Add GetUser() interface and implement LoginFromCallback() for GitHub

ALso fixed some of the GitHub test helpers
2025-12-23 14:25:50 +00:00 · 2024-05-17 16:37:11 -07:00
parent b7f79f0adc
commit 49c468f00a
9 changed files with 422 additions and 165 deletions
--- a/internal/federationdomain/endpoints/callback/callback_handler_github_test.go
+++ b/internal/federationdomain/endpoints/callback/callback_handler_github_test.go
@@ -22,7 +22,9 @@ import (
 	supervisorfake "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned/fake"
 	"go.pinniped.dev/internal/federationdomain/endpoints/jwks"
 	"go.pinniped.dev/internal/federationdomain/oidc"
+	"go.pinniped.dev/internal/federationdomain/oidcclientvalidator"
 	"go.pinniped.dev/internal/federationdomain/storage"
+	"go.pinniped.dev/internal/federationdomain/upstreamprovider"
 	"go.pinniped.dev/internal/psession"
 	"go.pinniped.dev/internal/testutil"
 	"go.pinniped.dev/internal/testutil/oidctestutil"
@@ -35,7 +37,7 @@ var (
 	githubUpstreamUsername    = "some-github-login"
 	githubUpstreamGroups      = []string{"org1/team1", "org2/team2"}
 	githubDownstreamSubject   = fmt.Sprintf("https://github.com?idpName=%s&sub=%s", githubIDPName, githubUpstreamUsername)
-	githubUpstreamAccessToken = "some-opaque-access-token-from-github"
+	githubUpstreamAccessToken = "some-opaque-access-token-from-github" //nolint:gosec // this is not a credential

 	happyDownstreamGitHubCustomSessionData = &psession.CustomSessionData{
 		Username:         githubUpstreamUsername,
@@ -74,6 +76,16 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {
 		RedirectURI: happyUpstreamRedirectURI,
 	}

+	// TODO: when we merge this file back into callback_handler_test.go, we do not need to copy this function
+	//  because it is already in callback_handler_test.go
+	addFullyCapableDynamicClientAndSecretToKubeResources := func(t *testing.T, supervisorClient *supervisorfake.Clientset, kubeClient *fake.Clientset) {
+		oidcClient, secret := testutil.FullyCapableOIDCClientAndStorageSecret(t,
+			"some-namespace", downstreamDynamicClientID, downstreamDynamicClientUID, downstreamRedirectURI, nil,
+			[]string{testutil.HashedPassword1AtGoMinCost}, oidcclientvalidator.Validate)
+		require.NoError(t, supervisorClient.Tracker().Add(oidcClient))
+		require.NoError(t, kubeClient.Tracker().Add(secret))
+	}
+
 	tests := []struct {
 		name string

@@ -95,14 +107,18 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {
 		wantDownstreamPKCEChallengeMethod string
 		wantDownstreamCustomSessionData   *psession.CustomSessionData
 		wantDownstreamAdditionalClaims    map[string]interface{}
-
-		wantAuthcodeExchangeCall *expectedAuthcodeExchange
+		wantGitHubAuthcodeExchangeCall    *expectedGitHubAuthcodeExchange
 	}{
 		{
 			name: "GitHub IDP: GET with good state and cookie and successful upstream token exchange returns 303 to downstream client callback",
 			idps: testidplister.NewUpstreamIDPListerBuilder().WithGitHub(
 				happyGitHubUpstream().
 					WithAccessToken(githubUpstreamAccessToken).
+					WithUser(&upstreamprovider.GitHubUser{
+						Username:          githubUpstreamUsername,
+						Groups:            githubUpstreamGroups,
+						DownstreamSubject: githubDownstreamSubject,
+					}).
 					Build()),
 			method: http.MethodGet,
 			path: newRequestPath().WithState(
@@ -125,7 +141,7 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamGitHubCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantGitHubAuthcodeExchangeCall: &expectedGitHubAuthcodeExchange{
 				performedByUpstreamName: githubIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -135,6 +151,11 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {
 			idps: testidplister.NewUpstreamIDPListerBuilder().WithGitHub(
 				happyGitHubUpstream().
 					WithAccessToken(githubUpstreamAccessToken).
+					WithUser(&upstreamprovider.GitHubUser{
+						Username:          githubUpstreamUsername,
+						Groups:            githubUpstreamGroups,
+						DownstreamSubject: githubDownstreamSubject,
+					}).
 					Build()),
 			method:        http.MethodGet,
 			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
@@ -163,7 +184,7 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamGitHubCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantGitHubAuthcodeExchangeCall: &expectedGitHubAuthcodeExchange{
 				performedByUpstreamName: githubIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -204,13 +225,12 @@ func TestCallbackEndpointWithGitHubIdentityProviders(t *testing.T) {

 			testutil.RequireSecurityHeadersWithFormPostPageCSPs(t, rsp)

-			require.NotNil(t, test.wantAuthcodeExchangeCall, "wantAuthcodeExchangeCall is required for testing purposes")
+			require.NotNil(t, test.wantGitHubAuthcodeExchangeCall, "wantOIDCAuthcodeExchangeCall is required for testing purposes")

-			test.wantAuthcodeExchangeCall.args.Ctx = reqContext
-			test.idps.RequireExactlyOneCallToExchangeAuthcodeAndValidateTokens(t,
-				test.wantAuthcodeExchangeCall.performedByUpstreamName,
-				idpdiscoveryv1alpha1.IDPTypeGitHub,
-				test.wantAuthcodeExchangeCall.args,
+			test.wantGitHubAuthcodeExchangeCall.args.Ctx = reqContext
+			test.idps.RequireExactlyOneGitHubAuthcodeExchange(t,
+				test.wantGitHubAuthcodeExchangeCall.performedByUpstreamName,
+				test.wantGitHubAuthcodeExchangeCall.args,
 			)

 			require.Equal(t, http.StatusSeeOther, rsp.Code)
--- a/internal/federationdomain/endpoints/callback/callback_handler_test.go
+++ b/internal/federationdomain/endpoints/callback/callback_handler_test.go
@@ -20,7 +20,6 @@ import (
 	"k8s.io/client-go/kubernetes/fake"

 	configv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/config/v1alpha1"
-	idpdiscoveryv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idpdiscovery/v1alpha1"
 	supervisorfake "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned/fake"
 	"go.pinniped.dev/internal/federationdomain/endpoints/jwks"
 	"go.pinniped.dev/internal/federationdomain/oidc"
@@ -93,6 +92,7 @@ var (
 	happyDownstreamRequestParamsQueryForDynamicClient = shallowCopyAndModifyQuery(happyDownstreamRequestParamsQuery,
 		map[string]string{"client_id": downstreamDynamicClientID},
 	)
+	happyDownstreamRequestParamsForDynamicClient = happyDownstreamRequestParamsQueryForDynamicClient.Encode()

 	happyDownstreamCustomSessionData = &psession.CustomSessionData{
 		Username:         oidcUpstreamUsername,
@@ -107,7 +107,6 @@ var (
 			UpstreamSubject:      oidcUpstreamSubject,
 		},
 	}
-
 	happyDownstreamCustomSessionDataWithUsernameAndGroups = func(wantDownstreamUsername, wantUpstreamUsername string, wantUpstreamGroups []string) *psession.CustomSessionData {
 		copyOfCustomSession := *happyDownstreamCustomSessionData
 		copyOfOIDC := *(happyDownstreamCustomSessionData.OIDC)
@@ -130,14 +129,6 @@ var (
 			UpstreamSubject:     oidcUpstreamSubject,
 		},
 	}
-
-	addFullyCapableDynamicClientAndSecretToKubeResources = func(t *testing.T, supervisorClient *supervisorfake.Clientset, kubeClient *fake.Clientset) {
-		oidcClient, secret := testutil.FullyCapableOIDCClientAndStorageSecret(t,
-			"some-namespace", downstreamDynamicClientID, downstreamDynamicClientUID, downstreamRedirectURI, nil,
-			[]string{testutil.HashedPassword1AtGoMinCost}, oidcclientvalidator.Validate)
-		require.NoError(t, supervisorClient.Tracker().Add(oidcClient))
-		require.NoError(t, kubeClient.Tracker().Add(secret))
-	}
 )

 func TestCallbackEndpoint(t *testing.T) {
@@ -162,13 +153,13 @@ func TestCallbackEndpoint(t *testing.T) {
 	happyCookieCodec.SetSerializer(securecookie.JSONEncoder{})

 	happyState := happyUpstreamStateParam().Build(t, happyStateCodec)
-	happyStateForDynamicClient := happyUpstreamStateParam().WithAuthorizeRequestParams(happyDownstreamRequestParamsQueryForDynamicClient.Encode()).Build(t, happyStateCodec)
+	happyStateForDynamicClient := happyUpstreamStateParamForDynamicClient().Build(t, happyStateCodec)

 	encodedIncomingCookieCSRFValue, err := happyCookieCodec.Encode("csrf", happyDownstreamCSRF)
 	require.NoError(t, err)
 	happyCSRFCookie := "__Host-pinniped-csrf=" + encodedIncomingCookieCSRFValue

-	happyExchangeAndValidateTokensArgs := &oidctestutil.ExchangeAuthcodeArgs{
+	happyExchangeAndValidateTokensArgs := &oidctestutil.ExchangeAuthcodeAndValidateTokenArgs{
 		Authcode:             happyUpstreamAuthcode,
 		PKCECodeVerifier:     oidcpkce.Code(happyDownstreamPKCE),
 		ExpectedIDTokenNonce: nonce.Nonce(happyDownstreamNonce),
@@ -178,6 +169,14 @@ func TestCallbackEndpoint(t *testing.T) {
 	// Note that fosite puts the granted scopes as a param in the redirect URI even though the spec doesn't seem to require it
 	happyDownstreamRedirectLocationRegexp := downstreamRedirectURI + `\?code=([^&]+)&scope=openid\+username\+groups&state=` + happyDownstreamState

+	addFullyCapableDynamicClientAndSecretToKubeResources := func(t *testing.T, supervisorClient *supervisorfake.Clientset, kubeClient *fake.Clientset) {
+		oidcClient, secret := testutil.FullyCapableOIDCClientAndStorageSecret(t,
+			"some-namespace", downstreamDynamicClientID, downstreamDynamicClientUID, downstreamRedirectURI, nil,
+			[]string{testutil.HashedPassword1AtGoMinCost}, oidcclientvalidator.Validate)
+		require.NoError(t, supervisorClient.Tracker().Add(oidcClient))
+		require.NoError(t, kubeClient.Tracker().Add(secret))
+	}
+
 	prefixUsernameAndGroupsPipeline := transformtestutil.NewPrefixingPipeline(t, transformationUsernamePrefix, transformationGroupsPrefix)
 	rejectAuthPipeline := transformtestutil.NewRejectAllAuthPipeline(t)

@@ -206,8 +205,7 @@ func TestCallbackEndpoint(t *testing.T) {
 		wantDownstreamPKCEChallengeMethod string
 		wantDownstreamCustomSessionData   *psession.CustomSessionData
 		wantDownstreamAdditionalClaims    map[string]interface{}
-
-		wantAuthcodeExchangeCall *expectedAuthcodeExchange
+		wantOIDCAuthcodeExchangeCall      *expectedOIDCAuthcodeExchange
 	}{
 		{
 			name:   "GET with good state and cookie and successful upstream token exchange with response_mode=form_post returns 200 with HTML+JS form",
@@ -235,7 +233,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -274,7 +272,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -302,7 +300,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -327,7 +325,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -351,7 +349,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamAccessTokenCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -386,7 +384,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -423,7 +421,7 @@ func TestCallbackEndpoint(t *testing.T) {
 					UpstreamSubject:     oidcUpstreamSubject,
 				},
 			},
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -453,7 +451,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamIssuer+"?sub="+oidcUpstreamSubjectQueryEscaped,
 				nil,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -483,7 +481,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				"joe@whitehouse.gov",
 				oidcUpstreamGroupMembership,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -515,7 +513,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				"joe@whitehouse.gov",
 				oidcUpstreamGroupMembership,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -548,7 +546,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				"joe",
 				oidcUpstreamGroupMembership,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -565,7 +563,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: email_verified claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -579,7 +577,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: access token was returned by upstream provider but there was no userinfo endpoint\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -593,7 +591,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: neither access token nor refresh token returned by upstream provider\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -607,7 +605,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: neither access token nor refresh token returned by upstream provider\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -621,7 +619,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: neither access token nor refresh token returned by upstream provider\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -635,7 +633,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: neither access token nor refresh token returned by upstream provider\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -653,7 +651,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: email_verified claim in upstream ID token has false value\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -683,7 +681,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamSubject,
 				oidcUpstreamGroupMembership,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -713,7 +711,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamUsername,
 				[]string{"notAnArrayGroup1 notAnArrayGroup2"},
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -743,7 +741,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamUsername,
 				[]string{"group1", "group2"},
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -754,7 +752,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
 			method:        http.MethodGet,
 			path: newRequestPath().WithState(
-				happyUpstreamStateParam().
+				happyUpstreamStateParamForDynamicClient().
 					WithAuthorizeRequestParams(shallowCopyAndModifyQuery(happyDownstreamRequestParamsQueryForDynamicClient,
 						map[string]string{"scope": "openid groups offline_access"}).Encode()).
 					Build(t, happyStateCodec),
@@ -773,7 +771,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -784,7 +782,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
 			method:        http.MethodGet,
 			path: newRequestPath().WithState(
-				happyUpstreamStateParam().
+				happyUpstreamStateParamForDynamicClient().
 					WithAuthorizeRequestParams(shallowCopyAndModifyQuery(happyDownstreamRequestParamsQueryForDynamicClient,
 						map[string]string{"scope": "openid username offline_access"}).Encode()).
 					Build(t, happyStateCodec),
@@ -803,7 +801,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -846,7 +844,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -889,7 +887,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -918,7 +916,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamUsername,
 				oidcUpstreamGroupMembership,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1004,7 +1002,7 @@ func TestCallbackEndpoint(t *testing.T) {
 					Build(t, happyStateCodec),
 			).String(),
 			csrfCookie: happyCSRFCookie,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1169,7 +1167,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1199,7 +1197,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1228,7 +1226,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1285,7 +1283,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusBadGateway,
 			wantBody:        "Bad Gateway: error exchanging and validating upstream tokens\n",
 			wantContentType: htmlContentType,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1301,7 +1299,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token missing\n",
 			wantContentType: htmlContentType,
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1331,7 +1329,7 @@ func TestCallbackEndpoint(t *testing.T) {
 				oidcUpstreamUsername,
 				nil,
 			),
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1347,7 +1345,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1363,7 +1361,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token is empty\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1379,7 +1377,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token missing\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1395,7 +1393,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token is empty\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1411,7 +1409,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1427,7 +1425,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token missing\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1443,7 +1441,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token is empty\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1459,7 +1457,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1475,7 +1473,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1491,7 +1489,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1507,7 +1505,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: required claim in upstream ID token has invalid format\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1522,7 +1520,7 @@ func TestCallbackEndpoint(t *testing.T) {
 			wantStatus:      http.StatusUnprocessableEntity,
 			wantContentType: htmlContentType,
 			wantBody:        "Unprocessable Entity: configured identity policy rejected this authentication: authentication was rejected by a configured policy\n",
-			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+			wantOIDCAuthcodeExchangeCall: &expectedOIDCAuthcodeExchange{
 				performedByUpstreamName: happyUpstreamIDPName,
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
@@ -1563,15 +1561,14 @@ func TestCallbackEndpoint(t *testing.T) {

 			testutil.RequireSecurityHeadersWithFormPostPageCSPs(t, rsp)

-			if test.wantAuthcodeExchangeCall != nil {
-				test.wantAuthcodeExchangeCall.args.Ctx = reqContext
-				test.idps.RequireExactlyOneCallToExchangeAuthcodeAndValidateTokens(t,
-					test.wantAuthcodeExchangeCall.performedByUpstreamName,
-					idpdiscoveryv1alpha1.IDPTypeOIDC,
-					test.wantAuthcodeExchangeCall.args,
+			if test.wantOIDCAuthcodeExchangeCall != nil {
+				test.wantOIDCAuthcodeExchangeCall.args.Ctx = reqContext
+				test.idps.RequireExactlyOneOIDCAuthcodeExchange(t,
+					test.wantOIDCAuthcodeExchangeCall.performedByUpstreamName,
+					test.wantOIDCAuthcodeExchangeCall.args,
 				)
 			} else {
-				test.idps.RequireExactlyZeroCallsToExchangeAuthcodeAndValidateTokens(t)
+				test.idps.RequireExactlyZeroAuthcodeExchanges(t)
 			}

 			require.Equal(t, test.wantStatus, rsp.Code)
@@ -1637,7 +1634,12 @@ func TestCallbackEndpoint(t *testing.T) {
 	}
 }

-type expectedAuthcodeExchange struct {
+type expectedOIDCAuthcodeExchange struct {
+	performedByUpstreamName string
+	args                    *oidctestutil.ExchangeAuthcodeAndValidateTokenArgs
+}
+
+type expectedGitHubAuthcodeExchange struct {
 	performedByUpstreamName string
 	args                    *oidctestutil.ExchangeAuthcodeArgs
 }
@@ -1699,6 +1701,12 @@ func happyUpstreamStateParam() *oidctestutil.UpstreamStateParamBuilder {
 	}
 }

+func happyUpstreamStateParamForDynamicClient() *oidctestutil.UpstreamStateParamBuilder {
+	p := happyUpstreamStateParam()
+	p.P = happyDownstreamRequestParamsForDynamicClient
+	return p
+}
+
 func happyUpstream() *oidctestutil.TestUpstreamOIDCIdentityProviderBuilder {
 	return oidctestutil.NewTestUpstreamOIDCIdentityProviderBuilder().
 		WithName(happyUpstreamIDPName).
--- a/internal/federationdomain/resolvedprovider/resolvedgithub/resolved_github_provider.go
+++ b/internal/federationdomain/resolvedprovider/resolvedgithub/resolved_github_provider.go
@@ -97,22 +97,29 @@ func (p *FederationDomainResolvedGitHubIdentityProvider) LoginFromCallback(
 	_ nonce.Nonce, // GitHub does not support OIDC, therefore there is no ID token that could contain the "nonce".
 	redirectURI string,
 ) (*resolvedprovider.Identity, *resolvedprovider.IdentityLoginExtras, error) {
-	token, _ := p.Provider.ExchangeAuthcode(
-		ctx,
-		authCode,
-		redirectURI,
-	)
+	accessToken, err := p.Provider.ExchangeAuthcode(ctx, authCode, redirectURI)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to exchange auth code using GitHub API: %w", err)
+	}
+
+	user, err := p.Provider.GetUser(ctx, accessToken)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get user info from GitHub API: %w", err)
+	}

 	return &resolvedprovider.Identity{
-			UpstreamUsername:  "some-github-login",
-			UpstreamGroups:    []string{"org1/team1", "org2/team2"},
-			DownstreamSubject: "https://github.com?idpName=upstream-github-idp-name&sub=some-github-login",
+			UpstreamUsername:  user.Username,
+			UpstreamGroups:    user.Groups,
+			DownstreamSubject: user.DownstreamSubject,
 			IDPSpecificSessionData: &psession.GitHubSessionData{
-				UpstreamAccessToken: token,
+				UpstreamAccessToken: accessToken,
 			},
 		},
-		&resolvedprovider.IdentityLoginExtras{},
-		nil
+		&resolvedprovider.IdentityLoginExtras{
+			DownstreamAdditionalClaims: nil, // not using this for GitHub
+			Warnings:                   nil, // not using this for GitHub
+		},
+		nil // no error
 }

 func (p *FederationDomainResolvedGitHubIdentityProvider) UpstreamRefresh(
--- a/internal/federationdomain/resolvedprovider/resolvedgithub/resolved_github_provider_test.go
+++ b/internal/federationdomain/resolvedprovider/resolvedgithub/resolved_github_provider_test.go
@@ -4,6 +4,8 @@
 package resolvedgithub

 import (
+	"context"
+	"errors"
 	"testing"

 	"github.com/stretchr/testify/require"
@@ -12,10 +14,11 @@ import (
 	idpv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idp/v1alpha1"
 	idpdiscoveryv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idpdiscovery/v1alpha1"
 	"go.pinniped.dev/internal/federationdomain/resolvedprovider"
+	"go.pinniped.dev/internal/federationdomain/upstreamprovider"
 	"go.pinniped.dev/internal/psession"
+	"go.pinniped.dev/internal/testutil/oidctestutil"
 	"go.pinniped.dev/internal/testutil/transformtestutil"
 	"go.pinniped.dev/internal/upstreamgithub"
-	"go.pinniped.dev/pkg/oidcclient/oidctypes"
 )

 func TestFederationDomainResolvedGitHubIdentityProvider(t *testing.T) {
@@ -59,11 +62,11 @@ func TestFederationDomainResolvedGitHubIdentityProvider(t *testing.T) {
 	originalCustomSession := &psession.CustomSessionData{
 		Username:         "fake-username",
 		UpstreamUsername: "fake-upstream-username",
-		GitHub:           &psession.GitHubSessionData{UpstreamAccessToken: &oidctypes.Token{AccessToken: &oidctypes.AccessToken{Token: "fake-upstream-access-token"}}},
+		GitHub:           &psession.GitHubSessionData{UpstreamAccessToken: "fake-upstream-access-token"},
 	}
 	clonedCustomSession := subject.CloneIDPSpecificSessionDataFromSession(originalCustomSession)
 	require.Equal(t,
-		&psession.GitHubSessionData{UpstreamAccessToken: &oidctypes.Token{AccessToken: &oidctypes.AccessToken{Token: "fake-upstream-access-token"}}},
+		&psession.GitHubSessionData{UpstreamAccessToken: "fake-upstream-access-token"},
 		clonedCustomSession,
 	)
 	require.NotSame(t, originalCustomSession, clonedCustomSession)
@@ -72,11 +75,11 @@ func TestFederationDomainResolvedGitHubIdentityProvider(t *testing.T) {
 		Username:         "fake-username2",
 		UpstreamUsername: "fake-upstream-username2",
 	}
-	subject.ApplyIDPSpecificSessionDataToSession(customSessionToBeMutated, &psession.GitHubSessionData{UpstreamAccessToken: &oidctypes.Token{AccessToken: &oidctypes.AccessToken{Token: "OTHER-upstream-access-token"}}})
+	subject.ApplyIDPSpecificSessionDataToSession(customSessionToBeMutated, &psession.GitHubSessionData{UpstreamAccessToken: "OTHER-upstream-access-token"})
 	require.Equal(t, &psession.CustomSessionData{
 		Username:         "fake-username2",
 		UpstreamUsername: "fake-upstream-username2",
-		GitHub:           &psession.GitHubSessionData{UpstreamAccessToken: &oidctypes.Token{AccessToken: &oidctypes.AccessToken{Token: "OTHER-upstream-access-token"}}},
+		GitHub:           &psession.GitHubSessionData{UpstreamAccessToken: "OTHER-upstream-access-token"},
 	}, customSessionToBeMutated)

 	redirectURL, err := subject.UpstreamAuthorizeRedirectURL(
@@ -101,3 +104,139 @@ func TestFederationDomainResolvedGitHubIdentityProvider(t *testing.T) {
 		redirectURL,
 	)
 }
+
+func TestLoginFromCallback(t *testing.T) {
+	uniqueCtx := context.WithValue(context.Background(), "some-unique-key", "some-value") //nolint:staticcheck // okay to use string key for test
+
+	tests := []struct {
+		name        string
+		provider    *oidctestutil.TestUpstreamGitHubIdentityProvider
+		authcode    string
+		redirectURI string
+
+		wantExchangeAuthcodeCall bool
+		wantExchangeAuthcodeArgs *oidctestutil.ExchangeAuthcodeArgs
+		wantGetUserCall          bool
+		wantGetUserArgs          *oidctestutil.GetUserArgs
+		wantIdentity             *resolvedprovider.Identity
+		wantExtras               *resolvedprovider.IdentityLoginExtras
+		wantErr                  string
+	}{
+		{
+			name: "happy path",
+			provider: oidctestutil.NewTestUpstreamGitHubIdentityProviderBuilder().
+				WithAccessToken("fake-access-token").
+				WithUser(&upstreamprovider.GitHubUser{
+					Username:          "fake-username",
+					Groups:            []string{"fake-group1", "fake-group2"},
+					DownstreamSubject: "https://fake-downstream-subject",
+				}).
+				Build(),
+			authcode:                 "fake-authcode",
+			redirectURI:              "https://fake-redirect-uri",
+			wantExchangeAuthcodeCall: true,
+			wantExchangeAuthcodeArgs: &oidctestutil.ExchangeAuthcodeArgs{
+				Ctx:         uniqueCtx,
+				Authcode:    "fake-authcode",
+				RedirectURI: "https://fake-redirect-uri",
+			},
+			wantGetUserCall: true,
+			wantGetUserArgs: &oidctestutil.GetUserArgs{
+				Ctx:         uniqueCtx,
+				AccessToken: "fake-access-token",
+			},
+			wantIdentity: &resolvedprovider.Identity{
+				UpstreamUsername:  "fake-username",
+				UpstreamGroups:    []string{"fake-group1", "fake-group2"},
+				DownstreamSubject: "https://fake-downstream-subject",
+				IDPSpecificSessionData: &psession.GitHubSessionData{
+					UpstreamAccessToken: "fake-access-token",
+				},
+			},
+			wantExtras: &resolvedprovider.IdentityLoginExtras{},
+		},
+		{
+			name: "error while exchanging authcode",
+			provider: oidctestutil.NewTestUpstreamGitHubIdentityProviderBuilder().
+				WithAuthcodeExchangeError(errors.New("fake authcode exchange error")).
+				Build(),
+			authcode:                 "fake-authcode",
+			redirectURI:              "https://fake-redirect-uri",
+			wantExchangeAuthcodeCall: true,
+			wantExchangeAuthcodeArgs: &oidctestutil.ExchangeAuthcodeArgs{
+				Ctx:         uniqueCtx,
+				Authcode:    "fake-authcode",
+				RedirectURI: "https://fake-redirect-uri",
+			},
+			wantGetUserCall: false,
+			wantIdentity:    nil,
+			wantExtras:      nil,
+			wantErr:         "failed to exchange auth code using GitHub API: fake authcode exchange error",
+		},
+		{
+			name: "error while getting user info",
+			provider: oidctestutil.NewTestUpstreamGitHubIdentityProviderBuilder().
+				WithAccessToken("fake-access-token").
+				WithGetUserError(errors.New("fake user info error")).
+				Build(),
+			authcode:                 "fake-authcode",
+			redirectURI:              "https://fake-redirect-uri",
+			wantExchangeAuthcodeCall: true,
+			wantExchangeAuthcodeArgs: &oidctestutil.ExchangeAuthcodeArgs{
+				Ctx:         uniqueCtx,
+				Authcode:    "fake-authcode",
+				RedirectURI: "https://fake-redirect-uri",
+			},
+			wantGetUserCall: true,
+			wantGetUserArgs: &oidctestutil.GetUserArgs{
+				Ctx:         uniqueCtx,
+				AccessToken: "fake-access-token",
+			},
+			wantIdentity: nil,
+			wantExtras:   nil,
+			wantErr:      "failed to get user info from GitHub API: fake user info error",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			transforms := transformtestutil.NewRejectAllAuthPipeline(t)
+
+			subject := FederationDomainResolvedGitHubIdentityProvider{
+				DisplayName:         "fake-display-name",
+				Provider:            test.provider,
+				SessionProviderType: psession.ProviderTypeGitHub,
+				Transforms:          transforms,
+			}
+
+			identity, loginExtras, err := subject.LoginFromCallback(uniqueCtx,
+				test.authcode,
+				"pkce-will-be-ignored",
+				"nonce-will-be-ignored",
+				test.redirectURI,
+			)
+
+			if test.wantExchangeAuthcodeCall {
+				require.Equal(t, 1, test.provider.ExchangeAuthcodeCallCount())
+				require.Equal(t, test.wantExchangeAuthcodeArgs, test.provider.ExchangeAuthcodeArgs(0))
+			} else {
+				require.Zero(t, test.provider.ExchangeAuthcodeCallCount())
+			}
+
+			if test.wantGetUserCall {
+				require.Equal(t, 1, test.provider.GetUserCallCount())
+				require.Equal(t, test.wantGetUserArgs, test.provider.GetUserArgs(0))
+			} else {
+				require.Zero(t, test.provider.GetUserCallCount())
+			}
+
+			if test.wantErr == "" {
+				require.NoError(t, err)
+			} else {
+				require.EqualError(t, err, test.wantErr)
+			}
+			require.Equal(t, test.wantExtras, loginExtras)
+			require.Equal(t, test.wantIdentity, identity)
+		})
+	}
+}
--- a/internal/federationdomain/upstreamprovider/upsteam_provider.go
+++ b/internal/federationdomain/upstreamprovider/upsteam_provider.go
@@ -127,6 +127,12 @@ type UpstreamLDAPIdentityProviderI interface {
 	PerformRefresh(ctx context.Context, storedRefreshAttributes RefreshAttributes, idpDisplayName string) (groups []string, err error)
 }

+type GitHubUser struct {
+	Username          string   // could be login name, id, or login:id
+	Groups            []string // could be names or slugs
+	DownstreamSubject string   // the whole downstream subject URI
+}
+
 type UpstreamGithubIdentityProviderI interface {
 	UpstreamIdentityProviderI

@@ -159,21 +165,11 @@ type UpstreamGithubIdentityProviderI interface {
 	// It will never include a username or password in the authority section.
 	GetAuthorizationURL() string

-	// TODO: This interface should be easily mockable to avoid all interactions with the actual server.
-	//  What interactions with the server do we want to hide behind this interface? Something like this?
-	// 	  ExchangeAuthcode(ctx, authcode, redirectURI) (AccessToken, error)
-	//    GetUser(ctx, accessToken) (User, error)
-	//    GetUserOrgs(ctx, accessToken) ([]Org, error)
-	//    GetUserTeams(ctx, accessToken) ([]Team, error)
-	//  Or maybe higher level interface like this?
-	// 	  ExchangeAuthcode(ctx, authcode, redirectURI) (AccessToken, error)
-	//    GetUser(ctx, accessToken) (User, error) // in this case User would include team and org info
-
 	// ExchangeAuthcode performs an upstream GitHub authorization code exchange.
 	// Returns the raw access token. The access token expiry is not known.
-	ExchangeAuthcode(
-		ctx context.Context,
-		authcode string,
-		redirectURI string,
-	) (string, error)
+	ExchangeAuthcode(ctx context.Context, authcode string, redirectURI string) (string, error)
+
+	// GetUser calls the user, orgs, and teams APIs of GitHub using the accessToken.
+	// It validates any required org memberships. It returns a User or an error.
+	GetUser(ctx context.Context, accessToken string) (*GitHubUser, error)
 }
--- a/internal/testutil/oidctestutil/testgithubprovider.go
+++ b/internal/testutil/oidctestutil/testgithubprovider.go
@@ -13,6 +13,21 @@ import (
 	"go.pinniped.dev/internal/idtransform"
 )

+// ExchangeAuthcodeArgs is used to spy on calls to
+// TestUpstreamGitHubIdentityProvider.ExchangeAuthcodeFunc().
+type ExchangeAuthcodeArgs struct {
+	Ctx         context.Context
+	Authcode    string
+	RedirectURI string
+}
+
+// GetUserArgs is used to spy on calls to
+// TestUpstreamGitHubIdentityProvider.GetUserFunc().
+type GetUserArgs struct {
+	Ctx         context.Context
+	AccessToken string
+}
+
 type TestUpstreamGitHubIdentityProviderBuilder struct {
 	name                           string
 	resourceUID                    types.UID
@@ -24,10 +39,10 @@ type TestUpstreamGitHubIdentityProviderBuilder struct {
 	groupNameAttribute             v1alpha1.GitHubGroupNameAttribute
 	allowedOrganizations           []string
 	authorizationURL               string
-
-	// Assertions stuff
-	authcodeExchangeErr error
-	accessToken         string
+	authcodeExchangeErr            error
+	accessToken                    string
+	getUserErr                     error
+	getUserUser                    *upstreamprovider.GitHubUser
 }

 func (u *TestUpstreamGitHubIdentityProviderBuilder) WithName(value string) *TestUpstreamGitHubIdentityProviderBuilder {
@@ -80,8 +95,18 @@ func (u *TestUpstreamGitHubIdentityProviderBuilder) WithAccessToken(token string
 	return u
 }

-func (u *TestUpstreamGitHubIdentityProviderBuilder) WithEmptyAccessToken() *TestUpstreamGitHubIdentityProviderBuilder {
-	u.accessToken = ""
+func (u *TestUpstreamGitHubIdentityProviderBuilder) WithAuthcodeExchangeError(err error) *TestUpstreamGitHubIdentityProviderBuilder {
+	u.authcodeExchangeErr = err
+	return u
+}
+
+func (u *TestUpstreamGitHubIdentityProviderBuilder) WithUser(user *upstreamprovider.GitHubUser) *TestUpstreamGitHubIdentityProviderBuilder {
+	u.getUserUser = user
+	return u
+}
+
+func (u *TestUpstreamGitHubIdentityProviderBuilder) WithGetUserError(err error) *TestUpstreamGitHubIdentityProviderBuilder {
+	u.getUserErr = err
 	return u
 }

@@ -96,8 +121,8 @@ func (u *TestUpstreamGitHubIdentityProviderBuilder) Build() *TestUpstreamGitHubI
 	}
 	return &TestUpstreamGitHubIdentityProvider{
 		Name:                           u.name,
-		ResourceUID:                    u.resourceUID,
 		ClientID:                       u.clientID,
+		ResourceUID:                    u.resourceUID,
 		Scopes:                         u.scopes,
 		DisplayNameForFederationDomain: u.displayNameForFederationDomain,
 		TransformsForFederationDomain:  u.transformsForFederationDomain,
@@ -105,7 +130,12 @@ func (u *TestUpstreamGitHubIdentityProviderBuilder) Build() *TestUpstreamGitHubI
 		GroupNameAttribute:             u.groupNameAttribute,
 		AllowedOrganizations:           u.allowedOrganizations,
 		AuthorizationURL:               u.authorizationURL,
-
+		GetUserFunc: func(ctx context.Context, accessToken string) (*upstreamprovider.GitHubUser, error) {
+			if u.getUserErr != nil {
+				return nil, u.getUserErr
+			}
+			return u.getUserUser, nil
+		},
 		ExchangeAuthcodeFunc: func(ctx context.Context, authcode string) (string, error) {
 			if u.authcodeExchangeErr != nil {
 				return "", u.authcodeExchangeErr
@@ -130,16 +160,14 @@ type TestUpstreamGitHubIdentityProvider struct {
 	GroupNameAttribute             v1alpha1.GitHubGroupNameAttribute
 	AllowedOrganizations           []string
 	AuthorizationURL               string
+	GetUserFunc                    func(ctx context.Context, accessToken string) (*upstreamprovider.GitHubUser, error)
+	ExchangeAuthcodeFunc           func(ctx context.Context, authcode string) (string, error)

-	authcodeExchangeErr error
-
-	ExchangeAuthcodeFunc func(
-		ctx context.Context,
-		authcode string,
-	) (string, error)
-
+	// Fields for tracking actual calls make to mock functions.
 	exchangeAuthcodeCallCount int
 	exchangeAuthcodeArgs      []*ExchangeAuthcodeArgs
+	getUserCallCount          int
+	getUserArgs               []*GetUserArgs
 }

 var _ upstreamprovider.UpstreamGithubIdentityProviderI = &TestUpstreamGitHubIdentityProvider{}
@@ -203,3 +231,26 @@ func (u *TestUpstreamGitHubIdentityProvider) ExchangeAuthcodeArgs(call int) *Exc
 	}
 	return u.exchangeAuthcodeArgs[call]
 }
+
+func (u *TestUpstreamGitHubIdentityProvider) GetUser(ctx context.Context, accessToken string) (*upstreamprovider.GitHubUser, error) {
+	if u.getUserArgs == nil {
+		u.getUserArgs = make([]*GetUserArgs, 0)
+	}
+	u.getUserCallCount++
+	u.getUserArgs = append(u.getUserArgs, &GetUserArgs{
+		Ctx:         ctx,
+		AccessToken: accessToken,
+	})
+	return u.GetUserFunc(ctx, accessToken)
+}
+
+func (u *TestUpstreamGitHubIdentityProvider) GetUserCallCount() int {
+	return u.getUserCallCount
+}
+
+func (u *TestUpstreamGitHubIdentityProvider) GetUserArgs(call int) *GetUserArgs {
+	if u.getUserArgs == nil {
+		u.getUserArgs = make([]*GetUserArgs, 0)
+	}
+	return u.getUserArgs[call]
+}
--- a/internal/testutil/oidctestutil/testoidcprovider.go
+++ b/internal/testutil/oidctestutil/testoidcprovider.go
@@ -18,9 +18,9 @@ import (
 	oidcpkce "go.pinniped.dev/pkg/oidcclient/pkce"
 )

-// ExchangeAuthcodeArgs is used to spy on calls to
+// ExchangeAuthcodeAndValidateTokenArgs is used to spy on calls to
 // TestUpstreamOIDCIdentityProvider.ExchangeAuthcodeAndValidateTokensFunc().
-type ExchangeAuthcodeArgs struct {
+type ExchangeAuthcodeAndValidateTokenArgs struct {
 	Ctx                  context.Context
 	Authcode             string
 	PKCECodeVerifier     oidcpkce.Code
@@ -101,7 +101,7 @@ type TestUpstreamOIDCIdentityProvider struct {

 	// Fields for tracking actual calls make to mock functions.
 	exchangeAuthcodeAndValidateTokensCallCount         int
-	exchangeAuthcodeAndValidateTokensArgs              []*ExchangeAuthcodeArgs
+	exchangeAuthcodeAndValidateTokensArgs              []*ExchangeAuthcodeAndValidateTokenArgs
 	passwordCredentialsGrantAndValidateTokensCallCount int
 	passwordCredentialsGrantAndValidateTokensArgs      []*PasswordCredentialsGrantAndValidateTokensArgs
 	performRefreshCallCount                            int
@@ -180,10 +180,10 @@ func (u *TestUpstreamOIDCIdentityProvider) ExchangeAuthcodeAndValidateTokens(
 	redirectURI string,
 ) (*oidctypes.Token, error) {
 	if u.exchangeAuthcodeAndValidateTokensArgs == nil {
-		u.exchangeAuthcodeAndValidateTokensArgs = make([]*ExchangeAuthcodeArgs, 0)
+		u.exchangeAuthcodeAndValidateTokensArgs = make([]*ExchangeAuthcodeAndValidateTokenArgs, 0)
 	}
 	u.exchangeAuthcodeAndValidateTokensCallCount++
-	u.exchangeAuthcodeAndValidateTokensArgs = append(u.exchangeAuthcodeAndValidateTokensArgs, &ExchangeAuthcodeArgs{
+	u.exchangeAuthcodeAndValidateTokensArgs = append(u.exchangeAuthcodeAndValidateTokensArgs, &ExchangeAuthcodeAndValidateTokenArgs{
 		Ctx:                  ctx,
 		Authcode:             authcode,
 		PKCECodeVerifier:     pkceCodeVerifier,
@@ -197,9 +197,9 @@ func (u *TestUpstreamOIDCIdentityProvider) ExchangeAuthcodeAndValidateTokensCall
 	return u.exchangeAuthcodeAndValidateTokensCallCount
 }

-func (u *TestUpstreamOIDCIdentityProvider) ExchangeAuthcodeAndValidateTokensArgs(call int) *ExchangeAuthcodeArgs {
+func (u *TestUpstreamOIDCIdentityProvider) ExchangeAuthcodeAndValidateTokensArgs(call int) *ExchangeAuthcodeAndValidateTokenArgs {
 	if u.exchangeAuthcodeAndValidateTokensArgs == nil {
-		u.exchangeAuthcodeAndValidateTokensArgs = make([]*ExchangeAuthcodeArgs, 0)
+		u.exchangeAuthcodeAndValidateTokensArgs = make([]*ExchangeAuthcodeAndValidateTokenArgs, 0)
 	}
 	return u.exchangeAuthcodeAndValidateTokensArgs[call]
 }
--- a/internal/testutil/testidplister/testidplister.go
+++ b/internal/testutil/testidplister/testidplister.go
@@ -9,7 +9,6 @@ import (

 	"github.com/stretchr/testify/require"

-	idpdiscoveryv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idpdiscovery/v1alpha1"
 	"go.pinniped.dev/internal/federationdomain/dynamicupstreamprovider"
 	"go.pinniped.dev/internal/federationdomain/resolvedprovider"
 	"go.pinniped.dev/internal/federationdomain/resolvedprovider/resolvedgithub"
@@ -264,48 +263,59 @@ func (b *UpstreamIDPListerBuilder) RequireExactlyZeroCallsToPasswordCredentialsG
 	)
 }

-func (b *UpstreamIDPListerBuilder) RequireExactlyOneCallToExchangeAuthcodeAndValidateTokens(
+func (b *UpstreamIDPListerBuilder) RequireExactlyOneOIDCAuthcodeExchange(
+	t *testing.T,
+	expectedPerformedByUpstreamName string,
+	expectedArgs *oidctestutil.ExchangeAuthcodeAndValidateTokenArgs,
+) {
+	t.Helper()
+	var actualArgs *oidctestutil.ExchangeAuthcodeAndValidateTokenArgs
+	var actualNameOfUpstreamWhichMadeCall string
+	actualCallCount := 0
+	for _, upstream := range b.upstreamOIDCIdentityProviders {
+		callCountOnThisUpstream := upstream.ExchangeAuthcodeAndValidateTokensCallCount()
+		actualCallCount += callCountOnThisUpstream
+		if callCountOnThisUpstream == 1 {
+			actualNameOfUpstreamWhichMadeCall = upstream.Name
+			actualArgs = upstream.ExchangeAuthcodeAndValidateTokensArgs(0)
+		}
+	}
+	require.Equal(t, 1, actualCallCount,
+		"expected exactly one call to OIDC ExchangeAuthcodeAndValidateTokens()",
+	)
+	require.Equal(t, expectedPerformedByUpstreamName, actualNameOfUpstreamWhichMadeCall,
+		"OIDC ExchangeAuthcodeAndValidateTokens() was called on the wrong upstream name",
+	)
+	require.Equal(t, expectedArgs, actualArgs)
+}
+
+func (b *UpstreamIDPListerBuilder) RequireExactlyOneGitHubAuthcodeExchange(
 	t *testing.T,
 	expectedPerformedByUpstreamName string,
-	expectedPerformedByUpstreamType idpdiscoveryv1alpha1.IDPType,
 	expectedArgs *oidctestutil.ExchangeAuthcodeArgs,
 ) {
 	t.Helper()
 	var actualArgs *oidctestutil.ExchangeAuthcodeArgs
 	var actualNameOfUpstreamWhichMadeCall string
-	var actualTypeOfUpstreamWhichMadeCall idpdiscoveryv1alpha1.IDPType
-	actualCallCountAcrossAllOIDCAndGitHubUpstreams := 0
-	for _, upstreamOIDC := range b.upstreamOIDCIdentityProviders {
-		callCountOnThisUpstream := upstreamOIDC.ExchangeAuthcodeAndValidateTokensCallCount()
-		actualCallCountAcrossAllOIDCAndGitHubUpstreams += callCountOnThisUpstream
+	actualCallCount := 0
+	for _, upstream := range b.upstreamGitHubIdentityProviders {
+		callCountOnThisUpstream := upstream.ExchangeAuthcodeCallCount()
+		actualCallCount += callCountOnThisUpstream
 		if callCountOnThisUpstream == 1 {
-			actualNameOfUpstreamWhichMadeCall = upstreamOIDC.Name
-			actualTypeOfUpstreamWhichMadeCall = idpdiscoveryv1alpha1.IDPTypeOIDC
-			actualArgs = upstreamOIDC.ExchangeAuthcodeAndValidateTokensArgs(0)
+			actualNameOfUpstreamWhichMadeCall = upstream.Name
+			actualArgs = upstream.ExchangeAuthcodeArgs(0)
 		}
 	}
-	for _, upstreamGitHub := range b.upstreamGitHubIdentityProviders {
-		callCountOnThisUpstream := upstreamGitHub.ExchangeAuthcodeCallCount()
-		actualCallCountAcrossAllOIDCAndGitHubUpstreams += callCountOnThisUpstream
-		if callCountOnThisUpstream == 1 {
-			actualNameOfUpstreamWhichMadeCall = upstreamGitHub.Name
-			actualTypeOfUpstreamWhichMadeCall = idpdiscoveryv1alpha1.IDPTypeGitHub
-			actualArgs = upstreamGitHub.ExchangeAuthcodeArgs(0)
-		}
-	}
-	require.Equal(t, 1, actualCallCountAcrossAllOIDCAndGitHubUpstreams,
-		"expected exactly one call to (OIDC) ExchangeAuthcodeAndValidateTokensCallCount() or (GitHub) ExchangeAuthcodeCallCount()",
+	require.Equal(t, 1, actualCallCount,
+		"expected exactly one call to GitHub ExchangeAuthcode()",
 	)
 	require.Equal(t, expectedPerformedByUpstreamName, actualNameOfUpstreamWhichMadeCall,
-		"(OIDC) ExchangeAuthcodeAndValidateTokensCallCount() or (GitHub) ExchangeAuthcodeCallCount() was called on the wrong upstream name",
-	)
-	require.Equal(t, expectedPerformedByUpstreamType, actualTypeOfUpstreamWhichMadeCall,
-		"(OIDC) ExchangeAuthcodeAndValidateTokensCallCount() or (GitHub) ExchangeAuthcodeCallCount() was called on the wrong upstream type",
+		"GitHub ExchangeAuthcode() was called on the wrong upstream name",
 	)
 	require.Equal(t, expectedArgs, actualArgs)
 }

-func (b *UpstreamIDPListerBuilder) RequireExactlyZeroCallsToExchangeAuthcodeAndValidateTokens(t *testing.T) {
+func (b *UpstreamIDPListerBuilder) RequireExactlyZeroAuthcodeExchanges(t *testing.T) {
 	t.Helper()
 	actualCallCount := 0
 	for _, upstreamOIDC := range b.upstreamOIDCIdentityProviders {
@@ -316,7 +326,7 @@ func (b *UpstreamIDPListerBuilder) RequireExactlyZeroCallsToExchangeAuthcodeAndV
 	}

 	require.Equal(t, 0, actualCallCount,
-		"expected exactly zero calls to (OIDC) ExchangeAuthcodeAndValidateTokensCallCount() or (GitHub) ExchangeAuthcodeCallCount()",
+		"expected exactly zero calls to OIDC ExchangeAuthcodeAndValidateTokens() or GitHub ExchangeAuthcode()",
 	)
 }

--- a/internal/upstreamgithub/upstreamgithub.go
+++ b/internal/upstreamgithub/upstreamgithub.go
@@ -8,6 +8,7 @@ import (
 	"context"
 	"net/http"

+	coreosoidc "github.com/coreos/go-oidc/v3/oidc"
 	"golang.org/x/oauth2"
 	"k8s.io/apimachinery/pkg/types"

@@ -88,12 +89,37 @@ func (p *Provider) GetAuthorizationURL() string {
 	return p.c.OAuth2Config.Endpoint.AuthURL
 }

-func (p *Provider) ExchangeAuthcode(_ context.Context, _ string, _ string) (string, error) {
-	//TODO implement me
-	panic("implement me")
+func (p *Provider) ExchangeAuthcode(ctx context.Context, authcode string, redirectURI string) (string, error) {
+	// TODO: write tests for this
+	panic("write some tests for this sketch of the implementation, maybe by running a test server in the unit tests")
+	//nolint:govet // this code is intentionally unreachable until we resolve the todos
+	tok, err := p.c.OAuth2Config.Exchange(
+		coreosoidc.ClientContext(ctx, p.c.HttpClient),
+		authcode,
+		oauth2.SetAuthURLParam("redirect_uri", redirectURI),
+	)
+	if err != nil {
+		return "", err
+	}
+	return tok.AccessToken, nil
 }

-// GetConfig returns the config. This is not part of the interface and is mostly just for testing.
+func (p *Provider) GetUser(_ctx context.Context, _accessToken string) (*upstreamprovider.GitHubUser, error) {
+	// TODO Implement this to make several https calls to github to learn about the user, using a lower-level githubclient package.
+	//   Pass the ctx, accessToken, p.c.HttpClient, and p.c.APIBaseURL to the lower-level package's functions.
+	// TODO: Reject the auth if the user does not belong to any of p.c.AllowedOrganizations (unless p.c.AllowedOrganizations is empty).
+	// TODO: Make use of p.c.UsernameAttribute and p.c.GroupNameAttribute when deciding the username and group names.
+	// TODO: Determine the downstream subject by first writing a helper in downstream_subject.go and then calling it here.
+	panic("implement me")
+	//nolint:govet // this code is intentionally unreachable until we resolve the todos
+	return &upstreamprovider.GitHubUser{
+		Username:          "TODO",
+		Groups:            []string{"org/TODO"},
+		DownstreamSubject: "TODO",
+	}, nil
+}
+
+// GetConfig returns the config. This is not part of the UpstreamGithubIdentityProviderI interface and is just for testing.
 func (p *Provider) GetConfig() ProviderConfig {
 	return p.c
 }