connector: add RefreshConnector interface

connector/connector.go

@@ -1,14 +1,25 @@
 // Package connector defines interfaces for federated identity strategies.
 package connector
 
-import "net/http"
+import (
+	"net/http"
+
+	"golang.org/x/net/context"
+)
 
 // Connector is a mechanism for federating login to a remote identity service.
 //
 // Implementations are expected to implement either the PasswordConnector or
 // CallbackConnector interface.
-type Connector interface {
+type Connector interface{}
-	Close() error
+
+// Scopes represents additional data requested by the clients about the end user.
+type Scopes struct {
+	// The client has requested a refresh token from the server.
+	OfflineAccess bool
+
+	// The client has requested group information about the end user.
+	Groups bool
 }
 
 // Identity represents the ID Token claims supported by the server.
@@ -18,6 +29,8 @@ type Identity struct {
 	Email         string
 	EmailVerified bool
 
+	Groups []string
+
 	// ConnectorData holds data used by the connector for subsequent requests after initial
 	// authentication, such as access tokens for upstream provides.
 	//
@@ -25,18 +38,38 @@ type Identity struct {
 	ConnectorData []byte
 }
 
-// PasswordConnector is an optional interface for password based connectors.
+// PasswordConnector is an interface implemented by connectors which take a
+// username and password.
 type PasswordConnector interface {
-	Login(username, password string) (identity Identity, validPassword bool, err error)
+	Login(ctx context.Context, s Scopes, username, password string) (identity Identity, validPassword bool, err error)
 }
 
-// CallbackConnector is an optional interface for callback based connectors.
+// CallbackConnector is an interface implemented by connectors which use an OAuth
+// style redirect flow to determine user information.
 type CallbackConnector interface {
-	LoginURL(callbackURL, state string) (string, error)
+	// The initial URL to redirect the user to.
-	HandleCallback(r *http.Request) (identity Identity, err error)
+	//
+	// OAuth2 implementations should request different scopes from the upstream
+	// identity provider based on the scopes requested by the downstream client.
+	// For example, if the downstream client requests a refresh token from the
+	// server, the connector should also request a token from the provider.
+	//
+	// Many identity providers have arbitrary restrictions on refresh tokens. For
+	// example Google only allows a single refresh token per client/user/scopes
+	// combination, and wont return a refresh token even if offline access is
+	// requested if one has already been issues. There's no good general answer
+	// for these kind of restrictions, and may require this package to become more
+	// aware of the global set of user/connector interactions.
+	LoginURL(s Scopes, callbackURL, state string) (string, error)
+
+	// Handle the callback to the server and return an identity.
+	HandleCallback(s Scopes, r *http.Request) (identity Identity, err error)
 }
 
-// GroupsConnector is an optional interface for connectors which can map a user to groups.
+// RefreshConnector is a connector that can update the client claims.
-type GroupsConnector interface {
+type RefreshConnector interface {
-	Groups(identity Identity) ([]string, error)
+	// Refresh is called when a client attempts to claim a refresh token. The
+	// connector should attempt to update the identity object to reflect any
+	// changes since the token was last refreshed.
+	Refresh(ctx context.Context, s Scopes, identity Identity) (Identity, error)
 }

connector/github/github.go

@@ -3,6 +3,7 @@ package github
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -15,7 +16,11 @@ import (
 	"github.com/coreos/dex/connector"
 )
 
-const baseURL = "https://api.github.com"
+const (
+	baseURL    = "https://api.github.com"
+	scopeEmail = "user:email"
+	scopeOrgs  = "read:org"
+)
 
 // Config holds configuration options for github logins.
 type Config struct {
@@ -30,15 +35,8 @@ func (c *Config) Open() (connector.Connector, error) {
 	return &githubConnector{
 		redirectURI:  c.RedirectURI,
 		org:          c.Org,
-		oauth2Config: &oauth2.Config{
+		clientID:     c.ClientID,
-			ClientID:     c.ClientID,
+		clientSecret: c.ClientSecret,
-			ClientSecret: c.ClientSecret,
-			Endpoint:     github.Endpoint,
-			Scopes: []string{
-				"user:email", // View user's email
-				"read:org",   // View user's org teams.
-			},
-		},
 	}, nil
 }
 
@@ -49,26 +47,36 @@ type connectorData struct {
 
 var (
 	_ connector.CallbackConnector = (*githubConnector)(nil)
-	_ connector.GroupsConnector   = (*githubConnector)(nil)
+	_ connector.RefreshConnector  = (*githubConnector)(nil)
 )
 
 type githubConnector struct {
 	redirectURI  string
 	org          string
-	oauth2Config *oauth2.Config
+	clientID     string
-	ctx          context.Context
+	clientSecret string
-	cancel       context.CancelFunc
 }
 
-func (c *githubConnector) Close() error {
+func (c *githubConnector) oauth2Config(scopes connector.Scopes) *oauth2.Config {
-	return nil
+	var githubScopes []string
+	if scopes.Groups {
+		githubScopes = []string{scopeEmail, scopeOrgs}
+	} else {
+		githubScopes = []string{scopeEmail}
+	}
+	return &oauth2.Config{
+		ClientID:     c.clientID,
+		ClientSecret: c.clientSecret,
+		Endpoint:     github.Endpoint,
+		Scopes:       githubScopes,
+	}
 }
 
-func (c *githubConnector) LoginURL(callbackURL, state string) (string, error) {
+func (c *githubConnector) LoginURL(scopes connector.Scopes, callbackURL, state string) (string, error) {
 	if c.redirectURI != callbackURL {
 		return "", fmt.Errorf("expected callback URL did not match the URL in the config")
 	}
-	return c.oauth2Config.AuthCodeURL(state), nil
+	return c.oauth2Config(scopes).AuthCodeURL(state), nil
 }
 
 type oauth2Error struct {
@@ -83,43 +91,25 @@ func (e *oauth2Error) Error() string {
 	return e.error + ": " + e.errorDescription
 }
 
-func (c *githubConnector) HandleCallback(r *http.Request) (identity connector.Identity, err error) {
+func (c *githubConnector) HandleCallback(s connector.Scopes, r *http.Request) (identity connector.Identity, err error) {
 	q := r.URL.Query()
 	if errType := q.Get("error"); errType != "" {
 		return identity, &oauth2Error{errType, q.Get("error_description")}
 	}
-	token, err := c.oauth2Config.Exchange(c.ctx, q.Get("code"))
+
+	oauth2Config := c.oauth2Config(s)
+	ctx := r.Context()
+
+	token, err := oauth2Config.Exchange(ctx, q.Get("code"))
 	if err != nil {
 		return identity, fmt.Errorf("github: failed to get token: %v", err)
 	}
 
-	resp, err := c.oauth2Config.Client(c.ctx, token).Get(baseURL + "/user")
+	client := oauth2Config.Client(ctx, token)
-	if err != nil {
-		return identity, fmt.Errorf("github: get URL %v", err)
-	}
-	defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusOK {
+	user, err := c.user(ctx, client)
-		body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-			return identity, fmt.Errorf("github: read body: %v", err)
+		return identity, fmt.Errorf("github: get user: %v", err)
-		}
-		return identity, fmt.Errorf("%s: %s", resp.Status, body)
-	}
-	var user struct {
-		Name  string `json:"name"`
-		Login string `json:"login"`
-		ID    int    `json:"id"`
-		Email string `json:"email"`
-	}
-	if err := json.NewDecoder(resp.Body).Decode(&user); err != nil {
-		return identity, fmt.Errorf("failed to decode response: %v", err)
-	}
-
-	data := connectorData{AccessToken: token.AccessToken}
-	connData, err := json.Marshal(data)
-	if err != nil {
-		return identity, fmt.Errorf("marshal connector data: %v", err)
 	}
 
 	username := user.Name
@@ -131,22 +121,114 @@ func (c *githubConnector) HandleCallback(r *http.Request) (identity connector.Id
 		Username:      username,
 		Email:         user.Email,
 		EmailVerified: true,
-		ConnectorData: connData,
 	}
+
+	if s.Groups && c.org != "" {
+		groups, err := c.teams(ctx, client, c.org)
+		if err != nil {
+			return identity, fmt.Errorf("github: get teams: %v", err)
+		}
+		identity.Groups = groups
+	}
+
+	if s.OfflineAccess {
+		data := connectorData{AccessToken: token.AccessToken}
+		connData, err := json.Marshal(data)
+		if err != nil {
+			return identity, fmt.Errorf("marshal connector data: %v", err)
+		}
+		identity.ConnectorData = connData
+	}
+
 	return identity, nil
 }
 
-func (c *githubConnector) Groups(identity connector.Identity) ([]string, error) {
+func (c *githubConnector) Refresh(ctx context.Context, s connector.Scopes, ident connector.Identity) (connector.Identity, error) {
-	var data connectorData
+	if len(ident.ConnectorData) == 0 {
-	if err := json.Unmarshal(identity.ConnectorData, &data); err != nil {
+		return ident, errors.New("no upstream access token found")
-		return nil, fmt.Errorf("decode connector data: %v", err)
 	}
-	token := &oauth2.Token{AccessToken: data.AccessToken}
+
-	resp, err := c.oauth2Config.Client(c.ctx, token).Get(baseURL + "/user/teams")
+	var data connectorData
+	if err := json.Unmarshal(ident.ConnectorData, &data); err != nil {
+		return ident, fmt.Errorf("github: unmarshal access token: %v", err)
+	}
+
+	client := c.oauth2Config(s).Client(ctx, &oauth2.Token{AccessToken: data.AccessToken})
+	user, err := c.user(ctx, client)
+	if err != nil {
+		return ident, fmt.Errorf("github: get user: %v", err)
+	}
+
+	username := user.Name
+	if username == "" {
+		username = user.Login
+	}
+	ident.Username = username
+	ident.Email = user.Email
+
+	if s.Groups && c.org != "" {
+		groups, err := c.teams(ctx, client, c.org)
+		if err != nil {
+			return ident, fmt.Errorf("github: get teams: %v", err)
+		}
+		ident.Groups = groups
+	}
+	return ident, nil
+}
+
+type user struct {
+	Name  string `json:"name"`
+	Login string `json:"login"`
+	ID    int    `json:"id"`
+	Email string `json:"email"`
+}
+
+// user queries the GitHub API for profile information using the provided client. The HTTP
+// client is expected to be constructed by the golang.org/x/oauth2 package, which inserts
+// a bearer token as part of the request.
+func (c *githubConnector) user(ctx context.Context, client *http.Client) (user, error) {
+	var u user
+	req, err := http.NewRequest("GET", baseURL+"/user", nil)
+	if err != nil {
+		return u, fmt.Errorf("github: new req: %v", err)
+	}
+	req = req.WithContext(ctx)
+	resp, err := client.Do(req)
+	if err != nil {
+		return u, fmt.Errorf("github: get URL %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return u, fmt.Errorf("github: read body: %v", err)
+		}
+		return u, fmt.Errorf("%s: %s", resp.Status, body)
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&u); err != nil {
+		return u, fmt.Errorf("failed to decode response: %v", err)
+	}
+	return u, nil
+}
+
+// teams queries the GitHub API for team membership within a specific organization.
+//
+// The HTTP passed client is expected to be constructed by the golang.org/x/oauth2 package,
+// which inserts a bearer token as part of the request.
+func (c *githubConnector) teams(ctx context.Context, client *http.Client, org string) ([]string, error) {
+	req, err := http.NewRequest("GET", baseURL+"/user/teams", nil)
+	if err != nil {
+		return nil, fmt.Errorf("github: new req: %v", err)
+	}
+	req = req.WithContext(ctx)
+	resp, err := client.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("github: get teams: %v", err)
 	}
 	defer resp.Body.Close()
+
 	if resp.StatusCode != http.StatusOK {
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {
@@ -167,7 +249,7 @@ func (c *githubConnector) Groups(identity connector.Identity) ([]string, error)
 	}
 	groups := []string{}
 	for _, team := range teams {
-		if team.Org.Login == c.org {
+		if team.Org.Login == org {
 			groups = append(groups, team.Name)
 		}
 	}

connector/ldap/ldap.go

@@ -10,6 +10,7 @@ import (
 	"log"
 	"net"
 
+	"golang.org/x/net/context"
 	"gopkg.in/ldap.v2"
 
 	"github.com/coreos/dex/connector"
@@ -57,6 +58,9 @@ type Config struct {
 	// Required if LDAP host does not use TLS.
 	InsecureNoSSL bool `json:"insecureNoSSL"`
 
+	// Don't verify the CA.
+	InsecureSkipVerify bool `json:"insecureSkipVerify"`
+
 	// Path to a trusted root certificate file.
 	RootCA string `json:"rootCA"`
 
@@ -139,11 +143,16 @@ func (c *Config) Open() (connector.Connector, error) {
 	return connector.Connector(conn), nil
 }
 
+type refreshData struct {
+	Username string     `json:"username"`
+	Entry    ldap.Entry `json:"entry"`
+}
+
 // OpenConnector is the same as Open but returns a type with all implemented connector interfaces.
 func (c *Config) OpenConnector() (interface {
 	connector.Connector
 	connector.PasswordConnector
-	connector.GroupsConnector
+	connector.RefreshConnector
 }, error) {
 
 	requiredFields := []struct {
@@ -174,7 +183,7 @@ func (c *Config) OpenConnector() (interface {
 		}
 	}
 
-	tlsConfig := &tls.Config{ServerName: host}
+	tlsConfig := &tls.Config{ServerName: host, InsecureSkipVerify: c.InsecureSkipVerify}
 	if c.RootCA != "" || len(c.RootCAData) != 0 {
 		data := c.RootCAData
 		if len(data) == 0 {
@@ -209,12 +218,16 @@ type ldapConnector struct {
 	tlsConfig *tls.Config
 }
 
-var _ connector.PasswordConnector = (*ldapConnector)(nil)
+var (
+	_ connector.PasswordConnector = (*ldapConnector)(nil)
+	_ connector.RefreshConnector  = (*ldapConnector)(nil)
+)
 
 // do initializes a connection to the LDAP directory and passes it to the
 // provided function. It then performs appropriate teardown or reuse before
 // returning.
-func (c *ldapConnector) do(f func(c *ldap.Conn) error) error {
+func (c *ldapConnector) do(ctx context.Context, f func(c *ldap.Conn) error) error {
+	// TODO(ericchiang): support context here
 	var (
 		conn *ldap.Conn
 		err  error
@@ -253,13 +266,32 @@ func getAttr(e ldap.Entry, name string) string {
 	return ""
 }
 
-func (c *ldapConnector) Login(username, password string) (ident connector.Identity, validPass bool, err error) {
+func (c *ldapConnector) identityFromEntry(user ldap.Entry) (ident connector.Identity, err error) {
-	var (
+	// If we're missing any attributes, such as email or ID, we want to report
-		// We want to return a different error if the user's password is incorrect vs
+	// an error rather than continuing.
-		// if there was an error.
+	missing := []string{}
-		incorrectPass = false
+
-		user          ldap.Entry
+	// Fill the identity struct using the attributes from the user entry.
-	)
+	if ident.UserID = getAttr(user, c.UserSearch.IDAttr); ident.UserID == "" {
+		missing = append(missing, c.UserSearch.IDAttr)
+	}
+	if ident.Email = getAttr(user, c.UserSearch.EmailAttr); ident.Email == "" {
+		missing = append(missing, c.UserSearch.EmailAttr)
+	}
+	if c.UserSearch.NameAttr != "" {
+		if ident.Username = getAttr(user, c.UserSearch.NameAttr); ident.Username == "" {
+			missing = append(missing, c.UserSearch.NameAttr)
+		}
+	}
+
+	if len(missing) != 0 {
+		err := fmt.Errorf("ldap: entry %q missing following required attribute(s): %q", user.DN, missing)
+		return connector.Identity{}, err
+	}
+	return ident, nil
+}
+
+func (c *ldapConnector) userEntry(conn *ldap.Conn, username string) (user ldap.Entry, found bool, err error) {
 
 	filter := fmt.Sprintf("(%s=%s)", c.UserSearch.Username, ldap.EscapeFilter(username))
 	if c.UserSearch.Filter != "" {
@@ -283,24 +315,40 @@ func (c *ldapConnector) Login(username, password string) (ident connector.Identi
 	if c.UserSearch.NameAttr != "" {
 		req.Attributes = append(req.Attributes, c.UserSearch.NameAttr)
 	}
-
-	err = c.do(func(conn *ldap.Conn) error {
 	resp, err := conn.Search(req)
 	if err != nil {
-			return fmt.Errorf("ldap: search with filter %q failed: %v", req.Filter, err)
+		return ldap.Entry{}, false, fmt.Errorf("ldap: search with filter %q failed: %v", req.Filter, err)
 	}
 
 	switch n := len(resp.Entries); n {
 	case 0:
 		log.Printf("ldap: no results returned for filter: %q", filter)
+		return ldap.Entry{}, false, nil
+	case 1:
+		return *resp.Entries[0], true, nil
+	default:
+		return ldap.Entry{}, false, fmt.Errorf("ldap: filter returned multiple (%d) results: %q", n, filter)
+	}
+}
+
+func (c *ldapConnector) Login(ctx context.Context, s connector.Scopes, username, password string) (ident connector.Identity, validPass bool, err error) {
+	var (
+		// We want to return a different error if the user's password is incorrect vs
+		// if there was an error.
+		incorrectPass = false
+		user          ldap.Entry
+	)
+
+	err = c.do(ctx, func(conn *ldap.Conn) error {
+		entry, found, err := c.userEntry(conn, username)
+		if err != nil {
+			return err
+		}
+		if !found {
 			incorrectPass = true
 			return nil
-		case 1:
-		default:
-			return fmt.Errorf("ldap: filter returned multiple (%d) results: %q", n, filter)
 		}
-
+		user = entry
-		user = *resp.Entries[0]
 
 		// Try to authenticate as the distinguished name.
 		if err := conn.Bind(user.DN, password); err != nil {
@@ -323,44 +371,75 @@ func (c *ldapConnector) Login(username, password string) (ident connector.Identi
 		return connector.Identity{}, false, nil
 	}
 
+	if ident, err = c.identityFromEntry(user); err != nil {
+		return connector.Identity{}, false, err
+	}
+
+	if s.Groups {
+		groups, err := c.groups(ctx, user)
+		if err != nil {
+			return connector.Identity{}, false, fmt.Errorf("ldap: failed to query groups: %v", err)
+		}
+		ident.Groups = groups
+	}
+
+	if s.OfflineAccess {
+		refresh := refreshData{
+			Username: username,
+			Entry:    user,
+		}
 		// Encode entry for follow up requests such as the groups query and
 		// refresh attempts.
-	if ident.ConnectorData, err = json.Marshal(user); err != nil {
+		if ident.ConnectorData, err = json.Marshal(refresh); err != nil {
 			return connector.Identity{}, false, fmt.Errorf("ldap: marshal entry: %v", err)
 		}
-
-	// If we're missing any attributes, such as email or ID, we want to report
-	// an error rather than continuing.
-	missing := []string{}
-
-	// Fill the identity struct using the attributes from the user entry.
-	if ident.UserID = getAttr(user, c.UserSearch.IDAttr); ident.UserID == "" {
-		missing = append(missing, c.UserSearch.IDAttr)
-	}
-	if ident.Email = getAttr(user, c.UserSearch.EmailAttr); ident.Email == "" {
-		missing = append(missing, c.UserSearch.EmailAttr)
-	}
-	if c.UserSearch.NameAttr != "" {
-		if ident.Username = getAttr(user, c.UserSearch.NameAttr); ident.Username == "" {
-			missing = append(missing, c.UserSearch.NameAttr)
-		}
-	}
-
-	if len(missing) != 0 {
-		err := fmt.Errorf("ldap: entry %q missing following required attribute(s): %q", user.DN, missing)
-		return connector.Identity{}, false, err
 	}
 
 	return ident, true, nil
 }
 
-func (c *ldapConnector) Groups(ident connector.Identity) ([]string, error) {
+func (c *ldapConnector) Refresh(ctx context.Context, s connector.Scopes, ident connector.Identity) (connector.Identity, error) {
-	// Decode the user entry from the identity.
+	var data refreshData
-	var user ldap.Entry
+	if err := json.Unmarshal(ident.ConnectorData, &data); err != nil {
-	if err := json.Unmarshal(ident.ConnectorData, &user); err != nil {
+		return ident, fmt.Errorf("ldap: failed to unamrshal internal data: %v", err)
-		return nil, fmt.Errorf("ldap: failed to unmarshal connector data: %v", err)
 	}
 
+	var user ldap.Entry
+	err := c.do(ctx, func(conn *ldap.Conn) error {
+		entry, found, err := c.userEntry(conn, data.Username)
+		if err != nil {
+			return err
+		}
+		if !found {
+			return fmt.Errorf("ldap: user not found %q", data.Username)
+		}
+		user = entry
+		return nil
+	})
+	if err != nil {
+		return ident, err
+	}
+	if user.DN != data.Entry.DN {
+		return ident, fmt.Errorf("ldap: refresh for username %q expected DN %q got %q", data.Username, data.Entry.DN, user.DN)
+	}
+
+	newIdent, err := c.identityFromEntry(user)
+	if err != nil {
+		return ident, err
+	}
+	newIdent.ConnectorData = ident.ConnectorData
+
+	if s.Groups {
+		groups, err := c.groups(ctx, user)
+		if err != nil {
+			return connector.Identity{}, fmt.Errorf("ldap: failed to query groups: %v", err)
+		}
+		newIdent.Groups = groups
+	}
+	return newIdent, nil
+}
+
+func (c *ldapConnector) groups(ctx context.Context, user ldap.Entry) ([]string, error) {
 	filter := fmt.Sprintf("(%s=%s)", c.GroupSearch.GroupAttr, ldap.EscapeFilter(getAttr(user, c.GroupSearch.UserAttr)))
 	if c.GroupSearch.Filter != "" {
 		filter = fmt.Sprintf("(&%s%s)", c.GroupSearch.Filter, filter)
@@ -374,7 +453,7 @@ func (c *ldapConnector) Groups(ident connector.Identity) ([]string, error) {
 	}
 
 	var groups []*ldap.Entry
-	if err := c.do(func(conn *ldap.Conn) error {
+	if err := c.do(ctx, func(conn *ldap.Conn) error {
 		resp, err := conn.Search(req)
 		if err != nil {
 			return fmt.Errorf("ldap: search failed: %v", err)
@@ -406,7 +485,3 @@ func (c *ldapConnector) Groups(ident connector.Identity) ([]string, error) {
 	}
 	return groupNames, nil
 }
-
-func (c *ldapConnector) Close() error {
-	return nil
-}

connector/mock/connectortest.go

@@ -2,12 +2,13 @@
 package mock
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
 
+	"golang.org/x/net/context"
+
 	"github.com/coreos/dex/connector"
 )
 
@@ -19,7 +20,6 @@ func NewCallbackConnector() connector.Connector {
 
 var (
 	_ connector.CallbackConnector = callbackConnector{}
-	_ connector.GroupsConnector   = callbackConnector{}
 
 	_ connector.PasswordConnector = passwordConnector{}
 )
@@ -28,7 +28,7 @@ type callbackConnector struct{}
 
 func (m callbackConnector) Close() error { return nil }
 
-func (m callbackConnector) LoginURL(callbackURL, state string) (string, error) {
+func (m callbackConnector) LoginURL(s connector.Scopes, callbackURL, state string) (string, error) {
 	u, err := url.Parse(callbackURL)
 	if err != nil {
 		return "", fmt.Errorf("failed to parse callbackURL %q: %v", callbackURL, err)
@@ -41,23 +41,22 @@ func (m callbackConnector) LoginURL(callbackURL, state string) (string, error) {
 
 var connectorData = []byte("foobar")
 
-func (m callbackConnector) HandleCallback(r *http.Request) (connector.Identity, error) {
+func (m callbackConnector) HandleCallback(s connector.Scopes, r *http.Request) (connector.Identity, error) {
+	var groups []string
+	if s.Groups {
+		groups = []string{"authors"}
+	}
+
 	return connector.Identity{
 		UserID:        "0-385-28089-0",
 		Username:      "Kilgore Trout",
 		Email:         "kilgore@kilgore.trout",
 		EmailVerified: true,
+		Groups:        groups,
 		ConnectorData: connectorData,
 	}, nil
 }
 
-func (m callbackConnector) Groups(identity connector.Identity) ([]string, error) {
-	if !bytes.Equal(identity.ConnectorData, connectorData) {
-		return nil, errors.New("connector data mismatch")
-	}
-	return []string{"authors"}, nil
-}
-
 // CallbackConfig holds the configuration parameters for a connector which requires no interaction.
 type CallbackConfig struct{}
 
@@ -91,7 +90,7 @@ type passwordConnector struct {
 
 func (p passwordConnector) Close() error { return nil }
 
-func (p passwordConnector) Login(username, password string) (identity connector.Identity, validPassword bool, err error) {
+func (p passwordConnector) Login(ctx context.Context, s connector.Scopes, username, password string) (identity connector.Identity, validPassword bool, err error) {
 	if username == p.username && password == p.password {
 		return connector.Identity{
 			UserID:        "0-385-28089-0",

connector/oidc/oidc.go

@@ -75,7 +75,7 @@ func (c *oidcConnector) Close() error {
 	return nil
 }
 
-func (c *oidcConnector) LoginURL(callbackURL, state string) (string, error) {
+func (c *oidcConnector) LoginURL(s connector.Scopes, callbackURL, state string) (string, error) {
 	if c.redirectURI != callbackURL {
 		return "", fmt.Errorf("expected callback URL did not match the URL in the config")
 	}
@@ -94,7 +94,7 @@ func (e *oauth2Error) Error() string {
 	return e.error + ": " + e.errorDescription
 }
 
-func (c *oidcConnector) HandleCallback(r *http.Request) (identity connector.Identity, err error) {
+func (c *oidcConnector) HandleCallback(s connector.Scopes, r *http.Request) (identity connector.Identity, err error) {
 	q := r.URL.Query()
 	if errType := q.Get("error"); errType != "" {
 		return identity, &oauth2Error{errType, q.Get("error_description")}

server/handlers.go

@@ -179,7 +179,13 @@ func (s *Server) handleConnectorLogin(w http.ResponseWriter, r *http.Request) {
 
 	authReqID := r.FormValue("req")
 
-	// TODO(ericchiang): cache user identity.
+	authReq, err := s.storage.GetAuthRequest(authReqID)
+	if err != nil {
+		log.Printf("Failed to get auth request: %v", err)
+		s.renderError(w, http.StatusInternalServerError, errServerError, "")
+		return
+	}
+	scopes := parseScopes(authReq.Scopes)
 
 	switch r.Method {
 	case "GET":
@@ -199,7 +205,7 @@ func (s *Server) handleConnectorLogin(w http.ResponseWriter, r *http.Request) {
 			// Use the auth request ID as the "state" token.
 			//
 			// TODO(ericchiang): Is this appropriate or should we also be using a nonce?
-			callbackURL, err := conn.LoginURL(s.absURL("/callback"), authReqID)
+			callbackURL, err := conn.LoginURL(scopes, s.absURL("/callback"), authReqID)
 			if err != nil {
 				log.Printf("Connector %q returned error when creating callback: %v", connID, err)
 				s.renderError(w, http.StatusInternalServerError, errServerError, "")
@@ -221,7 +227,7 @@ func (s *Server) handleConnectorLogin(w http.ResponseWriter, r *http.Request) {
 		username := r.FormValue("login")
 		password := r.FormValue("password")
 
-		identity, ok, err := passwordConnector.Login(username, password)
+		identity, ok, err := passwordConnector.Login(r.Context(), scopes, username, password)
 		if err != nil {
 			log.Printf("Failed to login user: %v", err)
 			s.renderError(w, http.StatusInternalServerError, errServerError, "")
@@ -231,12 +237,6 @@ func (s *Server) handleConnectorLogin(w http.ResponseWriter, r *http.Request) {
 			s.templates.password(w, authReqID, r.URL.String(), username, true)
 			return
 		}
-		authReq, err := s.storage.GetAuthRequest(authReqID)
-		if err != nil {
-			log.Printf("Failed to get auth request: %v", err)
-			s.renderError(w, http.StatusInternalServerError, errServerError, "")
-			return
-		}
 		redirectURL, err := s.finalizeLogin(identity, authReq, conn.Connector)
 		if err != nil {
 			log.Printf("Failed to finalize login: %v", err)
@@ -286,7 +286,7 @@ func (s *Server) handleConnectorCallback(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	identity, err := callbackConnector.HandleCallback(r)
+	identity, err := callbackConnector.HandleCallback(parseScopes(authReq.Scopes), r)
 	if err != nil {
 		log.Printf("Failed to authenticate: %v", err)
 		s.renderError(w, http.StatusInternalServerError, errServerError, "")
@@ -304,34 +304,12 @@ func (s *Server) handleConnectorCallback(w http.ResponseWriter, r *http.Request)
 }
 
 func (s *Server) finalizeLogin(identity connector.Identity, authReq storage.AuthRequest, conn connector.Connector) (string, error) {
-	if authReq.ConnectorID == "" {
-
-	}
-
 	claims := storage.Claims{
 		UserID:        identity.UserID,
 		Username:      identity.Username,
 		Email:         identity.Email,
 		EmailVerified: identity.EmailVerified,
-	}
+		Groups:        identity.Groups,
-
-	groupsConn, ok := conn.(connector.GroupsConnector)
-	if ok {
-		reqGroups := func() bool {
-			for _, scope := range authReq.Scopes {
-				if scope == scopeGroups {
-					return true
-				}
-			}
-			return false
-		}()
-		if reqGroups {
-			groups, err := groupsConn.Groups(identity)
-			if err != nil {
-				return "", fmt.Errorf("getting groups: %v", err)
-			}
-			claims.Groups = groups
-		}
 	}
 
 	updater := func(a storage.AuthRequest) (storage.AuthRequest, error) {
@@ -415,6 +393,7 @@ func (s *Server) sendCodeResponse(w http.ResponseWriter, r *http.Request, authRe
 				Claims:        authReq.Claims,
 				Expiry:        s.now().Add(time.Minute * 30),
 				RedirectURI:   authReq.RedirectURI,
+				ConnectorData: authReq.ConnectorData,
 			}
 			if err := s.storage.CreateAuthCode(code); err != nil {
 				log.Printf("Failed to create auth code: %v", err)
@@ -543,6 +522,7 @@ func (s *Server) handleAuthCode(w http.ResponseWriter, r *http.Request, client s
 			Scopes:        authCode.Scopes,
 			Claims:        authCode.Claims,
 			Nonce:         authCode.Nonce,
+			ConnectorData: authCode.ConnectorData,
 		}
 		if err := s.storage.CreateRefresh(refresh); err != nil {
 			log.Printf("failed to create refresh token: %v", err)
@@ -574,6 +554,10 @@ func (s *Server) handleRefreshToken(w http.ResponseWriter, r *http.Request, clie
 		return
 	}
 
+	// Per the OAuth2 spec, if the client has omitted the scopes, default to the original
+	// authorized scopes.
+	//
+	// https://tools.ietf.org/html/rfc6749#section-6
 	scopes := refresh.Scopes
 	if scope != "" {
 		requestedScopes := strings.Fields(scope)
@@ -601,7 +585,43 @@ func (s *Server) handleRefreshToken(w http.ResponseWriter, r *http.Request, clie
 		scopes = requestedScopes
 	}
 
-	// TODO(ericchiang): re-auth with backends
+	conn, ok := s.connectors[refresh.ConnectorID]
+	if !ok {
+		log.Printf("connector ID not found: %q", refresh.ConnectorID)
+		tokenErr(w, errServerError, "", http.StatusInternalServerError)
+		return
+	}
+
+	// Can the connector refresh the identity? If so, attempt to refresh the data
+	// in the connector.
+	//
+	// TODO(ericchiang): We may want a strict mode where connectors that don't implement
+	// this interface can't perform refreshing.
+	if refreshConn, ok := conn.Connector.(connector.RefreshConnector); ok {
+		ident := connector.Identity{
+			UserID:        refresh.Claims.UserID,
+			Username:      refresh.Claims.Username,
+			Email:         refresh.Claims.Email,
+			EmailVerified: refresh.Claims.EmailVerified,
+			Groups:        refresh.Claims.Groups,
+			ConnectorData: refresh.ConnectorData,
+		}
+		ident, err := refreshConn.Refresh(r.Context(), parseScopes(scopes), ident)
+		if err != nil {
+			log.Printf("failed to refresh identity: %v", err)
+			tokenErr(w, errServerError, "", http.StatusInternalServerError)
+			return
+		}
+
+		// Update the claims of the refresh token.
+		//
+		// UserID intentionally ignored for now.
+		refresh.Claims.Username = ident.Username
+		refresh.Claims.Email = ident.Email
+		refresh.Claims.EmailVerified = ident.EmailVerified
+		refresh.Claims.Groups = ident.Groups
+		refresh.ConnectorData = ident.ConnectorData
+	}
 
 	idToken, expiry, err := s.newIDToken(client.ID, refresh.Claims, scopes, refresh.Nonce)
 	if err != nil {
@@ -610,6 +630,8 @@ func (s *Server) handleRefreshToken(w http.ResponseWriter, r *http.Request, clie
 		return
 	}
 
+	// Refresh tokens are claimed exactly once. Delete the current token and
+	// create a new one.
 	if err := s.storage.DeleteRefresh(code); err != nil {
 		log.Printf("failed to delete auth code: %v", err)
 		tokenErr(w, errServerError, "", http.StatusInternalServerError)

server/oauth2.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/coreos/dex/connector"
 	"github.com/coreos/dex/storage"
 )
 
@@ -93,6 +94,19 @@ const (
 	responseTypeIDToken = "id_token" // ID Token in url fragment
 )
 
+func parseScopes(scopes []string) connector.Scopes {
+	var s connector.Scopes
+	for _, scope := range scopes {
+		switch scope {
+		case scopeOfflineAccess:
+			s.OfflineAccess = true
+		case scopeGroups:
+			s.Groups = true
+		}
+	}
+	return s
+}
+
 type audience []string
 
 func (a audience) MarshalJSON() ([]byte, error) {

server/server.go

@@ -211,9 +211,7 @@ type passwordDB struct {
 	s storage.Storage
 }
 
-func (db passwordDB) Close() error { return nil }
+func (db passwordDB) Login(ctx context.Context, s connector.Scopes, email, password string) (connector.Identity, bool, error) {
-
-func (db passwordDB) Login(email, password string) (connector.Identity, bool, error) {
 	p, err := db.s.GetPassword(email)
 	if err != nil {
 		if err != storage.ErrNotFound {
@@ -233,6 +231,31 @@ func (db passwordDB) Login(email, password string) (connector.Identity, bool, er
 	}, true, nil
 }
 
+func (db passwordDB) Refresh(ctx context.Context, s connector.Scopes, identity connector.Identity) (connector.Identity, error) {
+	// If the user has been deleted, the refresh token will be rejected.
+	p, err := db.s.GetPassword(identity.Email)
+	if err != nil {
+		if err == storage.ErrNotFound {
+			return connector.Identity{}, errors.New("user not found")
+		}
+		return connector.Identity{}, fmt.Errorf("get password: %v", err)
+	}
+
+	// User removed but a new user with the same email exists.
+	if p.UserID != identity.UserID {
+		return connector.Identity{}, errors.New("user not found")
+	}
+
+	// If a user has updated their username, that will be reflected in the
+	// refreshed token.
+	//
+	// No other fields are expected to be refreshable as email is effectively used
+	// as an ID and this implementation doesn't deal with groups.
+	identity.Username = p.Username
+
+	return identity, nil
+}
+
 // newKeyCacher returns a storage which caches keys so long as the next
 func newKeyCacher(s storage.Storage, now func() time.Time) storage.Storage {
 	if now == nil {

server/server_test.go

@@ -662,7 +662,6 @@ func TestCrossClientScopes(t *testing.T) {
 func TestPasswordDB(t *testing.T) {
 	s := memory.New()
 	conn := newPasswordDB(s)
-	defer conn.Close()
 
 	pw := "hi"
 
@@ -712,7 +711,7 @@ func TestPasswordDB(t *testing.T) {
 	}
 
 	for _, tc := range tests {
-		ident, valid, err := conn.Login(tc.username, tc.password)
+		ident, valid, err := conn.Login(context.Background(), connector.Scopes{}, tc.username, tc.password)
 		if err != nil {
 			if !tc.wantErr {
 				t.Errorf("%s: %v", tc.name, err)