/
oidc.go
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/
oidc.go
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package auth
import (
"context"
"encoding/json"
"fmt"
"net/http"
"net/url"
"strings"
"sync"
"time"
"github.com/coreos/go-oidc/v3/oidc"
"github.com/google/uuid"
"github.com/labstack/echo/v4"
glob "github.com/ryanuber/go-glob"
"github.com/tidwall/gjson"
"golang.org/x/oauth2"
"github.com/kinvolk/nebraska/backend/pkg/codegen"
"github.com/kinvolk/nebraska/backend/pkg/sessions"
echosessions "github.com/kinvolk/nebraska/backend/pkg/sessions/echo"
)
const (
stateCleanupDuration = time.Minute * 5
stateTimeoutDuration = time.Minute * 3
)
type stateMessage struct {
timeout time.Time
redirectURL string
}
type OIDCAuthConfig struct {
DefaultTeamID string
ClientID string
ClientSecret string
CallbackURL string
TokenPath string
IssuerURL string
LogoutURL string
ManagementURL string
ValidRedirectURLs []string
AdminRoles []string
ViewerRoles []string
RolesPath string
Scopes []string
SessionStore *sessions.Store
}
type oidcAuth struct {
provider *oidc.Provider
verifier *oidc.IDTokenVerifier
oauthConfig *oauth2.Config
defaultTeamID string
clientID string // OIDC Client ID
clientSecret string // OIDC Client Secret
issuerURL string // OIDC Issuer URL
callbackURL string // OIDC Callback URL, should be configured in OIDC provider. Default value is: http://localhost:8000/login/cb
validRedirectURLs []string // List of valid redirect URLs that the browser can redirect to after successful login
adminRoles []string // List of roles with admin access
viewerRoles []string // List of roles with viewer access
scopes []string // List of OIDC scopes
stateMap *sync.Map // Map used to store state between nebraska and oidc provider, used to prevent fake authentication response
rolesPath string // Json Path in which the roles will be found in ID Token
sessionStore *sessions.Store
}
// OIDCTokenProviderResp is used to bind response from OIDC provider password grant_type
type OIDCTokenProviderResp struct {
AccessToken string `json:"access_token"`
ExpiresIn int `json:"expires_in"`
RefreshExpiresIn int `json:"refresh_expires_in"`
RefreshToken string `json:"refresh_token"`
TokenType string `json:"token_type"`
IDToken string `json:"id_token"`
NotBeforePolicy int `json:"not-before-policy"`
SessionState string `json:"session_state"`
Scope string `json:"scope"`
}
func NewOIDCAuthenticator(config *OIDCAuthConfig) (Authenticator, error) {
ctx := context.Background()
// setup oidc provider
provider, err := oidc.NewProvider(ctx, config.IssuerURL)
if err != nil {
return nil, fmt.Errorf("Error setting up oidc provider: %w", err)
}
oidcProviderConfig := &oidc.Config{
ClientID: config.ClientID,
SkipClientIDCheck: true,
}
oauthConfig := &oauth2.Config{
ClientID: config.ClientID,
ClientSecret: config.ClientSecret,
Endpoint: provider.Endpoint(),
RedirectURL: config.CallbackURL,
Scopes: config.Scopes,
}
verifier := provider.Verifier(oidcProviderConfig)
// state map is used keep track of login and callback requests
var stateMap sync.Map
oidcAuthenticator := &oidcAuth{
provider: provider,
verifier: verifier,
oauthConfig: oauthConfig,
defaultTeamID: config.DefaultTeamID,
clientID: config.ClientID,
clientSecret: config.ClientSecret,
issuerURL: config.IssuerURL,
callbackURL: config.CallbackURL,
validRedirectURLs: config.ValidRedirectURLs,
adminRoles: config.AdminRoles,
viewerRoles: config.ViewerRoles,
scopes: config.Scopes,
stateMap: &stateMap,
rolesPath: config.RolesPath,
sessionStore: config.SessionStore,
}
stateTicker := time.NewTicker(stateCleanupDuration)
go func() {
for {
<-stateTicker.C
oidcAuthenticator.cleanState()
}
}()
return oidcAuthenticator, nil
}
func (oa *oidcAuth) SetupRouter(router *echo.Echo) {
router.Use(echosessions.SessionsMiddleware(oa.sessionStore, "oidc"))
}
func (oa *oidcAuth) ValidateToken(c echo.Context) error {
ctx := c.Request().Context()
// set request id in response header
requestID := c.Response().Writer.Header().Get("X-Request-ID")
// Check is the id token exists in the request
token := tokenFromRequest(c)
if token == "" {
logger.Debug().Str("request_id", requestID).Msg("ValidateToken, Authorization header is empty")
httpError(c, http.StatusUnauthorized)
return nil
}
// If refresh token is not available in the session
// mark the request as unauthorized so that the session
// can be recreated with refresh_token
session := echosessions.GetSession(c)
refreshToken := session.Get("refresh_token")
if refreshToken == nil {
logger.Debug().Str("request_id", requestID).Msg("ValidateToken, Refresh token not found in session")
httpError(c, http.StatusUnauthorized)
return nil
}
_, err := oa.verifier.Verify(ctx, token)
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("ValidateToken, Token verification error")
httpError(c, http.StatusUnauthorized)
return nil
}
return c.JSON(http.StatusOK, map[string]bool{"valid": true})
}
func (oa *oidcAuth) LoginCb(c echo.Context) error {
// get request id from response header
requestID := c.Response().Writer.Header().Get("X-Request-ID")
// Validate State received from provider
state := c.Request().URL.Query().Get("state")
rurl, ok := oa.stateMap.Load(state)
if !ok {
logger.Error().Str("request_id", requestID).Msg("Returned state not found in state map")
httpError(c, http.StatusInternalServerError)
return nil
}
// delete state from map as the callback is processed.
// this prevents the same state from being reused again.
defer oa.stateMap.Delete(state)
message, ok := rurl.(stateMessage)
if !ok {
logger.Error().Str("request_id", requestID).Msg("Cannot get stateMessage from state value")
httpError(c, http.StatusInternalServerError)
return nil
}
// Exchange code for token from oidc provider
token, err := oa.oauthConfig.Exchange(c.Request().Context(), c.Request().URL.Query().Get("code"))
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Can't exchange code for token")
httpError(c, http.StatusInternalServerError)
return nil
}
// Extract id_token from claims
idToken, ok := token.Extra("id_token").(string)
if !ok {
logger.Error().Str("request_id", requestID).Msg("Token doesn't contain ID Token")
httpError(c, http.StatusInternalServerError)
return nil
}
oidcToken, err := oa.verifier.Verify(c.Request().Context(), idToken)
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Can't verify the token")
httpError(c, http.StatusInternalServerError)
return nil
}
// Store refresh_token in session
session := echosessions.GetSession(c)
session.Set("refresh_token", token.RefreshToken)
session.Set("username", oidcToken.Subject)
sessionSave(c, session, "login_cb")
// Add token to redirect url provided by the client
redirectURL, err := url.Parse(message.redirectURL)
if err != nil {
logger.Error().Str("request_id", requestID).Msg(fmt.Sprintf("Invalid redirect URL: %s", rurl))
httpError(c, http.StatusBadRequest)
return nil
}
q := redirectURL.Query()
q.Set("id_token", idToken)
redirectURL.RawQuery = q.Encode()
redirectTo(c, redirectURL.String())
return nil
}
func (oa *oidcAuth) Login(c echo.Context) error {
// check if login_redirect_url is present in query params
loginRedirectURL := c.Request().URL.Query().Get("login_redirect_url")
isValidRedirect := false
for _, redirectURL := range oa.validRedirectURLs {
if glob.Glob(redirectURL, loginRedirectURL) {
isValidRedirect = true
break
}
}
if !isValidRedirect {
return c.String(http.StatusBadRequest, "Invalid login_redirect_url")
}
// Generate AuthURL of the OIDC provider
authURL, err := url.Parse(oa.provider.Endpoint().AuthURL)
if err != nil {
return c.String(http.StatusInternalServerError, "Invalid Auth Endpoint by Provider")
}
// Generate state to validate callback from provider
state := uuid.New().String()
q := authURL.Query()
q.Set("client_id", oa.clientID)
q.Set("redirect_uri", oa.callbackURL)
q.Set("scope", strings.Join(oa.scopes, " "))
q.Set("response_type", "code")
q.Set("response_mode", "query")
q.Set("state", state)
// Store login redirect url in State map
msg := stateMessage{
time.Now().Add(stateTimeoutDuration),
loginRedirectURL,
}
oa.stateMap.Store(state, msg)
authURL.RawQuery = q.Encode()
// Redirect to generated AuthURL
redirectTo(c, authURL.String())
return nil
}
func (oa *oidcAuth) LoginToken(c echo.Context) error {
requestID := c.Response().Writer.Header().Get("X-Request-ID")
resp, err := http.PostForm(oa.provider.Endpoint().TokenURL, url.Values{
"client_id": {oa.clientID},
"client_secret": {oa.clientSecret},
"grant_type": {"password"},
"scope": {strings.Join(oa.scopes, " ")},
"username": {c.Request().FormValue("username")},
"password": {c.Request().FormValue("password")},
})
if err != nil {
logger.Err(err).Str("request_id", requestID).Msg("OIDC provider password grant_type error")
return c.NoContent(http.StatusInternalServerError)
}
if resp.StatusCode != http.StatusOK {
logger.Error().Str("request_id", requestID).Msgf("Invalid response code %d from OIDC provider for password grant_type", resp.StatusCode)
return c.NoContent(http.StatusInternalServerError)
}
var oidcTokenResp OIDCTokenProviderResp
respDecoder := json.NewDecoder(resp.Body)
err = respDecoder.Decode(&oidcTokenResp)
if err != nil {
logger.Err(err).Str("request_id", requestID).Msg("Can't parse response from OIDC provider for password grant_type")
return c.NoContent(http.StatusInternalServerError)
}
oidcToken, err := oa.verifier.Verify(c.Request().Context(), oidcTokenResp.IDToken)
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Can't verify the token returned for password grant_type")
return c.NoContent(http.StatusInternalServerError)
}
// Store refresh_token in session
session := echosessions.GetSession(c)
session.Set("refresh_token", oidcTokenResp.RefreshToken)
session.Set("username", oidcToken.Subject)
sessionSave(c, session, "login_token")
return c.JSON(http.StatusOK, codegen.LoginToken{Token: oidcTokenResp.AccessToken})
}
// tokenFromRequest extracts token from request header. If Authorization header is not present returns id_token query param .
func tokenFromRequest(c echo.Context) string {
token := c.Request().Header.Get("Authorization")
split := strings.Split(token, " ")
if len(split) == 2 && split[0] == "Bearer" {
return split[1]
}
return c.Request().URL.Query().Get("id_token")
}
// rolesFromToken extracts roles from a token. Returns empty array if not present.
func rolesFromToken(token *oidc.IDToken, rolesPath string) ([]string, error) {
roles := []string{}
var claimsString interface{}
err := token.Claims(&claimsString)
if err != nil {
return roles, err
}
out, err := json.Marshal(claimsString)
if err != nil {
return roles, err
}
result := gjson.Get(string(out), rolesPath)
result.ForEach(func(key, value gjson.Result) bool {
roles = append(roles, value.String())
return true
})
return roles, nil
}
func (oa *oidcAuth) Authenticate(c echo.Context) (teamID string, replied bool) {
ctx := c.Request().Context()
// get request id from response header
requestID := c.Response().Writer.Header().Get("X-Request-ID")
// Check if the id token exists in the request
token := tokenFromRequest(c)
if token == "" {
logger.Debug().Str("request_id", requestID).Msg("Authorization header is empty")
httpError(c, http.StatusUnauthorized)
return "", true
}
// If refresh token is not available in the session
// mark the request as unauthorized so that the session
// can be recreated with refresh_token
session := echosessions.GetSession(c)
refreshToken := session.Get("refresh_token")
if refreshToken == nil {
logger.Debug().Str("request_id", requestID).Msg("Refresh token not found in session")
httpError(c, http.StatusUnauthorized)
return "", true
}
// Verify Token
tk, err := oa.verifier.Verify(ctx, token)
if err != nil {
// If token is expired, use the refresh_token to fetch a new token
// and set the new id_token in response header
if strings.Contains(err.Error(), "token is expired") {
ts := oa.oauthConfig.TokenSource(ctx, &oauth2.Token{RefreshToken: refreshToken.(string)})
newToken, err := ts.Token()
if err != nil {
logger.Warn().Str("request_id", requestID).AnErr("error", err).Msg("Failed to use refresh token, reauthenticating")
httpError(c, http.StatusUnauthorized)
return "", true
}
idToken, ok := newToken.Extra("id_token").(string)
if !ok {
logger.Debug().Str("request_id", requestID).Msg("New Token doesn't contain ID Token")
httpError(c, http.StatusInternalServerError)
return "", true
}
c.Response().Writer.Header().Set("id_token", idToken)
session.Set("refresh_token", newToken.RefreshToken)
tk, err = oa.verifier.Verify(ctx, idToken)
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Can't Verify New ID Token")
httpError(c, http.StatusInternalServerError)
return "", true
}
} else {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Token verification error")
httpError(c, http.StatusUnauthorized)
return "", true
}
}
roles, err := rolesFromToken(tk, oa.rolesPath)
if err != nil {
logger.Error().Str("request_id", requestID).AnErr("error", err).Msg("Can't extract roles from token")
httpError(c, http.StatusInternalServerError)
return "", true
}
accessLevel := ""
// Check and set access level
checkloop:
for _, role := range roles {
if accessLevel != "viewer" {
for _, roRole := range oa.viewerRoles {
if roRole == role {
accessLevel = "viewer"
break
}
}
}
for _, rwRole := range oa.adminRoles {
if rwRole == role {
accessLevel = "admin"
break checkloop
}
}
}
// If access level is empty or doesn't match role scope then return an error
if accessLevel == "" {
logger.Debug().Msg("Misconfigured Roles, Can't get access level from token")
httpError(c, http.StatusForbidden)
return "", true
} else if accessLevel != "admin" {
if c.Request().Method != "HEAD" && c.Request().Method != "GET" {
logger.Error().Str("request_id", requestID).Msg("User doesn't have admin access")
httpError(c, http.StatusForbidden)
return "", true
}
}
return oa.defaultTeamID, false
}
func (oa *oidcAuth) cleanState() {
now := time.Now()
oa.stateMap.Range(func(key, value interface{}) bool {
val, ok := value.(stateMessage)
if !ok {
oa.stateMap.Delete(key)
return true
}
if now.After(val.timeout) {
logger.Debug().Str("message", fmt.Sprintf("Deleting expired key %s from state map", key))
oa.stateMap.Delete(key)
}
return true
})
}
func (oa *oidcAuth) LoginWebhook(ctx echo.Context) error {
return ctx.NoContent(http.StatusNotImplemented)
}
func httpError(c echo.Context, status int) {
//nolint:errcheck
c.NoContent(status)
}
func redirectTo(c echo.Context, where string) {
//nolint:errcheck
c.Redirect(http.StatusTemporaryRedirect, where)
}
func sessionSave(c echo.Context, session *sessions.Session, msg string) {
if err := echosessions.SaveSession(c, session); err != nil {
logger.Error().Err(err).Str("failed to save the session", msg).Send()
httpError(c, http.StatusInternalServerError)
}
}