@recaptime-dev's working patches + fork for Phorge, a community fork of Phabricator. (Upstream dev and stable branches are at upstream/main and upstream/stable respectively.)
hq.recaptime.dev/wiki/Phorge
phorge
phabricator
Implement new profile transform with amazing "error handling" feature
Summary:
Ref T7707. Ref T4406. Ref T2479. This implements the profile-style (fixed width and height) transforms in a modern way.
- Added a "regnerate" feature to the support UI to make testing easier and surface errors.
- Laboriously check errors from everything.
- Fix the profile thumbnailing so it crops properly instead of leaving margins.
- Also defuses the "gigantic white PNG" attack.
This doesn't handle the imagemagick case (for animated GIFs) yet.
Test Plan:
- Uploaded a variety of wide/narrow/small/large files and converted them into sensible profile pictures.
- Tried to thumbnail some text files.
- Set the pixel-size and file-size limits artificially small and hit them.
- Used "regenerate" a bunch while testing the rest of this stuff.
- Verified that non-regenerate flows still produce a default/placeholder image.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T4406, T2479, T7707
Differential Revision: https://secure.phabricator.com/D12811
+352
-21
+30
-4
src/applications/files/controller/PhabricatorFileTransformController.php
+30
-4
src/applications/files/controller/PhabricatorFileTransformController.php
···
13
13
// NOTE: This is a public/CDN endpoint, and permission to see files is
14
14
// controlled by knowing the secret key, not by authentication.
15
15
16
+
$is_regenerate = $request->getBool('regenerate');
17
+
16
18
$source_phid = $request->getURIData('phid');
17
19
$file = id(new PhabricatorFileQuery())
18
20
->setViewer(PhabricatorUser::getOmnipotentUser())
···
35
37
$transform);
36
38
37
39
if ($xform) {
38
-
return $this->buildTransformedFileResponse($xform);
40
+
if ($is_regenerate) {
41
+
$this->destroyTransform($xform);
42
+
} else {
43
+
return $this->buildTransformedFileResponse($xform);
44
+
}
39
45
}
40
46
41
47
$type = $file->getMimeType();
···
57
63
try {
58
64
$xformed_file = $xforms[$transform]->applyTransform($file);
59
65
} catch (Exception $ex) {
60
-
// TODO: Provide a diagnostic mode to surface these to the viewer.
61
-
62
66
// In normal transform mode, we ignore failures and generate a
63
-
// default transform instead.
67
+
// default transform below. If we're explicitly regenerating the
68
+
// thumbnail, rethrow the exception.
69
+
if ($is_regenerate) {
70
+
throw $ex;
71
+
}
64
72
}
65
73
}
66
74
···
163
171
private function executeThumbTransform(PhabricatorFile $file, $x, $y) {
164
172
$xformer = new PhabricatorImageTransformer();
165
173
return $xformer->executeThumbTransform($file, $x, $y);
174
+
}
175
+
176
+
private function destroyTransform(PhabricatorTransformedFile $xform) {
177
+
$file = id(new PhabricatorFileQuery())
178
+
->setViewer(PhabricatorUser::getOmnipotentUser())
179
+
->withPHIDs(array($xform->getTransformedPHID()))
180
+
->executeOne();
181
+
182
+
$unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
183
+
184
+
if (!$file) {
185
+
$xform->delete();
186
+
} else {
187
+
$engine = new PhabricatorDestructionEngine();
188
+
$engine->destroyObject($file);
189
+
}
190
+
191
+
unset($unguarded);
166
192
}
167
193
168
194
}
+6
-5
src/applications/files/controller/PhabricatorFileTransformListController.php
+6
-5
src/applications/files/controller/PhabricatorFileTransformListController.php
···
58
58
59
59
if ($xform->canApplyTransform($file)) {
60
60
$can_apply = pht('Yes');
61
+
61
62
$view_href = $file->getURIForTransform($xform);
62
-
if ($dst_phid) {
63
-
$view_text = pht('View Transform');
64
-
} else {
65
-
$view_text = pht('Generate Transform');
66
-
}
63
+
$view_href = new PhutilURI($view_href);
64
+
$view_href->setQueryParam('regenerate', 'true');
65
+
66
+
$view_text = pht('Regenerate');
67
+
67
68
$view_link = phutil_tag(
68
69
'a',
69
70
array(
+284
src/applications/files/transform/PhabricatorFileImageTransform.php
+284
src/applications/files/transform/PhabricatorFileImageTransform.php
···
2
2
3
3
abstract class PhabricatorFileImageTransform extends PhabricatorFileTransform {
4
4
5
+
private $file;
6
+
private $data;
7
+
private $image;
8
+
private $imageX;
9
+
private $imageY;
10
+
5
11
public function canApplyTransform(PhabricatorFile $file) {
6
12
if (!$file->isViewableImage()) {
7
13
return false;
···
12
18
}
13
19
14
20
return true;
21
+
}
22
+
23
+
protected function willTransformFile(PhabricatorFile $file) {
24
+
$this->file = $file;
25
+
$this->data = null;
26
+
$this->image = null;
27
+
$this->imageX = null;
28
+
$this->imageY = null;
29
+
}
30
+
31
+
protected function applyCropAndScale(
32
+
$dst_w, $dst_h,
33
+
$src_x, $src_y,
34
+
$src_w, $src_h) {
35
+
36
+
// Figure out the effective destination width, height, and offsets. We
37
+
// never want to scale images up, so if we're copying a very small source
38
+
// image we're just going to center it in the destination image.
39
+
$cpy_w = min($dst_w, $src_w);
40
+
$cpy_h = min($dst_h, $src_h);
41
+
$off_x = ($dst_w - $cpy_w) / 2;
42
+
$off_y = ($dst_h - $cpy_h) / 2;
43
+
44
+
// TODO: Support imagemagick for animated GIFs.
45
+
46
+
$src = $this->getImage();
47
+
$dst = $this->newEmptyImage($dst_w, $dst_h);
48
+
49
+
$trap = new PhutilErrorTrap();
50
+
$ok = @imagecopyresampled(
51
+
$dst,
52
+
$src,
53
+
$off_x, $off_y,
54
+
$src_x, $src_y,
55
+
$cpy_w, $cpy_h,
56
+
$src_w, $src_h);
57
+
$errors = $trap->getErrorsAsString();
58
+
$trap->destroy();
59
+
60
+
if ($ok === false) {
61
+
throw new Exception(
62
+
pht(
63
+
'Failed to imagecopyresampled() image: %s',
64
+
$errors));
65
+
}
66
+
67
+
$data = PhabricatorImageTransformer::saveImageDataInAnyFormat(
68
+
$dst,
69
+
$this->file->getMimeType());
70
+
71
+
return $this->newFileFromData($data);
72
+
}
73
+
74
+
75
+
/**
76
+
* Create a new @{class:PhabricatorFile} from raw data.
77
+
*
78
+
* @param string Raw file data.
79
+
*/
80
+
protected function newFileFromData($data) {
81
+
$name = $this->getTransformKey().'-'.$this->file->getName();
82
+
83
+
return PhabricatorFile::newFromFileData(
84
+
$data,
85
+
array(
86
+
'name' => $name,
87
+
'canCDN' => true,
88
+
));
89
+
}
90
+
91
+
92
+
/**
93
+
* Create a new image filled with transparent pixels.
94
+
*
95
+
* @param int Desired image width.
96
+
* @param int Desired image height.
97
+
* @return resource New image resource.
98
+
*/
99
+
protected function newEmptyImage($w, $h) {
100
+
$w = (int)$w;
101
+
$h = (int)$h;
102
+
103
+
if (($w <= 0) || ($h <= 0)) {
104
+
throw new Exception(
105
+
pht('Can not create an image with nonpositive dimensions.'));
106
+
}
107
+
108
+
$trap = new PhutilErrorTrap();
109
+
$img = @imagecreatetruecolor($w, $h);
110
+
$errors = $trap->getErrorsAsString();
111
+
$trap->destroy();
112
+
if ($img === false) {
113
+
throw new Exception(
114
+
pht(
115
+
'Unable to imagecreatetruecolor() a new empty image: %s',
116
+
$errors));
117
+
}
118
+
119
+
$trap = new PhutilErrorTrap();
120
+
$ok = @imagesavealpha($img, true);
121
+
$errors = $trap->getErrorsAsString();
122
+
$trap->destroy();
123
+
if ($ok === false) {
124
+
throw new Exception(
125
+
pht(
126
+
'Unable to imagesavealpha() a new empty image: %s',
127
+
$errors));
128
+
}
129
+
130
+
$trap = new PhutilErrorTrap();
131
+
$color = @imagecolorallocatealpha($img, 255, 255, 255, 127);
132
+
$errors = $trap->getErrorsAsString();
133
+
$trap->destroy();
134
+
if ($color === false) {
135
+
throw new Exception(
136
+
pht(
137
+
'Unable to imagecolorallocatealpha() a new empty image: %s',
138
+
$errors));
139
+
}
140
+
141
+
$trap = new PhutilErrorTrap();
142
+
$ok = @imagefill($img, 0, 0, $color);
143
+
$errors = $trap->getErrorsAsString();
144
+
$trap->destroy();
145
+
if ($ok === false) {
146
+
throw new Exception(
147
+
pht(
148
+
'Unable to imagefill() a new empty image: %s',
149
+
$errors));
150
+
}
151
+
152
+
return $img;
153
+
}
154
+
155
+
156
+
/**
157
+
* Get the pixel dimensions of the image being transformed.
158
+
*
159
+
* @return list<int, int> Width and height of the image.
160
+
*/
161
+
protected function getImageDimensions() {
162
+
if ($this->imageX === null) {
163
+
$image = $this->getImage();
164
+
165
+
$trap = new PhutilErrorTrap();
166
+
$x = @imagesx($image);
167
+
$y = @imagesy($image);
168
+
$errors = $trap->getErrorsAsString();
169
+
$trap->destroy();
170
+
171
+
if (($x === false) || ($y === false) || ($x <= 0) || ($y <= 0)) {
172
+
throw new Exception(
173
+
pht(
174
+
'Unable to determine image dimensions with '.
175
+
'imagesx()/imagesy(): %s',
176
+
$errors));
177
+
}
178
+
179
+
$this->imageX = $x;
180
+
$this->imageY = $y;
181
+
}
182
+
183
+
return array($this->imageX, $this->imageY);
184
+
}
185
+
186
+
187
+
/**
188
+
* Get the raw file data for the image being transformed.
189
+
*
190
+
* @return string Raw file data.
191
+
*/
192
+
protected function getData() {
193
+
if ($this->data !== null) {
194
+
return $this->data;
195
+
}
196
+
197
+
$file = $this->file;
198
+
199
+
$max_size = (1024 * 1024 * 4);
200
+
$img_size = $file->getByteSize();
201
+
if ($img_size > $max_size) {
202
+
throw new Exception(
203
+
pht(
204
+
'This image is too large to transform. The transform limit is %s '.
205
+
'bytes, but the image size is %s bytes.',
206
+
new PhutilNumber($max_size),
207
+
new PhutilNumber($img_size)));
208
+
}
209
+
210
+
$data = $file->loadFileData();
211
+
$this->data = $data;
212
+
return $this->data;
213
+
}
214
+
215
+
216
+
/**
217
+
* Get the GD image resource for the image being transformed.
218
+
*
219
+
* @return resource GD image resource.
220
+
*/
221
+
protected function getImage() {
222
+
if ($this->image !== null) {
223
+
return $this->image;
224
+
}
225
+
226
+
if (!function_exists('imagecreatefromstring')) {
227
+
throw new Exception(
228
+
pht(
229
+
'Unable to transform image: the imagecreatefromstring() function '.
230
+
'is not available. Install or enable the "gd" extension for PHP.'));
231
+
}
232
+
233
+
$data = $this->getData();
234
+
$data = (string)$data;
235
+
236
+
// First, we're going to write the file to disk and use getimagesize()
237
+
// to determine its dimensions without actually loading the pixel data
238
+
// into memory. For very large images, we'll bail out.
239
+
240
+
// In particular, this defuses a resource exhaustion attack where the
241
+
// attacker uploads a 40,000 x 40,000 pixel PNGs of solid white. These
242
+
// kinds of files compress extremely well, but require a huge amount
243
+
// of memory and CPU to process.
244
+
245
+
$tmp = new TempFile();
246
+
Filesystem::writeFile($tmp, $data);
247
+
$tmp_path = (string)$tmp;
248
+
249
+
$trap = new PhutilErrorTrap();
250
+
$info = @getimagesize($tmp_path);
251
+
$errors = $trap->getErrorsAsString();
252
+
$trap->destroy();
253
+
254
+
unset($tmp);
255
+
256
+
if ($info === false) {
257
+
throw new Exception(
258
+
pht(
259
+
'Unable to get image information with getimagesize(): %s',
260
+
$errors));
261
+
}
262
+
263
+
list($width, $height) = $info;
264
+
if (($width <= 0) || ($height <= 0)) {
265
+
throw new Exception(
266
+
pht(
267
+
'Unable to determine image width and height with getimagesize().'));
268
+
}
269
+
270
+
$max_pixels = (4096 * 4096);
271
+
$img_pixels = ($width * $height);
272
+
273
+
if ($img_pixels > $max_pixels) {
274
+
throw new Exception(
275
+
pht(
276
+
'This image (with dimensions %spx x %spx) is too large to '.
277
+
'transform. The image has %s pixels, but transforms are limited '.
278
+
'to images with %s or fewer pixels.',
279
+
new PhutilNumber($width),
280
+
new PhutilNumber($height),
281
+
new PhutilNumber($img_pixels),
282
+
new PhutilNumber($max_pixels)));
283
+
}
284
+
285
+
$trap = new PhutilErrorTrap();
286
+
$image = @imagecreatefromstring($data);
287
+
$errors = $trap->getErrorsAsString();
288
+
$trap->destroy();
289
+
290
+
if ($image === false) {
291
+
throw new Exception(
292
+
pht(
293
+
'Unable to load image data with imagecreatefromstring(): %s',
294
+
$errors));
295
+
}
296
+
297
+
$this->image = $image;
298
+
return $this->image;
15
299
}
16
300
17
301
}
+32
-12
src/applications/files/transform/PhabricatorFileThumbnailTransform.php
+32
-12
src/applications/files/transform/PhabricatorFileThumbnailTransform.php
···
59
59
}
60
60
61
61
public function applyTransform(PhabricatorFile $file) {
62
-
$x = $this->dstX;
63
-
$y = $this->dstY;
62
+
$xformer = new PhabricatorImageTransformer();
63
+
if ($this->dstY === null) {
64
+
return $xformer->executePreviewTransform($file, $this->dstX);
65
+
}
64
66
65
-
$xformer = new PhabricatorImageTransformer();
67
+
$this->willTransformFile($file);
66
68
67
-
if ($y === null) {
68
-
return $xformer->executePreviewTransform($file, $x);
69
+
list($src_x, $src_y) = $this->getImageDimensions();
70
+
$dst_x = $this->dstX;
71
+
$dst_y = $this->dstY;
72
+
73
+
// Figure out how much we'd have to scale the image down along each
74
+
// dimension to get the entire thing to fit.
75
+
$scale_x = min(($dst_x / $src_x), 1);
76
+
$scale_y = min(($dst_y / $src_y), 1);
77
+
78
+
if ($scale_x > $scale_y) {
79
+
// This image is relatively tall and narrow. We're going to crop off the
80
+
// top and bottom.
81
+
$copy_x = $src_x;
82
+
$copy_y = min($src_y, $dst_y / $scale_x);
69
83
} else {
70
-
return $xformer->executeThumbTransform($file, $x, $y);
84
+
// This image is relatively short and wide. We're going to crop off the
85
+
// left and right.
86
+
$copy_x = min($src_x, $dst_x / $scale_y);
87
+
$copy_y = $src_y;
71
88
}
89
+
90
+
return $this->applyCropAndScale(
91
+
$dst_x,
92
+
$dst_y,
93
+
($src_x - $copy_x) / 2,
94
+
($src_y - $copy_y) / 2,
95
+
$copy_x,
96
+
$copy_y);
72
97
}
73
98
74
99
public function getDefaultTransform(PhabricatorFile $file) {
···
76
101
$y = (int)$this->dstY;
77
102
$name = 'image-'.$x.'x'.nonempty($y, $x).'.png';
78
103
79
-
$params = array(
80
-
'name' => $name,
81
-
'canCDN' => true,
82
-
);
83
-
84
104
$root = dirname(phutil_get_library_root('phabricator'));
85
105
$data = Filesystem::readFile($root.'/resources/builtin/'.$name);
86
106
87
-
return PhabricatorFile::newFromFileData($data, $params);
107
+
return $this->newFileFromData($data);
88
108
}
89
109
90
110
}