Change links to posts and profiles in posts to open in web UI

app/controllers/redirects_controller.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class RedirectsController < ApplicationController
+  before_action :set_url
+  before_action :set_resource
+
+  def show
+    expires_in(1.day, public: true, stale_while_revalidate: 30.seconds, stale_if_error: 1.day) unless user_signed_in?
+
+    case @resource
+    when Account
+      redirect_to web_url("@#{@resource.pretty_acct}")
+    when Status
+      redirect_to web_url("@#{@resource.account.pretty_acct}/#{@resource.id}")
+    else
+      redirect_to @url, allow_other_host: true
+    end
+  end
+
+  private
+
+  def set_url
+    @url = params.require(:url)
+  end
+
+  def set_resource
+    @resource = ResolveURLService.new.call(@url) if user_signed_in?
+  end
+end

app/javascript/mastodon/components/status_content.jsx

@@ -125,6 +125,7 @@ class StatusContent extends PureComponent {
         link.setAttribute('href', `/tags/${link.text.replace(/^#/, '')}`);
       } else {
         link.setAttribute('title', link.href);
+        link.setAttribute('href', `/redirect?url=${encodeURIComponent(link.href)}`);
         link.classList.add('unhandled-link');
       }
     }

app/javascript/mastodon/features/account/components/header.jsx

@@ -235,10 +235,18 @@ class Header extends ImmutablePureComponent {
     for (var i = 0; i < links.length; ++i) {
       link = links[i];
 
+      if (link.classList.contains('status-link')) {
+        continue;
+      }
+
+      link.classList.add('status-link');
+
       if (link.textContent[0] === '#' || (link.previousSibling && link.previousSibling.textContent && link.previousSibling.textContent[link.previousSibling.textContent.length - 1] === '#')) {
         link.addEventListener('click', this.handleHashtagClick, false);
       } else if (link.classList.contains('mention')) {
         link.addEventListener('click', this.handleMentionClick, false);
+      } else {
+        link.setAttribute('href', `/redirect?url=${encodeURIComponent(link.href)}`);
       }
     }
   }

app/javascript/mastodon/features/status/components/card.jsx

@@ -201,7 +201,7 @@ export default class Card extends PureComponent {
               <div className='status-card__actions' onClick={this.handleEmbedClick} role='none'>
                 <div>
                   <button type='button' onClick={this.handleEmbedClick}><Icon id='play' icon={PlayArrowIcon} /></button>
-                  <a href={card.get('url')} target='_blank' rel='noopener noreferrer'><Icon id='external-link' icon={OpenInNewIcon} /></a>
+                  <a href={`/redirect?url=${encodeURIComponent(card.get('url'))}`} target='_blank' rel='noopener noreferrer'><Icon id='external-link' icon={OpenInNewIcon} /></a>
                 </div>
               </div>
             ) : spoilerButton}
@@ -212,7 +212,7 @@ export default class Card extends PureComponent {
       return (
         <div className={classNames('status-card', { expanded: largeImage })} ref={this.setRef} onClick={revealed ? null : this.handleReveal} role={revealed ? 'button' : null}>
           {embed}
-          <a href={card.get('url')} target='_blank' rel='noopener noreferrer'>{description}</a>
+          <a href={`/redirect?url=${encodeURIComponent(card.get('url'))}`} target='_blank' rel='noopener noreferrer'>{description}</a>
         </div>
       );
     } else if (card.get('image')) {
@@ -231,7 +231,7 @@ export default class Card extends PureComponent {
     }
 
     return (
-      <a href={card.get('url')} className={classNames('status-card', { expanded: largeImage })} target='_blank' rel='noopener noreferrer' ref={this.setRef}>
+      <a href={`/redirect?url=${encodeURIComponent(card.get('url'))}`} className={classNames('status-card', { expanded: largeImage })} target='_blank' rel='noopener noreferrer' ref={this.setRef}>
         {embed}
         {description}
       </a>

config/brakeman.ignore

@@ -0,0 +1,29 @@
+{
+  "ignored_warnings": [
+    {
+      "warning_type": "Redirect",
+      "warning_code": 18,
+      "fingerprint": "8b543fdb2adb90f9c9e26ab6a67065ed577be23bc7fa3ed8158bb022394d0382",
+      "check_name": "Redirect",
+      "message": "Possible unprotected redirect",
+      "file": "app/controllers/redirects_controller.rb",
+      "line": 16,
+      "link": "https://brakemanscanner.org/docs/warning_types/redirect/",
+      "code": "redirect_to(params.require(:url), :allow_other_host => true)",
+      "render_path": null,
+      "location": {
+        "type": "method",
+        "class": "RedirectsController",
+        "method": "show"
+      },
+      "user_input": "params.require(:url)",
+      "confidence": "Weak",
+      "cwe_id": [
+        601
+      ],
+      "note": ""
+    }
+  ],
+  "updated": "2023-10-30 04:08:29 +0100",
+  "brakeman_version": "6.0.1"
+}

config/routes.rb

@@ -182,6 +182,7 @@ Rails.application.routes.draw do
 
   get '/media_proxy/:id/(*any)', to: 'media_proxy#show', as: :media_proxy, format: false
   get '/backups/:id/download', to: 'backups#download', as: :download_backup, format: false
+  get '/redirect', to: 'redirects#show', format: false
 
   resource :authorize_interaction, only: [:show]
   resource :share, only: [:show]