileType.js";
 
@@ -43,6 +44,28 @@ const Image = {
         }
     },
 
+    /**
+     * Remove EXIF operation.
+     *
+     * Removes EXIF data from a byteArray, representing a JPG.
+     *
+     * @author David Moodie [davidmoodie12@gmail.com]
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    removeEXIF(input, args) {
+        // Do nothing if input is empty
+        if (input.length === 0) return input;
+
+        try {
+            return removeEXIF(input);
+        } catch (err) {
+            // Simply return input if no EXIF data is found
+            if (err === "Exif not found.") return input;
+            throw "Could not remove EXIF data from image: " + err;
+        }
+    },
 
     /**
      * @constant