Add limitInputPixels option to reject input #115

README.md

@@ -254,6 +254,12 @@ A Promises/A+ promise is returned when `callback` is not provided.
 
 An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`. This will reduce memory usage and can improve performance on some systems.
 
+#### limitInputPixels(pixels)
+
+Do not process input images where the number of pixels (width * height) exceeds this limit.
+
+`pixels` is the integral Number of pixels, with a value between 1 and the default 268402689 (0x3FFF * 0x3FFF).
+
 ### Image transformation options
 
 #### resize(width, [height])

index.js

@@ -11,6 +11,12 @@ var BluebirdPromise = require('bluebird');
 var sharp = require('./build/Release/sharp');
 var libvipsVersion = sharp.libvipsVersion();
 
+var maximum = {
+  width: 0x3FFF,
+  height: 0x3FFF,
+  pixels: Math.pow(0x3FFF, 2)
+};
+
 var Sharp = function(input) {
   if (!(this instanceof Sharp)) {
     return new Sharp(input);
@@ -21,6 +27,7 @@ var Sharp = function(input) {
     bufferIn: null,
     streamIn: false,
     sequentialRead: false,
+    limitInputPixels: maximum.pixels,
     // ICC profiles
     iccProfilePath: path.join(__dirname, 'icc') + path.sep,
     // resize options
@@ -366,24 +373,37 @@ Sharp.prototype.resize = function(width, height) {
   if (!width) {
     this.options.width = -1;
   } else {
-    if (typeof width === 'number' && !Number.isNaN(width) && width % 1 === 0 && width > 0 && width <= 0x3FFF) {
+    if (typeof width === 'number' && !Number.isNaN(width) && width % 1 === 0 && width > 0 && width <= maximum.width) {
       this.options.width = width;
     } else {
-      throw new Error('Invalid width ' + width);
+      throw new Error('Invalid width (1 to ' + maximum.width + ') ' + width);
     }
   }
   if (!height) {
     this.options.height = -1;
   } else {
-    if (typeof height === 'number' && !Number.isNaN(height) && height % 1 === 0 && height > 0 && height <= 0x3FFF) {
+    if (typeof height === 'number' && !Number.isNaN(height) && height % 1 === 0 && height > 0 && height <= maximum.height) {
       this.options.height = height;
     } else {
-      throw new Error('Invalid height ' + height);
+      throw new Error('Invalid height (1 to ' + maximum.height + ') ' + height);
     }
   }
   return this;
 };
 
+/*
+  Limit the total number of pixels for input images
+  Assumes the image dimensions contained in the file header can be trusted
+*/
+Sharp.prototype.limitInputPixels = function(limit) {
+  if (typeof limit === 'number' && !Number.isNaN(limit) && limit % 1 === 0 && limit > 0 && limit <= maximum.pixels) {
+    this.options.limitInputPixels = limit;
+  } else {
+    throw new Error('Invalid pixel limit (1 to ' + maximum.pixels + ') ' + limit);
+  }
+  return this;
+};
+
 /*
   Write output image data to a file
 */

src/resize.cc

@@ -54,6 +54,7 @@ struct ResizeBaton {
   void* bufferIn;
   size_t bufferInLength;
   std::string iccProfilePath;
+  int limitInputPixels;
   std::string output;
   std::string outputFormat;
   void* bufferOut;
@@ -94,6 +95,7 @@ struct ResizeBaton {
 
   ResizeBaton():
     bufferInLength(0),
+    limitInputPixels(0),
     outputFormat(""),
     bufferOutLength(0),
     topOffsetPre(-1),
@@ -178,6 +180,12 @@ class ResizeWorker : public NanAsyncWorker {
     }
     vips_object_local(hook, image);
 
+    // Limit input images to a given number of pixels, where pixels = width * height
+    if (image->Xsize * image->Ysize > baton->limitInputPixels) {
+      (baton->err).append("Input image exceeds pixel limit");
+      return Error(baton, hook);
+    }
+
     // Calculate angle of rotation
     Angle rotation;
     bool flip;
@@ -923,6 +931,8 @@ NAN_METHOD(resize) {
   }
   // ICC profile to use when input CMYK image has no embedded profile
   baton->iccProfilePath = *String::Utf8Value(options->Get(NanNew<String>("iccProfilePath"))->ToString());
+  // Limit input images to a given number of pixels, where pixels = width * height
+  baton->limitInputPixels = options->Get(NanNew<String>("limitInputPixels"))->Int32Value();
   // Extract image options
   baton->topOffsetPre = options->Get(NanNew<String>("topOffsetPre"))->Int32Value();
   baton->leftOffsetPre = options->Get(NanNew<String>("leftOffsetPre"))->Int32Value();

test/unit/io.js

@@ -524,4 +524,72 @@ describe('Input/output', function() {
     });
   }
 
+  describe('Limit pixel count of input image', function() {
+
+    it('Invalid fails - negative', function(done) {
+      var isValid = false;
+      try {
+        sharp().limitInputPixels(-1);
+        isValid = true;
+      } catch (e) {}
+      assert(!isValid);
+      done();
+    });
+
+    it('Invalid fails - float', function(done) {
+      var isValid = false;
+      try {
+        sharp().limitInputPixels(12.3);
+        isValid = true;
+      } catch (e) {}
+      assert(!isValid);
+      done();
+    });
+
+    it('Invalid fails - huge', function(done) {
+      var isValid = false;
+      try {
+        sharp().limitInputPixels(Math.pow(0x3FFF, 2) + 1);
+        isValid = true;
+      } catch (e) {}
+      assert(!isValid);
+      done();
+    });
+
+    it('Invalid fails - string', function(done) {
+      var isValid = false;
+      try {
+        sharp().limitInputPixels('fail');
+        isValid = true;
+      } catch (e) {}
+      assert(!isValid);
+      done();
+    });
+
+    it('Same size as input works', function(done) {
+      sharp(fixtures.inputJpg).metadata(function(err, metadata) {
+        if (err) throw err;
+        sharp(fixtures.inputJpg)
+          .limitInputPixels(metadata.width * metadata.height)
+          .toBuffer(function(err) {
+            assert.strictEqual(true, !err);
+            done();
+          });
+      });
+    });
+
+    it('Smaller than input fails', function(done) {
+      sharp(fixtures.inputJpg).metadata(function(err, metadata) {
+        if (err) throw err;
+        sharp(fixtures.inputJpg)
+          .limitInputPixels(metadata.width * metadata.height - 1)
+          .toBuffer(function(err) {
+            assert.strictEqual(true, !!err);
+            done();
+          });
+      });
+    });
+
+  });
+
 });