{{.}}
`) if err != nil { return } err = tmpl.Execute(&resp.HTML, sendError.Error()) return } func (ctrl *oidcLoginController) newOAuth2State(key []byte, remote, returnTo string) oauth2State { s := oauth2State{ Time: time.Now().Unix(), Remote: remote, ReturnTo: returnTo, } s.HMAC = s.computeHMAC(key) return s } type oauth2State struct { HMAC []byte // hash of other fields; see computeHMAC() Time int64 // creation time (unix timestamp) Remote string // remote cluster if requesting a salted token, otherwise blank ReturnTo string // redirect target } func (ctrl *oidcLoginController) parseOAuth2State(encoded string) (s oauth2State) { // Errors are not checked. If decoding/parsing fails, the // token will be rejected by verify(). decoded, _ := base64.RawURLEncoding.DecodeString(encoded) f := strings.Split(string(decoded), "\n") if len(f) != 4 { return } fmt.Sscanf(f[0], "%x", &s.HMAC) fmt.Sscanf(f[1], "%x", &s.Time) fmt.Sscanf(f[2], "%s", &s.Remote) fmt.Sscanf(f[3], "%s", &s.ReturnTo) return } func (s oauth2State) verify(key []byte) bool { if delta := time.Now().Unix() - s.Time; delta < 0 || delta > 300 { return false } return hmac.Equal(s.computeHMAC(key), s.HMAC) } func (s oauth2State) String() string { var buf bytes.Buffer enc := base64.NewEncoder(base64.RawURLEncoding, &buf) fmt.Fprintf(enc, "%x\n%x\n%s\n%s", s.HMAC, s.Time, s.Remote, s.ReturnTo) enc.Close() return buf.String() } func (s oauth2State) computeHMAC(key []byte) []byte { mac := hmac.New(sha256.New, key) fmt.Fprintf(mac, "%x %s %s", s.Time, s.Remote, s.ReturnTo) return mac.Sum(nil) } func OIDCAccessTokenAuthorizer(cluster *arvados.Cluster, getdb func(context.Context) (*sqlx.DB, error)) *oidcTokenAuthorizer { // We want ctrl to be nil if the chosen controller is not a // *oidcLoginController, so we can ignore the 2nd return value // of this type cast. ctrl, _ := NewConn(cluster).loginController.(*oidcLoginController) cache, err := lru.New2Q(tokenCacheSize) if err != nil { panic(err) } return &oidcTokenAuthorizer{ ctrl: ctrl, getdb: getdb, cache: cache, } } type oidcTokenAuthorizer struct { ctrl *oidcLoginController getdb func(context.Context) (*sqlx.DB, error) cache *lru.TwoQueueCache } func (ta *oidcTokenAuthorizer) Middleware(w http.ResponseWriter, r *http.Request, next http.Handler) { if ta.ctrl == nil { // Not using a compatible (OIDC) login controller. } else if authhdr := strings.Split(r.Header.Get("Authorization"), " "); len(authhdr) > 1 && (authhdr[0] == "OAuth2" || authhdr[0] == "Bearer") { err := ta.registerToken(r.Context(), authhdr[1]) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } } next.ServeHTTP(w, r) } func (ta *oidcTokenAuthorizer) WrapCalls(origFunc api.RoutableFunc) api.RoutableFunc { if ta.ctrl == nil { // Not using a compatible (OIDC) login controller. return origFunc } return func(ctx context.Context, opts interface{}) (_ interface{}, err error) { creds, ok := auth.FromContext(ctx) if !ok { return origFunc(ctx, opts) } // Check each token in the incoming request. If any // are valid OAuth2 access tokens, insert/update them // in the database so RailsAPI's auth code accepts // them. for _, tok := range creds.Tokens { err = ta.registerToken(ctx, tok) if err != nil { return nil, err } } return origFunc(ctx, opts) } } // registerToken checks whether tok is a valid OIDC Access Token and, // if so, ensures that an api_client_authorizations row exists so that // RailsAPI will accept it as an Arvados token. func (ta *oidcTokenAuthorizer) registerToken(ctx context.Context, tok string) error { if tok == ta.ctrl.Cluster.SystemRootToken || strings.HasPrefix(tok, "v2/") { return nil } if cached, hit := ta.cache.Get(tok); !hit { // Fall through to database and OIDC provider checks // below } else if exp, ok := cached.(time.Time); ok { // cached negative result (value is expiry time) if time.Now().Before(exp) { return nil } ta.cache.Remove(tok) } else { // cached positive result aca := cached.(arvados.APIClientAuthorization) var expiring bool if !aca.ExpiresAt.IsZero() { t := aca.ExpiresAt expiring = t.Before(time.Now().Add(time.Minute)) } if !expiring { return nil } } db, err := ta.getdb(ctx) if err != nil { return err } tx, err := db.Beginx() if err != nil { return err } defer tx.Rollback() ctx = ctrlctx.NewWithTransaction(ctx, tx) // We use hmac-sha256(accesstoken,systemroottoken) as the // secret part of our own token, and avoid storing the auth // provider's real secret in our database. mac := hmac.New(sha256.New, []byte(ta.ctrl.Cluster.SystemRootToken)) io.WriteString(mac, tok) hmac := fmt.Sprintf("%x", mac.Sum(nil)) var expiring bool err = tx.QueryRowContext(ctx, `select (expires_at is not null and expires_at - interval '1 minute' <= current_timestamp at time zone 'UTC') from api_client_authorizations where api_token=$1`, hmac).Scan(&expiring) if err != nil && err != sql.ErrNoRows { return fmt.Errorf("database error while checking token: %w", err) } else if err == nil && !expiring { // Token is already in the database as an Arvados // token, and isn't about to expire, so we can pass it // through to RailsAPI etc. regardless of whether it's // an OIDC access token. return nil } updating := err == nil // Check whether the token is a valid OIDC access token. If // so, swap it out for an Arvados token (creating/updating an // api_client_authorizations row if needed) which downstream // server components will accept. err = ta.ctrl.setup() if err != nil { return fmt.Errorf("error setting up OpenID Connect provider: %s", err) } if ok, err := ta.checkAccessTokenScope(ctx, tok); err != nil || !ok { ta.cache.Add(tok, time.Now().Add(tokenCacheNegativeTTL)) return err } oauth2Token := &oauth2.Token{ AccessToken: tok, } userinfo, err := ta.ctrl.provider.UserInfo(ctx, oauth2.StaticTokenSource(oauth2Token)) if err != nil { ta.cache.Add(tok, time.Now().Add(tokenCacheNegativeTTL)) return nil } ctxlog.FromContext(ctx).WithField("userinfo", userinfo).Debug("(*oidcTokenAuthorizer)registerToken: got userinfo") authinfo, err := ta.ctrl.getAuthInfo(ctx, oauth2Token, userinfo) if err != nil { return err } // Expiry time for our token is one minute longer than our // cache TTL, so we don't pass it through to RailsAPI just as // it's expiring. exp := time.Now().UTC().Add(tokenCacheTTL + tokenCacheRaceWindow) if updating { _, err = tx.ExecContext(ctx, `update api_client_authorizations set expires_at=$1 where api_token=$2`, exp, hmac) if err != nil { return fmt.Errorf("error updating token expiry time: %w", err) } ctxlog.FromContext(ctx).WithField("HMAC", hmac).Debug("(*oidcTokenAuthorizer)registerToken: updated api_client_authorizations row") } else { aca, err := ta.ctrl.Parent.CreateAPIClientAuthorization(ctx, ta.ctrl.Cluster.SystemRootToken, *authinfo) if err != nil { return err } _, err = tx.ExecContext(ctx, `savepoint upd`) if err != nil { return err } _, err = tx.ExecContext(ctx, `update api_client_authorizations set api_token=$1, expires_at=$2 where uuid=$3`, hmac, exp, aca.UUID) if e, ok := err.(*pq.Error); ok && e.Code == pqCodeUniqueViolation { // unique_violation, given that the above // query did not find a row with matching // api_token, means another thread/process // also received this same token and won the // race to insert it -- in which case this // thread doesn't need to update the database. // Discard the redundant row. _, err = tx.ExecContext(ctx, `rollback to savepoint upd`) if err != nil { return err } _, err = tx.ExecContext(ctx, `delete from api_client_authorizations where uuid=$1`, aca.UUID) if err != nil { return err } ctxlog.FromContext(ctx).WithField("HMAC", hmac).Debug("(*oidcTokenAuthorizer)registerToken: api_client_authorizations row inserted by another thread") } else if err != nil { ctxlog.FromContext(ctx).Errorf("%#v", err) return fmt.Errorf("error adding OIDC access token to database: %w", err) } else { ctxlog.FromContext(ctx).WithFields(logrus.Fields{"UUID": aca.UUID, "HMAC": hmac}).Debug("(*oidcTokenAuthorizer)registerToken: inserted api_client_authorizations row") } } err = tx.Commit() if err != nil { return err } ta.cache.Add(tok, arvados.APIClientAuthorization{ExpiresAt: exp}) return nil } // Check that the provided access token is a JWT with the required // scope. If it is a valid JWT but missing the required scope, we // return a 403 error, otherwise true (acceptable as an API token) or // false (pass through unmodified). // // Return false if configured not to accept access tokens at all. // // Note we don't check signature or expiry here. We are relying on the // caller to verify those separately (e.g., by calling the UserInfo // endpoint). func (ta *oidcTokenAuthorizer) checkAccessTokenScope(ctx context.Context, tok string) (bool, error) { if !ta.ctrl.AcceptAccessToken { return false, nil } else if ta.ctrl.AcceptAccessTokenScope == "" { return true, nil } var claims struct { Scope string `json:"scope"` } if t, err := jwt.ParseSigned(tok); err != nil { ctxlog.FromContext(ctx).WithError(err).Debug("error parsing jwt") return false, nil } else if err = t.UnsafeClaimsWithoutVerification(&claims); err != nil { ctxlog.FromContext(ctx).WithError(err).Debug("error extracting jwt claims") return false, nil } for _, s := range strings.Split(claims.Scope, " ") { if s == ta.ctrl.AcceptAccessTokenScope { return true, nil } } ctxlog.FromContext(ctx).WithFields(logrus.Fields{"have": claims.Scope, "need": ta.ctrl.AcceptAccessTokenScope}).Infof("unacceptable access token scope") return false, httpserver.ErrorWithStatus(errors.New("unacceptable access token scope"), http.StatusUnauthorized) }