From 12f8338977a32f53d9979d7831f5c80619e8509a Mon Sep 17 00:00:00 2001
From: bergquist <carl.bergquist@gmail.com>
Date: Tue, 22 Jan 2019 15:20:44 +0100
Subject: [PATCH] stores hashed state code in cookie

---
 pkg/api/login_oauth.go          | 39 ++++++++++++++++++++++++++++-----
 pkg/services/auth/auth_token.go |  2 +-
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/pkg/api/login_oauth.go b/pkg/api/login_oauth.go
index 6013df8ea02..36c9c12905f 100644
--- a/pkg/api/login_oauth.go
+++ b/pkg/api/login_oauth.go
@@ -3,9 +3,11 @@ package api
 import (
 	"context"
 	"crypto/rand"
+	"crypto/sha256"
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/base64"
+	"encoding/hex"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -18,12 +20,14 @@ import (
 	"github.com/grafana/grafana/pkg/login"
 	"github.com/grafana/grafana/pkg/metrics"
 	m "github.com/grafana/grafana/pkg/models"
-	"github.com/grafana/grafana/pkg/services/session"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/social"
 )
 
-var oauthLogger = log.New("oauth")
+var (
+	oauthLogger          = log.New("oauth")
+	OauthStateCookieName = "oauth_state"
+)
 
 func GenStateString() string {
 	rnd := make([]byte, 32)
@@ -55,7 +59,9 @@ func (hs *HTTPServer) OAuthLogin(ctx *m.ReqContext) {
 	code := ctx.Query("code")
 	if code == "" {
 		state := GenStateString()
-		ctx.Session.Set(session.SESS_KEY_OAUTH_STATE, state)
+		hashedState := hashStatecode(state, setting.OAuthService.OAuthInfos[name].ClientSecret)
+		hs.writeOauthStateCookie(ctx, hashedState, 60)
+
 		if setting.OAuthService.OAuthInfos[name].HostedDomain == "" {
 			ctx.Redirect(connect.AuthCodeURL(state, oauth2.AccessTypeOnline))
 		} else {
@@ -64,13 +70,18 @@ func (hs *HTTPServer) OAuthLogin(ctx *m.ReqContext) {
 		return
 	}
 
-	savedState, ok := ctx.Session.Get(session.SESS_KEY_OAUTH_STATE).(string)
-	if !ok {
+	savedState := ctx.GetCookie(OauthStateCookieName)
+
+	// delete cookie
+	ctx.Resp.Header().Del("Set-Cookie")
+	hs.writeOauthStateCookie(ctx, "", -1)
+
+	if savedState == "" {
 		ctx.Handle(500, "login.OAuthLogin(missing saved state)", nil)
 		return
 	}
 
-	queryState := ctx.Query("state")
+	queryState := hashStatecode(ctx.Query("state"), setting.OAuthService.OAuthInfos[name].ClientSecret)
 	if savedState != queryState {
 		ctx.Handle(500, "login.OAuthLogin(state mismatch)", nil)
 		return
@@ -191,6 +202,22 @@ func (hs *HTTPServer) OAuthLogin(ctx *m.ReqContext) {
 	ctx.Redirect(setting.AppSubUrl + "/")
 }
 
+func (hs *HTTPServer) writeOauthStateCookie(ctx *m.ReqContext, value string, maxAge int) {
+	http.SetCookie(ctx.Resp, &http.Cookie{
+		Name:     OauthStateCookieName,
+		MaxAge:   maxAge,
+		Value:    value,
+		HttpOnly: true,
+		Path:     setting.AppSubUrl + "/",
+		Secure:   hs.Cfg.LoginCookieSecure,
+	})
+}
+
+func hashStatecode(code, seed string) string {
+	hashBytes := sha256.Sum256([]byte(code + setting.SecretKey + seed))
+	return hex.EncodeToString(hashBytes[:])
+}
+
 func redirectWithError(ctx *m.ReqContext, err error, v ...interface{}) {
 	ctx.Logger.Error(err.Error(), v...)
 	ctx.Session.Set("loginError", err.Error())
diff --git a/pkg/services/auth/auth_token.go b/pkg/services/auth/auth_token.go
index b2d9ab09200..c04389ab557 100644
--- a/pkg/services/auth/auth_token.go
+++ b/pkg/services/auth/auth_token.go
@@ -86,7 +86,7 @@ func (s *UserAuthTokenServiceImpl) InitContextWithToken(ctx *models.ReqContext,
 
 func (s *UserAuthTokenServiceImpl) writeSessionCookie(ctx *models.ReqContext, value string, maxAge int) {
 	if setting.Env == setting.DEV {
-		ctx.Logger.Info("new token", "unhashed token", value, "cookieName", s.Cfg.LoginCookieName, "secure", s.Cfg.LoginCookieSecure)
+		ctx.Logger.Info("new token", "unhashed token", value)
 	}
 
 	ctx.Resp.Header().Del("Set-Cookie")