Update authorization endpoint to redirect to new login page

Also fix some test failures on the callback handler, register the
new login handler in manager.go and add a (half baked) integration test

Signed-off-by: Margo Crawford <margaretc@vmware.com>

internal/oidc/auth/auth_handler.go

@@ -7,6 +7,7 @@ package auth
 import (
 	"fmt"
 	"net/http"
+	"net/url"
 	"time"
 
 	coreosoidc "github.com/coreos/go-oidc/v3/oidc"
@@ -75,15 +76,33 @@ func NewHandler(
 				cookieCodec,
 			)
 		}
-		return handleAuthRequestForLDAPUpstream(r, w,
+
-			oauthHelperWithStorage,
+		// we know it's an AD/LDAP upstream.
+		if len(r.Header.Values(supervisoroidc.AuthorizeUsernameHeaderName)) > 0 || len(r.Header.Values(supervisoroidc.AuthorizePasswordHeaderName)) > 0 {
+			// The client set a username header, so they are trying to log in with a username/password.
+			return handleAuthRequestForLDAPUpstreamCLIFlow(r, w,
+				oauthHelperWithStorage,
+				ldapUpstream,
+				idpType,
+			)
+		}
+		return handleAuthRequestForLDAPUpstreamBrowserFlow(
+			r,
+			w,
+			oauthHelperWithoutStorage,
+			generateCSRF,
+			generateNonce,
+			generatePKCE,
 			ldapUpstream,
 			idpType,
+			downstreamIssuer,
+			upstreamStateEncoder,
+			cookieCodec,
 		)
 	}))
 }
 
-func handleAuthRequestForLDAPUpstream(
+func handleAuthRequestForLDAPUpstreamCLIFlow(
 	r *http.Request,
 	w http.ResponseWriter,
 	oauthHelper fosite.OAuth2Provider,
@@ -138,6 +157,93 @@ func handleAuthRequestForLDAPUpstream(
 		oauthHelper, authorizeRequester, subject, username, groups, customSessionData)
 }
 
+func handleAuthRequestForLDAPUpstreamBrowserFlow(
+	r *http.Request,
+	w http.ResponseWriter,
+	oauthHelper fosite.OAuth2Provider,
+	generateCSRF func() (csrftoken.CSRFToken, error),
+	generateNonce func() (nonce.Nonce, error),
+	generatePKCE func() (pkce.Code, error),
+	ldapUpstream provider.UpstreamLDAPIdentityProviderI,
+	idpType psession.ProviderType,
+	downstreamIssuer string,
+	upstreamStateEncoder oidc.Encoder,
+	cookieCodec oidc.Codec,
+) error {
+	authorizeRequester, created := newAuthorizeRequest(r, w, oauthHelper, false)
+	if !created {
+		return nil
+	}
+
+	now := time.Now()
+	_, err := oauthHelper.NewAuthorizeResponse(r.Context(), authorizeRequester, &psession.PinnipedSession{
+		Fosite: &openid.DefaultSession{
+			Claims: &jwt.IDTokenClaims{
+				// Temporary claim values to allow `NewAuthorizeResponse` to perform other OIDC validations.
+				Subject:     "none",
+				AuthTime:    now,
+				RequestedAt: now,
+			},
+		},
+	})
+	if err != nil {
+		return writeAuthorizeError(w, oauthHelper, authorizeRequester, err, false)
+	}
+
+	csrfValue, nonceValue, pkceValue, err := generateValues(generateCSRF, generateNonce, generatePKCE)
+	if err != nil {
+		plog.Error("authorize generate error", err)
+		return err
+	}
+	csrfFromCookie := readCSRFCookie(r, cookieCodec)
+	if csrfFromCookie != "" {
+		csrfValue = csrfFromCookie
+	}
+
+	encodedStateParamValue, err := upstreamStateParam(
+		authorizeRequester,
+		ldapUpstream.GetName(),
+		string(idpType),
+		nonceValue,
+		csrfValue,
+		pkceValue,
+		upstreamStateEncoder,
+	)
+	if err != nil {
+		plog.Error("authorize upstream state param error", err)
+		return err
+	}
+
+	promptParam := r.Form.Get(promptParamName)
+	if promptParam == promptParamNone && oidc.ScopeWasRequested(authorizeRequester, coreosoidc.ScopeOpenID) {
+		return writeAuthorizeError(w, oauthHelper, authorizeRequester, fosite.ErrLoginRequired, false)
+	}
+
+	if csrfFromCookie == "" {
+		// We did not receive an incoming CSRF cookie, so write a new one.
+		err := addCSRFSetCookieHeader(w, csrfValue, cookieCodec)
+		if err != nil {
+			plog.Error("error setting CSRF cookie", err)
+			return err
+		}
+	}
+
+	loginURL, err := url.Parse(downstreamIssuer + "/login")
+	if err != nil {
+		return err
+	}
+	q := loginURL.Query()
+	q.Set("state", encodedStateParamValue)
+	loginURL.RawQuery = q.Encode()
+
+	http.Redirect(w, r,
+		loginURL.String(),
+		http.StatusSeeOther, // match fosite and https://tools.ietf.org/id/draft-ietf-oauth-security-topics-18.html#section-4.11
+	)
+
+	return nil
+}
+
 func handleAuthRequestForOIDCUpstreamPasswordGrant(
 	r *http.Request,
 	w http.ResponseWriter,
@@ -246,6 +352,7 @@ func handleAuthRequestForOIDCUpstreamAuthcodeGrant(
 	encodedStateParamValue, err := upstreamStateParam(
 		authorizeRequester,
 		oidcUpstream.GetName(),
+		string(psession.ProviderTypeOIDC),
 		nonceValue,
 		csrfValue,
 		pkceValue,
@@ -463,6 +570,7 @@ func generateValues(
 func upstreamStateParam(
 	authorizeRequester fosite.AuthorizeRequester,
 	upstreamName string,
+	upstreamType string,
 	nonceValue nonce.Nonce,
 	csrfValue csrftoken.CSRFToken,
 	pkceValue pkce.Code,
@@ -471,6 +579,7 @@ func upstreamStateParam(
 	stateParamData := oidc.UpstreamStateParamData{
 		AuthParams:    authorizeRequester.GetRequestForm().Encode(),
 		UpstreamName:  upstreamName,
+		UpstreamType:  upstreamType,
 		Nonce:         nonceValue,
 		CSRFToken:     csrfValue,
 		PKCECode:      pkceValue,

internal/oidc/auth/auth_handler_test.go

@@ -409,23 +409,20 @@ func TestAuthorizationEndpoint(t *testing.T) {
 		return pathWithQuery("/some/path", modifiedHappyGetRequestQueryMap(queryOverrides))
 	}
 
-	expectedUpstreamStateParam := func(queryOverrides map[string]string, csrfValueOverride, upstreamNameOverride string) string {
+	expectedUpstreamStateParam := func(queryOverrides map[string]string, csrfValueOverride, upstreamName, upstreamType string) string {
 		csrf := happyCSRF
 		if csrfValueOverride != "" {
 			csrf = csrfValueOverride
 		}
-		upstreamName := oidcUpstreamName
-		if upstreamNameOverride != "" {
-			upstreamName = upstreamNameOverride
-		}
 		encoded, err := happyStateEncoder.Encode("s",
 			oidctestutil.ExpectedUpstreamStateParamFormat{
 				P: encodeQuery(modifiedHappyGetRequestQueryMap(queryOverrides)),
 				U: upstreamName,
+				T: upstreamType,
 				N: happyNonce,
 				C: csrf,
 				K: happyPKCE,
-				V: "1",
+				V: "2",
 			},
 		)
 		require.NoError(t, err)
@@ -558,7 +555,24 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantStatus:                             http.StatusSeeOther,
 			wantContentType:                        htmlContentType,
 			wantCSRFValueInCookieHeader:            happyCSRF,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), nil),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", oidcUpstreamName, "oidc"), nil),
+			wantUpstreamStateParamInLocationHeader: true,
+			wantBodyStringWithLocationInHref:       true,
+		},
+		{
+			name:                                   "LDAP upstream browser flow happy path using GET without a CSRF cookie",
+			idps:                                   oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
+			generateCSRF:                           happyCSRFGenerator,
+			generatePKCE:                           happyPKCEGenerator,
+			generateNonce:                          happyNonceGenerator,
+			stateEncoder:                           happyStateEncoder,
+			cookieEncoder:                          happyCookieEncoder,
+			method:                                 http.MethodGet,
+			path:                                   happyGetRequestPath,
+			wantStatus:                             http.StatusSeeOther,
+			wantContentType:                        htmlContentType,
+			wantCSRFValueInCookieHeader:            happyCSRF,
+			wantLocationHeader:                     urlWithQuery(downstreamIssuer+"/login", map[string]string{"state": expectedUpstreamStateParam(nil, "", ldapUpstreamName, "ldap")}),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
 		},
@@ -639,7 +653,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			csrfCookie:                             "__Host-pinniped-csrf=" + encodedIncomingCookieCSRFValue + " ",
 			wantStatus:                             http.StatusSeeOther,
 			wantContentType:                        htmlContentType,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, incomingCookieCSRFValue, ""), nil),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, incomingCookieCSRFValue, oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
 		},
@@ -659,7 +673,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantContentType:                        "",
 			wantBodyString:                         "",
 			wantCSRFValueInCookieHeader:            happyCSRF,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), nil),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 		},
 		{
@@ -748,7 +762,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantContentType:                        htmlContentType,
 			wantBodyStringWithLocationInHref:       true,
 			wantCSRFValueInCookieHeader:            happyCSRF,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{"prompt": "login"}, "", ""), nil),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{"prompt": "login"}, "", oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 		},
 		{
@@ -767,7 +781,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantContentType:                        htmlContentType,
 			wantBodyStringWithLocationInHref:       true,
 			wantCSRFValueInCookieHeader:            happyCSRF,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{"prompt": "login"}, "", ""), map[string]string{"prompt": "consent", "abc": "123", "def": "456"}),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{"prompt": "login"}, "", oidcUpstreamName, "oidc"), map[string]string{"prompt": "consent", "abc": "123", "def": "456"}),
 			wantUpstreamStateParamInLocationHeader: true,
 		},
 		{
@@ -802,7 +816,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantContentType: htmlContentType,
 			// Generated a new CSRF cookie and set it in the response.
 			wantCSRFValueInCookieHeader:            happyCSRF,
-			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), nil),
+			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
 		},
@@ -823,7 +837,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantCSRFValueInCookieHeader: happyCSRF,
 			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{
 				"redirect_uri": downstreamRedirectURIWithDifferentPort, // not the same port number that is registered for the client
-			}, "", ""), nil),
+			}, "", oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
 		},
@@ -889,7 +903,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantCSRFValueInCookieHeader: happyCSRF,
 			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{
 				"scope": "openid offline_access",
-			}, "", ""), nil),
+			}, "", oidcUpstreamName, "oidc"), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
 		},
@@ -1063,7 +1077,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantBodyString:       "",
 		},
 		{
-			name:                 "missing upstream username on request for LDAP authentication",
+			name:                 "missing upstream username but has password on request for LDAP authentication",
 			idps:                 oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
 			method:               http.MethodGet,
 			path:                 happyGetRequestPath,
@@ -1338,21 +1352,45 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantBodyString:       "",
 		},
 		{
-			name:               "response type is unsupported when using LDAP upstream",
+			name:                 "response type is unsupported when using LDAP cli upstream",
+			idps:                 oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
+			method:               http.MethodGet,
+			path:                 modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
+			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
+			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
+			wantStatus:           http.StatusFound,
+			wantContentType:      "application/json; charset=utf-8",
+			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
+			wantBodyString:       "",
+		},
+		{
+			name:               "response type is unsupported when using LDAP browser upstream",
 			idps:               oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
 			method:             http.MethodGet,
 			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
-			wantStatus:         http.StatusFound,
+			wantStatus:         http.StatusSeeOther,
 			wantContentType:    "application/json; charset=utf-8",
 			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
 			wantBodyString:     "",
 		},
 		{
-			name:               "response type is unsupported when using active directory upstream",
+			name:                 "response type is unsupported when using active directory cli upstream",
+			idps:                 oidctestutil.NewUpstreamIDPListerBuilder().WithActiveDirectory(&upstreamActiveDirectoryIdentityProvider),
+			method:               http.MethodGet,
+			path:                 modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
+			customUsernameHeader: pointer.StringPtr(oidcUpstreamUsername),
+			customPasswordHeader: pointer.StringPtr(oidcUpstreamPassword),
+			wantStatus:           http.StatusFound,
+			wantContentType:      "application/json; charset=utf-8",
+			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
+			wantBodyString:       "",
+		},
+		{
+			name:               "response type is unsupported when using active directory browser upstream",
 			idps:               oidctestutil.NewUpstreamIDPListerBuilder().WithActiveDirectory(&upstreamActiveDirectoryIdentityProvider),
 			method:             http.MethodGet,
 			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
-			wantStatus:         http.StatusFound,
+			wantStatus:         http.StatusSeeOther,
 			wantContentType:    "application/json; charset=utf-8",
 			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
 			wantBodyString:     "",
@@ -1436,21 +1474,45 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantBodyString:       "",
 		},
 		{
-			name:               "missing response type in request using LDAP upstream",
+			name:                 "missing response type in request using LDAP cli upstream",
+			idps:                 oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
+			method:               http.MethodGet,
+			path:                 modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
+			customUsernameHeader: pointer.StringPtr(oidcUpstreamUsername),
+			customPasswordHeader: pointer.StringPtr(oidcUpstreamPassword),
+			wantStatus:           http.StatusFound,
+			wantContentType:      "application/json; charset=utf-8",
+			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
+			wantBodyString:       "",
+		},
+		{
+			name:               "missing response type in request using LDAP browser upstream",
 			idps:               oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
 			method:             http.MethodGet,
 			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
-			wantStatus:         http.StatusFound,
+			wantStatus:         http.StatusSeeOther,
 			wantContentType:    "application/json; charset=utf-8",
 			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
 			wantBodyString:     "",
 		},
 		{
-			name:               "missing response type in request using Active Directory upstream",
+			name:                 "missing response type in request using Active Directory cli upstream",
+			idps:                 oidctestutil.NewUpstreamIDPListerBuilder().WithActiveDirectory(&upstreamActiveDirectoryIdentityProvider),
+			method:               http.MethodGet,
+			path:                 modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
+			customUsernameHeader: pointer.StringPtr(oidcUpstreamUsername),
+			customPasswordHeader: pointer.StringPtr(oidcUpstreamPassword),
+			wantStatus:           http.StatusFound,
+			wantContentType:      "application/json; charset=utf-8",
+			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
+			wantBodyString:       "",
+		},
+		{
+			name:               "missing response type in request using Active Directory browser upstream",
 			idps:               oidctestutil.NewUpstreamIDPListerBuilder().WithActiveDirectory(&upstreamActiveDirectoryIdentityProvider),
 			method:             http.MethodGet,
 			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
-			wantStatus:         http.StatusFound,
+			wantStatus:         http.StatusSeeOther,
 			wantContentType:    "application/json; charset=utf-8",
 			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
 			wantBodyString:     "",
@@ -1720,7 +1782,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantContentType:             htmlContentType,
 			wantCSRFValueInCookieHeader: happyCSRF,
 			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(
-				map[string]string{"prompt": "none login", "scope": "email"}, "", "",
+				map[string]string{"prompt": "none login", "scope": "email"}, "", oidcUpstreamName, "oidc",
 			), nil),
 			wantUpstreamStateParamInLocationHeader: true,
 			wantBodyStringWithLocationInHref:       true,
@@ -2543,7 +2605,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 				"scope":         "some-other-new-scope1 some-other-new-scope2", // updated expectation
 				"client_id":     "some-other-new-client-id",                    // updated expectation
 				"state": expectedUpstreamStateParam(
-					nil, "", "some-other-new-idp-name",
+					nil, "", "some-other-new-idp-name", "oidc",
 				), // updated expectation
 				"nonce":                 happyNonce,
 				"code_challenge":        expectedUpstreamCodeChallenge,

internal/oidc/callback/callback_handler_test.go

@@ -48,7 +48,7 @@ const (
 	happyDownstreamCSRF         = "test-csrf"
 	happyDownstreamPKCE         = "test-pkce"
 	happyDownstreamNonce        = "test-nonce"
-	happyDownstreamStateVersion = "1"
+	happyDownstreamStateVersion = "2"
 
 	downstreamIssuer              = "https://my-downstream-issuer.com/path"
 	downstreamRedirectURI         = "http://127.0.0.1/callback"
@@ -1162,6 +1162,7 @@ func happyUpstreamStateParam() *upstreamStateParamBuilder {
 	return &upstreamStateParamBuilder{
 		U: happyUpstreamIDPName,
 		P: happyDownstreamRequestParams,
+		T: "oidc",
 		N: happyDownstreamNonce,
 		C: happyDownstreamCSRF,
 		K: happyDownstreamPKCE,

internal/oidc/provider/manager/manager.go

@@ -1,4 +1,4 @@
-// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package manager
@@ -8,6 +8,8 @@ import (
 	"strings"
 	"sync"
 
+	"go.pinniped.dev/internal/oidc/login"
+
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
 
 	"go.pinniped.dev/internal/oidc"
@@ -134,6 +136,8 @@ func (m *Manager) SetProviders(federationDomains ...*provider.FederationDomainIs
 			oauthHelperWithKubeStorage,
 		)
 
+		m.providerHandlers[(issuerHostWithPath + oidc.PinnipedLoginPath)] = login.NewHandler()
+
 		plog.Debug("oidc provider manager added or updated issuer", "issuer", issuer)
 	}
 }

internal/testutil/oidctestutil/oidctestutil.go

@@ -830,6 +830,7 @@ func NewTestUpstreamOIDCIdentityProviderBuilder() *TestUpstreamOIDCIdentityProvi
 type ExpectedUpstreamStateParamFormat struct {
 	P string `json:"p"`
 	U string `json:"u"`
+	T string `json:"t"`
 	N string `json:"n"`
 	C string `json:"c"`
 	K string `json:"k"`

test/integration/e2e_test.go

@@ -964,6 +964,122 @@ func TestE2EFullIntegration_Browser(t *testing.T) { // nolint:gocyclo
 			expectedGroups,
 		)
 	})
+
+	// Add an OIDC upstream IDP and try using it to authenticate during kubectl commands.
+	t.Run("with Supervisor LDAP upstream IDP and browser flow", func(t *testing.T) {
+		testCtx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+		t.Cleanup(cancel)
+
+		// Start a fresh browser driver because we don't want to share cookies between the various tests in this file.
+		page := browsertest.Open(t)
+
+		expectedUsername := env.SupervisorUpstreamLDAP.TestUserMailAttributeValue
+
+		setupClusterForEndToEndLDAPTest(t, expectedUsername, env)
+
+		// Use a specific session cache for this test.
+		sessionCachePath := tempDir + "/ldap-test-sessions.yaml"
+
+		kubeconfigPath := runPinnipedGetKubeconfig(t, env, pinnipedExe, tempDir, []string{
+			"get", "kubeconfig",
+			"--concierge-api-group-suffix", env.APIGroupSuffix,
+			"--concierge-authenticator-type", "jwt",
+			"--concierge-authenticator-name", authenticator.Name,
+			"--oidc-skip-browser",
+			"--oidc-ca-bundle", testCABundlePath,
+			"--upstream-identity-provider-flow", "browser_authcode",
+			"--oidc-session-cache", sessionCachePath,
+		})
+
+		// Run "kubectl get namespaces" which should trigger a browser login via the plugin.
+		kubectlCmd := exec.CommandContext(testCtx, "kubectl", "get", "namespace", "--kubeconfig", kubeconfigPath, "-v", "6")
+		kubectlCmd.Env = append(os.Environ(), env.ProxyEnv()...)
+
+		// Wrap the stdout and stderr pipes with TeeReaders which will copy each incremental read to an
+		// in-memory buffer, so we can have the full output available to us at the end.
+		originalStderrPipe, err := kubectlCmd.StderrPipe()
+		require.NoError(t, err)
+		originalStdoutPipe, err := kubectlCmd.StdoutPipe()
+		require.NoError(t, err)
+		var stderrPipeBuf, stdoutPipeBuf bytes.Buffer
+		stderrPipe := io.TeeReader(originalStderrPipe, &stderrPipeBuf)
+		stdoutPipe := io.TeeReader(originalStdoutPipe, &stdoutPipeBuf)
+
+		t.Logf("starting kubectl subprocess")
+		require.NoError(t, kubectlCmd.Start())
+		t.Cleanup(func() {
+			// Consume readers so that the tee buffers will contain all the output so far.
+			_, stdoutReadAllErr := readAllCtx(testCtx, stdoutPipe)
+			_, stderrReadAllErr := readAllCtx(testCtx, stderrPipe)
+
+			// Note that Wait closes the stdout/stderr pipes, so we don't need to close them ourselves.
+			waitErr := kubectlCmd.Wait()
+			t.Logf("kubectl subprocess exited with code %d", kubectlCmd.ProcessState.ExitCode())
+
+			// Upon failure, print the full output so far of the kubectl command.
+			var testAlreadyFailedErr error
+			if t.Failed() {
+				testAlreadyFailedErr = errors.New("test failed prior to clean up function")
+			}
+			cleanupErrs := utilerrors.NewAggregate([]error{waitErr, stdoutReadAllErr, stderrReadAllErr, testAlreadyFailedErr})
+
+			if cleanupErrs != nil {
+				t.Logf("kubectl stdout was:\n----start of stdout\n%s\n----end of stdout", stdoutPipeBuf.String())
+				t.Logf("kubectl stderr was:\n----start of stderr\n%s\n----end of stderr", stderrPipeBuf.String())
+			}
+			require.NoErrorf(t, cleanupErrs, "kubectl process did not exit cleanly and/or the test failed. "+
+				"Note: if kubectl's first call to the Pinniped CLI results in the Pinniped CLI returning an error, "+
+				"then kubectl may call the Pinniped CLI again, which may hang because it will wait for the user "+
+				"to finish the login. This test will kill the kubectl process after a timeout. In this case, the "+
+				" kubectl output printed above will include multiple prompts for the user to enter their authcode.",
+			)
+		})
+
+		// Start a background goroutine to read stderr from the CLI and parse out the login URL.
+		loginURLChan := make(chan string, 1)
+		spawnTestGoroutine(testCtx, t, func() error {
+			reader := bufio.NewReader(testlib.NewLoggerReader(t, "stderr", stderrPipe))
+			scanner := bufio.NewScanner(reader)
+			for scanner.Scan() {
+				loginURL, err := url.Parse(strings.TrimSpace(scanner.Text()))
+				if err == nil && loginURL.Scheme == "https" {
+					loginURLChan <- loginURL.String() // this channel is buffered so this will not block
+					return nil
+				}
+			}
+			return fmt.Errorf("expected stderr to contain login URL")
+		})
+
+		// Start a background goroutine to read stdout from kubectl and return the result as a string.
+		kubectlOutputChan := make(chan string, 1)
+		spawnTestGoroutine(testCtx, t, func() error {
+			output, err := readAllCtx(testCtx, stdoutPipe)
+			if err != nil {
+				return err
+			}
+			t.Logf("kubectl output:\n%s\n", output)
+			kubectlOutputChan <- string(output) // this channel is buffered so this will not block
+			return nil
+		})
+
+		// Wait for the CLI to print out the login URL and open the browser to it.
+		t.Logf("waiting for CLI to output login URL")
+		var loginURL string
+		select {
+		case <-time.After(1 * time.Minute):
+			require.Fail(t, "timed out waiting for login URL")
+		case loginURL = <-loginURLChan:
+		}
+		t.Logf("navigating to login page: %q", loginURL)
+		require.NoError(t, page.Navigate(loginURL))
+
+		// Expect to be redirected to the supervisor's ldap login page.
+		t.Logf("waiting for redirect to supervisor ldap login page")
+		regex := regexp.MustCompile(`\A` + downstream.Spec.Issuer + `/login.+`)
+		browsertest.WaitForURL(t, page, regex)
+
+		// TODO actually log in :P
+	})
 }
 
 func setupClusterForEndToEndLDAPTest(t *testing.T, username string, env *testlib.TestEnv) {