228 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			228 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package proxy
 | |
| 
 | |
| import (
 | |
| 	"context"
 | |
| 	"errors"
 | |
| 	"fmt"
 | |
| 	"net/http"
 | |
| 	"net/url"
 | |
| 	"strings"
 | |
| 
 | |
| 	sessionsapi "github.com/oauth2-proxy/oauth2-proxy/pkg/apis/sessions"
 | |
| 	"github.com/oauth2-proxy/oauth2-proxy/pkg/encryption"
 | |
| )
 | |
| 
 | |
| // GetRedirectURI returns the redirectURL that the upstream OAuth Provider will
 | |
| // redirect clients to once authenticated
 | |
| func (p *OAuthProxy) GetRedirectURI(host string) string {
 | |
| 	// default to the request Host if not set
 | |
| 	if p.redirectURL.Host != "" {
 | |
| 		return p.redirectURL.String()
 | |
| 	}
 | |
| 	u := *p.redirectURL
 | |
| 	if u.Scheme == "" {
 | |
| 		if p.CookieSecure {
 | |
| 			u.Scheme = httpsScheme
 | |
| 		} else {
 | |
| 			u.Scheme = httpScheme
 | |
| 		}
 | |
| 	}
 | |
| 	u.Host = host
 | |
| 	return u.String()
 | |
| }
 | |
| 
 | |
| // HTTPClient is the context key to use with golang.org/x/net/context's
 | |
| // WithValue function to associate an *http.Client value with a context.
 | |
| var HTTPClient ContextKey
 | |
| 
 | |
| // ContextKey is just an empty struct. It exists so HTTPClient can be
 | |
| // an immutable public variable with a unique type. It's immutable
 | |
| // because nobody else can create a ContextKey, being unexported.
 | |
| type ContextKey struct{}
 | |
| 
 | |
| func (p *OAuthProxy) redeemCode(ctx context.Context, host, code string) (s *sessionsapi.SessionState, err error) {
 | |
| 	if code == "" {
 | |
| 		return nil, errors.New("missing code")
 | |
| 	}
 | |
| 	redirectURI := p.GetRedirectURI(host)
 | |
| 	redeemCtx := context.WithValue(ctx, HTTPClient, p.client)
 | |
| 	s, err = p.provider.Redeem(redeemCtx, redirectURI, code)
 | |
| 	if err != nil {
 | |
| 		return
 | |
| 	}
 | |
| 
 | |
| 	if s.Email == "" {
 | |
| 		s.Email, err = p.provider.GetEmailAddress(ctx, s)
 | |
| 	}
 | |
| 
 | |
| 	if s.PreferredUsername == "" {
 | |
| 		s.PreferredUsername, err = p.provider.GetPreferredUsername(ctx, s)
 | |
| 		if err != nil && err.Error() == "not implemented" {
 | |
| 			err = nil
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if s.User == "" {
 | |
| 		s.User, err = p.provider.GetUserName(ctx, s)
 | |
| 		if err != nil && err.Error() == "not implemented" {
 | |
| 			err = nil
 | |
| 		}
 | |
| 	}
 | |
| 	return
 | |
| }
 | |
| 
 | |
| // GetRedirect reads the query parameter to get the URL to redirect clients to
 | |
| // once authenticated with the OAuthProxy
 | |
| func (p *OAuthProxy) GetRedirect(req *http.Request) (redirect string, err error) {
 | |
| 	err = req.ParseForm()
 | |
| 	if err != nil {
 | |
| 		return
 | |
| 	}
 | |
| 
 | |
| 	redirect = req.Header.Get("X-Auth-Request-Redirect")
 | |
| 	if req.Form.Get("rd") != "" {
 | |
| 		redirect = req.Form.Get("rd")
 | |
| 	}
 | |
| 	if !p.IsValidRedirect(redirect) {
 | |
| 		// Use RequestURI to preserve ?query
 | |
| 		redirect = req.URL.RequestURI()
 | |
| 		if strings.HasPrefix(redirect, p.ProxyPrefix) {
 | |
| 			redirect = "/"
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	return
 | |
| }
 | |
| 
 | |
| // IsValidRedirect checks whether the redirect URL is whitelisted
 | |
| func (p *OAuthProxy) IsValidRedirect(redirect string) bool {
 | |
| 	switch {
 | |
| 	case redirect == "":
 | |
| 		// The user didn't specify a redirect, should fallback to `/`
 | |
| 		return false
 | |
| 	case strings.HasPrefix(redirect, "/") && !strings.HasPrefix(redirect, "//") && !invalidRedirectRegex.MatchString(redirect):
 | |
| 		return true
 | |
| 	case strings.HasPrefix(redirect, "http://") || strings.HasPrefix(redirect, "https://"):
 | |
| 		redirectURL, err := url.Parse(redirect)
 | |
| 		if err != nil {
 | |
| 			p.logger.WithField("redirect", redirect).Printf("Rejecting invalid redirect %q: scheme unsupported or missing", redirect)
 | |
| 			return false
 | |
| 		}
 | |
| 		redirectHostname := redirectURL.Hostname()
 | |
| 
 | |
| 		for _, domain := range p.CookieDomains {
 | |
| 			if strings.HasSuffix(redirectHostname, domain) {
 | |
| 				p.logger.WithField("redirect", redirect).WithField("domain", domain).Debug("allowing redirect")
 | |
| 				return true
 | |
| 			}
 | |
| 		}
 | |
| 
 | |
| 		p.logger.WithField("redirect", redirect).Printf("Rejecting invalid redirect %q: domain / port not in whitelist", redirect)
 | |
| 		return false
 | |
| 	default:
 | |
| 		p.logger.WithField("redirect", redirect).Printf("Rejecting invalid redirect %q: not an absolute or relative URL", redirect)
 | |
| 		return false
 | |
| 	}
 | |
| }
 | |
| 
 | |
| // IsWhitelistedRequest is used to check if auth should be skipped for this request
 | |
| func (p *OAuthProxy) IsWhitelistedRequest(req *http.Request) bool {
 | |
| 	isPreflightRequestAllowed := p.skipAuthPreflight && req.Method == "OPTIONS"
 | |
| 	return isPreflightRequestAllowed || p.IsWhitelistedPath(req.URL.Path)
 | |
| }
 | |
| 
 | |
| // IsWhitelistedPath is used to check if the request path is allowed without auth
 | |
| func (p *OAuthProxy) IsWhitelistedPath(path string) bool {
 | |
| 	for _, u := range p.compiledRegex {
 | |
| 		if u.MatchString(path) {
 | |
| 			return true
 | |
| 		}
 | |
| 	}
 | |
| 	return false
 | |
| }
 | |
| 
 | |
| // OAuthStart starts the OAuth2 authentication flow
 | |
| func (p *OAuthProxy) OAuthStart(rw http.ResponseWriter, req *http.Request) {
 | |
| 	prepareNoCache(rw)
 | |
| 	nonce, err := encryption.Nonce()
 | |
| 	if err != nil {
 | |
| 		p.logger.Errorf("Error obtaining nonce: %v", err)
 | |
| 		p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", err.Error())
 | |
| 		return
 | |
| 	}
 | |
| 	p.SetCSRFCookie(rw, req, nonce)
 | |
| 	redirect, err := p.GetRedirect(req)
 | |
| 	if err != nil {
 | |
| 		p.logger.Errorf("Error obtaining redirect: %v", err)
 | |
| 		p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", err.Error())
 | |
| 		return
 | |
| 	}
 | |
| 	redirectURI := p.GetRedirectURI(req.Host)
 | |
| 	http.Redirect(rw, req, p.provider.GetLoginURL(redirectURI, fmt.Sprintf("%v:%v", nonce, redirect)), http.StatusFound)
 | |
| }
 | |
| 
 | |
| // OAuthCallback is the OAuth2 authentication flow callback that finishes the
 | |
| // OAuth2 authentication flow
 | |
| func (p *OAuthProxy) OAuthCallback(rw http.ResponseWriter, req *http.Request) {
 | |
| 	// finish the oauth cycle
 | |
| 	err := req.ParseForm()
 | |
| 	if err != nil {
 | |
| 		p.logger.Errorf("Error while parsing OAuth2 callback: %v", err)
 | |
| 		p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", err.Error())
 | |
| 		return
 | |
| 	}
 | |
| 	errorString := req.Form.Get("error")
 | |
| 	if errorString != "" {
 | |
| 		p.logger.Errorf("Error while parsing OAuth2 callback: %s", errorString)
 | |
| 		p.ErrorPage(rw, http.StatusForbidden, "Permission Denied", errorString)
 | |
| 		return
 | |
| 	}
 | |
| 
 | |
| 	session, err := p.redeemCode(req.Context(), req.Host, req.Form.Get("code"))
 | |
| 	if err != nil {
 | |
| 		p.logger.Errorf("Error redeeming code during OAuth2 callback: %v", err)
 | |
| 		p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", "Internal Error")
 | |
| 		return
 | |
| 	}
 | |
| 
 | |
| 	s := strings.SplitN(req.Form.Get("state"), ":", 2)
 | |
| 	if len(s) != 2 {
 | |
| 		p.logger.Error("Error while parsing OAuth2 state: invalid length")
 | |
| 		p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", "Invalid State")
 | |
| 		return
 | |
| 	}
 | |
| 	nonce := s[0]
 | |
| 	redirect := s[1]
 | |
| 	c, err := req.Cookie(p.CSRFCookieName)
 | |
| 	if err != nil {
 | |
| 		p.logger.WithField("user", session.Email).WithField("status", "AuthFailure").Info("Invalid authentication via OAuth2: unable to obtain CSRF cookie")
 | |
| 		p.ErrorPage(rw, http.StatusForbidden, "Permission Denied", err.Error())
 | |
| 		return
 | |
| 	}
 | |
| 	p.ClearCSRFCookie(rw, req)
 | |
| 	if c.Value != nonce {
 | |
| 		p.logger.WithField("is", c.Value).WithField("should", nonce).WithField("user", session.Email).WithField("status", "AuthFailure").Info("Invalid authentication via OAuth2: CSRF token mismatch, potential attack")
 | |
| 		p.ErrorPage(rw, http.StatusForbidden, "Permission Denied", "CSRF Failed")
 | |
| 		return
 | |
| 	}
 | |
| 
 | |
| 	if !p.IsValidRedirect(redirect) {
 | |
| 		redirect = "/"
 | |
| 	}
 | |
| 
 | |
| 	// set cookie, or deny
 | |
| 	if p.provider.ValidateGroup(session.Email) {
 | |
| 		p.logger.WithField("user", session.Email).WithField("status", "AuthFailure").Infof("Authenticated via OAuth2: %s", session)
 | |
| 		err := p.SaveSession(rw, req, session)
 | |
| 		if err != nil {
 | |
| 			p.logger.Printf("Error saving session state for client %v", err)
 | |
| 			p.ErrorPage(rw, http.StatusInternalServerError, "Internal Server Error", err.Error())
 | |
| 			return
 | |
| 		}
 | |
| 		http.Redirect(rw, req, redirect, http.StatusFound)
 | |
| 	} else {
 | |
| 		p.logger.WithField("user", session.Email).WithField("status", "AuthFailure").Info("Invalid authentication via OAuth2: unauthorized")
 | |
| 		p.ErrorPage(rw, http.StatusForbidden, "Permission Denied", "Invalid Account")
 | |
| 	}
 | |
| }
 | 
