Commit fc8c1a77 authored by Tiger's avatar Tiger

Validate session key when authorizing with GCP to create a cluster

It was previously possible to link a GCP account to another
user's GitLab account by having them visit the callback URL,
as there was no check that they were the initiator of the
request.

We now reject the callback unless the state parameter
matches the one added to the initiating user's session.
parent 0f20c401
......@@ -2,6 +2,10 @@
module GoogleApi
class AuthorizationsController < ApplicationController
include Gitlab::Utils::StrongMemoize
before_action :validate_session_key!
def callback
token, expires_at = GoogleApi::CloudPlatform::Client
.new(nil, callback_google_api_auth_url)
......@@ -11,21 +15,27 @@ def callback
session[GoogleApi::CloudPlatform::Client.session_key_for_expires_at] =
expires_at.to_s
state_redirect_uri = redirect_uri_from_session_key(params[:state])
if state_redirect_uri
redirect_to state_redirect_uri
else
redirect_to root_path
end
redirect_to redirect_uri_from_session
end
private
def redirect_uri_from_session_key(state)
key = GoogleApi::CloudPlatform::Client
.session_key_for_redirect_uri(params[:state])
session[key] if key
def validate_session_key!
access_denied! unless redirect_uri_from_session.present?
end
def redirect_uri_from_session
strong_memoize(:redirect_uri_from_session) do
if params[:state].present?
session[session_key_for_redirect_uri(params[:state])]
else
nil
end
end
end
def session_key_for_redirect_uri(state)
GoogleApi::CloudPlatform::Client.session_key_for_redirect_uri(state)
end
end
end
---
title: Validate session key when authorizing with GCP to create a cluster
merge_request:
author:
type: security
......@@ -6,7 +6,7 @@
let(:token) { 'token' }
let(:expires_at) { 1.hour.since.strftime('%s') }
subject { get :callback, params: { code: 'xxx', state: @state } }
subject { get :callback, params: { code: 'xxx', state: state } }
before do
sign_in(user)
......@@ -15,35 +15,57 @@
.to receive(:get_token).and_return([token, expires_at])
end
it 'sets token and expires_at in session' do
subject
shared_examples_for 'access denied' do
it 'returns a 404' do
subject
expect(session[GoogleApi::CloudPlatform::Client.session_key_for_token])
.to eq(token)
expect(session[GoogleApi::CloudPlatform::Client.session_key_for_expires_at])
.to eq(expires_at)
expect(session[GoogleApi::CloudPlatform::Client.session_key_for_token]).to be_nil
expect(response).to have_http_status(:not_found)
end
end
context 'when redirect uri key is stored in state' do
set(:project) { create(:project) }
let(:redirect_uri) { project_clusters_url(project).to_s }
context 'session key is present' do
let(:session_key) { 'session-key' }
let(:redirect_uri) { 'example.com' }
before do
@state = GoogleApi::CloudPlatform::Client
.new_session_key_for_redirect_uri do |key|
session[key] = redirect_uri
session[GoogleApi::CloudPlatform::Client.session_key_for_redirect_uri(session_key)] = redirect_uri
end
context 'session key matches state param' do
let(:state) { session_key }
it 'sets token and expires_at in session' do
subject
expect(session[GoogleApi::CloudPlatform::Client.session_key_for_token])
.to eq(token)
expect(session[GoogleApi::CloudPlatform::Client.session_key_for_expires_at])
.to eq(expires_at)
end
it 'redirects to the URL stored in state param' do
expect(subject).to redirect_to(redirect_uri)
end
end
it 'redirects to the URL stored in state param' do
expect(subject).to redirect_to(redirect_uri)
context 'session key does not match state param' do
let(:state) { 'bad-key' }
it_behaves_like 'access denied'
end
end
context 'when redirection url is not stored in state' do
it 'redirects to root_path' do
expect(subject).to redirect_to(root_path)
context 'state param is blank' do
let(:state) { '' }
it_behaves_like 'access denied'
end
end
context 'state param is present, but session key is blank' do
let(:state) { 'session-key' }
it_behaves_like 'access denied'
end
end
end
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