middleware.go

/*
Copyright 2015 All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"fmt"
	"net/http"
	"regexp"
	"strings"
	"time"

	"github.com/PuerkitoBio/purell"
	log "github.com/Sirupsen/logrus"
	"github.com/coreos/go-oidc/jose"
	"github.com/labstack/echo"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/unrolled/secure"
)

const normalizeFlags purell.NormalizationFlags = purell.FlagRemoveDotSegments | purell.FlagRemoveDuplicateSlashes

// proxyRevokeMiddleware is just a helper to drop all requests proxying
func (r *oauthProxy) proxyRevokeMiddleware() echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(cx echo.Context) error {
			r.revokeProxy(cx)
			cx.NoContent(http.StatusForbidden)
			return next(cx)
		}
	}
}

// filterMiddleware is custom filtering for incoming requests
func (r *oauthProxy) filterMiddleware() echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(cx echo.Context) error {
			// step: keep a copy of the original
			keep := cx.Request().URL.Path
			purell.NormalizeURL(cx.Request().URL, normalizeFlags)
			cx.Request().URL.RawPath = cx.Request().URL.Path
			cx.Request().RequestURI = cx.Request().URL.Path
			// step: continue the flow
			next(cx)
			// step: place back the original uri for proxying request
			cx.Request().URL.Path = keep
			cx.Request().URL.RawPath = keep
			cx.Request().RequestURI = keep

			return nil
		}
	}
}

// loggingMiddleware is a custom http logger
func (r *oauthProxy) loggingMiddleware() echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(cx echo.Context) error {