internal/oidc/provider/manager: route to callback endpoint

Signed-off-by: Andrew Keesler <akeesler@vmware.com>

internal/oidc/oidc.go

@@ -18,6 +18,7 @@ const (
 	WellKnownEndpointPath     = "/.well-known/openid-configuration"
 	AuthorizationEndpointPath = "/oauth2/authorize"
 	TokenEndpointPath         = "/oauth2/token" //nolint:gosec // ignore lint warning that this is a credential
+	CallbackEndpointPath      = "/callback"
 	JWKSEndpointPath          = "/jwks.json"
 )
 

internal/oidc/provider/manager/manager.go

@@ -12,6 +12,7 @@ import (
 
 	"go.pinniped.dev/internal/oidc"
 	"go.pinniped.dev/internal/oidc/auth"
+	"go.pinniped.dev/internal/oidc/callback"
 	"go.pinniped.dev/internal/oidc/csrftoken"
 	"go.pinniped.dev/internal/oidc/discovery"
 	"go.pinniped.dev/internal/oidc/jwks"
@@ -84,6 +85,9 @@ func (m *Manager) SetProviders(oidcProviders ...*provider.OIDCProvider) {
 		authURL := strings.ToLower(incomingProvider.IssuerHost()) + "/" + incomingProvider.IssuerPath() + oidc.AuthorizationEndpointPath
 		m.providerHandlers[authURL] = auth.NewHandler(incomingProvider.Issuer(), m.idpListGetter, oauthHelper, csrftoken.Generate, pkce.Generate, nonce.Generate, encoder, encoder)
 
+		callbackURL := strings.ToLower(incomingProvider.IssuerHost()) + "/" + incomingProvider.IssuerPath() + oidc.CallbackEndpointPath
+		m.providerHandlers[callbackURL] = callback.NewHandler(incomingProvider.Issuer(), m.idpListGetter, oauthHelper, encoder, encoder)
+
 		plog.Debug("oidc provider manager added or updated issuer", "issuer", incomingProvider.Issuer())
 	}
 }

internal/oidc/provider/manager/manager_test.go

@@ -42,6 +42,7 @@ func TestManager(t *testing.T) {
 			issuer2DifferentCaseHostname = "https://exAmPlE.Com/some/path/more/deeply/nested/path"
 			issuer2KeyID                 = "issuer2-key"
 			upstreamIDPAuthorizationURL  = "https://test-upstream.com/auth"
+			downstreamRedirectURL        = "http://127.0.0.1:12345/callback"
 		)
 
 		newGetRequest := func(url string) *http.Request {
@@ -82,6 +83,18 @@ func TestManager(t *testing.T) {
 			)
 		}
 
+		requireCallbackRequestToBeHandled := func(requestIssuer, requestURLSuffix string) {
+			recorder := httptest.NewRecorder()
+
+			subject.ServeHTTP(recorder, newGetRequest(requestIssuer+oidc.CallbackEndpointPath+requestURLSuffix))
+
+			r.False(fallbackHandlerWasCalled)
+
+			// Minimal check to ensure that the right endpoint was called - when we don't send a CSRF
+			// cookie to the callback endpoint, the callback endpoint responds with a 403.
+			r.Equal(http.StatusForbidden, recorder.Code)
+		}
+
 		requireJWKSRequestToBeHandled := func(requestIssuer, requestURLSuffix, expectedJWKKeyID string) {
 			recorder := httptest.NewRecorder()
 
@@ -162,7 +175,6 @@ func TestManager(t *testing.T) {
 			requireJWKSRequestToBeHandled(issuer2DifferentCaseHostname, "", issuer2KeyID)
 			requireJWKSRequestToBeHandled(issuer2DifferentCaseHostname, "?some=query", issuer2KeyID)
 
-			authRedirectURI := "http://127.0.0.1/callback"
 			authRequestParams := "?" + url.Values{
 				"response_type":         []string{"code"},
 				"scope":                 []string{"openid profile email"},
@@ -171,7 +183,7 @@ func TestManager(t *testing.T) {
 				"nonce":                 []string{"some-nonce-value"},
 				"code_challenge":        []string{"some-challenge"},
 				"code_challenge_method": []string{"S256"},
-				"redirect_uri":          []string{authRedirectURI},
+				"redirect_uri":          []string{downstreamRedirectURL},
 			}.Encode()
 
 			requireAuthorizationRequestToBeHandled(issuer1, authRequestParams, upstreamIDPAuthorizationURL)
@@ -180,6 +192,18 @@ func TestManager(t *testing.T) {
 			// Hostnames are case-insensitive, so test that we can handle that.
 			requireAuthorizationRequestToBeHandled(issuer1DifferentCaseHostname, authRequestParams, upstreamIDPAuthorizationURL)
 			requireAuthorizationRequestToBeHandled(issuer2DifferentCaseHostname, authRequestParams, upstreamIDPAuthorizationURL)
+
+			callbackRequestParams := "?" + url.Values{
+				"code":  []string{"some-code"},
+				"state": []string{"some-state-value"},
+			}.Encode()
+
+			requireCallbackRequestToBeHandled(issuer1, callbackRequestParams)
+			requireCallbackRequestToBeHandled(issuer2, callbackRequestParams)
+
+			// // Hostnames are case-insensitive, so test that we can handle that.
+			requireCallbackRequestToBeHandled(issuer1DifferentCaseHostname, callbackRequestParams)
+			requireCallbackRequestToBeHandled(issuer2DifferentCaseHostname, callbackRequestParams)
 		}
 
 		when("given some valid providers via SetProviders()", func() {