Merge branch 'sh-fix-issue-56663-11-7' into 'security-11-7'

[11.7] Alias GitHub and BitBucket OAuth2 callback URLs

See merge request gitlab/gitlabhq!2845

(cherry picked from commit 7d3c6d8ba58e0e9875fdd2dfbe7690ddc50fad81)

9ec0072d Alias GitHub and BitBucket OAuth2 callback URLs

app/controllers/import/bitbucket_controller.rb

@@ -8,7 +8,7 @@ class Import::BitbucketController < Import::BaseController
   rescue_from Bitbucket::Error::Unauthorized, with: :bitbucket_unauthorized
 
   def callback
-    response = client.auth_code.get_token(params[:code], redirect_uri: callback_import_bitbucket_url)
+    response = client.auth_code.get_token(params[:code], redirect_uri: users_import_bitbucket_callback_url)
 
     session[:bitbucket_token]         = response.token
     session[:bitbucket_expires_at]    = response.expires_at
@@ -89,7 +89,7 @@ class Import::BitbucketController < Import::BaseController
   end
 
   def go_to_bitbucket_for_permissions
-    redirect_to client.auth_code.authorize_url(redirect_uri: callback_import_bitbucket_url)
+    redirect_to client.auth_code.authorize_url(redirect_uri: users_import_bitbucket_callback_url)
   end
 
   def bitbucket_unauthorized

app/controllers/import/github_controller.rb

@@ -86,7 +86,7 @@ class Import::GithubController < Import::BaseController
   end
 
   def callback_import_url
-    public_send("callback_import_#{provider}_url", extra_import_params) # rubocop:disable GitlabSecurity/PublicSend
+    public_send("users_import_#{provider}_callback_url", extra_import_params) # rubocop:disable GitlabSecurity/PublicSend
   end
 
   def provider_unauthorized

changelogs/unreleased/sh-fix-issue-56663-11-7.yml

+---
+title: Alias GitHub and BitBucket OAuth2 callback URLs
+merge_request:
+author:
+type: security

config/routes/import.rb

+# Alias import callbacks under the /users/auth endpoint so that
+# the OAuth2 callback URL can be restricted under http://example.com/users/auth
+# instead of http://example.com.
+Devise.omniauth_providers.each do |provider|
+  next if provider == 'ldapmain'
+
+  get "/users/auth/-/import/#{provider}/callback", to: "import/#{provider}#callback", as: "users_import_#{provider}_callback"
+end
+
 namespace :import do
   resource :github, only: [:create, :new], controller: :github do
     post :personal_access_token

doc/integration/bitbucket.md

@@ -43,9 +43,13 @@ you to use.
     | :--- | :---------- |
     | **Name** | This can be anything. Consider something like `<Organization>'s GitLab` or `<Your Name>'s GitLab` or something else descriptive. |
     | **Application description** | Fill this in if you wish. |
-    | **Callback URL** | The URL to your GitLab installation, e.g., `https://gitlab.example.com`. |
+    | **Callback URL** | The URL to your GitLab installation, e.g., `https://gitlab.example.com/users/auth`. |
     | **URL** | The URL to your GitLab installation, e.g., `https://gitlab.example.com`. |
 
+    NOTE: Be sure to append `/users/auth` to the end of the callback URL
+    to prevent a [OAuth2 convert
+    redirect](http://tetraph.com/covert_redirect/) vulnerability.
+
     NOTE: Starting in GitLab 8.15, you MUST specify a callback URL, or you will
     see an "Invalid redirect_uri" message. For more details, see [the
     Bitbucket documentation](https://confluence.atlassian.com/bitbucket/oauth-faq-338365710.html).

doc/integration/github.md

@@ -21,9 +21,13 @@ To get the credentials (a pair of Client ID and Client Secret), you must registe
     - Application name: This can be anything. Consider something like `<Organization>'s GitLab` or `<Your Name>'s GitLab` or something else descriptive.
     - Homepage URL: the URL to your GitLab installation. e.g., `https://gitlab.company.com`
     - Application description: Fill this in if you wish.
-    - Authorization callback URL: `http(s)://${YOUR_DOMAIN}`. Please make sure the port is included if your GitLab instance is not configured on default port.
+    - Authorization callback URL: `http(s)://${YOUR_DOMAIN}/users/auth`. Please make sure the port is included if your GitLab instance is not configured on default port.
     ![Register OAuth App](img/github_register_app.png)
 
+    NOTE: Be sure to append `/users/auth` to the end of the callback URL
+    to prevent a [OAuth2 convert
+    redirect](http://tetraph.com/covert_redirect/) vulnerability.
+
 1.  Select **Register application**.
 
 1.  You should now see a pair of **Client ID** and **Client Secret** near the top right of the page (see screenshot).

spec/controllers/import/bitbucket_controller_spec.rb

@@ -8,6 +8,7 @@ describe Import::BitbucketController do
   let(:secret) { "sekrettt" }
   let(:refresh_token) { SecureRandom.hex(15) }
   let(:access_params) { { token: token, expires_at: nil, expires_in: nil, refresh_token: nil } }
+  let(:code) { SecureRandom.hex(8) }
 
   def assign_session_tokens
     session[:bitbucket_token] = token
@@ -32,10 +33,16 @@ describe Import::BitbucketController do
                             expires_in: expires_in,
                             refresh_token: refresh_token)
       allow_any_instance_of(OAuth2::Client)
-        .to receive(:get_token).and_return(access_token)
+        .to receive(:get_token)
+        .with(hash_including(
+                'grant_type' => 'authorization_code',
+                'code' => code,
+                redirect_uri: users_import_bitbucket_callback_url),
+              {})
+        .and_return(access_token)
       stub_omniauth_provider('bitbucket')
 
-      get :callback
+      get :callback, params: { code: code }
 
       expect(session[:bitbucket_token]).to eq(token)
       expect(session[:bitbucket_refresh_token]).to eq(refresh_token)

spec/controllers/import/github_controller_spec.rb

@@ -12,9 +12,15 @@ describe Import::GithubController do
 
     it "redirects to GitHub for an access token if logged in with GitHub" do
       allow(controller).to receive(:logged_in_with_provider?).and_return(true)
-      expect(controller).to receive(:go_to_provider_for_permissions)
+      expect(controller).to receive(:go_to_provider_for_permissions).and_call_original
+      allow_any_instance_of(Gitlab::LegacyGithubImport::Client)
+        .to receive(:authorize_url)
+        .with(users_import_github_callback_url)
+        .and_call_original
 
       get :new
+
+      expect(response).to have_http_status(302)
     end
 
     it "prompts for an access token if GitHub not configured" do