// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

package auth

import (
	"context"
	"fmt"
	"html"
	"net/http"
	"net/http/httptest"
	"net/url"
	"regexp"
	"strings"
	"testing"

	"github.com/gorilla/securecookie"
	"github.com/ory/fosite"
	"github.com/stretchr/testify/require"
	"k8s.io/apiserver/pkg/authentication/authenticator"
	"k8s.io/apiserver/pkg/authentication/user"
	"k8s.io/client-go/kubernetes/fake"
	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
	"k8s.io/utils/pointer"

	"go.pinniped.dev/internal/here"
	"go.pinniped.dev/internal/oidc"
	"go.pinniped.dev/internal/oidc/csrftoken"
	"go.pinniped.dev/internal/oidc/jwks"
	"go.pinniped.dev/internal/oidc/provider"
	"go.pinniped.dev/internal/testutil"
	"go.pinniped.dev/internal/testutil/oidctestutil"
	"go.pinniped.dev/pkg/oidcclient/nonce"
	"go.pinniped.dev/pkg/oidcclient/pkce"
)

func TestAuthorizationEndpoint(t *testing.T) {
	const (
		downstreamIssuer                       = "https://my-downstream-issuer.com/some-path"
		downstreamRedirectURI                  = "http://127.0.0.1/callback"
		downstreamRedirectURIWithDifferentPort = "http://127.0.0.1:42/callback"
		downstreamNonce                        = "some-nonce-value"
		downstreamPKCEChallenge                = "some-challenge"
		downstreamPKCEChallengeMethod          = "S256"
		happyState                             = "8b-state"
		downstreamClientID                     = "pinniped-cli"
		upstreamLDAPURL                        = "ldaps://some-ldap-host:123"
		htmlContentType                        = "text/html; charset=utf-8"
	)

	require.Len(t, happyState, 8, "we expect fosite to allow 8 byte state params, so we want to test that boundary case")

	var (
		fositeInvalidClientErrorBody = here.Doc(`
			{
				"error":             "invalid_client",
				"error_description": "Client authentication failed (e.g., unknown client, no client authentication included, or unsupported authentication method). The requested OAuth 2.0 Client does not exist."
			 }
		`)

		fositeInvalidRedirectURIErrorBody = here.Doc(`
			{
				"error":             "invalid_request",
				"error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. The 'redirect_uri' parameter does not match any of the OAuth 2.0 Client's pre-registered redirect urls."
			}
		`)

		fositePromptHasNoneAndOtherValueErrorQuery = map[string]string{
			"error":             "invalid_request",
			"error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. Parameter 'prompt' was set to 'none', but contains other values as well which is not allowed.",
			"state":             happyState,
		}

		fositeMissingCodeChallengeErrorQuery = map[string]string{
			"error":             "invalid_request",
			"error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. Clients must include a code_challenge when performing the authorize code flow, but it is missing.",
			"state":             happyState,
		}

		fositeMissingCodeChallengeMethodErrorQuery = map[string]string{
			"error":             "invalid_request",
			"error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. Clients must use code_challenge_method=S256, plain is not allowed.",
			"state":             happyState,
		}

		fositeInvalidCodeChallengeErrorQuery = map[string]string{
			"error":             "invalid_request",
			"error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. The code_challenge_method is not supported, use S256 instead.",
			"state":             happyState,
		}

		fositeUnsupportedResponseTypeErrorQuery = map[string]string{
			"error":             "unsupported_response_type",
			"error_description": "The authorization server does not support obtaining a token using this method. The client is not allowed to request response_type 'unsupported'.",
			"state":             happyState,
		}

		fositeInvalidScopeErrorQuery = map[string]string{
			"error":             "invalid_scope",
			"error_description": "The requested scope is invalid, unknown, or malformed. The OAuth 2.0 Client is not allowed to request scope 'tuna'.",
			"state":             happyState,
		}

		fositeInvalidStateErrorQuery = map[string]string{
			"error":             "invalid_state",
			"error_description": "The state is missing or does not have enough characters and is therefore considered too weak. Request parameter 'state' must be at least be 8 characters long to ensure sufficient entropy.",
			"state":             "short",
		}

		fositeMissingResponseTypeErrorQuery = map[string]string{
			"error":             "unsupported_response_type",
			"error_description": "The authorization server does not support obtaining a token using this method. `The request is missing the 'response_type' parameter.",
			"state":             happyState,
		}

		fositeAccessDeniedWithBadUsernamePasswordHintErrorQuery = map[string]string{
			"error":             "access_denied",
			"error_description": "The resource owner or authorization server denied the request. Username/password not accepted by LDAP provider.",
			"state":             happyState,
		}

		fositeAccessDeniedWithMissingUsernamePasswordHintErrorQuery = map[string]string{
			"error":             "access_denied",
			"error_description": "The resource owner or authorization server denied the request. Missing or blank username or password.",
			"state":             happyState,
		}
	)

	hmacSecretFunc := func() []byte { return []byte("some secret - must have at least 32 bytes") }
	require.GreaterOrEqual(t, len(hmacSecretFunc()), 32, "fosite requires that hmac secrets have at least 32 bytes")
	jwksProviderIsUnused := jwks.NewDynamicJWKSProvider()
	timeoutsConfiguration := oidc.DefaultOIDCTimeoutsConfiguration()

	createOauthHelperWithRealStorage := func(secretsClient v1.SecretInterface) (fosite.OAuth2Provider, *oidc.KubeStorage) {
		// Configure fosite the same way that the production code would when using Kube storage.
		// Inject this into our test subject at the last second so we get a fresh storage for every test.
		kubeOauthStore := oidc.NewKubeStorage(secretsClient, timeoutsConfiguration)
		return oidc.FositeOauth2Helper(kubeOauthStore, downstreamIssuer, hmacSecretFunc, jwksProviderIsUnused, timeoutsConfiguration), kubeOauthStore
	}

	// Configure fosite the same way that the production code would, using NullStorage to turn off storage.
	nullOauthStore := oidc.NullStorage{}
	oauthHelperWithNullStorage := oidc.FositeOauth2Helper(nullOauthStore, downstreamIssuer, hmacSecretFunc, jwksProviderIsUnused, timeoutsConfiguration)

	upstreamAuthURL, err := url.Parse("https://some-upstream-idp:8443/auth")
	require.NoError(t, err)

	upstreamOIDCIdentityProvider := oidctestutil.TestUpstreamOIDCIdentityProvider{
		Name:             "some-oidc-idp",
		ClientID:         "some-client-id",
		AuthorizationURL: *upstreamAuthURL,
		Scopes:           []string{"scope1", "scope2"}, // the scopes to request when starting the upstream authorization flow
	}

	happyLDAPUsername := "some-ldap-user"
	happyLDAPUsernameFromAuthenticator := "some-mapped-ldap-username"
	happyLDAPPassword := "some-ldap-password" //nolint:gosec
	happyLDAPUID := "some-ldap-uid"
	happyLDAPGroups := []string{"group1", "group2", "group3"}

	upstreamLDAPIdentityProvider := oidctestutil.TestUpstreamLDAPIdentityProvider{
		Name: "some-ldap-idp",
		URL:  upstreamLDAPURL,
		AuthenticateFunc: func(ctx context.Context, username, password string) (*authenticator.Response, bool, error) {
			if username == "" || password == "" {
				return nil, false, fmt.Errorf("should not have passed empty username or password to the authenticator")
			}
			if username == happyLDAPUsername && password == happyLDAPPassword {
				return &authenticator.Response{
					User: &user.DefaultInfo{
						Name:   happyLDAPUsernameFromAuthenticator,
						UID:    happyLDAPUID,
						Groups: happyLDAPGroups,
					},
				}, true, nil
			}
			return nil, false, nil
		},
	}

	erroringUpstreamLDAPIdentityProvider := oidctestutil.TestUpstreamLDAPIdentityProvider{
		Name: "some-ldap-idp",
		AuthenticateFunc: func(ctx context.Context, username, password string) (*authenticator.Response, bool, error) {
			return nil, false, fmt.Errorf("some ldap upstream auth error")
		},
	}

	happyCSRF := "test-csrf"
	happyPKCE := "test-pkce"
	happyNonce := "test-nonce"
	happyCSRFGenerator := func() (csrftoken.CSRFToken, error) { return csrftoken.CSRFToken(happyCSRF), nil }
	happyPKCEGenerator := func() (pkce.Code, error) { return pkce.Code(happyPKCE), nil }
	happyNonceGenerator := func() (nonce.Nonce, error) { return nonce.Nonce(happyNonce), nil }
	sadCSRFGenerator := func() (csrftoken.CSRFToken, error) { return "", fmt.Errorf("some csrf generator error") }
	sadPKCEGenerator := func() (pkce.Code, error) { return "", fmt.Errorf("some PKCE generator error") }
	sadNonceGenerator := func() (nonce.Nonce, error) { return "", fmt.Errorf("some nonce generator error") }

	// This is the PKCE challenge which is calculated as base64(sha256("test-pkce")). For example:
	// $ echo -n test-pkce | shasum -a 256 | cut -d" " -f1 | xxd -r -p | base64 | cut -d"=" -f1
	expectedUpstreamCodeChallenge := "VVaezYqum7reIhoavCHD1n2d-piN3r_mywoYj7fCR7g"

	var stateEncoderHashKey = []byte("fake-hash-secret")
	var stateEncoderBlockKey = []byte("0123456789ABCDEF") // block encryption requires 16/24/32 bytes for AES
	var cookieEncoderHashKey = []byte("fake-hash-secret2")
	var cookieEncoderBlockKey = []byte("0123456789ABCDE2") // block encryption requires 16/24/32 bytes for AES
	require.NotEqual(t, stateEncoderHashKey, cookieEncoderHashKey)
	require.NotEqual(t, stateEncoderBlockKey, cookieEncoderBlockKey)

	var happyStateEncoder = securecookie.New(stateEncoderHashKey, stateEncoderBlockKey)
	happyStateEncoder.SetSerializer(securecookie.JSONEncoder{})
	var happyCookieEncoder = securecookie.New(cookieEncoderHashKey, cookieEncoderBlockKey)
	happyCookieEncoder.SetSerializer(securecookie.JSONEncoder{})

	encodeQuery := func(query map[string]string) string {
		values := url.Values{}
		for k, v := range query {
			values[k] = []string{v}
		}
		return values.Encode()
	}

	pathWithQuery := func(path string, query map[string]string) string {
		pathToReturn := fmt.Sprintf("%s?%s", path, encodeQuery(query))
		require.NotRegexp(t, "^http", pathToReturn, "pathWithQuery helper was used to create a URL")
		return pathToReturn
	}

	urlWithQuery := func(baseURL string, query map[string]string) string {
		urlToReturn := fmt.Sprintf("%s?%s", baseURL, encodeQuery(query))
		_, err := url.Parse(urlToReturn)
		require.NoError(t, err, "urlWithQuery helper was used to create an illegal URL")
		return urlToReturn
	}

	happyDownstreamScopesRequested := []string{"openid", "profile", "email"}
	happyDownstreamScopesGranted := []string{"openid"}

	happyGetRequestQueryMap := map[string]string{
		"response_type":         "code",
		"scope":                 strings.Join(happyDownstreamScopesRequested, " "),
		"client_id":             downstreamClientID,
		"state":                 happyState,
		"nonce":                 downstreamNonce,
		"code_challenge":        downstreamPKCEChallenge,
		"code_challenge_method": downstreamPKCEChallengeMethod,
		"redirect_uri":          downstreamRedirectURI,
	}

	happyGetRequestPath := pathWithQuery("/some/path", happyGetRequestQueryMap)

	modifiedHappyGetRequestQueryMap := func(queryOverrides map[string]string) map[string]string {
		copyOfHappyGetRequestQueryMap := map[string]string{}
		for k, v := range happyGetRequestQueryMap {
			copyOfHappyGetRequestQueryMap[k] = v
		}
		for k, v := range queryOverrides {
			_, hasKey := copyOfHappyGetRequestQueryMap[k]
			if v == "" && hasKey {
				delete(copyOfHappyGetRequestQueryMap, k)
			} else {
				copyOfHappyGetRequestQueryMap[k] = v
			}
		}
		return copyOfHappyGetRequestQueryMap
	}

	modifiedHappyGetRequestPath := func(queryOverrides map[string]string) string {
		return pathWithQuery("/some/path", modifiedHappyGetRequestQueryMap(queryOverrides))
	}

	expectedUpstreamStateParam := func(queryOverrides map[string]string, csrfValueOverride, upstreamNameOverride string) string {
		csrf := happyCSRF
		if csrfValueOverride != "" {
			csrf = csrfValueOverride
		}
		upstreamName := upstreamOIDCIdentityProvider.Name
		if upstreamNameOverride != "" {
			upstreamName = upstreamNameOverride
		}
		encoded, err := happyStateEncoder.Encode("s",
			oidctestutil.ExpectedUpstreamStateParamFormat{
				P: encodeQuery(modifiedHappyGetRequestQueryMap(queryOverrides)),
				U: upstreamName,
				N: happyNonce,
				C: csrf,
				K: happyPKCE,
				V: "1",
			},
		)
		require.NoError(t, err)
		return encoded
	}

	expectedRedirectLocationForUpstreamOIDC := func(expectedUpstreamState string, expectedPrompt string) string {
		query := map[string]string{
			"response_type":         "code",
			"access_type":           "offline",
			"scope":                 "scope1 scope2",
			"client_id":             "some-client-id",
			"state":                 expectedUpstreamState,
			"nonce":                 happyNonce,
			"code_challenge":        expectedUpstreamCodeChallenge,
			"code_challenge_method": downstreamPKCEChallengeMethod,
			"redirect_uri":          downstreamIssuer + "/callback",
		}
		if expectedPrompt != "" {
			query["prompt"] = expectedPrompt
		}
		return urlWithQuery(upstreamAuthURL.String(), query)
	}

	// Note that fosite puts the granted scopes as a param in the redirect URI even though the spec doesn't seem to require it
	happyAuthcodeDownstreamRedirectLocationRegexp := downstreamRedirectURI + `\?code=([^&]+)&scope=openid&state=` + happyState

	incomingCookieCSRFValue := "csrf-value-from-cookie"
	encodedIncomingCookieCSRFValue, err := happyCookieEncoder.Encode("csrf", incomingCookieCSRFValue)
	require.NoError(t, err)

	type testCase struct {
		name string

		idpLister            provider.DynamicUpstreamIDPProvider
		generateCSRF         func() (csrftoken.CSRFToken, error)
		generatePKCE         func() (pkce.Code, error)
		generateNonce        func() (nonce.Nonce, error)
		stateEncoder         oidc.Codec
		cookieEncoder        oidc.Codec
		method               string
		path                 string
		contentType          string
		body                 string
		csrfCookie           string
		customUsernameHeader *string // nil means do not send header, empty means send header with empty value
		customPasswordHeader *string // nil means do not send header, empty means send header with empty value

		wantStatus                             int
		wantContentType                        string
		wantBodyString                         string
		wantBodyJSON                           string
		wantCSRFValueInCookieHeader            string
		wantBodyStringWithLocationInHref       bool
		wantLocationHeader                     string
		wantUpstreamStateParamInLocationHeader bool

		// For when the request was authenticated by an upstream LDAP provider and an authcode is being returned.
		wantRedirectLocationRegexp        string
		wantDownstreamRedirectURI         string
		wantDownstreamGrantedScopes       []string
		wantDownstreamIDTokenSubject      string
		wantDownstreamIDTokenUsername     string
		wantDownstreamIDTokenGroups       []string
		wantDownstreamRequestedScopes     []string
		wantDownstreamPKCEChallenge       string
		wantDownstreamPKCEChallengeMethod string
		wantDownstreamNonce               string
		wantUnnecessaryStoredRecords      int
	}
	tests := []testCase{
		{
			name:                                   "OIDC upstream happy path using GET without a CSRF cookie",
			idpLister:                              oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:                           happyCSRFGenerator,
			generatePKCE:                           happyPKCEGenerator,
			generateNonce:                          happyNonceGenerator,
			stateEncoder:                           happyStateEncoder,
			cookieEncoder:                          happyCookieEncoder,
			method:                                 http.MethodGet,
			path:                                   happyGetRequestPath,
			wantStatus:                             http.StatusFound,
			wantContentType:                        htmlContentType,
			wantCSRFValueInCookieHeader:            happyCSRF,
			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:                              "LDAP upstream happy path using GET",
			idpLister:                         oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                            http.MethodGet,
			path:                              happyGetRequestPath,
			customUsernameHeader:              pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:              pointer.StringPtr(happyLDAPPassword),
			wantStatus:                        http.StatusFound,
			wantContentType:                   htmlContentType,
			wantRedirectLocationRegexp:        happyAuthcodeDownstreamRedirectLocationRegexp,
			wantBodyStringWithLocationInHref:  false,
			wantDownstreamIDTokenSubject:      upstreamLDAPURL + "?sub=" + happyLDAPUID,
			wantDownstreamIDTokenUsername:     happyLDAPUsernameFromAuthenticator,
			wantDownstreamIDTokenGroups:       happyLDAPGroups,
			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
			wantDownstreamRedirectURI:         downstreamRedirectURI,
			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
			wantDownstreamNonce:               downstreamNonce,
			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
		},
		{
			name:                                   "OIDC upstream happy path using GET with a CSRF cookie",
			idpLister:                              oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:                           happyCSRFGenerator,
			generatePKCE:                           happyPKCEGenerator,
			generateNonce:                          happyNonceGenerator,
			stateEncoder:                           happyStateEncoder,
			cookieEncoder:                          happyCookieEncoder,
			method:                                 http.MethodGet,
			path:                                   happyGetRequestPath,
			csrfCookie:                             "__Host-pinniped-csrf=" + encodedIncomingCookieCSRFValue + " ",
			wantStatus:                             http.StatusFound,
			wantContentType:                        htmlContentType,
			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, incomingCookieCSRFValue, ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:                                   "OIDC upstream happy path using POST",
			idpLister:                              oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:                           happyCSRFGenerator,
			generatePKCE:                           happyPKCEGenerator,
			generateNonce:                          happyNonceGenerator,
			stateEncoder:                           happyStateEncoder,
			cookieEncoder:                          happyCookieEncoder,
			method:                                 http.MethodPost,
			path:                                   "/some/path",
			contentType:                            "application/x-www-form-urlencoded",
			body:                                   encodeQuery(happyGetRequestQueryMap),
			wantStatus:                             http.StatusFound,
			wantContentType:                        "",
			wantBodyString:                         "",
			wantCSRFValueInCookieHeader:            happyCSRF,
			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
		},
		{
			name:                              "LDAP upstream happy path using POST",
			idpLister:                         oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                            http.MethodPost,
			path:                              "/some/path",
			contentType:                       "application/x-www-form-urlencoded",
			body:                              encodeQuery(happyGetRequestQueryMap),
			customUsernameHeader:              pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:              pointer.StringPtr(happyLDAPPassword),
			wantStatus:                        http.StatusFound,
			wantContentType:                   htmlContentType,
			wantRedirectLocationRegexp:        happyAuthcodeDownstreamRedirectLocationRegexp,
			wantBodyStringWithLocationInHref:  false,
			wantDownstreamIDTokenSubject:      upstreamLDAPURL + "?sub=" + happyLDAPUID,
			wantDownstreamIDTokenUsername:     happyLDAPUsernameFromAuthenticator,
			wantDownstreamIDTokenGroups:       happyLDAPGroups,
			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
			wantDownstreamRedirectURI:         downstreamRedirectURI,
			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
			wantDownstreamNonce:               downstreamNonce,
			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
		},
		{
			name:                                   "OIDC upstream happy path with prompt param login passed through to redirect uri",
			idpLister:                              oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:                           happyCSRFGenerator,
			generatePKCE:                           happyPKCEGenerator,
			generateNonce:                          happyNonceGenerator,
			stateEncoder:                           happyStateEncoder,
			cookieEncoder:                          happyCookieEncoder,
			method:                                 http.MethodGet,
			path:                                   modifiedHappyGetRequestPath(map[string]string{"prompt": "login"}),
			contentType:                            "application/x-www-form-urlencoded",
			body:                                   encodeQuery(happyGetRequestQueryMap),
			wantStatus:                             http.StatusFound,
			wantContentType:                        htmlContentType,
			wantBodyStringWithLocationInHref:       true,
			wantCSRFValueInCookieHeader:            happyCSRF,
			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{"prompt": "login"}, "", ""), "login"),
			wantUpstreamStateParamInLocationHeader: true,
		},
		{
			name:            "OIDC upstream with error while decoding CSRF cookie just generates a new cookie and succeeds as usual",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			csrfCookie:      "__Host-pinniped-csrf=this-value-was-not-signed-by-pinniped",
			wantStatus:      http.StatusFound,
			wantContentType: htmlContentType,
			// Generated a new CSRF cookie and set it in the response.
			wantCSRFValueInCookieHeader:            happyCSRF,
			wantLocationHeader:                     expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(nil, "", ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:          "OIDC upstream happy path when downstream redirect uri matches what is configured for client except for the port number",
			idpLister:     oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:  happyCSRFGenerator,
			generatePKCE:  happyPKCEGenerator,
			generateNonce: happyNonceGenerator,
			stateEncoder:  happyStateEncoder,
			cookieEncoder: happyCookieEncoder,
			method:        http.MethodGet,
			path: modifiedHappyGetRequestPath(map[string]string{
				"redirect_uri": downstreamRedirectURIWithDifferentPort, // not the same port number that is registered for the client
			}),
			wantStatus:                  http.StatusFound,
			wantContentType:             htmlContentType,
			wantCSRFValueInCookieHeader: happyCSRF,
			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{
				"redirect_uri": downstreamRedirectURIWithDifferentPort, // not the same port number that is registered for the client
			}, "", ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:      "LDAP upstream happy path when downstream redirect uri matches what is configured for client except for the port number",
			idpLister: oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:    http.MethodGet,
			path: modifiedHappyGetRequestPath(map[string]string{
				"redirect_uri": downstreamRedirectURIWithDifferentPort, // not the same port number that is registered for the client
			}),
			customUsernameHeader:              pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:              pointer.StringPtr(happyLDAPPassword),
			wantStatus:                        http.StatusFound,
			wantContentType:                   htmlContentType,
			wantRedirectLocationRegexp:        downstreamRedirectURIWithDifferentPort + `\?code=([^&]+)&scope=openid&state=` + happyState,
			wantBodyStringWithLocationInHref:  false,
			wantDownstreamIDTokenSubject:      upstreamLDAPURL + "?sub=" + happyLDAPUID,
			wantDownstreamIDTokenUsername:     happyLDAPUsernameFromAuthenticator,
			wantDownstreamIDTokenGroups:       happyLDAPGroups,
			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
			wantDownstreamRedirectURI:         downstreamRedirectURIWithDifferentPort,
			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
			wantDownstreamNonce:               downstreamNonce,
			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
		},
		{
			name:                        "OIDC upstream happy path when downstream requested scopes include offline_access",
			idpLister:                   oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:                happyCSRFGenerator,
			generatePKCE:                happyPKCEGenerator,
			generateNonce:               happyNonceGenerator,
			stateEncoder:                happyStateEncoder,
			cookieEncoder:               happyCookieEncoder,
			method:                      http.MethodGet,
			path:                        modifiedHappyGetRequestPath(map[string]string{"scope": "openid offline_access"}),
			wantStatus:                  http.StatusFound,
			wantContentType:             htmlContentType,
			wantCSRFValueInCookieHeader: happyCSRF,
			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(map[string]string{
				"scope": "openid offline_access",
			}, "", ""), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:                 "error during upstream LDAP authentication",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&erroringUpstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 happyGetRequestPath,
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusBadGateway,
			wantContentType:      htmlContentType,
			wantBodyString:       "Bad Gateway: unexpected error during upstream authentication\n",
		},
		{
			name:                 "wrong upstream password for LDAP authentication",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 happyGetRequestPath,
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: pointer.StringPtr("wrong-password"),
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeAccessDeniedWithBadUsernamePasswordHintErrorQuery),
			wantBodyString:       "",
		},
		{
			name:                 "wrong upstream username for LDAP authentication",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 happyGetRequestPath,
			customUsernameHeader: pointer.StringPtr("wrong-username"),
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeAccessDeniedWithBadUsernamePasswordHintErrorQuery),
			wantBodyString:       "",
		},
		{
			name:                 "missing upstream username on request for LDAP authentication",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 happyGetRequestPath,
			customUsernameHeader: nil, // do not send header
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeAccessDeniedWithMissingUsernamePasswordHintErrorQuery),
			wantBodyString:       "",
		},
		{
			name:                 "missing upstream password on request for LDAP authentication",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 happyGetRequestPath,
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: nil, // do not send header
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeAccessDeniedWithMissingUsernamePasswordHintErrorQuery),
			wantBodyString:       "",
		},
		{
			name:          "downstream redirect uri does not match what is configured for client when using OIDC upstream",
			idpLister:     oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:  happyCSRFGenerator,
			generatePKCE:  happyPKCEGenerator,
			generateNonce: happyNonceGenerator,
			stateEncoder:  happyStateEncoder,
			cookieEncoder: happyCookieEncoder,
			method:        http.MethodGet,
			path: modifiedHappyGetRequestPath(map[string]string{
				"redirect_uri": "http://127.0.0.1/does-not-match-what-is-configured-for-pinniped-cli-client",
			}),
			wantStatus:      http.StatusBadRequest,
			wantContentType: "application/json; charset=utf-8",
			wantBodyJSON:    fositeInvalidRedirectURIErrorBody,
		},
		{
			name:      "downstream redirect uri does not match what is configured for client when using LDAP upstream",
			idpLister: oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:    http.MethodGet,
			path: modifiedHappyGetRequestPath(map[string]string{
				"redirect_uri": "http://127.0.0.1/does-not-match-what-is-configured-for-pinniped-cli-client",
			}),
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusBadRequest,
			wantContentType:      "application/json; charset=utf-8",
			wantBodyJSON:         fositeInvalidRedirectURIErrorBody,
		},
		{
			name:            "downstream client does not exist when using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            modifiedHappyGetRequestPath(map[string]string{"client_id": "invalid-client"}),
			wantStatus:      http.StatusUnauthorized,
			wantContentType: "application/json; charset=utf-8",
			wantBodyJSON:    fositeInvalidClientErrorBody,
		},
		{
			name:            "downstream client does not exist when using LDAP upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:          http.MethodGet,
			path:            modifiedHappyGetRequestPath(map[string]string{"client_id": "invalid-client"}),
			wantStatus:      http.StatusUnauthorized,
			wantContentType: "application/json; charset=utf-8",
			wantBodyJSON:    fositeInvalidClientErrorBody,
		},
		{
			name:               "response type is unsupported when using OIDC upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:               "response type is unsupported when using LDAP upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": "unsupported"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeUnsupportedResponseTypeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:               "downstream scopes do not match what is configured for client using OIDC upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"scope": "openid profile email tuna"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeInvalidScopeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                 "downstream scopes do not match what is configured for client using LDAP upstream",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 modifiedHappyGetRequestPath(map[string]string{"scope": "openid tuna"}),
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeInvalidScopeErrorQuery),
			wantBodyString:       "",
		},
		{
			name:               "missing response type in request using OIDC upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:               "missing response type in request using LDAP upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"response_type": ""}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingResponseTypeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:            "missing client id in request using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            modifiedHappyGetRequestPath(map[string]string{"client_id": ""}),
			wantStatus:      http.StatusUnauthorized,
			wantContentType: "application/json; charset=utf-8",
			wantBodyJSON:    fositeInvalidClientErrorBody,
		},
		{
			name:            "missing client id in request using LDAP upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:          http.MethodGet,
			path:            modifiedHappyGetRequestPath(map[string]string{"client_id": ""}),
			wantStatus:      http.StatusUnauthorized,
			wantContentType: "application/json; charset=utf-8",
			wantBodyJSON:    fositeInvalidClientErrorBody,
		},
		{
			name:               "missing PKCE code_challenge in request using OIDC upstream", // See https://tools.ietf.org/html/rfc7636#section-4.4.1
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"code_challenge": ""}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                         "missing PKCE code_challenge in request using LDAP upstream", // See https://tools.ietf.org/html/rfc7636#section-4.4.1
			idpLister:                    oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                       http.MethodGet,
			path:                         modifiedHappyGetRequestPath(map[string]string{"code_challenge": ""}),
			customUsernameHeader:         pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:         pointer.StringPtr(happyLDAPPassword),
			wantStatus:                   http.StatusFound,
			wantContentType:              "application/json; charset=utf-8",
			wantLocationHeader:           urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeErrorQuery),
			wantBodyString:               "",
			wantUnnecessaryStoredRecords: 2, // fosite already stored the authcode and oidc session before it noticed the error
		},
		{
			name:               "invalid value for PKCE code_challenge_method in request using OIDC upstream", // https://tools.ietf.org/html/rfc7636#section-4.3
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": "this-is-not-a-valid-pkce-alg"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeInvalidCodeChallengeErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                         "invalid value for PKCE code_challenge_method in request using LDAP upstream", // https://tools.ietf.org/html/rfc7636#section-4.3
			idpLister:                    oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                       http.MethodGet,
			path:                         modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": "this-is-not-a-valid-pkce-alg"}),
			customUsernameHeader:         pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:         pointer.StringPtr(happyLDAPPassword),
			wantStatus:                   http.StatusFound,
			wantContentType:              "application/json; charset=utf-8",
			wantLocationHeader:           urlWithQuery(downstreamRedirectURI, fositeInvalidCodeChallengeErrorQuery),
			wantBodyString:               "",
			wantUnnecessaryStoredRecords: 2, // fosite already stored the authcode and oidc session before it noticed the error
		},
		{
			name:               "when PKCE code_challenge_method in request is `plain` using OIDC upstream", // https://tools.ietf.org/html/rfc7636#section-4.3
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": "plain"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeMethodErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                         "when PKCE code_challenge_method in request is `plain` using LDAP upstream", // https://tools.ietf.org/html/rfc7636#section-4.3
			idpLister:                    oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                       http.MethodGet,
			path:                         modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": "plain"}),
			customUsernameHeader:         pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:         pointer.StringPtr(happyLDAPPassword),
			wantStatus:                   http.StatusFound,
			wantContentType:              "application/json; charset=utf-8",
			wantLocationHeader:           urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeMethodErrorQuery),
			wantBodyString:               "",
			wantUnnecessaryStoredRecords: 2, // fosite already stored the authcode and oidc session before it noticed the error
		},
		{
			name:               "missing PKCE code_challenge_method in request using OIDC upstream", // See https://tools.ietf.org/html/rfc7636#section-4.4.1
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": ""}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeMethodErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                         "missing PKCE code_challenge_method in request using LDAP upstream", // See https://tools.ietf.org/html/rfc7636#section-4.4.1
			idpLister:                    oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                       http.MethodGet,
			path:                         modifiedHappyGetRequestPath(map[string]string{"code_challenge_method": ""}),
			customUsernameHeader:         pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:         pointer.StringPtr(happyLDAPPassword),
			wantStatus:                   http.StatusFound,
			wantContentType:              "application/json; charset=utf-8",
			wantLocationHeader:           urlWithQuery(downstreamRedirectURI, fositeMissingCodeChallengeMethodErrorQuery),
			wantBodyString:               "",
			wantUnnecessaryStoredRecords: 2, // fosite already stored the authcode and oidc session before it noticed the error
		},
		{
			// This is just one of the many OIDC validations run by fosite. This test is to ensure that we are running
			// through that part of the fosite library when using an OIDC upstream.
			name:               "prompt param is not allowed to have none and another legal value at the same time using OIDC upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"prompt": "none login"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositePromptHasNoneAndOtherValueErrorQuery),
			wantBodyString:     "",
		},
		{
			// This is just one of the many OIDC validations run by fosite. This test is to ensure that we are running
			// through that part of the fosite library when using an LDAP upstream.
			name:                         "prompt param is not allowed to have none and another legal value at the same time using LDAP upstream",
			idpLister:                    oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:                       http.MethodGet,
			path:                         modifiedHappyGetRequestPath(map[string]string{"prompt": "none login"}),
			customUsernameHeader:         pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:         pointer.StringPtr(happyLDAPPassword),
			wantStatus:                   http.StatusFound,
			wantContentType:              "application/json; charset=utf-8",
			wantLocationHeader:           urlWithQuery(downstreamRedirectURI, fositePromptHasNoneAndOtherValueErrorQuery),
			wantBodyString:               "",
			wantUnnecessaryStoredRecords: 1, // fosite already stored the authcode before it noticed the error
		},
		{
			name:          "happy path: downstream OIDC validations are skipped when the openid scope was not requested using OIDC upstream",
			idpLister:     oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:  happyCSRFGenerator,
			generatePKCE:  happyPKCEGenerator,
			generateNonce: happyNonceGenerator,
			stateEncoder:  happyStateEncoder,
			cookieEncoder: happyCookieEncoder,
			method:        http.MethodGet,
			// The following prompt value is illegal when openid is requested, but note that openid is not requested.
			path:                        modifiedHappyGetRequestPath(map[string]string{"prompt": "none login", "scope": "email"}),
			wantStatus:                  http.StatusFound,
			wantContentType:             htmlContentType,
			wantCSRFValueInCookieHeader: happyCSRF,
			wantLocationHeader: expectedRedirectLocationForUpstreamOIDC(expectedUpstreamStateParam(
				map[string]string{"prompt": "none login", "scope": "email"}, "", "",
			), ""),
			wantUpstreamStateParamInLocationHeader: true,
			wantBodyStringWithLocationInHref:       true,
		},
		{
			name:      "happy path: downstream OIDC validations are skipped when the openid scope was not requested using LDAP upstream",
			idpLister: oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:    http.MethodGet,
			// The following prompt value is illegal when openid is requested, but note that openid is not requested.
			path:                              modifiedHappyGetRequestPath(map[string]string{"prompt": "none login", "scope": "email"}),
			customUsernameHeader:              pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader:              pointer.StringPtr(happyLDAPPassword),
			wantStatus:                        http.StatusFound,
			wantContentType:                   htmlContentType,
			wantRedirectLocationRegexp:        downstreamRedirectURI + `\?code=([^&]+)&scope=&state=` + happyState, // no scopes granted
			wantBodyStringWithLocationInHref:  false,
			wantDownstreamIDTokenSubject:      upstreamLDAPURL + "?sub=" + happyLDAPUID,
			wantDownstreamIDTokenUsername:     happyLDAPUsernameFromAuthenticator,
			wantDownstreamIDTokenGroups:       happyLDAPGroups,
			wantDownstreamRequestedScopes:     []string{"email"}, // only email was requested
			wantDownstreamRedirectURI:         downstreamRedirectURI,
			wantDownstreamGrantedScopes:       []string{}, // no scopes granted
			wantDownstreamNonce:               downstreamNonce,
			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
		},
		{
			name:               "downstream state does not have enough entropy using OIDC upstream",
			idpLister:          oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:       happyCSRFGenerator,
			generatePKCE:       happyPKCEGenerator,
			generateNonce:      happyNonceGenerator,
			stateEncoder:       happyStateEncoder,
			cookieEncoder:      happyCookieEncoder,
			method:             http.MethodGet,
			path:               modifiedHappyGetRequestPath(map[string]string{"state": "short"}),
			wantStatus:         http.StatusFound,
			wantContentType:    "application/json; charset=utf-8",
			wantLocationHeader: urlWithQuery(downstreamRedirectURI, fositeInvalidStateErrorQuery),
			wantBodyString:     "",
		},
		{
			name:                 "downstream state does not have enough entropy using LDAP upstream",
			idpLister:            oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider).Build(),
			method:               http.MethodGet,
			path:                 modifiedHappyGetRequestPath(map[string]string{"state": "short"}),
			customUsernameHeader: pointer.StringPtr(happyLDAPUsername),
			customPasswordHeader: pointer.StringPtr(happyLDAPPassword),
			wantStatus:           http.StatusFound,
			wantContentType:      "application/json; charset=utf-8",
			wantLocationHeader:   urlWithQuery(downstreamRedirectURI, fositeInvalidStateErrorQuery),
			wantBodyString:       "",
		},
		{
			name:            "error while encoding upstream state param using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    &errorReturningEncoder{},
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusInternalServerError,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Internal Server Error: error encoding upstream state param\n",
		},
		{
			name:            "error while encoding CSRF cookie value for new cookie using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   &errorReturningEncoder{},
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusInternalServerError,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Internal Server Error: error encoding CSRF cookie\n",
		},
		{
			name:            "error while generating CSRF token using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    sadCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusInternalServerError,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Internal Server Error: error generating CSRF token\n",
		},
		{
			name:            "error while generating nonce using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    happyPKCEGenerator,
			generateNonce:   sadNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusInternalServerError,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Internal Server Error: error generating nonce param\n",
		},
		{
			name:            "error while generating PKCE using OIDC upstream",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			generateCSRF:    happyCSRFGenerator,
			generatePKCE:    sadPKCEGenerator,
			generateNonce:   happyNonceGenerator,
			stateEncoder:    happyStateEncoder,
			cookieEncoder:   happyCookieEncoder,
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusInternalServerError,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Internal Server Error: error generating PKCE param\n",
		},
		{
			name:            "no upstream providers are configured",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC().Build(), // empty
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusUnprocessableEntity,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Unprocessable Entity: No upstream providers are configured\n",
		},
		{
			name:            "too many upstream providers are configured: multiple OIDC",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider, &upstreamOIDCIdentityProvider).Build(), // more than one not allowed
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusUnprocessableEntity,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Unprocessable Entity: Too many upstream providers are configured (support for multiple upstreams is not yet implemented)\n",
		},
		{
			name:            "too many upstream providers are configured: multiple LDAP",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider, &upstreamLDAPIdentityProvider).Build(), // more than one not allowed
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusUnprocessableEntity,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Unprocessable Entity: Too many upstream providers are configured (support for multiple upstreams is not yet implemented)\n",
		},
		{
			name:            "too many upstream providers are configured: both OIDC and LDAP",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).WithLDAP(&upstreamLDAPIdentityProvider).Build(), // more than one not allowed
			method:          http.MethodGet,
			path:            happyGetRequestPath,
			wantStatus:      http.StatusUnprocessableEntity,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Unprocessable Entity: Too many upstream providers are configured (support for multiple upstreams is not yet implemented)\n",
		},
		{
			name:            "PUT is a bad method",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			method:          http.MethodPut,
			path:            "/some/path",
			wantStatus:      http.StatusMethodNotAllowed,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Method Not Allowed: PUT (try GET or POST)\n",
		},
		{
			name:            "PATCH is a bad method",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			method:          http.MethodPatch,
			path:            "/some/path",
			wantStatus:      http.StatusMethodNotAllowed,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Method Not Allowed: PATCH (try GET or POST)\n",
		},
		{
			name:            "DELETE is a bad method",
			idpLister:       oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(&upstreamOIDCIdentityProvider).Build(),
			method:          http.MethodDelete,
			path:            "/some/path",
			wantStatus:      http.StatusMethodNotAllowed,
			wantContentType: "text/plain; charset=utf-8",
			wantBodyString:  "Method Not Allowed: DELETE (try GET or POST)\n",
		},
	}

	runOneTestCase := func(t *testing.T, test testCase, subject http.Handler, kubeOauthStore *oidc.KubeStorage, kubeClient *fake.Clientset, secretsClient v1.SecretInterface) {
		req := httptest.NewRequest(test.method, test.path, strings.NewReader(test.body))
		req.Header.Set("Content-Type", test.contentType)
		if test.csrfCookie != "" {
			req.Header.Set("Cookie", test.csrfCookie)
		}
		if test.customUsernameHeader != nil {
			req.Header.Set("Pinniped-Username", *test.customUsernameHeader)
		}
		if test.customPasswordHeader != nil {
			req.Header.Set("Pinniped-Password", *test.customPasswordHeader)
		}
		rsp := httptest.NewRecorder()
		subject.ServeHTTP(rsp, req)
		t.Logf("response: %#v", rsp)
		t.Logf("response body: %q", rsp.Body.String())

		require.Equal(t, test.wantStatus, rsp.Code)
		testutil.RequireEqualContentType(t, rsp.Header().Get("Content-Type"), test.wantContentType)
		testutil.RequireSecurityHeaders(t, rsp)

		actualLocation := rsp.Header().Get("Location")
		switch {
		case test.wantLocationHeader != "":
			if test.wantUpstreamStateParamInLocationHeader {
				requireEqualDecodedStateParams(t, actualLocation, test.wantLocationHeader, test.stateEncoder)
			}
			// The upstream state param is encoded using a timestamp at the beginning so we don't want to
			// compare those states since they may be different, but we do want to compare the downstream
			// state param that should be exactly the same.
			requireEqualURLs(t, actualLocation, test.wantLocationHeader, test.wantUpstreamStateParamInLocationHeader)

			// Authorization requests for either a successful OIDC upstream or for an error with any upstream
			// should never use Kube storage. There is only one exception to this rule, which is that certain
			// OIDC validations are checked in fosite after the OAuth authcode (and sometimes the OIDC session)
			// is stored, so it is possible with an LDAP upstream to store objects and then return an error to
			// the client anyway (which makes the stored objects useless, but oh well).
			require.Len(t, kubeClient.Actions(), test.wantUnnecessaryStoredRecords)
		case test.wantRedirectLocationRegexp != "":
			require.Len(t, rsp.Header().Values("Location"), 1)
			oidctestutil.RequireAuthcodeRedirectLocation(
				t,
				rsp.Header().Get("Location"),
				test.wantRedirectLocationRegexp,
				kubeClient,
				secretsClient,
				kubeOauthStore,
				test.wantDownstreamGrantedScopes,
				test.wantDownstreamIDTokenSubject,
				test.wantDownstreamIDTokenUsername,
				test.wantDownstreamIDTokenGroups,
				test.wantDownstreamRequestedScopes,
				test.wantDownstreamPKCEChallenge,
				test.wantDownstreamPKCEChallengeMethod,
				test.wantDownstreamNonce,
				downstreamClientID,
				test.wantDownstreamRedirectURI,
			)
		default:
			require.Empty(t, rsp.Header().Values("Location"))
		}

		switch {
		case test.wantBodyJSON != "":
			require.JSONEq(t, test.wantBodyJSON, rsp.Body.String())
		case test.wantBodyStringWithLocationInHref:
			anchorTagWithLocationHref := fmt.Sprintf("<a href=\"%s\">Found</a>.\n\n", html.EscapeString(actualLocation))
			require.Equal(t, anchorTagWithLocationHref, rsp.Body.String())
		default:
			require.Equal(t, test.wantBodyString, rsp.Body.String())
		}

		if test.wantCSRFValueInCookieHeader != "" {
			require.Len(t, rsp.Header().Values("Set-Cookie"), 1)
			actualCookie := rsp.Header().Get("Set-Cookie")
			regex := regexp.MustCompile("__Host-pinniped-csrf=([^;]+); Path=/; HttpOnly; Secure; SameSite=Lax")
			submatches := regex.FindStringSubmatch(actualCookie)
			require.Len(t, submatches, 2)
			captured := submatches[1]
			var decodedCSRFCookieValue string
			err := test.cookieEncoder.Decode("csrf", captured, &decodedCSRFCookieValue)
			require.NoError(t, err)
			require.Equal(t, test.wantCSRFValueInCookieHeader, decodedCSRFCookieValue)
		} else {
			require.Empty(t, rsp.Header().Values("Set-Cookie"))
		}
	}

	for _, test := range tests {
		test := test
		t.Run(test.name, func(t *testing.T) {
			kubeClient := fake.NewSimpleClientset()
			secretsClient := kubeClient.CoreV1().Secrets("some-namespace")
			oauthHelperWithRealStorage, kubeOauthStore := createOauthHelperWithRealStorage(secretsClient)
			subject := NewHandler(
				downstreamIssuer,
				test.idpLister,
				oauthHelperWithNullStorage, oauthHelperWithRealStorage,
				test.generateCSRF, test.generatePKCE, test.generateNonce,
				test.stateEncoder, test.cookieEncoder,
			)
			runOneTestCase(t, test, subject, kubeOauthStore, kubeClient, secretsClient)
		})
	}

	t.Run("allows upstream provider configuration to change between requests", func(t *testing.T) {
		test := tests[0]
		require.Equal(t, "OIDC upstream happy path using GET without a CSRF cookie", test.name) // re-use the happy path test case

		kubeClient := fake.NewSimpleClientset()
		secretsClient := kubeClient.CoreV1().Secrets("some-namespace")
		oauthHelperWithRealStorage, kubeOauthStore := createOauthHelperWithRealStorage(secretsClient)
		subject := NewHandler(
			downstreamIssuer,
			test.idpLister,
			oauthHelperWithNullStorage, oauthHelperWithRealStorage,
			test.generateCSRF, test.generatePKCE, test.generateNonce,
			test.stateEncoder, test.cookieEncoder,
		)

		runOneTestCase(t, test, subject, kubeOauthStore, kubeClient, secretsClient)

		// Call the setter to change the upstream IDP settings.
		newProviderSettings := oidctestutil.TestUpstreamOIDCIdentityProvider{
			Name:             "some-other-idp",
			ClientID:         "some-other-client-id",
			AuthorizationURL: *upstreamAuthURL,
			Scopes:           []string{"other-scope1", "other-scope2"},
		}
		test.idpLister.SetOIDCIdentityProviders([]provider.UpstreamOIDCIdentityProviderI{provider.UpstreamOIDCIdentityProviderI(&newProviderSettings)})

		// Update the expectations of the test case to match the new upstream IDP settings.
		test.wantLocationHeader = urlWithQuery(upstreamAuthURL.String(),
			map[string]string{
				"response_type":         "code",
				"access_type":           "offline",
				"scope":                 "other-scope1 other-scope2",
				"client_id":             "some-other-client-id",
				"state":                 expectedUpstreamStateParam(nil, "", newProviderSettings.Name),
				"nonce":                 happyNonce,
				"code_challenge":        expectedUpstreamCodeChallenge,
				"code_challenge_method": downstreamPKCEChallengeMethod,
				"redirect_uri":          downstreamIssuer + "/callback",
			},
		)
		test.wantBodyString = fmt.Sprintf(`<a href="%s">Found</a>.%s`,
			html.EscapeString(test.wantLocationHeader),
			"\n\n",
		)

		// Run again on the same instance of the subject with the modified upstream IDP settings and the
		// modified expectations. This should ensure that the implementation is using the in-memory cache
		// of upstream IDP settings appropriately in terms of always getting the values from the cache
		// on every request.
		runOneTestCase(t, test, subject, kubeOauthStore, kubeClient, secretsClient)
	})
}

type errorReturningEncoder struct {
	oidc.Codec
}

func (*errorReturningEncoder) Encode(_ string, _ interface{}) (string, error) {
	return "", fmt.Errorf("some encoding error")
}

func requireEqualDecodedStateParams(t *testing.T, actualURL string, expectedURL string, stateParamDecoder oidc.Codec) {
	t.Helper()
	actualLocationURL, err := url.Parse(actualURL)
	require.NoError(t, err)
	expectedLocationURL, err := url.Parse(expectedURL)
	require.NoError(t, err)

	expectedQueryStateParam := expectedLocationURL.Query().Get("state")
	require.NotEmpty(t, expectedQueryStateParam)
	var expectedDecodedStateParam oidctestutil.ExpectedUpstreamStateParamFormat
	err = stateParamDecoder.Decode("s", expectedQueryStateParam, &expectedDecodedStateParam)
	require.NoError(t, err)

	actualQueryStateParam := actualLocationURL.Query().Get("state")
	require.NotEmpty(t, actualQueryStateParam)
	var actualDecodedStateParam oidctestutil.ExpectedUpstreamStateParamFormat
	err = stateParamDecoder.Decode("s", actualQueryStateParam, &actualDecodedStateParam)
	require.NoError(t, err)

	require.Equal(t, expectedDecodedStateParam, actualDecodedStateParam)
}

func requireEqualURLs(t *testing.T, actualURL string, expectedURL string, ignoreState bool) {
	t.Helper()
	actualLocationURL, err := url.Parse(actualURL)
	require.NoError(t, err)
	expectedLocationURL, err := url.Parse(expectedURL)
	require.NoError(t, err)
	require.Equal(t, expectedLocationURL.Scheme, actualLocationURL.Scheme,
		"schemes were not equal: expected %s but got %s", expectedURL, actualURL,
	)
	require.Equal(t, expectedLocationURL.User, actualLocationURL.User,
		"users were not equal: expected %s but got %s", expectedURL, actualURL,
	)

	require.Equal(t, expectedLocationURL.Host, actualLocationURL.Host,
		"hosts were not equal: expected %s but got %s", expectedURL, actualURL,
	)

	require.Equal(t, expectedLocationURL.Path, actualLocationURL.Path,
		"paths were not equal: expected %s but got %s", expectedURL, actualURL,
	)

	expectedLocationQuery := expectedLocationURL.Query()
	actualLocationQuery := actualLocationURL.Query()
	// Let the caller ignore the state, since it may contain a digest at the end that is difficult to
	// predict because it depends on a time.Now() timestamp.
	if ignoreState {
		expectedLocationQuery.Del("state")
		actualLocationQuery.Del("state")
	}
	require.Equal(t, expectedLocationQuery, actualLocationQuery)
}