ContainerImage.Pinniped/internal/upstreamldap/upstreamldap_test.go

// Copyright 2021 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

package upstreamldap

import (
	"context"
	"crypto/tls"
	"errors"
	"fmt"
	"net"
	"net/http"
	"net/url"
	"testing"

	"github.com/go-ldap/ldap/v3"
	"github.com/golang/mock/gomock"
	"github.com/stretchr/testify/require"
	"k8s.io/apiserver/pkg/authentication/authenticator"
	"k8s.io/apiserver/pkg/authentication/user"

	"go.pinniped.dev/internal/mocks/mockldapconn"
	"go.pinniped.dev/internal/testutil"
)

const (
	testHost                               = "ldap.example.com:8443"
	testBindUsername                       = "some-bind-username"
	testBindPassword                       = "some-bind-password"
	testUpstreamUsername                   = "some-upstream-username"
	testUpstreamPassword                   = "some-upstream-password"
	testUserSearchBase                     = "some-upstream-base-dn"
	testUserSearchFilter                   = "some-filter={}-and-more-filter={}"
	testUserSearchUsernameAttribute        = "some-upstream-username-attribute"
	testUserSearchUIDAttribute             = "some-upstream-uid-attribute"
	testSearchResultDNValue                = "some-upstream-user-dn"
	testSearchResultUsernameAttributeValue = "some-upstream-username-value"
	testSearchResultUIDAttributeValue      = "some-upstream-uid-value"
)

var (
	testUserSearchFilterInterpolated = fmt.Sprintf("some-filter=%s-and-more-filter=%s", testUpstreamUsername, testUpstreamUsername)
)

func TestAuthenticateUser(t *testing.T) {
	provider := func(editFunc func(p *Provider)) *Provider {
		provider := &Provider{
			Host:         testHost,
			BindUsername: testBindUsername,
			BindPassword: testBindPassword,
			UserSearch: &UserSearch{
				Base:              testUserSearchBase,
				Filter:            testUserSearchFilter,
				UsernameAttribute: testUserSearchUsernameAttribute,
				UIDAttribute:      testUserSearchUIDAttribute,
			},
		}
		if editFunc != nil {
			editFunc(provider)
		}
		return provider
	}

	expectedSearch := func(editFunc func(r *ldap.SearchRequest)) *ldap.SearchRequest {
		request := &ldap.SearchRequest{
			BaseDN:       testUserSearchBase,
			Scope:        ldap.ScopeWholeSubtree,
			DerefAliases: ldap.DerefAlways,
			SizeLimit:    2,
			TimeLimit:    90,
			TypesOnly:    false,
			Filter:       testUserSearchFilterInterpolated,
			Attributes:   []string{testUserSearchUsernameAttribute, testUserSearchUIDAttribute},
			Controls:     nil,
		}
		if editFunc != nil {
			editFunc(request)
		}
		return request
	}

	tests := []struct {
		name             string
		username         string
		password         string
		provider         *Provider
		setupMocks       func(conn *mockldapconn.MockConn)
		dialError        error
		wantError        string
		wantAuthResponse *authenticator.Response
	}{
		{
			name:     "happy path",
			username: testUpstreamUsername,
			password: testUpstreamPassword,
			provider: provider(nil),
			setupMocks: func(conn *mockldapconn.MockConn) {
				conn.EXPECT().Bind(testBindUsername, testBindPassword).Times(1)
				conn.EXPECT().Search(expectedSearch(nil)).Return(&ldap.SearchResult{
					Entries: []*ldap.Entry{
						{
							DN: testSearchResultDNValue,
							Attributes: []*ldap.EntryAttribute{
								ldap.NewEntryAttribute(testUserSearchUsernameAttribute, []string{testSearchResultUsernameAttributeValue}),
								ldap.NewEntryAttribute(testUserSearchUIDAttribute, []string{testSearchResultUIDAttributeValue}),
							},
						},
					},
					Referrals: []string{},       // note that we are not following referrals at this time
					Controls:  []ldap.Control{}, // TODO are there any response controls that we need to be able to handle?
				}, nil).Times(1)
				conn.EXPECT().Bind(testSearchResultDNValue, testUpstreamPassword).Times(1)
				conn.EXPECT().Close().Times(1)
			},
			wantAuthResponse: &authenticator.Response{
				User: &user.DefaultInfo{
					Name:   testSearchResultUsernameAttributeValue,
					Groups: []string{}, // We don't support group search yet. Coming soon!
					UID:    testSearchResultUIDAttributeValue,
				},
			},
		},
		{
			name:     "when the UsernameAttribute is dn",
			username: testUpstreamUsername,
			password: testUpstreamPassword,
			provider: provider(func(p *Provider) {
				p.UserSearch.UsernameAttribute = "dn"
			}),
			setupMocks: func(conn *mockldapconn.MockConn) {
				conn.EXPECT().Bind(testBindUsername, testBindPassword).Times(1)
				conn.EXPECT().Search(expectedSearch(func(r *ldap.SearchRequest) {
					r.Attributes = []string{testUserSearchUIDAttribute}
				})).Return(&ldap.SearchResult{
					Entries: []*ldap.Entry{
						{
							DN: testSearchResultDNValue,
							Attributes: []*ldap.EntryAttribute{
								ldap.NewEntryAttribute(testUserSearchUIDAttribute, []string{testSearchResultUIDAttributeValue}),
							},
						},
					},
				}, nil).Times(1)
				conn.EXPECT().Bind(testSearchResultDNValue, testUpstreamPassword).Times(1)
				conn.EXPECT().Close().Times(1)
			},
			wantAuthResponse: &authenticator.Response{
				User: &user.DefaultInfo{
					Name:   testSearchResultDNValue,
					Groups: []string{}, // We don't support group search yet. Coming soon!
					UID:    testSearchResultUIDAttributeValue,
				},
			},
		},
		{
			name:     "when the UIDAttribute is dn",
			username: testUpstreamUsername,
			password: testUpstreamPassword,
			provider: provider(func(p *Provider) {
				p.UserSearch.UIDAttribute = "dn"
			}),
			setupMocks: func(conn *mockldapconn.MockConn) {
				conn.EXPECT().Bind(testBindUsername, testBindPassword).Times(1)
				conn.EXPECT().Search(expectedSearch(func(r *ldap.SearchRequest) {
					r.Attributes = []string{testUserSearchUsernameAttribute}
				})).Return(&ldap.SearchResult{
					Entries: []*ldap.Entry{
						{
							DN: testSearchResultDNValue,
							Attributes: []*ldap.EntryAttribute{
								ldap.NewEntryAttribute(testUserSearchUsernameAttribute, []string{testSearchResultUsernameAttributeValue}),
							},
						},
					},
				}, nil).Times(1)
				conn.EXPECT().Bind(testSearchResultDNValue, testUpstreamPassword).Times(1)
				conn.EXPECT().Close().Times(1)
			},
			wantAuthResponse: &authenticator.Response{
				User: &user.DefaultInfo{
					Name:   testSearchResultUsernameAttributeValue,
					Groups: []string{}, // We don't support group search yet. Coming soon!
					UID:    testSearchResultDNValue,
				},
			},
		},
		{
			name:     "when Filter is blank it derives a search filter from the UsernameAttribute",
			username: testUpstreamUsername,
			password: testUpstreamPassword,
			provider: provider(func(p *Provider) {
				p.UserSearch.Filter = ""
			}),
			setupMocks: func(conn *mockldapconn.MockConn) {
				conn.EXPECT().Bind(testBindUsername, testBindPassword).Times(1)
				conn.EXPECT().Search(expectedSearch(func(r *ldap.SearchRequest) {
					r.Filter = testUserSearchUsernameAttribute + "=" + testUpstreamUsername
				})).Return(&ldap.SearchResult{
					Entries: []*ldap.Entry{
						{
							DN: testSearchResultDNValue,
							Attributes: []*ldap.EntryAttribute{
								ldap.NewEntryAttribute(testUserSearchUsernameAttribute, []string{testSearchResultUsernameAttributeValue}),
								ldap.NewEntryAttribute(testUserSearchUIDAttribute, []string{testSearchResultUIDAttributeValue}),
							},
						},
					},
				}, nil).Times(1)
				conn.EXPECT().Bind(testSearchResultDNValue, testUpstreamPassword).Times(1)
				conn.EXPECT().Close().Times(1)
			},
			wantAuthResponse: &authenticator.Response{
				User: &user.DefaultInfo{
					Name:   testSearchResultUsernameAttributeValue,
					Groups: []string{}, // We don't support group search yet. Coming soon!
					UID:    testSearchResultUIDAttributeValue,
				},
			},
		},
		{
			name:     "when the username has special LDAP search filter characters then they must be properly escaped in the search filter",
			username: `a&b|c(d)e\f*g`,
			password: testUpstreamPassword,
			provider: provider(nil),
			setupMocks: func(conn *mockldapconn.MockConn) {
				conn.EXPECT().Bind(testBindUsername, testBindPassword).Times(1)
				conn.EXPECT().Search(expectedSearch(func(r *ldap.SearchRequest) {
					r.Filter = fmt.Sprintf("some-filter=%s-and-more-filter=%s", `a&b|c\28d\29e\5cf\2ag`, `a&b|c\28d\29e\5cf\2ag`)
				})).Return(&ldap.SearchResult{
					Entries: []*ldap.Entry{
						{
							DN: testSearchResultDNValue,
							Attributes: []*ldap.EntryAttribute{
								ldap.NewEntryAttribute(testUserSearchUsernameAttribute, []string{testSearchResultUsernameAttributeValue}),
								ldap.NewEntryAttribute(testUserSearchUIDAttribute, []string{testSearchResultUIDAttributeValue}),
							},
						},
					},
				}, nil).Times(1)
				conn.EXPECT().Bind(testSearchResultDNValue, testUpstreamPassword).Times(1)
				conn.EXPECT().Close().Times(1)
			},
			wantAuthResponse: &authenticator.Response{
				User: &user.DefaultInfo{
					Name:   testSearchResultUsernameAttributeValue,
					Groups: []string{}, // We don't support group search yet. Coming soon!
					UID:    testSearchResultUIDAttributeValue,
				},
			},
		},
		// TODO are LDAP attribute names case sensitive? do we need any special handling for case?
		{
			name:      "when dial fails",
			provider:  provider(nil),
			dialError: errors.New("some dial error"),
			wantError: fmt.Sprintf(`error dialing host "%s": some dial error`, testHost),
		},
	}

	for _, test := range tests {
		tt := test
		t.Run(tt.name, func(t *testing.T) {
			ctrl := gomock.NewController(t)
			t.Cleanup(ctrl.Finish)

			conn := mockldapconn.NewMockConn(ctrl)
			if tt.setupMocks != nil {
				tt.setupMocks(conn)
			}

			dialWasAttempted := false
			tt.provider.Dialer = LDAPDialerFunc(func(ctx context.Context, hostAndPort string) (Conn, error) {
				dialWasAttempted = true
				require.Equal(t, tt.provider.Host, hostAndPort)
				if tt.dialError != nil {
					return nil, tt.dialError
				}
				return conn, nil
			})

			authResponse, authenticated, err := tt.provider.AuthenticateUser(context.Background(), tt.username, tt.password)

			require.True(t, dialWasAttempted, "AuthenticateUser was supposed to try to dial, but didn't")

			if tt.wantError != "" {
				require.EqualError(t, err, tt.wantError)
				require.False(t, authenticated)
				require.Nil(t, authResponse)
			} else {
				require.NoError(t, err)
				require.True(t, authenticated)
				require.Equal(t, tt.wantAuthResponse, authResponse)
			}
		})
	}
}

func TestGetURL(t *testing.T) {
	require.Equal(t, "ldaps://ldap.example.com:1234", (&Provider{Host: "ldap.example.com:1234"}).GetURL())
	require.Equal(t, "ldaps://ldap.example.com", (&Provider{Host: "ldap.example.com"}).GetURL())
}

// Testing of host parsing, TLS negotiation, and CA bundle, etc. for the production code's dialer.
func TestRealTLSDialing(t *testing.T) {
	testServerCABundle, testServerURL := testutil.TLSTestServer(t, func(w http.ResponseWriter, r *http.Request) {})
	parsedURL, err := url.Parse(testServerURL)
	require.NoError(t, err)
	testServerHostAndPort := parsedURL.Host

	unusedPortGrabbingListener, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)
	recentlyClaimedHostAndPort := unusedPortGrabbingListener.Addr().String()
	require.NoError(t, unusedPortGrabbingListener.Close())

	alreadyCancelledContext, cancelFunc := context.WithCancel(context.Background())
	cancelFunc() // cancel it immediately

	tests := []struct {
		name      string
		host      string
		caBundle  []byte
		context   context.Context
		wantError string
	}{
		{
			name:     "happy path",
			host:     testServerHostAndPort,
			caBundle: []byte(testServerCABundle),
			context:  context.Background(),
		},
		{
			name:      "invalid CA bundle",
			host:      testServerHostAndPort,
			caBundle:  []byte("not a ca bundle"),
			context:   context.Background(),
			wantError: `LDAP Result Code 200 "Network Error": could not parse CA bundle`,
		},
		{
			name:      "missing CA bundle when it is required because the host is not using a trusted CA",
			host:      testServerHostAndPort,
			caBundle:  nil,
			context:   context.Background(),
			wantError: `LDAP Result Code 200 "Network Error": x509: certificate signed by unknown authority`,
		},
		{
			name: "cannot connect to host",
			// This is assuming that this port was not reclaimed by another app since the test setup ran. Seems safe enough.
			host:      recentlyClaimedHostAndPort,
			caBundle:  []byte(testServerCABundle),
			context:   context.Background(),
			wantError: fmt.Sprintf(`LDAP Result Code 200 "Network Error": dial tcp %s: connect: connection refused`, recentlyClaimedHostAndPort),
		},
		{
			name:      "pays attention to the passed context",
			host:      testServerHostAndPort,
			caBundle:  []byte(testServerCABundle),
			context:   alreadyCancelledContext,
			wantError: fmt.Sprintf(`LDAP Result Code 200 "Network Error": dial tcp %s: operation was canceled`, testServerHostAndPort),
		},
	}
	for _, test := range tests {
		test := test
		t.Run(test.name, func(t *testing.T) {
			provider := &Provider{
				Host:     test.host,
				CABundle: test.caBundle,
				Dialer:   nil, // this test is for the default (production) dialer
			}
			conn, err := provider.dial(test.context)
			if conn != nil {
				defer conn.Close()
			}
			if test.wantError != "" {
				require.Nil(t, conn)
				require.EqualError(t, err, test.wantError)
			} else {
				require.NoError(t, err)
				require.NotNil(t, conn)

				// Should be an instance of the real production LDAP client type.
				// Can't test its methods here because we are not dialed to a real LDAP server.
				require.IsType(t, &ldap.Conn{}, conn)

				// Indirectly checking that the Dialer method constructed the ldap.Conn with isTLS set to true,
				// since this is always the correct behavior unless/until we want to support StartTLS.
				err := conn.(*ldap.Conn).StartTLS(&tls.Config{})
				require.EqualError(t, err, `LDAP Result Code 200 "Network Error": ldap: already encrypted`)
			}
		})
	}
}

// Test various cases of host and port parsing.
func TestHostAndPortWithDefaultPort(t *testing.T) {
	tests := []struct {
		name            string
		hostAndPort     string
		defaultPort     string
		wantError       string
		wantHostAndPort string
	}{
		{
			name:            "host already has port",
			hostAndPort:     "host.example.com:99",
			defaultPort:     "42",
			wantHostAndPort: "host.example.com:99",
		},
		{
			name:            "host does not have port",
			hostAndPort:     "host.example.com",
			defaultPort:     "42",
			wantHostAndPort: "host.example.com:42",
		},
		{
			name:            "host does not have port and default port is empty",
			hostAndPort:     "host.example.com",
			defaultPort:     "",
			wantHostAndPort: "host.example.com",
		},
		{
			name:            "IPv6 host already has port",
			hostAndPort:     "[::1%lo0]:80",
			defaultPort:     "42",
			wantHostAndPort: "[::1%lo0]:80",
		},
		{
			name:            "IPv6 host does not have port",
			hostAndPort:     "[::1%lo0]",
			defaultPort:     "42",
			wantHostAndPort: "[::1%lo0]:42",
		},
		{
			name:            "IPv6 host does not have port and default port is empty",
			hostAndPort:     "[::1%lo0]",
			defaultPort:     "",
			wantHostAndPort: "[::1%lo0]",
		},
		{
			name:        "host is not valid",
			hostAndPort: "host.example.com:port1:port2",
			defaultPort: "42",
			wantError:   "address host.example.com:port1:port2: too many colons in address",
		},
	}
	for _, test := range tests {
		test := test
		t.Run(test.name, func(t *testing.T) {
			hostAndPort, err := hostAndPortWithDefaultPort(test.hostAndPort, test.defaultPort)
			if test.wantError != "" {
				require.EqualError(t, err, test.wantError)
			} else {
				require.NoError(t, err)
			}
			require.Equal(t, test.wantHostAndPort, hostAndPort)
		})
	}
}