dex/connector/gitlab/gitlab.go

301 lines
7.5 KiB
Go

// Package gitlab provides authentication strategies using Gitlab.
package gitlab
import (
"context"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/http"
"regexp"
"strconv"
"github.com/coreos/dex/connector"
"github.com/sirupsen/logrus"
"golang.org/x/oauth2"
)
const (
// https://docs.gitlab.com/ee/integration/oauth_provider.html#authorized-applications
scopeUser = "read_user"
scopeAPI = "api"
)
var (
reNext = regexp.MustCompile("<([^>]+)>; rel=\"next\"")
reLast = regexp.MustCompile("<([^>]+)>; rel=\"last\"")
)
// Config holds configuration options for gilab logins.
type Config struct {
BaseURL string `json:"baseURL"`
ClientID string `json:"clientID"`
ClientSecret string `json:"clientSecret"`
RedirectURI string `json:"redirectURI"`
}
type gitlabUser struct {
ID int
Name string
Username string
State string
Email string
IsAdmin bool
}
type gitlabGroup struct {
ID int
Name string
Path string
}
// Open returns a strategy for logging in through GitLab.
func (c *Config) Open(id string, logger logrus.FieldLogger) (connector.Connector, error) {
if c.BaseURL == "" {
c.BaseURL = "https://www.gitlab.com"
}
return &gitlabConnector{
baseURL: c.BaseURL,
redirectURI: c.RedirectURI,
clientID: c.ClientID,
clientSecret: c.ClientSecret,
logger: logger,
}, nil
}
type connectorData struct {
// GitLab's OAuth2 tokens never expire. We don't need a refresh token.
AccessToken string `json:"accessToken"`
}
var (
_ connector.CallbackConnector = (*gitlabConnector)(nil)
_ connector.RefreshConnector = (*gitlabConnector)(nil)
)
type gitlabConnector struct {
baseURL string
redirectURI string
org string
clientID string
clientSecret string
logger logrus.FieldLogger
}
func (c *gitlabConnector) oauth2Config(scopes connector.Scopes) *oauth2.Config {
gitlabScopes := []string{scopeUser}
if scopes.Groups {
gitlabScopes = []string{scopeAPI}
}
gitlabEndpoint := oauth2.Endpoint{AuthURL: c.baseURL + "/oauth/authorize", TokenURL: c.baseURL + "/oauth/token"}
return &oauth2.Config{
ClientID: c.clientID,
ClientSecret: c.clientSecret,
Endpoint: gitlabEndpoint,
Scopes: gitlabScopes,
RedirectURL: c.redirectURI,
}
}
func (c *gitlabConnector) LoginURL(scopes connector.Scopes, callbackURL, state string) (string, error) {
if c.redirectURI != callbackURL {
return "", fmt.Errorf("expected callback URL %q did not match the URL in the config %q", c.redirectURI, callbackURL)
}
return c.oauth2Config(scopes).AuthCodeURL(state), nil
}
type oauth2Error struct {
error string
errorDescription string
}
func (e *oauth2Error) Error() string {
if e.errorDescription == "" {
return e.error
}
return e.error + ": " + e.errorDescription
}
func (c *gitlabConnector) 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")}
}
oauth2Config := c.oauth2Config(s)
ctx := r.Context()
token, err := oauth2Config.Exchange(ctx, q.Get("code"))
if err != nil {
return identity, fmt.Errorf("gitlab: failed to get token: %v", err)
}
client := oauth2Config.Client(ctx, token)
user, err := c.user(ctx, client)
if err != nil {
return identity, fmt.Errorf("gitlab: get user: %v", err)
}
username := user.Name
if username == "" {
username = user.Email
}
identity = connector.Identity{
UserID: strconv.Itoa(user.ID),
Username: username,
Email: user.Email,
EmailVerified: true,
}
if s.Groups {
groups, err := c.groups(ctx, client)
if err != nil {
return identity, fmt.Errorf("gitlab: get groups: %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 *gitlabConnector) Refresh(ctx context.Context, s connector.Scopes, ident connector.Identity) (connector.Identity, error) {
if len(ident.ConnectorData) == 0 {
return ident, errors.New("no upstream access token found")
}
var data connectorData
if err := json.Unmarshal(ident.ConnectorData, &data); err != nil {
return ident, fmt.Errorf("gitlab: 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("gitlab: get user: %v", err)
}
username := user.Name
if username == "" {
username = user.Email
}
ident.Username = username
ident.Email = user.Email
if s.Groups {
groups, err := c.groups(ctx, client)
if err != nil {
return ident, fmt.Errorf("gitlab: get groups: %v", err)
}
ident.Groups = groups
}
return ident, nil
}
// user queries the GitLab 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 *gitlabConnector) user(ctx context.Context, client *http.Client) (gitlabUser, error) {
var u gitlabUser
req, err := http.NewRequest("GET", c.baseURL+"/api/v4/user", nil)
if err != nil {
return u, fmt.Errorf("gitlab: new req: %v", err)
}
req = req.WithContext(ctx)
resp, err := client.Do(req)
if err != nil {
return u, fmt.Errorf("gitlab: 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("gitlab: 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
}
// groups queries the GitLab API for group membership.
//
// 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 *gitlabConnector) groups(ctx context.Context, client *http.Client) ([]string, error) {
apiURL := c.baseURL + "/api/v4/groups"
groups := []string{}
var gitlabGroups []gitlabGroup
for {
// 100 is the maximum number for per_page that allowed by gitlab
req, err := http.NewRequest("GET", apiURL, nil)
if err != nil {
return nil, fmt.Errorf("gitlab: new req: %v", err)
}
req = req.WithContext(ctx)
resp, err := client.Do(req)
if err != nil {
return nil, fmt.Errorf("gitlab: get groups: %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("gitlab: read body: %v", err)
}
return nil, fmt.Errorf("%s: %s", resp.Status, body)
}
if err := json.NewDecoder(resp.Body).Decode(&gitlabGroups); err != nil {
return nil, fmt.Errorf("gitlab: unmarshal groups: %v", err)
}
for _, group := range gitlabGroups {
groups = append(groups, group.Name)
}
link := resp.Header.Get("Link")
apiURL = nextURL(apiURL, link)
if apiURL == "" {
break
}
}
return groups, nil
}
func nextURL(url string, link string) string {
if len(reLast.FindStringSubmatch(link)) > 1 {
lastPageURL := reLast.FindStringSubmatch(link)[1]
if url == lastPageURL {
return ""
}
} else {
return ""
}
if len(reNext.FindStringSubmatch(link)) > 1 {
return reNext.FindStringSubmatch(link)[1]
}
return ""
}