oauth2_proxy/providers/gitlab.go
Alexander Overvoorde 4de49983fb Rework GitLab provider (#231)
* Initial version of OIDC based GitLab provider

* Add support for email domain check to GitLab provider

* Add gitlab.com as default issuer for GitLab provider

* Update documentation for GitLab provider

* Update unit tests for new GitLab provider implementation

* Update CHANGELOG for GitLab provider

* Rename GitLab test access token as response to linter
2019-08-06 12:20:54 +01:00

259 lines
6.7 KiB
Go

package providers
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"strings"
"time"
oidc "github.com/coreos/go-oidc"
"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
"golang.org/x/oauth2"
)
// GitLabProvider represents a GitLab based Identity Provider
type GitLabProvider struct {
*ProviderData
Group string
EmailDomains []string
Verifier *oidc.IDTokenVerifier
AllowUnverifiedEmail bool
}
// NewGitLabProvider initiates a new GitLabProvider
func NewGitLabProvider(p *ProviderData) *GitLabProvider {
p.ProviderName = "GitLab"
if p.Scope == "" {
p.Scope = "openid email"
}
return &GitLabProvider{ProviderData: p}
}
// Redeem exchanges the OAuth2 authentication token for an ID token
func (p *GitLabProvider) Redeem(redirectURL, code string) (s *sessions.SessionState, err error) {
ctx := context.Background()
c := oauth2.Config{
ClientID: p.ClientID,
ClientSecret: p.ClientSecret,
Endpoint: oauth2.Endpoint{
TokenURL: p.RedeemURL.String(),
},
RedirectURL: redirectURL,
}
token, err := c.Exchange(ctx, code)
if err != nil {
return nil, fmt.Errorf("token exchange: %v", err)
}
s, err = p.createSessionState(ctx, token)
if err != nil {
return nil, fmt.Errorf("unable to update session: %v", err)
}
return
}
// RefreshSessionIfNeeded checks if the session has expired and uses the
// RefreshToken to fetch a new ID token if required
func (p *GitLabProvider) RefreshSessionIfNeeded(s *sessions.SessionState) (bool, error) {
if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
return false, nil
}
origExpiration := s.ExpiresOn
err := p.redeemRefreshToken(s)
if err != nil {
return false, fmt.Errorf("unable to redeem refresh token: %v", err)
}
fmt.Printf("refreshed id token %s (expired on %s)\n", s, origExpiration)
return true, nil
}
func (p *GitLabProvider) redeemRefreshToken(s *sessions.SessionState) (err error) {
c := oauth2.Config{
ClientID: p.ClientID,
ClientSecret: p.ClientSecret,
Endpoint: oauth2.Endpoint{
TokenURL: p.RedeemURL.String(),
},
}
ctx := context.Background()
t := &oauth2.Token{
RefreshToken: s.RefreshToken,
Expiry: time.Now().Add(-time.Hour),
}
token, err := c.TokenSource(ctx, t).Token()
if err != nil {
return fmt.Errorf("failed to get token: %v", err)
}
newSession, err := p.createSessionState(ctx, token)
if err != nil {
return fmt.Errorf("unable to update session: %v", err)
}
s.AccessToken = newSession.AccessToken
s.IDToken = newSession.IDToken
s.RefreshToken = newSession.RefreshToken
s.CreatedAt = newSession.CreatedAt
s.ExpiresOn = newSession.ExpiresOn
s.Email = newSession.Email
return
}
type gitlabUserInfo struct {
Username string `json:"nickname"`
Email string `json:"email"`
EmailVerified bool `json:"email_verified"`
Groups []string `json:"groups"`
}
func (p *GitLabProvider) getUserInfo(s *sessions.SessionState) (*gitlabUserInfo, error) {
// Retrieve user info JSON
// https://docs.gitlab.com/ee/integration/openid_connect_provider.html#shared-information
// Build user info url from login url of GitLab instance
userInfoURL := *p.LoginURL
userInfoURL.Path = "/oauth/userinfo"
req, err := http.NewRequest("GET", userInfoURL.String(), nil)
if err != nil {
return nil, fmt.Errorf("failed to create user info request: %v", err)
}
req.Header.Set("Authorization", "Bearer "+s.AccessToken)
resp, err := http.DefaultClient.Do(req)
if err != nil {
return nil, fmt.Errorf("failed to perform user info request: %v", err)
}
var body []byte
body, err = ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
return nil, fmt.Errorf("failed to read user info response: %v", err)
}
if resp.StatusCode != 200 {
return nil, fmt.Errorf("got %d during user info request: %s", resp.StatusCode, body)
}
var userInfo gitlabUserInfo
err = json.Unmarshal(body, &userInfo)
if err != nil {
return nil, fmt.Errorf("failed to parse user info: %v", err)
}
return &userInfo, nil
}
func (p *GitLabProvider) verifyGroupMembership(userInfo *gitlabUserInfo) error {
if p.Group == "" {
return nil
}
// Collect user group memberships
membershipSet := make(map[string]bool)
for _, group := range userInfo.Groups {
membershipSet[group] = true
}
// Find a valid group that they are a member of
validGroups := strings.Split(p.Group, " ")
for _, validGroup := range validGroups {
if _, ok := membershipSet[validGroup]; ok {
return nil
}
}
return fmt.Errorf("user is not a member of '%s'", p.Group)
}
func (p *GitLabProvider) verifyEmailDomain(userInfo *gitlabUserInfo) error {
if len(p.EmailDomains) == 0 || p.EmailDomains[0] == "*" {
return nil
}
for _, domain := range p.EmailDomains {
if strings.HasSuffix(userInfo.Email, domain) {
return nil
}
}
return fmt.Errorf("user email is not one of the valid domains '%v'", p.EmailDomains)
}
func (p *GitLabProvider) createSessionState(ctx context.Context, token *oauth2.Token) (*sessions.SessionState, error) {
rawIDToken, ok := token.Extra("id_token").(string)
if !ok {
return nil, fmt.Errorf("token response did not contain an id_token")
}
// Parse and verify ID Token payload.
idToken, err := p.Verifier.Verify(ctx, rawIDToken)
if err != nil {
return nil, fmt.Errorf("could not verify id_token: %v", err)
}
return &sessions.SessionState{
AccessToken: token.AccessToken,
IDToken: rawIDToken,
RefreshToken: token.RefreshToken,
CreatedAt: time.Now(),
ExpiresOn: idToken.Expiry,
}, nil
}
// ValidateSessionState checks that the session's IDToken is still valid
func (p *GitLabProvider) ValidateSessionState(s *sessions.SessionState) bool {
ctx := context.Background()
_, err := p.Verifier.Verify(ctx, s.IDToken)
if err != nil {
return false
}
return true
}
// GetEmailAddress returns the Account email address
func (p *GitLabProvider) GetEmailAddress(s *sessions.SessionState) (string, error) {
// Retrieve user info
userInfo, err := p.getUserInfo(s)
if err != nil {
return "", fmt.Errorf("failed to retrieve user info: %v", err)
}
// Check if email is verified
if !p.AllowUnverifiedEmail && !userInfo.EmailVerified {
return "", fmt.Errorf("user email is not verified")
}
// Check if email has valid domain
err = p.verifyEmailDomain(userInfo)
if err != nil {
return "", fmt.Errorf("email domain check failed: %v", err)
}
// Check group membership
err = p.verifyGroupMembership(userInfo)
if err != nil {
return "", fmt.Errorf("group membership check failed: %v", err)
}
return userInfo.Email, nil
}
// GetUserName returns the Account user name
func (p *GitLabProvider) GetUserName(s *sessions.SessionState) (string, error) {
userInfo, err := p.getUserInfo(s)
if err != nil {
return "", fmt.Errorf("failed to retrieve user info: %v", err)
}
return userInfo.Username, nil
}