Restore image proxying to Remarkup

Summary:
Previously, Remarkup allowed you to paste in an image URI and get an inline
image. However, it did this by hotlinking the image which isn't so hot in an
open source product.

Restore this feature, but use image proxying instead. The existing image macro
code does most of the work.

There is a mild security risk depending on the network setup so I've left this
default-disabled and made a note about it. It should be safe to enable for
Facebook.

Test Plan:
Pasted in image and non-image links, got reasonable behavior. Verified proxying
appears to work. Verified that file:// shenanigans produce 400.

Reviewed By: tuomaspelkonen
Reviewers: aran, jungejason, tuomaspelkonen
Commenters: cpiro
CC: aran, cpiro, tuomaspelkonen
Differential Revision: 214

conf/default.conf.php

@@ -292,6 +292,16 @@ return array(
     'text/plain'  => 'text/plain; charset=utf-8',
   ),
 
+  // Phabricator can proxy images from other servers so you can paste the URI
+  // to a funny picture of a cat into the comment box and have it show up as an
+  // image. However, this means the webserver Phabricator is running on will
+  // make HTTP requests to arbitrary URIs. If the server has access to internal
+  // resources, this could be a security risk. You should only enable it if you
+  // are installed entirely a VPN and VPN access is required to access
+  // Phabricator, or if the webserver has no special access to anything. If
+  // unsure, it is safer to leave this disabled.
+  'files.enable-proxy' => false,
+
 // -- Differential ---------------------------------------------------------- //
 
   'differential.revision-custom-detail-renderer'  => null,

resources/sql/patches/035.proxyimage.sql

@@ -0,0 +1,6 @@
+CREATE TABLE phabricator_file.file_proxyimage (
+  id int unsigned not null primary key auto_increment,
+  uri varchar(255) binary not null,
+  unique key(uri),
+  filePHID varchar(64) binary not null
+) ENGINE=InnoDB;

src/__celerity_resource_map__.php

@@ -616,7 +616,7 @@ celerity_register_resource_map(array(
   ),
   'phabricator-remarkup-css' =>
   array(
-    'uri' => '/res/1fc75ba6/rsrc/css/core/remarkup.css',
+    'uri' => '/res/41748e59/rsrc/css/core/remarkup.css',
     'type' => 'css',
     'requires' =>
     array(
@@ -653,7 +653,7 @@ celerity_register_resource_map(array(
 ), array (
   'packages' =>
   array (
-    '14e8c91d' =>
+    '4270730a' =>
     array (
       'name' => 'core.pkg.css',
       'symbols' =>
@@ -673,7 +673,7 @@ celerity_register_resource_map(array(
         12 => 'phabricator-remarkup-css',
         13 => 'syntax-highlighting-css',
       ),
-      'uri' => '/res/pkg/14e8c91d/core.pkg.css',
+      'uri' => '/res/pkg/4270730a/core.pkg.css',
       'type' => 'css',
     ),
     '6c786373' =>
@@ -720,14 +720,14 @@ celerity_register_resource_map(array(
   ),
   'reverse' =>
   array (
-    'aphront-crumbs-view-css' => '14e8c91d',
-    'aphront-dialog-view-css' => '14e8c91d',
-    'aphront-form-view-css' => '14e8c91d',
-    'aphront-panel-view-css' => '14e8c91d',
-    'aphront-side-nav-view-css' => '14e8c91d',
-    'aphront-table-view-css' => '14e8c91d',
-    'aphront-tokenizer-control-css' => '14e8c91d',
-    'aphront-typeahead-control-css' => '14e8c91d',
+    'aphront-crumbs-view-css' => '4270730a',
+    'aphront-dialog-view-css' => '4270730a',
+    'aphront-form-view-css' => '4270730a',
+    'aphront-panel-view-css' => '4270730a',
+    'aphront-side-nav-view-css' => '4270730a',
+    'aphront-table-view-css' => '4270730a',
+    'aphront-tokenizer-control-css' => '4270730a',
+    'aphront-typeahead-control-css' => '4270730a',
     'differential-changeset-view-css' => '8d8a971a',
     'differential-core-view-css' => '8d8a971a',
     'differential-revision-add-comment-css' => '8d8a971a',
@@ -742,11 +742,11 @@ celerity_register_resource_map(array(
     'javelin-behavior-differential-feedback-preview' => '6c786373',
     'javelin-behavior-differential-populate' => '6c786373',
     'javelin-behavior-differential-show-more' => '6c786373',
-    'phabricator-core-buttons-css' => '14e8c91d',
-    'phabricator-core-css' => '14e8c91d',
-    'phabricator-directory-css' => '14e8c91d',
-    'phabricator-remarkup-css' => '14e8c91d',
-    'phabricator-standard-page-view' => '14e8c91d',
-    'syntax-highlighting-css' => '14e8c91d',
+    'phabricator-core-buttons-css' => '4270730a',
+    'phabricator-core-css' => '4270730a',
+    'phabricator-directory-css' => '4270730a',
+    'phabricator-remarkup-css' => '4270730a',
+    'phabricator-standard-page-view' => '4270730a',
+    'syntax-highlighting-css' => '4270730a',
   ),
 ));

src/__phutil_library_map__.php

@@ -310,6 +310,8 @@ phutil_register_library_map(array(
     'PhabricatorFileMacroDeleteController' => 'applications/files/controller/macrodelete',
     'PhabricatorFileMacroEditController' => 'applications/files/controller/macroedit',
     'PhabricatorFileMacroListController' => 'applications/files/controller/macrolist',
+    'PhabricatorFileProxyController' => 'applications/files/controller/proxy',
+    'PhabricatorFileProxyImage' => 'applications/files/storage/proxyimage',
     'PhabricatorFileStorageBlob' => 'applications/files/storage/storageblob',
     'PhabricatorFileURI' => 'applications/files/uri',
     'PhabricatorFileUploadController' => 'applications/files/controller/upload',
@@ -382,6 +384,7 @@ phutil_register_library_map(array(
     'PhabricatorRemarkupRuleDiffusion' => 'infrastructure/markup/remarkup/markuprule/diffusion',
     'PhabricatorRemarkupRuleImageMacro' => 'infrastructure/markup/remarkup/markuprule/imagemacro',
     'PhabricatorRemarkupRuleManiphest' => 'infrastructure/markup/remarkup/markuprule/maniphest',
+    'PhabricatorRemarkupRuleProxyImage' => 'infrastructure/markup/remarkup/markuprule/proxyimage',
     'PhabricatorRepository' => 'applications/repository/storage/repository',
     'PhabricatorRepositoryArcanistProject' => 'applications/repository/storage/arcanistproject',
     'PhabricatorRepositoryArcanistProjectEditController' => 'applications/repository/controller/arcansistprojectedit',
@@ -718,6 +721,8 @@ phutil_register_library_map(array(
     'PhabricatorFileMacroDeleteController' => 'PhabricatorFileController',
     'PhabricatorFileMacroEditController' => 'PhabricatorFileController',
     'PhabricatorFileMacroListController' => 'PhabricatorFileController',
+    'PhabricatorFileProxyController' => 'PhabricatorFileController',
+    'PhabricatorFileProxyImage' => 'PhabricatorFileDAO',
     'PhabricatorFileStorageBlob' => 'PhabricatorFileDAO',
     'PhabricatorFileUploadController' => 'PhabricatorFileController',
     'PhabricatorFileViewController' => 'PhabricatorFileController',
@@ -782,6 +787,7 @@ phutil_register_library_map(array(
     'PhabricatorRemarkupRuleDiffusion' => 'PhutilRemarkupRule',
     'PhabricatorRemarkupRuleImageMacro' => 'PhutilRemarkupRule',
     'PhabricatorRemarkupRuleManiphest' => 'PhutilRemarkupRule',
+    'PhabricatorRemarkupRuleProxyImage' => 'PhutilRemarkupRule',
     'PhabricatorRepository' => 'PhabricatorRepositoryDAO',
     'PhabricatorRepositoryArcanistProject' => 'PhabricatorRepositoryDAO',
     'PhabricatorRepositoryArcanistProjectEditController' => 'PhabricatorRepositoryController',

src/aphront/default/configuration/AphrontDefaultApplicationConfiguration.php

@@ -60,6 +60,7 @@ class AphrontDefaultApplicationConfiguration
           'edit/(?:(?P<id>\d+)/)?$' => 'PhabricatorFileMacroEditController',
           'delete/(?P<id>\d+)/$' => 'PhabricatorFileMacroDeleteController',
         ),
+        'proxy/$' => 'PhabricatorFileProxyController',
       ),
       '/phid/' => array(
         '$' => 'PhabricatorPHIDLookupController',

src/applications/differential/parser/markup/DifferentialMarkupEngineFactory.php

@@ -28,6 +28,9 @@ class DifferentialMarkupEngineFactory {
 
     $rules = array();
     $rules[] = new PhutilRemarkupRuleEscapeRemarkup();
+    if (PhabricatorEnv::getEnvConfig('files.enable-proxy')) {
+      $rules[] = new PhabricatorRemarkupRuleProxyImage();
+    }
     $rules[] = new PhutilRemarkupRuleHyperlink();
 
     $rules[] = new PhabricatorRemarkupRuleDifferential();

src/applications/differential/parser/markup/__init__.php

@@ -11,6 +11,7 @@ phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/diffusion');
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/imagemacro');
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/maniphest');
+phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/proxyimage');
 
 phutil_require_module('phutil', 'markup/engine/remarkup');
 phutil_require_module('phutil', 'markup/engine/remarkup/blockrule/remarkupcode');

src/applications/files/controller/proxy/PhabricatorFileProxyController.php

@@ -0,0 +1,55 @@
+<?php
+
+/*
+ * Copyright 2011 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class PhabricatorFileProxyController extends PhabricatorFileController {
+
+  private $uri;
+
+  public function processRequest() {
+
+    if (!PhabricatorEnv::getEnvConfig('files.enable-proxy')) {
+      return new Aphront400Response();
+    }
+
+    $request = $this->getRequest();
+    $uri = $request->getStr('uri');
+
+    $proxy = id(new PhabricatorFileProxyImage())->loadOneWhere(
+      'uri = %s',
+      $uri);
+
+    if (!$proxy) {
+      $file = PhabricatorFile::newFromFileDownload(
+        $uri,
+        nonempty(basename($uri), 'proxied-file'));
+      if ($file) {
+        $proxy = new PhabricatorFileProxyImage();
+        $proxy->setURI($uri);
+        $proxy->setFilePHID($file->getPHID());
+        $proxy->save();
+      }
+    }
+
+    if ($proxy) {
+      $view_uri = PhabricatorFileURI::getViewURIForPHID($proxy->getFilePHID());
+      return id(new AphrontRedirectResponse())->setURI($view_uri);
+    }
+
+    return new Aphront400Response();
+  }
+}

src/applications/files/controller/proxy/__init__.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'aphront/response/400');
+phutil_require_module('phabricator', 'aphront/response/redirect');
+phutil_require_module('phabricator', 'applications/files/controller/base');
+phutil_require_module('phabricator', 'applications/files/storage/file');
+phutil_require_module('phabricator', 'applications/files/storage/proxyimage');
+phutil_require_module('phabricator', 'applications/files/uri');
+phutil_require_module('phabricator', 'infrastructure/env');
+
+phutil_require_module('phutil', 'utils');
+
+
+phutil_require_source('PhabricatorFileProxyController.php');

src/applications/files/storage/file/PhabricatorFile.php

@@ -123,6 +123,17 @@ class PhabricatorFile extends PhabricatorFileDAO {
 
   public static function newFromFileDownload($uri, $name) {
     $uri = new PhutilURI($uri);
+
+    $protocol = $uri->getProtocol();
+    switch ($protocol) {
+      case 'http':
+      case 'https':
+        break;
+      default:
+        // Make sure we are not accessing any file:// URIs or similar.
+        return null;
+    }
+
     $timeout = stream_context_create(
       array(
         'http' => array(

src/applications/files/storage/proxyimage/PhabricatorFileProxyImage.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * Copyright 2011 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class PhabricatorFileProxyImage extends PhabricatorFileDAO {
+
+  protected $uri;
+  protected $filePHID;
+
+  public function getConfiguration() {
+    return array(
+      self::CONFIG_TIMESTAMPS => false,
+    ) + parent::getConfiguration();
+  }
+
+  static public function getProxyImageURI($uri) {
+    return '/file/proxy/?uri='.phutil_escape_uri($uri);
+  }
+}
+

src/applications/files/storage/proxyimage/__init__.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/files/storage/base');
+
+phutil_require_module('phutil', 'markup');
+
+
+phutil_require_source('PhabricatorFileProxyImage.php');

src/infrastructure/markup/remarkup/markuprule/proxyimage/PhabricatorRemarkupRuleProxyImage.php

@@ -0,0 +1,61 @@
+<?php
+
+/*
+ * Copyright 2011 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @group markup
+ */
+class PhabricatorRemarkupRuleProxyImage
+  extends PhutilRemarkupRule {
+
+  public function apply($text) {
+
+    $filetypes = '(?:\.jpe?g|.png|.gif)';
+
+    $text = preg_replace_callback(
+      '@[<](\w{3,}://.+?'.$filetypes.')[>]@',
+      array($this, 'markupProxyImage'),
+      $text);
+
+    $text = preg_replace_callback(
+      '@(?<=^|\s)(\w{3,}://\S+'.$filetypes.')(?=\s|$)@',
+      array($this, 'markupProxyImage'),
+      $text);
+
+    return $text;
+  }
+
+  public function markupProxyImage($matches) {
+
+    $uri = PhabricatorFileProxyImage::getProxyImageURI($matches[1]);
+
+    return $this->getEngine()->storeText(
+      phutil_render_tag(
+        'a',
+        array(
+          'href' => $uri,
+          'target' => '_blank',
+        ),
+        phutil_render_tag(
+          'img',
+          array(
+            'src' => $uri,
+            'class' => 'remarkup-proxy-image',
+          ))));
+  }
+
+}

src/infrastructure/markup/remarkup/markuprule/proxyimage/__init__.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/files/storage/proxyimage');
+
+phutil_require_module('phutil', 'markup');
+phutil_require_module('phutil', 'markup/engine/remarkup/markuprule/base');
+
+
+phutil_require_source('PhabricatorRemarkupRuleProxyImage.php');

webroot/rsrc/css/core/remarkup.css

@@ -48,3 +48,8 @@
   margin:      .5em 0em;
   padding:     .25em 1em;
 }
+
+.phabricator-remarkup img.remarkup-proxy-image {
+  max-width: 640px;
+  max-height: 640px;
+}