diff options
author | Sebastian Arcila Valenzuela <sarcila@gitlab.com> | 2019-08-19 16:19:19 +0300 |
---|---|---|
committer | Sebastian Arcila Valenzuela <sarcila@gitlab.com> | 2019-09-16 11:55:07 +0300 |
commit | 21338fd70cc1e3e07a7a88f4546899522fb28385 (patch) | |
tree | 8cfcb640c4875330a53818157380523f597d9d9f | |
parent | 0dbd7139caefb94eac3cc51beac53453663b04c2 (diff) |
Validate that SAML requests are originated from gitlab
If the request wasn't initiated by gitlab we shouldn't add the new
identity to the user, and instead show that we weren't able to link
the identity to the user.
This should fix: https://gitlab.com/gitlab-org/gitlab-ce/issues/56509
-rw-r--r-- | app/controllers/omniauth_callbacks_controller.rb | 9 | ||||
-rw-r--r-- | changelogs/unreleased/security-sarcila-verify-saml-request-origin.yml | 5 | ||||
-rw-r--r-- | lib/gitlab/auth/omniauth_identity_linker_base.rb | 5 | ||||
-rw-r--r-- | lib/gitlab/auth/saml/identity_linker.rb | 24 | ||||
-rw-r--r-- | lib/gitlab/auth/saml/origin_validator.rb | 41 | ||||
-rw-r--r-- | lib/omni_auth/strategies/saml.rb | 29 | ||||
-rw-r--r-- | locale/gitlab.pot | 3 | ||||
-rw-r--r-- | spec/controllers/omniauth_callbacks_controller_spec.rb | 58 | ||||
-rw-r--r-- | spec/lib/gitlab/auth/saml/identity_linker_spec.rb | 66 | ||||
-rw-r--r-- | spec/lib/gitlab/auth/saml/origin_validator_spec.rb | 42 | ||||
-rw-r--r-- | spec/lib/omni_auth/strategies/saml_spec.rb | 22 | ||||
-rw-r--r-- | spec/support/omniauth_strategy.rb | 39 |
12 files changed, 303 insertions, 40 deletions
diff --git a/app/controllers/omniauth_callbacks_controller.rb b/app/controllers/omniauth_callbacks_controller.rb index 2a8dd997d04..9a131875bc3 100644 --- a/app/controllers/omniauth_callbacks_controller.rb +++ b/app/controllers/omniauth_callbacks_controller.rb @@ -40,6 +40,8 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController def saml omniauth_flow(Gitlab::Auth::Saml) + rescue Gitlab::Auth::Saml::IdentityLinker::UnverifiedRequest + redirect_unverified_saml_initiation end def omniauth_error @@ -84,8 +86,7 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController return render_403 unless link_provider_allowed?(oauth['provider']) log_audit_event(current_user, with: oauth['provider']) - - identity_linker ||= auth_module::IdentityLinker.new(current_user, oauth) + identity_linker ||= auth_module::IdentityLinker.new(current_user, oauth, session) link_identity(identity_linker) @@ -178,6 +179,10 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController redirect_to new_user_session_path end + def redirect_unverified_saml_initiation + redirect_to profile_account_path, notice: _('Request to link SAML account must be authorized') + end + def handle_disabled_provider label = Gitlab::Auth::OAuth::Provider.label_for(oauth['provider']) flash[:alert] = _("Signing in using %{label} has been disabled") % { label: label } diff --git a/changelogs/unreleased/security-sarcila-verify-saml-request-origin.yml b/changelogs/unreleased/security-sarcila-verify-saml-request-origin.yml new file mode 100644 index 00000000000..9022bc8a26f --- /dev/null +++ b/changelogs/unreleased/security-sarcila-verify-saml-request-origin.yml @@ -0,0 +1,5 @@ +--- +title: Prevent GitLab accounts takeover if SAML is configured +merge_request: +author: +type: security diff --git a/lib/gitlab/auth/omniauth_identity_linker_base.rb b/lib/gitlab/auth/omniauth_identity_linker_base.rb index c620fc5d6bd..a6c247f31a7 100644 --- a/lib/gitlab/auth/omniauth_identity_linker_base.rb +++ b/lib/gitlab/auth/omniauth_identity_linker_base.rb @@ -3,12 +3,13 @@ module Gitlab module Auth class OmniauthIdentityLinkerBase - attr_reader :current_user, :oauth + attr_reader :current_user, :oauth, :session - def initialize(current_user, oauth) + def initialize(current_user, oauth, session = {}) @current_user = current_user @oauth = oauth @changed = false + @session = session end def link diff --git a/lib/gitlab/auth/saml/identity_linker.rb b/lib/gitlab/auth/saml/identity_linker.rb index ae0d6dded4e..93195c3189f 100644 --- a/lib/gitlab/auth/saml/identity_linker.rb +++ b/lib/gitlab/auth/saml/identity_linker.rb @@ -4,6 +4,30 @@ module Gitlab module Auth module Saml class IdentityLinker < OmniauthIdentityLinkerBase + extend ::Gitlab::Utils::Override + + UnverifiedRequest = Class.new(StandardError) + + override :link + def link + raise_unless_request_is_gitlab_initiated! if unlinked? + + super + end + + protected + + def raise_unless_request_is_gitlab_initiated! + raise UnverifiedRequest unless valid_gitlab_initiated_request? + end + + def valid_gitlab_initiated_request? + OriginValidator.new(session).gitlab_initiated?(saml_response) + end + + def saml_response + oauth.fetch(:extra, {}).fetch(:response_object, {}) + end end end end diff --git a/lib/gitlab/auth/saml/origin_validator.rb b/lib/gitlab/auth/saml/origin_validator.rb new file mode 100644 index 00000000000..4ecc688888f --- /dev/null +++ b/lib/gitlab/auth/saml/origin_validator.rb @@ -0,0 +1,41 @@ +# frozen_string_literal: true + +module Gitlab + module Auth + module Saml + class OriginValidator + AUTH_REQUEST_SESSION_KEY = "last_authn_request_id".freeze + + def initialize(session) + @session = session || {} + end + + def store_origin(authn_request) + session[AUTH_REQUEST_SESSION_KEY] = authn_request.uuid + end + + def gitlab_initiated?(saml_response) + return false if identity_provider_initiated?(saml_response) + + matches?(saml_response) + end + + private + + attr_reader :session + + def matches?(saml_response) + saml_response.in_response_to == expected_request_id + end + + def identity_provider_initiated?(saml_response) + saml_response.in_response_to.blank? + end + + def expected_request_id + session[AUTH_REQUEST_SESSION_KEY] + end + end + end + end +end diff --git a/lib/omni_auth/strategies/saml.rb b/lib/omni_auth/strategies/saml.rb new file mode 100644 index 00000000000..ebe062f17e0 --- /dev/null +++ b/lib/omni_auth/strategies/saml.rb @@ -0,0 +1,29 @@ +# frozen_string_literal: true + +module OmniAuth + module Strategies + class SAML + extend ::Gitlab::Utils::Override + + # NOTE: This method duplicates code from omniauth-saml + # so that we can access authn_request to store it + # See: https://github.com/omniauth/omniauth-saml/issues/172 + override :request_phase + def request_phase + authn_request = OneLogin::RubySaml::Authrequest.new + + store_authn_request_id(authn_request) + + with_settings do |settings| + redirect(authn_request.create(settings, additional_params_for_authn_request)) + end + end + + private + + def store_authn_request_id(authn_request) + Gitlab::Auth::Saml::OriginValidator.new(session).store_origin(authn_request) + end + end + end +end diff --git a/locale/gitlab.pot b/locale/gitlab.pot index f9c15929c7c..53ac629237f 100644 --- a/locale/gitlab.pot +++ b/locale/gitlab.pot @@ -8967,6 +8967,9 @@ msgstr "" msgid "Request Access" msgstr "" +msgid "Request to link SAML account must be authorized" +msgstr "" + msgid "Requested %{time_ago}" msgstr "" diff --git a/spec/controllers/omniauth_callbacks_controller_spec.rb b/spec/controllers/omniauth_callbacks_controller_spec.rb index 6e374a8daa7..f41cd55ce8c 100644 --- a/spec/controllers/omniauth_callbacks_controller_spec.rb +++ b/spec/controllers/omniauth_callbacks_controller_spec.rb @@ -219,34 +219,70 @@ describe OmniauthCallbacksController, type: :controller do end describe '#saml' do + let(:last_request_id) { 'ONELOGIN_4fee3b046395c4e751011e97f8900b5273d56685' } let(:user) { create(:omniauth_user, :two_factor, extern_uid: 'my-uid', provider: 'saml') } let(:mock_saml_response) { File.read('spec/fixtures/authentication/saml_response.xml') } let(:saml_config) { mock_saml_config_with_upstream_two_factor_authn_contexts } + def stub_last_request_id(id) + session['last_authn_request_id'] = id + end + before do + stub_last_request_id(last_request_id) stub_omniauth_saml_config({ enabled: true, auto_link_saml_user: true, allow_single_sign_on: ['saml'], providers: [saml_config] }) mock_auth_hash_with_saml_xml('saml', +'my-uid', user.email, mock_saml_response) - request.env["devise.mapping"] = Devise.mappings[:user] + request.env['devise.mapping'] = Devise.mappings[:user] request.env['omniauth.auth'] = Rails.application.env_config['omniauth.auth'] - post :saml, params: { SAMLResponse: mock_saml_response } end - context 'when worth two factors' do - let(:mock_saml_response) do - File.read('spec/fixtures/authentication/saml_response.xml') + context 'with GitLab initiated request' do + before do + post :saml, params: { SAMLResponse: mock_saml_response } + end + + context 'when worth two factors' do + let(:mock_saml_response) do + File.read('spec/fixtures/authentication/saml_response.xml') .gsub('urn:oasis:names:tc:SAML:2.0:ac:classes:Password', 'urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorIGTOKEN') + end + + it 'expects user to be signed_in' do + expect(request.env['warden']).to be_authenticated + end end - it 'expects user to be signed_in' do - expect(request.env['warden']).to be_authenticated + context 'when not worth two factors' do + it 'expects user to provide second factor' do + expect(response).to render_template('devise/sessions/two_factor') + expect(request.env['warden']).not_to be_authenticated + end end end - context 'when not worth two factors' do - it 'expects user to provide second factor' do - expect(response).to render_template('devise/sessions/two_factor') - expect(request.env['warden']).not_to be_authenticated + context 'with IdP initiated request' do + let(:user) { create(:user) } + let(:last_request_id) { '99999' } + + before do + sign_in user + end + + it 'lets the user know their account isn\'t linked yet' do + post :saml, params: { SAMLResponse: mock_saml_response } + + expect(flash[:notice]).to eq 'Request to link SAML account must be authorized' + end + + it 'redirects to profile account page' do + post :saml, params: { SAMLResponse: mock_saml_response } + + expect(response).to redirect_to(profile_account_path) + end + + it 'doesn\'t link a new identity to the user' do + expect { post :saml, params: { SAMLResponse: mock_saml_response } }.not_to change { user.identities.count } end end end diff --git a/spec/lib/gitlab/auth/saml/identity_linker_spec.rb b/spec/lib/gitlab/auth/saml/identity_linker_spec.rb index f3305d574cc..6c4db25a02f 100644 --- a/spec/lib/gitlab/auth/saml/identity_linker_spec.rb +++ b/spec/lib/gitlab/auth/saml/identity_linker_spec.rb @@ -4,45 +4,61 @@ describe Gitlab::Auth::Saml::IdentityLinker do let(:user) { create(:user) } let(:provider) { 'saml' } let(:uid) { user.email } - let(:oauth) { { 'provider' => provider, 'uid' => uid } } + let(:in_response_to) { '12345' } + let(:saml_response) { instance_double(OneLogin::RubySaml::Response, in_response_to: in_response_to) } + let(:session) { { 'last_authn_request_id' => in_response_to } } - subject { described_class.new(user, oauth) } + let(:oauth) do + OmniAuth::AuthHash.new(provider: provider, uid: uid, extra: { response_object: saml_response }) + end - context 'linked identity exists' do - let!(:identity) { user.identities.create!(provider: provider, extern_uid: uid) } + subject { described_class.new(user, oauth, session) } - it "doesn't create new identity" do - expect { subject.link }.not_to change { Identity.count } - end + context 'with valid GitLab initiated request' do + context 'linked identity exists' do + let!(:identity) { user.identities.create!(provider: provider, extern_uid: uid) } - it "sets #changed? to false" do - subject.link + it "doesn't create new identity" do + expect { subject.link }.not_to change { Identity.count } + end - expect(subject).not_to be_changed - end - end + it "sets #changed? to false" do + subject.link - context 'identity needs to be created' do - it 'creates linked identity' do - expect { subject.link }.to change { user.identities.count } + expect(subject).not_to be_changed + end end - it 'sets identity provider' do - subject.link + context 'identity needs to be created' do + it 'creates linked identity' do + expect { subject.link }.to change { user.identities.count } + end - expect(user.identities.last.provider).to eq provider - end + it 'sets identity provider' do + subject.link - it 'sets identity extern_uid' do - subject.link + expect(user.identities.last.provider).to eq provider + end - expect(user.identities.last.extern_uid).to eq uid + it 'sets identity extern_uid' do + subject.link + + expect(user.identities.last.extern_uid).to eq uid + end + + it 'sets #changed? to true' do + subject.link + + expect(subject).to be_changed + end end + end - it 'sets #changed? to true' do - subject.link + context 'with identity provider initiated request' do + let(:session) { { 'last_authn_request_id' => nil } } - expect(subject).to be_changed + it 'attempting to link accounts raises an exception' do + expect { subject.link }.to raise_error(Gitlab::Auth::Saml::IdentityLinker::UnverifiedRequest) end end end diff --git a/spec/lib/gitlab/auth/saml/origin_validator_spec.rb b/spec/lib/gitlab/auth/saml/origin_validator_spec.rb new file mode 100644 index 00000000000..ae120b328ab --- /dev/null +++ b/spec/lib/gitlab/auth/saml/origin_validator_spec.rb @@ -0,0 +1,42 @@ +# frozen_string_literal: true + +require 'spec_helper' + +describe Gitlab::Auth::Saml::OriginValidator do + let(:session) { instance_double(ActionDispatch::Request::Session) } + + subject { described_class.new(session) } + + describe '#store_origin' do + it 'stores the SAML request ID' do + request_id = double + authn_request = instance_double(OneLogin::RubySaml::Authrequest, uuid: request_id) + + expect(session).to receive(:[]=).with('last_authn_request_id', request_id) + + subject.store_origin(authn_request) + end + end + + describe '#gitlab_initiated?' do + it 'returns false if InResponseTo is not present' do + saml_response = instance_double(OneLogin::RubySaml::Response, in_response_to: nil) + + expect(subject.gitlab_initiated?(saml_response)).to eq(false) + end + + it 'returns false if InResponseTo does not match stored value' do + saml_response = instance_double(OneLogin::RubySaml::Response, in_response_to: "abc") + allow(session).to receive(:[]).with('last_authn_request_id').and_return('123') + + expect(subject.gitlab_initiated?(saml_response)).to eq(false) + end + + it 'returns true if InResponseTo matches stored value' do + saml_response = instance_double(OneLogin::RubySaml::Response, in_response_to: "123") + allow(session).to receive(:[]).with('last_authn_request_id').and_return('123') + + expect(subject.gitlab_initiated?(saml_response)).to eq(true) + end + end +end diff --git a/spec/lib/omni_auth/strategies/saml_spec.rb b/spec/lib/omni_auth/strategies/saml_spec.rb new file mode 100644 index 00000000000..3c59de86d98 --- /dev/null +++ b/spec/lib/omni_auth/strategies/saml_spec.rb @@ -0,0 +1,22 @@ +require 'spec_helper' + +describe OmniAuth::Strategies::SAML, type: :strategy do + let(:idp_sso_target_url) { 'https://login.example.com/idp' } + let(:strategy) { [OmniAuth::Strategies::SAML, { idp_sso_target_url: idp_sso_target_url }] } + + describe 'POST /users/auth/saml' do + it 'redirects to the provider login page' do + post '/users/auth/saml' + + expect(last_response).to redirect_to(/\A#{Regexp.quote(idp_sso_target_url)}/) + end + + it 'stores request ID during request phase' do + request_id = double + allow_any_instance_of(OneLogin::RubySaml::Authrequest).to receive(:uuid).and_return(request_id) + + post '/users/auth/saml' + expect(session['last_authn_request_id']).to eq(request_id) + end + end +end diff --git a/spec/support/omniauth_strategy.rb b/spec/support/omniauth_strategy.rb new file mode 100644 index 00000000000..eefa04bd9dd --- /dev/null +++ b/spec/support/omniauth_strategy.rb @@ -0,0 +1,39 @@ +module StrategyHelpers + include Rack::Test::Methods + include ActionDispatch::Assertions::ResponseAssertions + include Shoulda::Matchers::ActionController + include OmniAuth::Test::StrategyTestCase + + def post(*args) + super.tap do + @response = ActionDispatch::TestResponse.from_response(last_response) + end + end + + def auth_hash + last_request.env['omniauth.auth'] + end + + def self.without_test_mode + original_mode = OmniAuth.config.test_mode + original_on_failure = OmniAuth.config.on_failure + + OmniAuth.config.test_mode = false + OmniAuth.config.on_failure = OmniAuth::FailureEndpoint + + yield + ensure + OmniAuth.config.test_mode = original_mode + OmniAuth.config.on_failure = original_on_failure + end +end + +RSpec.configure do |config| + config.include StrategyHelpers, type: :strategy + + config.around(:all, type: :strategy) do |example| + StrategyHelpers.without_test_mode do + example.run + end + end +end |